We are a clinical-stage biotechnology company focused on the discovery and development of direct lytic agents (“DLAs”), including lysins and amurin peptides, as new medical modalities for the treatment of life-threatening, antibiotic-resistant infections. Antibiotic-resistant infections account for 2,000,000 illnesses in the United States and 700,000 deaths worldwide each year. We intend to address antibiotic-resistant infections using product candidates from our lysin and amurin peptide platforms. We believe DLAs are fundamentally different than antibiotics and offer a potential paradigm shift in the treatment of antibiotic-resistant infections.

Lysins are recombinantly-produced enzymes, that when applied to bacteria cleave a key component of the target bacteria’s peptidoglycan cell wall, resulting in rapid bacterial cell death. In addition to the speed of action and potent cidality, we believe lysins are differentiated by their other hallmark features, which include the demonstrated ability to eradicate biofilms and synergistically boost the efficacy of conventional antibiotics in animal models. Lysins also tend to have a “targeted spectrum,” meaning they kill only specific species of bacteria or closely related bacteria. Amurin peptides are a new class of DLAs, discovered in our laboratories, which disrupt the outer membrane of gram-negative bacteria, resulting in rapid bacterial cell death, offering a distinct mechanism of action from lysins. Amurins are further differentiated from lysins by potent “broad spectrum” in vitro activity against a wide range of gram-negative pathogens in, including deadly, drug-resistant Pseudomonas aeruginosa (“P. aeruginosa”), Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii and Enterobacter cloacae bacteria species as well as difficult to treat pathogens such as Stenotrophomonas, Achromobacter and Burkholderia species. The highly differentiated properties of DLAs have shown these agents to be complementary to and synergistic with conventional antibiotics enabling their potential use in addition to antibiotics with the goal of improving clinical outcomes compared to antibiotics alone. The development of DLAs involves a novel clinical and regulatory strategy, using superiority design clinical trials with the goal of delivering significantly improved clinical outcomes for patients with serious, antibiotic-resistant bacterial infections, including biofilm-associated infections. We believe this approach affords potential clinical benefits to patients as well as the potential ability to mitigate against further development of antibiotic resistance.

Our most advanced clinical candidate, exebacase, is an investigational novel lysin that targets Staphylococcus aureus (“Staph aureus”), including methicillin-resistant (“MRSA”) strains, which causes serious infections such as bacteremia, pneumonia and osteomyelitis. Staph aureus is also a common cause of biofilm-associated infections of heart valves (endocarditis), prosthetic joints, indwelling devices and catheters. These infections result in significant morbidity and mortality despite currently available antibiotic therapies. Exebacase completed a Phase 2 superiority study that evaluated its safety, tolerability, efficacy and pharmacokinetics (“PK”) when used in addition to background standard of care (“SOC”) antibiotics compared to SOC antibiotics alone for the treatment of Staph aureus bacteremia, including endocarditis in adult patients. In January 2019, we announced topline results from this study which showed clinically meaningful improvement in clinical responder rates among patients treated with exebacase in addition to SOC antibiotics compared to SOC antibiotics alone.

In the Phase 2 study, the primary efficacy analysis population of 116 patients with documented Staph aureus bacteremia, including endocarditis, who received a single intravenous (“IV”) infusion of blinded study drug, the clinical responder rate at Day 14 was 70.4% for patients treated with exebacase and 60.0% for patients dosed with SOC antibiotics alone (p=0.314). The clinical responder rate at Day 14 in the subset of patients with bacteremia including right-sided endocarditis was 80.0% for patients treated with exebacase compared to 59.5% for patients treated with SOC antibiotics alone, an increase of 20.5% (p=0.028). In the subset of patients with bacteremia alone, the clinical responder rate at Day 14 was 81.8% for patients treated with exebacase compared to 61.5% for patients treated with SOC antibiotics alone, an increase of 20.3% (p=0.035). In a pre-specified analysis of MRSA-infected patients, the clinical responder rate at Day 14 in patients treated with exebacase was nearly 43-percentage points higher than in patients treated with SOC antibiotics alone (74.1% for patients treated with exebacase compared to 31.3% for patients treated with SOC antibiotics alone (p=0.010)). In addition to the higher rate of clinical response, MRSA-infected patients treated with exebacase showed a 21-percentage point reduction in 30-day all-cause mortality (p=0.056), a four day lower mean length of hospital stay and meaningful

1

reductions in hospital readmission rates. Exebacase was well-tolerated and treatment emergent adverse events, including serious treatment-emergent serious adverse events (“SAEs”) were balanced between the treatment groups. There were no SAEs that we determined to be related to exebacase, there were no reports of hypersensitivity related to exebacase and no patients discontinued treatment with study drug in either treatment group. We believe these data have established proof of concept for exebacase and for DLAs as therapeutic agents. In particular, the data for MRSA-infected patients treated with exebacase, which, in this study, demonstrated superior outcomes in clinical response at Day 14 and in 30-day all-cause mortality as well as health economics benefits, provided the basis for our proposed Phase 3 study design and our application for Breakthrough Therapy designation to the U.S. Food and Drug Administration (“FDA”).

In September 2019, we held an End-of-Phase 2 meeting with the FDA regarding the results from the Phase 2 study and the potential for advancing exebacase into Phase 3 clinical development based on the data discussed above. Our proposed Phase 3 study design excluded patients outside the U.S. or with left-sided endocarditis due to the differences in standard-of-care for these patients. We obtained concurrence with the FDA on our proposed Phase 3 protocol, including the key design features of the study population, the endpoints and the size of the safety database that would be needed to support a Biologics License Application (“BLA”) for approval of exebacase, under the FDA’s “streamlined development” paradigm for agents to treat bacterial infections associated with high unmet medical need. Based on the outcome of the meeting, we proceeded to initiate the single Phase 3 DISRUPT (Direct Lysis of Staph aureus Resistant Pathogen Trial) study of exebacase in December 2019. The DISRUPT study is a randomized, double-blind, placebo-controlled Phase 3 clinical trial conducted in the U.S. alone to assess the efficacy and safety of exebacase in approximately 350 patients with complicated Staph aureus bacteremia, including right-sided endocarditis. Patients entering the study will be randomized 2:1 to either exebacase or placebo, with all patients receiving SOC antibiotics. The primary efficacy endpoint of the study is clinical response at Day 14 in patients with MRSA bacteremia, including right-sided endocarditis. Secondary endpoints will include clinical response at Day 14 in the All Staph aureus patient group (MRSA and methicillin-sensitive Staph aureus (“MSSA”)), 30-day all-cause mortality in MRSA patients, and clinical response at later timepoints. We will also evaluate the impact of treatment with exebacase on health resource utilization, including hospital length of stay, ICU length of stay and 30-day readmission rates. We plan to conduct an interim futility analysis following the enrollment of approximately 60% of the study population.

The FDA recently granted Breakthrough Therapy designation to exebacase for the treatment of MRSA bloodstream infections (bacteremia), including right-sided endocarditis, when used in addition to SOC anti-staphylococcal antibiotics in adult patients, based on the final data from the Phase 2 superiority trial of exebacase. Breakthrough Therapy designation is a program designed by the FDA to expedite the development and review of medicines for serious or life-threatening diseases where preliminary clinical evidence suggests that the investigational therapy may demonstrate substantial improvement on at least one clinically significant endpoint over available therapies. The Breakthrough Therapy designation provides additional benefits, such as intensified interactions with the FDA and the potential for priority review, over the Fast Track designation granted to exebacase in August 2015.

We performed a post-hoc Phase 3 simulation analysis using the Phase 2 data to evaluate the clinical outcomes for the Phase 2 patient population that would meet the Phase 3 inclusion criteria. In this simulated Phase 3 analysis population of 84 U.S. patients with documented Staph aureus bacteremia, including right-sided endocarditis, who received a single IV infusion of blinded study drug, the clinical responder rate at Day 14 was 83.7% for patients treated with exebacase and 54.3% for patients dosed with SOC antibiotics alone, an improvement in the responder rate of over 29-percentage points. The clinical responder rate at Day 14 in the subset of patients with MRSA bacteremia including right-sided endocarditis was 82.6% for patients treated with exebacase compared to 33.3% for patients treated with SOC antibiotics alone, an improvement in the responder rate of over 49-percentage points. In the subset of patients with MSSA bacteremia including right-sided, the clinical responder rate at Day 14 was 84.6% for patients treated with exebacase compared to 66.7% for patients treated with SOC antibiotics alone, an increase of nearly 18-percentage points.

2

Our Portfolio

We intend to develop and commercialize novel therapeutic agents to treat life-threatening infections, including those caused by antibiotic-resistant pathogens. The increasing prevalence of antibiotic resistance among bacterial pathogens has been widely recognized as an urgent public health threat by the U.S. Center for Disease Control (“CDC”), the World Health Organization (“WHO”) and the Infectious Disease Society of America (“IDSA”). According to the IDSA, as of 2010 the estimated cost to the U.S. healthcare system of antibiotic-resistant infections was approximately $21 billion to $34 billion annually, a substantial portion of which is due to increased length of hospital stays necessary to treat these patients. Antibiotic resistance has limited the effectiveness of many conventional antibiotics and the discovery and development of new therapeutics to address resistance has not kept pace with the increasing incidence of these difficult-to-treat microbial infections. As Dr. Tedros Adhanom Ghebreyesus, Director-General of WHO, has accordingly stated “never has the threat of antimicrobial resistance been more immediate and the need for solutions more urgent. Numerous initiatives are underway to reduce resistance, but we also need countries and the pharmaceutical industry to step up and contribute with sustainable funding and innovative new medicines.”

We take this mandate very seriously and have focused our research and discovery efforts on those pathogens that are considered to be urgent or serious threats to global health by the CDC or considered critical priority by the WHO. In particular, species of bacteria that are part of the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are urgent or serious threats, and are also the leading causes of hospital acquired infections throughout the world. We believe that DLAs will be highly complementary to conventional antibiotics in addressing these infections. We aim to improve outcomes in patient with these life-threatening bacterial infections through use of our DLA candidates developed from our novel lysin and amurin platforms.

We continue to advance novel lytic agents across our portfolio. We initiated the single Phase 3 DISRUPT study of exebacase in December 2019. We also expanded the investigator-initiated early access program for compassionate use of exebacase for individual named patients with chronic post-operative prosthetic joint infections (“PJIs”) under Temporary Authorizations for Use from the French National Agency for Medicines and Health Products Safety in collaboration with Dr. Tristan Ferry at the Hôpital de la Croix Rousse in Lyon, France. We have developed a novel, engineered variant of exebacase, known as CF-296, which we believe provides an additional opportunity to advance a potential targeted therapy for deep-seated, invasive biofilm-associated Staph aureus infections. We are conducting further in vitro and in vivo characterization of CF-296 to evaluate the full profile of this compound. We have been awarded up to $7.2 million of funding from the Military Infectious Diseases Research Program, United States Army Medical Research and Development Command (“USAMRDC”) over the course of three years to advance CF-296 through Investigational New Drug application (“IND”)-enabling studies.

We have discovered and engineered a new lysin product candidate, CF-370, which in preclinical studies has demonstrated potent activity against antibiotic-resistant P. aeruginosa bacteria, a major cause of morbidity and mortality in patients with hospital acquired pneumonia and a major medical challenge for patients with cystic fibrosis. We have initiated IND-enabling activities and we expect CF-370 to be our next molecule in clinical studies. We have been awarded up to $3.3 million in funding from CARB-X (Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator) in support of the advancement of anti-pseudomonal lysins. Beyond our lysin programs, we continue our research to advance potential product candidates from our amurin peptide platform. We will be initiating animal studies of our most promising amurins with the goal of moving this program into clinical studies as soon as possible. We have been awarded up to $6.9 million of funding from CARB-X to support the amurin peptide program. In summary, we now have three modalities within the DLA therapeutic umbrella, including (i) native lysins for gram-positive pathogens (ii) engineered lysins for gram-negative pathogens and (iii) amurins for a wide spectrum of gram-negative pathogens.

3

Our current portfolio of programs is reflected below:

Our Strategy

Our strategy is to use our novel, highly differentiated therapeutic DLAs, if approved, to achieve a leading market position in the treatment of life-threatening infectious diseases, including those caused by antibiotic-resistant pathogens. We plan to pursue commercialization of therapeutic products through discovery, acquisition and development as follows:

Our Lead Program: Exebacase (CF-301)

Medical Opportunity

Staph aureus bacteremia is a serious bacterial infection associated with high morbidity and mortality. In the U.S. alone, there are approximately 200,000 hospitalizations for Staph aureus bacteremia annually. Mortality

4

rates from this bloodstream infection have been reported as ranging from 20-40% despite conventional antibiotics. The last new agent for Staph aureus bacteremia and right-sided endocarditis, daptomycin, was approved over 13 years ago based on non-inferiority to vancomycin (approved in 1958) with clinical cure rates of less than 50% in the Phase 3 study that led to its approval.

Staph aureus bacteremia can lead to infectious endocarditis, a serious infection affecting the heart valves. The incidence of infective endocarditis in the U.S. has increased over the past decade, with over 47,000 cases in 2011, and is likely due to the growth of the at-risk populations, such as older, diabetic and hemodialysis patients. Staph aureus endocarditis remains difficult to treat with current standard of care antibiotics. One reason for this is biofilm formation which prevents antibiotics from eradicating the bacteria, leading to the need for long courses of antibiotic therapy, which are often unsuccessful and necessitate surgery to eradicate bacteria from infected heart valves. Mortality attributed to Staph aureus bacteremia is higher when the infection is caused by MRSA as compared to methicillin-susceptible (“MSSA”) Staph aureus. MRSA is considered a serious threat to global health by the CDC and a high priority threat by the WHO. Emerging resistance to conventional antibiotics such as vancomycin and daptomycin, which are used to treat MSSA and MRSA, represents an additional serious threat which may have serious consequences in terms of increasing morbidity, mortality and health care utilization.

Exebacase Development

Exebacase is the first lysin to enter U.S. clinical trials and represents a first-in-class anti-bacterial therapeutic candidate. Exebacase has been granted both Breakthrough Therapy and Fast Track designations by the FDA for the treatment of MRSA bloodstream infections (bacteremia), including right-sided endocarditis, when used in addition to SOC anti-staphylococcal antibiotics in adult patients. If we are able to obtain regulatory approval of exebacase for this initial indication, we believe exebacase, and/or engineered variants, may be further developed for the treatment of other serious diseases caused by Staph aureus including biofilm-related infections in prosthetic joints and indwelling devices, as well as pneumonia and osteomyelitis.

Clinical Studies

Phase 3 Clinical Study

We are conducting a multi-center Phase 3 clinical study of exebacase for the treatment of Staph aureus bacteremia, including right-sided endocarditis, caused by MRSA or MSSA. This randomized, double-blind, placebo-controlled study compares the efficacy, safety and tolerability of exebacase used in addition to SOC antibiotics to SOC antibiotics alone. The study is targeting enrollment of approximately 350 patients randomized 2:1 to receive either a single dose of exebacase administered as a 2-hour IV infusion in addition to SOC antibiotics or placebo plus SOC antibiotics. The primary efficacy endpoint is clinical response at Day 14 in patients with MRSA bacteremia, including right-sided endocarditis. Secondary endpoints include clinical response at Day 14 in the All Staph aureus patient group (MRSA and MSSA), 30-day all-cause mortality in MRSA patients, and clinical response at Day 30 and Day 60 in both the MRSA and the All Staph aureus patient group. A summary of the statistical parameters of the key efficacy endpoints is shown in Table 1 below.

Clinical response is defined by objective clinical response criteria including (1) resolution of signs and symptoms attributable to Staph aureus bacteremia/right-sided endocarditis (“SAB/RIE”) that were present at

5

baseline, (2) no new signs and symptoms attributable to SAB/RIE, (3) no complications of SAB/RIE (e.g. no development of a new foci of Staph aureus infection after Day 7 and no septic emboli), (4) no changes in anti-staphylococcal antibiotics after treatment with study drug due to persistence, worsening or recurrence of signs or symptoms of SAB/RIE, (5) Blood culture(s) negative for Staph aureus by Day 14 and (6) the patient is alive. Clinical response will be determined by an independent, blinded clinical adjudication committee.

We will evaluate the impact of treatment with exebacase on health resource utilization, including length of hospital stay, length of stay in the intensive care unit and 30-day readmission rates for both all-cause and Staph aureus infection readmissions. We plan to conduct an interim futility analysis following the enrollment of approximately 60% of the study population.

Based on feedback from our End-of-Phase 2 meeting with the FDA, including the advancement of exebacase under the streamlined development pathway, we believe that this single confirmatory Phase 3 clinical trial evaluating the superiority of exebacase used in addition to SOC antibiotics compared to SOC antibiotics alone for the treatment of Staph aureus bacteremia, including right-sided endocarditis, if the results are positive, together with the full package of Phase 1 and Phase 2 clinical data, along with a robust non-clinical and PK/PD data package will be sufficient to support the biologics license application (“BLA”) submission. If the Phase 3 study demonstrates superiority of exebacase, used in addition to SOC antibiotics as compared to antibiotics alone, we would seek inclusion of a superiority claim in the product labeling, which we believe would be highly differentiated from conventional antibiotics and would lead to rapid uptake by providers and favorable reimbursements from payors.

Phase 2 Clinical Study

We completed a multi-national Phase 2 clinical study of exebacase for the treatment of Staph aureus bacteremia, including endocarditis, caused by MRSA or MSSA. This randomized, double-blind, placebo-controlled study compared the efficacy, safety and tolerability of exebacase used in addition to SOC antibiotics to SOC antibiotics alone. The study enrolled 121 patients randomized 3:2 to receive either a single dose of exebacase administered as a 2-hour IV infusion in addition to SOC antibiotics or placebo plus SOC antibiotics. The primary efficacy analysis population (also known as the microbiological intent-to-treat population, or “mITT”) consisted of 116 patients with confirmed Staph aureus infection based on blood culture who received study drug, of which 71 patients received exebacase and 45 patients received placebo. All patients were treated with SOC antibiotics as prescribed by the study investigators, consisting of vancomycin or daptomycin for MRSA and a semi-synthetic penicillin or first-generation cephalosporin for MSSA, prescribed in accordance with treatment guidelines, accepted medical practice and the study protocol. The majority of patients were enrolled in the U.S. (79.3%) with the remainder of patient enrolled from sites in Europe, Latin America, Russia and Israel. A total of 38.8% of exebacase-treated and 35.5% of placebo patients, respectively, had a MRSA infection. The majority of patients in both treatment groups had bacteremia, 77.5% of the exebacase-treated group and 86.7% of the placebo group. Final diagnosis was determined by an independent, blinded clinical adjudication committee.

Topline efficacy results from the core study demonstrated the clinical responder rate was 70.4% for patients treated with exebacase and 60.0% for patients treated with SOC antibiotics alone (p=0.314). In a pre-specified analysis of MRSA-infected patients, the clinical responder rate was nearly 43-percentage points higher in the exebacase group compared to the SOC antibiotics alone group (74.1% for patients treated with exebacase compared to 31.3% for patients dosed with SOC antibiotics alone (p=0.010)). In addition to the higher rate of clinical response, MRSA-infected patients treated with exebacase showed a 21-percentage point reduction in 30-day all-cause mortality (p=0.056), a four day lower mean length of hospital stay and meaningful reductions in hospital readmission rates.

The clinical responder rate in the subset of patients with bacteremia, including right-sided endocarditis was 80.0% for patients treated with exebacase compared to 59.5% for patients treated with SOC antibiotics alone, an increase of 20.5% (p=0.028). Similarly, in the subset of patients with bacteremia alone, the clinical responder rate was 81.8% for patients treated with exebacase compared to 61.5% for patients treated with SOC antibiotics alone, an increase of 20.3% (p=0.035).

6

Based on these efficacy data, summarized in Table 2 below, treatment with exebacase in addition to SOC antibiotics resulted in clinically meaningful improvements in outcomes compared to antibiotic therapy alone.

Another primary objective of the study was to describe the safety and tolerability of exebacase used in addition to SOC antibacterial therapy compared to SOC antibiotics alone in hospitalized patients with Staph aureus bacteremia, including endocarditis. An independent Data Safety Monitoring Board (“DSMB”) reviewed unblinded safety and pharmacokinetic data during the study. Treatment emergent adverse events (“TEAEs”) were defined as an untoward medical event reported from the study drug administration until 28 days after last dose of standard of care antibiotics, regardless of whether or not the event was considered related to study drug. The incidence of TEAEs was balanced between the treatment groups (88.9% and 85.1% of the exebacase and SOC antibiotics alone groups, respectively), with incidence rates as expected for this population, given the severity of the disease under study and that patients had multiple co-morbidities. The incidence rates of TEAEs reported within approximately one week after administration of the single dose of study drug were also balanced between the treatment groups (66.7% and 66.0% in the exebacase and SOC antibiotics alone groups, respectively). The overall rate of SAEs through day 180 was also similar between the treatment groups (62.5% for the exebacase group and 59.5% for the SOC antibiotics alone group). Among all patients who received study drug, 23.6% of exebacase patients and 19.1% of placebo patients died through day 180. There were no SAEs, including deaths, that we determined to be related to exebacase. Exebacase was well-tolerated and there were no reports of hypersensitivity related to exebacase and no patients prematurely discontinued study drug in either treatment group.

Based on these safety and tolerability data, summarized in Table 3 below, we concluded that exebacase was well-tolerated in this study.

7

The Phase 2 Clinical Study Report, as well as PK/PD modeling and any additional in vitro or in vivo studies were submitted and an End-of-Phase 2 Meeting with FDA was conducted prior to advancing into Phase 3.

Phase 1 Clinical Study

In 2015, we concluded a Phase 1 single ascending dose study in healthy volunteers. This trial was a randomized, double-blind, placebo-controlled trial designed to evaluate the safety, tolerability and PK of four different intravenous doses of exebacase. Healthy normal subjects were randomized to receive a single IV dose of exebacase or placebo, each administered as a 2-hour IV infusion.

In this Phase 1 study, exebacase was generally well tolerated and there were no clinical adverse safety signals. No SAEs or hypersensitivity adverse events (“AEs”) related to exebacase were reported, and no study stopping rules were met. A total of five non-serious AEs were reporting during the study as follows: two subjects who received exebacase reported a total of three non-serious AEs (headache, contact dermatitis, and allergic rhinitis); two subjects who received placebo reported a total of two non-serious AEs (viral upper respiratory tract infection and viral infection). All of these events were mild in intensity and resolved. No patients withdrew from the study due to an AE. There were no clinically relevant changes in inflammatory markers (e.g., erythrocyte sedimentation rate, high sensitivity c-reactive protein, or complement factors including total hemolytic complement (CH50) associated with exebacase dosing.

Nine out of 13 subjects dosed with exebacase developed anti-drug antibodies (“ADAs”) in the study. These ADAs were waning or absent by day 180, and were not correlated with mediators of allergic immune response. Exposure was generally linear, dose dependent and intra-subject variability was low. A pharmacometric analysis of the relationship between exebacase exposure and heart rate (“HR”), blood pressure and QT interval parameters showed no significant changes in systolic or diastolic blood pressure, HR or HR-corrected QT intervals with increases in exebacase plasma concentration at the doses tested in the Phase 1 study.

Estimated effective exposure of exebacase, based on in vivo pharmacology, PK/PD exposure target attainment analysis and PK/PD modeling was attained at the 0.25mg/kg dose in healthy subjects. The Phase 1 Clinical Study Report, as well as reports of the animal studies, PK/PD modeling and in vitro clinical microbiology studies were submitted to the regulatory authorities and an End-of-Phase 1 Meeting with FDA was conducted prior to advancing into Phase 2.

In vitro Microbiologic Studies and Animal Models Demonstrate the Therapeutic Potential of Exebacase

We believe exebacase is well differentiated from conventional antibiotics by its spectrum of activity, including:

8

We believe exebacase has other competitive advantages as well, including:

Eradication of Antibiotic-Resistant Biofilms

Biofilm formation is a common characteristic of certain pathogenic bacteria such as Staph aureus and P. aeruginosa and represents a major therapeutic challenge. Biofilms are characterized by densely packed bacterial cells that grow in communities and are enclosed within a complex matrix of dead bacteria and excess cell wall components. Bacteria harbored within biofilms exhibit significant tolerance to conventional antibiotics, and can be up to 1,000-fold less susceptible than planktonic (or, free-floating) bacteria. Infected human tissues, such as the heart valve in endocarditis or bone in osteomyelitis, and the abiotic surfaces of indwelling medical devices, such as central venous catheters, prosthetic joints and cardiac devices are common sites for biofilm formation in the setting of systemic Staph aureus infections. Because conventional antibiotics are relatively ineffective at penetrating biofilms, long courses of antibiotics are generally required and are often unsuccessful, necessitating surgery (e.g., heart valve or prosthetic joint removal and replacement to eradicate the infection). There is a significant unmet medical need for novel treatment strategies to eradicate biofilms, as there are no medical products currently indicated for, or effective in, the eradication of biofilms.

Because exebacase disrupts the cell wall of Staph aureus bacteria by enzymatic lysis, we expected exebacase to be highly active against biofilms and we have performed an extensive battery of studies to profile

9

exebacase’s activity against Staph aureus biofilms. These studies tested exebacase against biofilms formed on a range of surfaces, including polystyrene (i.e., microtiter plates), glass (i.e., chamber slides), and PVC (i.e., catheter tubing), as well as in human serum, plasma, blood and synovial fluid. The results of these studies as detailed and recently published in Antimicrobial Agents and Chemotherapy (Schuch, et al, AAC, July 2017), provide evidence that exebacase is a potent anti-staphylococcal biofilm agent.

We conducted a pilot study evaluating exebacase’s ability to eradicate Staph aureus biofilm from the inside of a hemodialysis catheter removed from an infected patient. The endpoint of the model was a reduction in the amount of bacteria (measured in CFUs). Segments of the catheter were assigned to one of three different treatment groups: exebacase, daptomycin (DAP) or exebacase + DAP at the clinically relevant concentration of 1 µg/mL. As shown in Figure 1 below, exebacase eradicated the biofilm at 1 µg/mL whereas daptomycin alone did not clear biofilm at 1 µg/mL. The addition of exebacase with daptomycin resulted in the same clearance of biofilm as exebacase alone. The catheter biofilm contained MRSA as well as other Staph species. We believe these data provide important translation of the previously reported potent efficacy of exebacase against biofilms formed in vitro and in animal models, to biofilms formed in the setting of human disease.

Figure 1: Sensitivity of MRSA Biofilms on Explanted Human Catheter to Exebacase (CF-301)

In view of the lack of efficacy of conventional antibiotics against biofilms, we believe exebacase, if approved, may provide an important new therapeutic option to address the biofilm components of invasive Staph aureus infections and potentially forestall or eliminate the need for surgical intervention.

Rapid, potent and selective bactericidal activity

Lysins have demonstrated rapid bactericidal activity. We have performed timekill assays comparing the time it has taken exebacase to kill bacteria in vitro and exert a bactericidal effect to the time required for daptomycin or vancomycin to do the same. All drugs were administered at a concentration of 1x minimal inhibitory concentration (“MIC”). Exebacase reduced the number of Staph aureus bacteria in tests on 62 strains

10

(20 MSSA and 42 MRSA strains) by 3-logs within 30 minutes. In contrast, daptomycin required six hours to achieve the same level of cell killing, while vancomycin failed to achieve a 2-log, or 99%, cell kill during the same six-hour test period. The rapid bactericidal activity of exebacase is one of the important reasons that we believe it could be a highly desirable therapeutic option, if approved, for the treatment of Staph aureus infections.

Exebacase has been bactericidal against all Staph aureus isolates tested to date, regardless of their antibiotic-resistance profile. We have tested over 250 different drug sensitive and resistant isolates of Staph aureus. The isolates tested can be classified by the particular drugs to which they are sensitive or resistant, including MSSA, MRSA, VRSA, linezolid-resistant (“LRSA”) and daptomycin-resistant (“DRSA”) Staph aureus. Exebacase was shown to be active against all the strains tested. Our Standard Bacteremia Model utilizes animals infected with 10 million (10⁷) CFU of MRSA and treated 3 hours later with various doses of therapy or buffer. In this model, exebacase produced a dose-dependent increase in survival rates, with mice receiving at least 0.5 mg/kg of exebacase having demonstrated at least 90% survival, whereas doses below 0.5 mg/kg resulted in lower survival.

Synergy with Standard-of-Care Antibiotics

Synergy is defined as the interaction of two or more agents so that their combined effect is greater than the sum of their individual effects. We identified a strong synergy between lysins and a wide range of anti-staphylococcal antibiotics, including daptomycin, vancomycin and oxacillin through in vitro synergy assays. In these tests, synergy was assessed by checkerboard assay using the fractional inhibitory concentration index (“FICI”) for each combination. An FICI mean was derived from each checkerboard based on two consecutive FIC values along the growth/no growth interface. Synergy was defined as an FICI of £0.5; strongly additive was >0.5-<1; indifference was 1 to <2; and antagonism was ³2.

To test and demonstrate this synergy in vivo, we developed the Drug Failure Bacteremia Model where exebacase could be tested in combination with a SOC antibiotic. The Drug Failure Bacteremia Model utilizes an extremely high infection burden of one billion (10⁹) CFU. This produces such an overwhelming infection in the animals such that SOC antibiotics used as monotherapies at their human equivalent doses failed to produce significant cure rates. We tested daptomycin, vancomycin and oxacillin in this model. We then adjusted the dose of exebacase so that monotherapy with exebacase would also fail to have significant cure rates under these intense infection conditions. To test and demonstrate whether the synergy that we had observed in vitro between exebacase and SOC antibiotics would lead to improved efficacy in vivo, we then treated groups of animals in the Drug Failure Bacteremia Model with the drugs as monotherapies and also in combination to evaluate if there was an improvement in efficacy.

In the Drug Failure Bacteremia Model, all control mice treated with buffer succumbed to bacterial infection within 12 hours. Administration of a clinical dose of daptomycin as a single agent resulted in clinical failure, as only 31% of mice survived. Similarly, when exebacase was dosed as a single agent at this chosen dose, only 18% of mice survived. In contrast, when mice received the exebacase in addition to daptomycin, 82% survived the bacterial challenge, demonstrating superiority of the combination therapy over either of the single-drug regimens, with a significantly higher survival rate than the sum of the results from the two monotherapies.

We have tested the combination of exebacase with daptomycin, vancomycin and oxacillin in multiple experiments with the Drug Failure Bacteremia Model. In each experiment, the combination therapy was shown to be superior to monotherapy with a single drug alone. We have also studied the combination of exebacase with other anti-staphylococcal agents, including linezolid, televancin, nafcillin, cefazolin, clindamycin and azithromycin, in vitro and found exebacase to be synergistic or strongly additive with each agent against both MSSA and MRSA strains.

To further explore the activity of exebacase in combination with SOC antibiotics for the treatment of life-threatening, drug-resistant infections, we engaged the LA Biomed Research Institute at Harbor-UCLA Medical

11

Center (“UCLA”) to perform studies in their standard, well characterized rat and rabbit infective endocarditis models. The endpoint of the model is a reduction in the amount of bacteria (measured as CFUs) on the heart valve, in the kidney and in the spleen. The studies examined the activity of exebacase in combination with daptomycin, in UCLA’s prototypical high-burden biofilm-based model.

In this study, a single dose of exebacase used in addition to daptomycin resulted in an additional substantial reduction in CFUs, on top of the reduction in CFUs by daptomycin alone. This study is highly relevant to our understanding of the therapeutic potential of exebacase and the intended clinical application in a difficult to treat biofilm-based infection. This study demonstrated that a single dose of exebacase, when combined with four days of daptomycin treatment, resulted in a 3-log drop in bacterial burden in the cardiac vegetations and >2-log drop in the kidney and spleen of infected animals relative to daptomycin treatment alone. Importantly, four out of nine animals treated with exebacase and daptomycin were found to have sterilized kidney, spleen and heart valve vegetations, whereas none of the animals treated with daptomycin alone had tissues that were sterilized.

We have subsequently conducted additional experiments at UCLA in the rabbit infective endocarditis model in order to both replicate the results of the rat study, but also to examine a range of exebacase doses used in addition to daptomycin as compared to both buffer and daptomycin alone. The results of a dose-ranging study, where a range of single doses of exebacase was assessed when administered in addition to four days of daptomycin treatment are shown in Figure 2 below. As seen in the rat studies, administration of daptomycin alone resulted in a 3-log reduction in CFUs in the heart valve vegetations in these animals infected with MRSA. The addition of a single dose of exebacase, resulted in an additional ~3-log reduction in CFUs in the cardiac vegetations compared to daptomycin alone at all doses of exebacase tested (p < 0.002). Using conventional allometric scaling, the 0.7 mg/kg dose of exebacase approximates the human clinical dose of 0.25mg/kg, which is the dose being studied in our Phase 2 clinical trial. This dose together with daptomycin resulted in a 6-log reduction in CFUs compared to buffer (p < 0.001). Of note, efficacy was maintained even at the lowest dose of exebacase tested (0.09 mg/kg) in this study (p < 0.001).

Figure 2: Dose Ranging Study of Exebacase (CF-301) with Daptomycin in Rabbit Infective Endocarditis Model

12

Collectively, we believe these preclinical data provided significant support to the design of our clinical trials.

Non-Clinical Activities

Chemistry, Manufacturing and Controls (“CMC”)

Exebacase is manufactured using a proprietary engineered E. coli strain that expresses the product in a recombinant manner during the fermentation process. This technology allows production of up to nine grams of exebacase per liter of fermentation broth. After fermentation, the broth containing exebacase is separated and purified through a process containing two chromatographic columns. The resulting product has greater than 99% purity.

We recently achieved concurrence with the FDA on our CMC plans for Phase 3 and BLA submission. We intend to further optimize the manufacturing process for increased purity and yield. Once completed, we plan to begin a program to manufacture Phase 3 material. The process will then be scaled up from the current fermentation size and validated in a series of manufacturing batches to demonstrate consistency. In parallel to the validation, we intend to conduct a comparability program that demonstrates comparability between the final product used in Phase 3 and commercial manufacturing. We intend to include the results in the BLA that we expect to submit to the FDA. Following submission, we expect that the FDA will conduct pre-approval inspections of all manufacturing facilities and determine whether it agrees that our commercial material is sufficiently comparable to our Phase 3 material.

Safety Pharmacology and Toxicology

We conducted non-clinical safety pharmacology and toxicology studies in connection with our IND application for exebacase. In these studies exebacase was well-tolerated in rats for a single two-hour IV administration of doses up to 25mg/kg (determined by us to be the no observable adverse effect level, or “NOAEL”) and that a single dose of 2.5 mg/kg was not associated with any effects, adverse or not, and was therefore determined to be the no observable effect level (“NOEL”). Exebacase was well tolerated in these studies in both rats and dogs for seven consecutive days of once daily two-hour IV infusions of up to 2.5 mg/kg. In a non-GLP pilot study in rats, 1.0 mg/kg/day was well tolerated for up to seven consecutive days of once daily two-hour IV infusions or IV boluses.

Dose-dependent adverse effects were seen in both species at doses above 25 mg/kg/day for 1 day in the rat and above 2.5 mg/kg/day for seven-consecutive days in both the rat and the dog. The dose limiting toxicity observed was a localized microscopic histopathological change surrounding certain blood vessels. In accordance with industry practice, we have studied exebacase in clinical trials at doses much lower than those that caused adverse effects in animals, and we believe these doses to be within the efficacious range of the drug.

Upon first exposure to exebacase, no hypersensitivity reaction was observed in any of our animal studies. Upon administration of a second course of exebacase, given two weeks after completion of the first course, including multiple-day courses, hypersensitivity or hypersensitivity-like findings were observed in mice, rats and dogs. In a dedicated hypersensitivity study in rats, using a model intended to elicit hypersensitivity, findings consistent with hypersensitivity were observed after a two-week delayed re-challenge with a second course of exebacase and were not dose-dependent. In general, in humans, Type I hypersensitivity is an allergic anaphylaxis-like response (e.g., an immediate and potentially life-threatening allergic reaction) and Type III hypersensitivity is a serum sickness-like response (e.g., fever, joint pain, protein in urine, vascular changes). While the nature of hypersensitivity reactions in rats may not necessarily be predictive of hypersensitivity reactions that may occur in humans, we have also considered the risk of hypersensitivity occurring upon first administration of exebacase due to potential prior exposure to the active protein component of exebacase from the environment, as it is a naturally occurring protein. Testing for anti-drug antibodies was performed in Phase 1 subjects. No clinical hypersensitivity related to exebacase was observed in subjects dosed in our Phase 1 or Phase 2 study.

13

CF-296: An Engineered Lysin for Invasive Staph aureus Infections

We have engineered a lysin variant of exebacase which we believe may suitable for the potential treatment of the most challenging invasive infections caused by Staph aureus including biofilm-related infections in prosthetic joints and indwelling devices and osteomyelitis. Based on the safety pharmacology and toxicology profile of exebacase described above, our objectives for the program were to maintain the spectrum of activity of an anti-staphylococcal lysin while improving the non-clinical safety profile.

CF-370: A Novel Engineered Lysin for P. aeruginosa Infections

Medical Opportunity

P. aeruginosa is a gram-negative pathogen that is common in the environment and is an important and much-feared potential pathogen in hospitals. P. aeruginosa readily develops resistance to conventional antibiotics resulting in the emergence of multidrug resistant (“MDR”) strains, which have become common in some hospitals and regions. P. aeruginosa is a major cause of hospital-acquired infections and is a particularly important cause of infections in immunocompromised hosts, and is also a major pathogen in burn and surgical wound infections. P. aeruginosa is also the most common pathogen isolated from adults with cystic fibrosis, the most common cause of respiratory failure in cystic fibrosis and responsible for the deaths of the majority of these patients.

Invasive P. aeruginosa infections, including ventilator associated pneumonia, blood stream infections, complicated urinary tract infections, and infections following surgery carry some of the highest risks of mortality among hospital acquired infections. More than 32,000 P. aeruginosa infections are multidrug-resistant, with roughly 2,700 deaths per year attributed to these infections. Infections caused by multidrug resistant P. aeruginosa are associated with high all-cause mortality, hospital mortality and higher health-care related costs compared to infections caused by susceptible strains.

CF-370 Development

CF-370 is an investigational first-in-class anti-bacterial therapeutic candidate targeting a gram-negative pathogen. CF-370 has been engineered to bypass the outer membrane of the bacteria and to enable potent activity in human serum. We believe this is a significant milestone for direct lytic agents as native lysins are typically unable to penetrate the outer membrane of gram-negative bacteria and consequently unable to work in vitro in human blood or in animal models. However, based on the proprietary methods we have identified and utilize to engineer lysins, CF-370 has exhibited the hallmark in vitro features of the lysin class, including rapid and potent bactericidal activity, synergy with a broad range of standard of care agents and the eradication of biofilms in preclinical studies. In preclinical rabbit pneumonia models, single doses of CF-370 alone and in combination with meropenem, were tested against multi-drug resistant P. aeruginosa to evaluate survival and bacterial burden in lung and secondary organs. In these models, strong activity was observed for CF-370 as a monotherapy, showing that rabbits dosed with CF-370 alone had longer survival, as compared to vehicle control, and reductions in bacterial burden in the lung, kidney and spleen with single doses of CF-370. Synergy with meropenem was also noted with greater reductions in bacterial burden compared to monotherapy. In these models, CF-370 was well tolerated with no adverse clinical consequences and no deaths among animals infected with P. aeruginosa.

We have advanced CF-370 into IND-enabling activities and we expect it to be our next molecule in clinical studies. We have been awarded up to $3.3 million in funding from CARB-X in support of the advancement of anti-pseudomonal lysins.

14

Lysin Discovery Platform

The main objective of our lysin discovery platform has been to bring forth a portfolio of lysins that selectively target the largest threats of resistant bacteria, commonly referred to as the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species), which are the leading causes of hospital acquired infections throughout the world.

Lysins are enzymes derived from naturally occurring bacteriophage, which are viruses that infect bacteria. When recombinantly produced and then applied to bacteria, lysins cleave a key component of the target bacteria’s peptidoglycan cell wall, resulting in rapid bacterial cell death. Conventional antibiotics require bacterial cell division and metabolism to occur in order to exert their effect (i.e., cell death or cessation of growth). Based on in vitro tests, lysins, however, are fundamentally different in that they kill bacteria rapidly by enzymatic cleavage of the bacterial cell wall without need for bacterial growth and cell division. In addition to the speed of action and potent cidality, we believe lysins are differentiated by their other hallmark features which include the demonstrated ability to eradicate biofilms and synergistically boost the efficacy of conventional antibiotics in animal models. Importantly, lysins also have a “narrow spectrum” meaning they kill only specific species of bacteria or closely related bacteria. As such, we believe that lysins targeting gram-positive pathogens will not have negative effects on the beneficial, normal human GI microbiome in contrast to conventional “broad spectrum” antibiotics which can kill the body’s normal, beneficial bacteria. We believe that the potential therapeutic profile of lysins is complementary to that of conventional antibiotics. As such, our approach includes the use of lysins in addition to conventional antibiotics for the treatment of serious, drug-resistant bacterial infections, including biofilm-associated infections, in an effort to achieve greater efficacy and improve clinical outcomes, as well as potentially protect against antibiotic resistance.

We employ bioinformatics and a series of metagenomic-based techniques to identify and clone bacteriophage lysins from bacterial, viral, and environmental sources. The field of metagenomics is based on the bulk extraction of DNA/RNA from environmental samples (e.g., soil, water, etc.) without prior isolation of individual microbial sources. This is useful when one considers that less than 1% of microbes are culturable under standard laboratory conditions. Once extracted, the metagenomic DNA can then be examined using sequence-based methods or by proprietary functional screens. These functional screens for bacteriophage lysin activity form the major component of our lysin discovery work. Once cloned, our scientists also employ a variety of techniques to further optimize and ‘engineer’ changes to the lysins to introduce specific characteristics which we believe may be favorable for potential therapeutic use.

For the functional metagenomic work that we perform, environmental genes are expressed in a recombinant format in a standard host organism (i.e., Escherichia coli) and cells are monitored for the acquisition of a desired phenotype. We can vary both the source of environmental DNA and the way we monitor for desired phenotypes to focus only on environmental populations enriched for bacteriophage lysins that can actively kill a pathogen of interest. We sample various DNA sources including viral, prophage, and pathogen-amplified viral metagenomics. Multiple methods for both DNA library construction and for functional screening are used in parallel in order to maximize lysin identification.

The application of these methods enables the large scale identification of lysins, enabling the production of lysin banks specific for any particular pathogen. We believe the ability to rapidly identify lysins specific for any pathogen of interest, either by in vitro or in silico methods, will provide a steady pipeline of novel lysins for consideration as potential antimicrobial therapeutic candidates.

The focus of our research and discovery efforts is on identifying lysins which selectively kill specific species of gram-negative bacteria that are considered to be urgent or serious threats to global health by the CDC or critical priorities by the WHO. Emerging strains of multi-drug resistant gram-negative pathogens that are resistant to all or nearly all available antibiotics are considered to be a major global health threat. We believe that

15

lysins targeting gram-negative pathogens have the potential to be important therapeutics to combat antimicrobial resistance due to their novel mechanism of action and therapeutic profile, which is complementary to conventional antibiotics.

We have discovered and engineered a novel lysin, CF-370, an investigational first-in-class anti-bacterial therapeutic candidate targeting a gram-negative pathogen, P. aeruginosa. CF-370 has been engineered to bypass the outer membrane of the bacteria and to enable potent activity in human serum. We will continue to pursue new lysins that target other gram-negative pathogens, such as the Enterobacteriaceae family of bacteria.

Enterobacteriaceae

The Enterobacteriaceae family of gram-negative bacteria includes Klebsiella pneumoniae (“K. pneumoniae”), Enterobacter species (“Enterobacter” e.g. Enterobacter cloacae) and Escherichia coli (“E. coli”), all of which can cause serious, life-threatening infections, and have demonstrated concerning resistance patterns.

The emergence and spread of antimicrobial resistance among Enterobacteriaceae are recognized public health threats which complicate the treatment of serious nosocomial infections.

Enterobacteriaceae can produce enzymes (e.g., “extended-spectrum beta-lactamases (“ESBL”)) that confer resistance to most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam. Infections with ESBL-producing organisms have been associated with poor outcomes. Approximately 20% of K. pneumoniae infections and 31% of Enterobacter infections in intensive care units in the United States now involve strains which are not susceptible to third-generation cephalosporins. Community and hospital-acquired ESBL-producing Enterobacteriaceae are prevalent worldwide, and their prevalence may be underestimated because reliable identification of ESBL-producing organisms in clinical laboratories can be challenging.

Carbapenem antibiotics are considered to be the best currently available antimicrobial agent to treat infections caused by ESBL-producing Enterobacteriaceae. However, resistance to carbapenems is becoming increasingly prevalent, and the resulting Carbapenem-resistant Enterobacteriaceae (“CRE”), have high levels of resistance to antibiotics. K. pneumoniae and E. coli are a normal part of the human gut bacteria that can become carbapenem-resistant due to enzymes that breakdown carbapenem antibiotics and make them ineffective. Klebsiella pneumoniae carbapenemase (“KPC”) and New Delhi Metallo-beta-lactamase (“NDM”) are two such enzymes that break down carbapenems and make them ineffective. Both of these enzymes have also been reported in P. aeruginosa. CRE infections typically occur in hospitals, nursing homes, and other healthcare settings. Patients who require devices like ventilators (breathing machines), urinary (bladder) catheters, or intravenous (vein) catheters, and/or patients who are taking long courses of certain antibiotics are most at risk for CRE infections. Some CRE bacteria have become resistant to most available antibiotics, are very difficult to treat, and can lead to death in up to 50% of patients who become infected.

16

We believe that lysins which target K. pneumoniae, Enterobacter and E. coli may be important therapeutic options for the treatment of serious, potentially life-threatening invasive infections caused by multidrug resistant pathogens. Because of the novel mechanism by which lysins kill bacterial, no cross resistance to conventional antibiotics, and as such, KPC, NDM and similar enzymes are not expected to have any effect on the activity of lysins. We believe that lysins may help to improve clinical outcomes of infections caused by these pathogens and thus we are also focusing research efforts to identify and develop lysins which target them.

Gram-positive lysins

In addition to our proprietary lysin discovery program, we hold worldwide exclusive license rights to patents for composition of matter for nine lysins from The Rockefeller University (“Rockefeller”). The lysins each target a specific species of gram-positive bacteria, including drug-sensitive and drug-resistant forms as exemplified in Table 4 below.

Table 4: Lysins Licensed From The Rockefeller University

Amurin Discovery Program

Amurin peptides are a class of novel, phage-derived lytic agents discovered in our laboratories. In preclinical studies, amurin peptides have shown some features common to lysins, including potent bacteriocidality, including antibiotic-resistant strains, the ability to clear biofilms and synergize with conventional antibiotics. However, amurin peptides are further differentiated in their potential ability to exert these actions on the full range of gram-negative ESKAPE pathogens, as well as a range of additional, serious and difficult to treat gram-negative bacteria, including Burkholderia and Stenotrophomonas, in the context of human serum, without apparent ‘off target’ effects against gram-negatives. As such, amurin peptides have shown a highly differentiated spectrum of action, and we believe, if successfully developed, would be extremely well suited as potential treatments for patients suffering from polymicrobial gram-negative infections, such as cystic fibrosis, ventilator-associated pneumonia, intra-abdominal infections, and serious burns or certain chronic wound infections. Given their powerful in vitro activity against a broad range of resistant pathogens, as shown in Table 5 below, we believe that amurin peptides have the potential to become a powerful addition to our armamentarium against strains of gram-negative pathogens which have extreme- or pan- drug resistance to all or almost all currently available antibiotics.

Table 5: In Vitro Activity (minimal inhibitory concentrations) of Amurin

Candidates (AM1, AM2 and AM3) Observed Against Carbapenem-Resistant Pathogens*

17

Similar to the pilot study performed with exebacase, we evaluated the ability of one of our lead amurins, AM2, to eradicate Stenotrophomonas maltophilia biofilms from the inside of hemodialysis catheters removed from infected patients. The endpoint of the model was a reduction in the amount of bacteria (measured in CFUs) in sections of the catheters treated with amurin AM2 compared to a control group (sections with no treatment) and sections treated with clinically relevant concentrations of meropenem. Treatment with amurin AM2 resulted in the reduction in the amount of bacteria below the limit of detection, 0.7 log₁₀ CFU/g, while both the control groups and sections treated with meropenem had CFU counts >3.0 log₁₀ CFU/g. We believe these results provide important ex vivo translation of the in vivo activity to biofilms formed in the setting of human disease.

We plan to progress our amurin peptide program as rapidly as possible through preclinical profiling and into clinical studies. We are currently evaluating the in vitro profiles of the amurins as we continue to advance the program. We have been awarded up to $9.6 million of funding from CARB-X to support the development of amurin peptides as potential therapeutics to treat serious and potentially life-threatening infections, including those caused by antibiotic-resistant gram-negative ESKAPE pathogens.

Intellectual Property

Our goal is to obtain, maintain and enforce patent protection for our products, formulations, processes, methods and other proprietary technologies, preserve our trade secrets, and operate without infringing on the valid proprietary rights of other parties, both in the United States and in other countries. Our policy is to actively seek to obtain, where appropriate, the broadest intellectual property protection possible for our product candidates, proprietary information and proprietary technology through a combination of contractual arrangements and patents, both in the United States and abroad. However, patent protection does not always afford us with complete protection against competitors who seek to circumvent our patents.

We also depend upon the skills, knowledge, experience and know-how of our management and research and development personnel, as well as that of our advisors, consultants and other contractors. To help protect our proprietary know-how, which is not patentable, and for certain inventions, in accordance with our business strategies, we currently rely and will in the future rely on trade secret protection and confidentiality agreements to protect our interests. To this end, we will require all of our employees, consultants, and other contractors (including any consultants or contractors we may retain for purposes of any of our ad hoc Clinical Advisory Boards) to enter into confidentiality agreements that prohibit the disclosure of confidential information and, where applicable, require disclosure and assignment to us of the ideas, developments, discoveries and inventions important to our business.

Our lysin portfolio consists of twenty (20) U.S. patents, one-hundred and fourteen (114) foreign patents and two hundred and eighteen (218) U.S. and international patent applications that we have licensed from Rockefeller and/or developed in-house. Certain patents related to our lysin portfolio will expire between 2024 and 2033. Our patents and patent applications include those that are directed to compositions and methods for the treatment of infections caused by gram-positive bacteria (Group B Streptococci, Staph aureus, Streptococcus pneumonia, Bacillus anthracis (anthrax), Enterococcus faecalis and Enterococcus faecium) and infections caused by gram-negative bacteria (P. aeruginosa, K. pneumoniae, Enterobacter cloacae and E. coli). If patents are granted on our patent applications, which include certain patent applications related to exebacase, CF-296 and the gram-negative lysins, they would expire between 2029 and 2040.

The U.S. patent system permits the filing of provisional and non-provisional patent applications. A non-provisional patent application is examined by the United States Patent and Trademark Office (“USPTO”), and can issue as a patent once the USPTO determines that the claimed invention meets the various standards for patentability. A provisional patent application is not examined or prosecuted, and automatically expires 12 months after its filing date if a non-provisional application is not filed based on the provisional application within that 12-month period. Provisional applications are often used, among other things, to establish a priority filing date for the subsequently filed non-provisional patent application. The term of individual patents depends upon the legal term for patents in the countries in which they are filed. In most countries in which we file, the patent

18

term is 20 years from the earliest filing date of a non-provisional patent application. In the United States, a patent’s term may be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the USPTO in granting a patent. Alternatively, a patent’s term may be shortened if a patent is terminally disclaimed over another patent.

The term of a patent that covers an FDA-approved drug may also be eligible for patent term extension (“PTE”), which permits patent term restoration as compensation for the patent term lost during the FDA regulatory review process. The Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Amendments, permits a PTE of up to five years beyond the expiration of the patent. The length of the PTE is related to the length of time the drug is under regulatory review. Patent extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be extended. Similar provisions are available in Europe and certain other foreign jurisdictions to extend the term of a patent that covers an approved drug. In the future, if and when our pharmaceutical product candidates receive FDA or other regulatory approval, we may be able to apply for or receive the benefit of PTEs on patents covering those products.

License Agreements—The Rockefeller University

We have entered into the following license agreements with Rockefeller:

In consideration for the licenses, we paid Rockefeller license initiation fees in cash and stock and may be required to pay an annual maintenance fee, milestone payments and royalties on net sales from products to Rockefeller. We are allowed to grant sublicenses to third parties without prior approval, subject to certain conditions and the payment of a certain percentage of all payments we receive from sublicensees.

Each license agreement terminates upon the later of (i) the expiration or abandonment of the last licensed patent under the license agreement to expire or become abandoned, or (ii) 10 years after the first commercial sale of the first licensed product. Rockefeller may terminate any license agreement in the event of a breach of such agreement by us or if we challenge the validity or enforceability of the underlying patent rights. We may terminate any license agreement at any time on 60 days’ notice.

19

Competition

The pharmaceutical and biotechnology industries are intensely competitive. While we believe that our technology and scientific knowledge provide us with competitive advantages, we face potential competition from many different sources, including major pharmaceutical, specialty pharmaceutical and biotechnology companies and academic and research organizations in developing therapies to treat diseases.

Exebacase is a potential first-in-class drug candidate and we believe it is the first lysin to enter human clinical trials in the U.S. We believe there is currently no clinical competitor to exebacase, which is highly differentiated from conventional antibiotics by at least six attributes that no single antibiotic possesses, including: (1) a novel mechanism of action, (2) specificity for a target bacteria (only Staph aureus), (3) rapid speed of action, (4) activity across all drug-sensitive and drug-resistant strains of the target bacteria (including MRSA, VRSA and DRSA), (5) the ability to eradicate biofilms, and (6) synergy with antibiotics.

Staph aureus bacteremia is typically treated with oxacillin or other semi-synthetic penicillin or first-generation cephalosporin, or for MRSA strains, daptomycin or vancomycin. We do not see market competition with these drugs, as our strategy is to administer exebacase in addition to these drugs with the goal of achieving clinical superiority over any one of those SOC antibiotics alone. We are aware of several other clinical trials currently being conducted or recently concluded in patients with Staph aureus bacteremia. Most of these agents are small molecules being studied in non-inferiority trials. We believe that exebacase has demonstrated synergy in vitro with a broad range of conventional anti-staphylococcal agents of different classes and, in the event any of these non-inferior small molecules are approved, we believe that exebacase will also be synergistic and non-competitive with them.

Based on recent data published by the WHO, there are only five biologic agents, other than ours, in clinical development for Staph aureus infections from iNtRon Biotechnology, Inc., (“iNtRon”), Aridis Pharmaceuticals, Inc. (“Aridis”), MedImmune (a subsidiary of AstraZenenca plc), XBiotech, Inc (“XBiotech”) and Genentech, Inc. (“Genentech”). Aridis is studying AR-301, a monoclonal antibody, in Staph aureus pneumonia, not bacteremia. MedImmune has been studying MEDI-4893, a monoclonal antibody, for the prevention of Staph aureus pneumonia in a Phase 2 study since 2014. XBiotech is planning to study 514G3, a monoclonal antibody, for the prevention of Staph aureus infection in hemodialysis patients. Genentech has been studying DSTA-4637S, an antibody-drug conjugate, in a Phase 1 study since 2017. Depending on the outcomes of these and future trials, exebacase may compete with these products. We believe iNtRon, a biotechnology company located in South Korea, is currently conducting a human clinical trial in South Korea alone for SAL-200, an endolysin-based drug candidate, to evaluate it as a treatment for Staph aureus bacteremia. Additionally, in November 2018, iNtRon announced a licensing arrangement with Roivant Sciences with a stated purpose to pursue the global development and commercialization of its endolysin products, including SAL-200. We will continue to monitor the advancement of SAL-200 as data and information become available. We are not aware of SAL-200 or any other anti-staphylococcal lysins having been applied for under an IND for clinical development in the United States.

Many of our competitors may have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved medicines than we do. We compete with companies that have products on the market or in development for the same indications as our product candidates. Mergers and acquisitions in the pharmaceutical, biotechnology and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials. Smaller or early stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

The key competitive factors affecting the success of all of our product candidates, if approved, are likely to be their efficacy, safety, convenience, price and the availability of reimbursement from government and other third-party payors. Our commercial opportunity could be reduced or eliminated if our competitors develop and

20

commercialize medicines that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any medicines that we may develop. Our competitors also may obtain FDA or other regulatory approval for their medicines more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market.

Manufacturing

We do not own or operate, and currently have no plans to establish, any manufacturing facilities. We currently rely, and expect to continue to rely, on third parties for the manufacture of our product candidates for preclinical or clinical manufacturing, testing, as well as for commercial manufacture of any products that we may commercialize. We employ the services of Fujifilm Diosynth Biotechnologies UK LTD (“Fujifilm UK”) to supply the drug substance for exebacase. We do not yet have contracts to produce a commercial supply of the drug substance for exebacase; however, we intend to pursue agreements with Fujifilm UK to do so. We employ the services of various vendors to produce exebacase in its final vialed drug product form. We do not have contracts for the commercial supply of exebacase. We intend to pursue agreements with third party manufacturers regarding commercial supply of vialed drug product at an appropriate future time. We may choose to locate second fill finish third party manufacturers to supply other world regions such as the European Union (the “E.U.”) or Asia.

Sales, Marketing and Distribution

We do not currently have an organization for the sales, marketing and distribution of pharmaceutical products. We may rely on licensing and co-promotion agreements with strategic partners for the commercialization of our products in the United States and other territories. If we choose to build a commercial infrastructure to support marketing in the United States, such commercial infrastructure could be expected to include a targeted sales force supported by sales management, internal sales support, an internal marketing group and distribution support. To develop the appropriate commercial infrastructure internally, we would have to invest financial and management resources, some of which would have to be deployed prior to any confirmation that any of our other products will be approved.

Government Regulation

The production, distribution, and marketing of products employing our research and intellectual property or that we may license from third parties are subject to extensive governmental regulation in the United States and in other countries. In the United States, our products will be regulated as biologics and subject to the Federal Food, Drug, and Cosmetic Act, as amended (the “FDC Act”), the Public Health Service Act, as amended (the “PHSA”) and the regulations of the FDA, as well as to other federal, state, and local statutes and regulations. These laws, and similar laws outside the United States, govern the research, development, clinical and preclinical testing, manufacture, safety, effectiveness, approval, labeling, distribution, sale, import, export, storage, record-keeping, reporting, advertising, and promotion and marketing of our products. Product development and approval within this regulatory framework, if successful, will require the expenditure of substantial resources and take years to achieve. Violations of regulatory requirements at any stage may result in various adverse consequences, including the FDA’s and other health authorities’ delay in approving or refusal to approve a product and may result in enforcement actions and administrative or judicial sanctions.

The following provides further information on certain legal and regulatory requirements that have the potential to affect our operations and the future marketing of our products.

FDA Approval Process

In the United States, pharmaceutical products are subject to extensive regulation by the FDA. The FDC Act and other federal and state statutes and regulations govern, among other things, the research, development, testing, manufacture, storage, recordkeeping, approval, labeling, promotion and marketing, distribution, post-approval monitoring and reporting, sampling, and import and export of pharmaceutical products. In addition to

21

regulation under the FDC Act, biological products used for the prevention, treatment, or cure of a disease or condition of a human being are subject to regulation under provisions of the PHSA, and FDA reviews applications for approval of a biologic pursuant to a BLA. FDA review applications for approval of drug products pursuant to a new drug application (“NDA”). Failure to comply with applicable U.S. requirements may subject a company to a variety of administrative or judicial sanctions, such as FDA refusal to approve pending NDAs or BLAs, warning or untitled letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, civil penalties, and criminal prosecution.

Pharmaceutical product development for a new product or certain changes to an approved product in the United States typically involves preclinical laboratory and animal tests, the submission to the FDA of an IND, which must become effective before clinical testing may commence, and adequate and well-controlled clinical trials to establish the safety and effectiveness of the drug for each indication for which FDA approval is sought. Satisfaction of FDA pre-market approval requirements typically takes many years and the actual time required may vary substantially based upon the type, complexity, and novelty of the product or disease.

Preclinical tests include laboratory evaluation of product chemistry, formulation, and toxicity, as well as animal trials to assess the characteristics and potential safety and efficacy of the product. The conduct of the preclinical tests must comply with federal regulations and requirements, including good laboratory practices. The results of preclinical testing are submitted to the FDA as part of an IND along with other information, including information about product chemistry, manufacturing and controls, and a proposed clinical trial protocol. Long term preclinical tests, such as animal tests of reproductive toxicity and carcinogenicity, may continue after the IND is submitted.

A 30-day waiting period after the submission of each IND is required prior to the commencement of clinical testing in humans. If the FDA has neither commented on nor questioned the IND within this 30-day period, the clinical trial proposed in the IND may begin.

Clinical trials involve the administration of the investigational new drug or biologic to healthy volunteers or patients under the supervision of a qualified investigator. Clinical trials must be conducted: (i) in compliance with federal regulations; (ii) in compliance with good clinical practice (“GCP”) regulations meant to protect the rights and health of healthy volunteers or patients and to define the roles of clinical trial sponsors, administrators, and monitors; as well as (iii) under protocols detailing the objectives of the trial, the parameters to be used in monitoring safety, and the effectiveness criteria to be evaluated. Each protocol involving testing on healthy volunteers or patients in the U.S. and subsequent protocol amendments must be submitted to the FDA as part of the IND.

The FDA may order the temporary, or permanent, discontinuation of a clinical trial at any time, or impose other sanctions, if it believes that the clinical trial either is not being conducted in accordance with FDA requirements or presents an unacceptable risk to the clinical trial patients. The study protocol and informed consent information for patients in clinical trials must also be submitted to an institutional review board (“IRB”) for approval. An IRB may also require the clinical trial at the site to be halted, either temporarily or permanently, for failure to comply with the IRB’s requirements, or may impose other conditions.

Clinical trials to support NDAs or BLAs for marketing approval are typically conducted in three sequential phases, but the phases may overlap. In Phase 1, the initial introduction of the drug or biologic into healthy human subjects or patients, the product is tested to assess metabolism, pharmacokinetics, pharmacological actions, side effects associated with increasing doses, and, if possible, early evidence of effectiveness. Phase 2 usually involves trials in a limited patient population to determine the effectiveness of the drug or biologic for a particular indication, dosage tolerance, and optimum dosage, and to identify common adverse effects and safety risks. If a compound demonstrates evidence of effectiveness and an acceptable safety profile in Phase 2 evaluations, Phase 3 trials are undertaken to obtain the additional information about clinical efficacy and safety in a larger number of patients, typically at geographically dispersed clinical trial sites, to permit the FDA to evaluate the overall benefit-risk relationship of the drug or biologic and to provide adequate information for the

22

labeling of the product. In most cases, the FDA typically requires two adequate and well-controlled Phase 3 clinical trials to demonstrate the efficacy of the drug or biologic. A single Phase 3 trial with other confirmatory evidence may be sufficient in some instances where the study is a large multicenter trial demonstrating internal consistency and a statistically very persuasive finding of a clinically meaningful effect on mortality, irreversible morbidity or prevention of a disease with a potentially serious outcome and confirmation of the result in a second trial would be practically or ethically impossible.

After completion of the required clinical testing, an NDA or BLA is prepared and submitted to the FDA. FDA approval of the NDA or BLA is required before marketing of the product may begin in the United States. The NDA or BLA must include the results of all preclinical, clinical, and other testing and a compilation of data relating to the product’s pharmacology, chemistry, manufacture, and controls. The cost of preparing and submitting an NDA or BLA is substantial. The submission of most NDAs and BLAs is additionally subject to a substantial application user fee. For fiscal year 2020, the application user fee is $2,942,965. The manufacturer and/or sponsor under an approved NDA or BLA are also subject to annual program user fees, currently set at $325,424 per program. These fees are typically adjusted annually.

The FDA has 60 days from its receipt of an NDA or BLA to determine whether the application will be accepted for filing based on the agency’s threshold determination that it is sufficiently complete to permit substantive review. Once the submission is accepted for filing, the FDA begins an in-depth review. The FDA has agreed to certain performance goals in the review of NDAs and BLAs. The FDA aims to review applications for standard review drugs containing new molecular entities or original biologic products within ten months of the date the application was accepted for filing, and the goal is to review applications for priority review drugs or biologics in six months of the date the application was accepted for filing. Priority review can be applied to applications for drugs containing new molecular entities or biologics that are intended to treat a serious disease or condition and that, if approved, would provide a significant improvement in safety or effectiveness. The review process for both standard and priority review may be extended by the FDA to consider certain late-submitted information, or information intended to clarify information already provided in the submission.

The FDA may also refer applications for novel drug or biologic products, or drug or biologic products that present difficult questions of safety or efficacy, to an advisory committee—typically a panel that includes clinicians and other experts—for review, evaluation, and a recommendation as to whether the application should be approved. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendations. Before approving an NDA or BLA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP. Additionally, the FDA will inspect the facility or the facilities at which the drug is manufactured. The FDA will not approve the product unless compliance with current good manufacturing practices (“cGMPs”) is satisfactory and the BLA contains data that provide substantial evidence that the proposed biologic is safe, pure and potent for its intended use, and has an acceptable purity profile. In the case of an NDA, whether the drug is safe and effective for its intended use.

After the FDA evaluates the NDA or BLA and the manufacturing facilities, it issues either an approval letter or a complete response letter. A complete response letter generally outlines the deficiencies in the submission and may require substantial additional testing, or information, in order for the FDA to reconsider the application. If, or when, those deficiencies have been addressed to the FDA’s satisfaction in a resubmission of the NDA or BLA, the FDA will issue an approval letter. The FDA has committed to reviewing such resubmissions in two or six months depending on the type of information included.

An approval letter authorizes commercial marketing of the drug or biologic with specific prescribing information for specific indications. As a condition of NDA or BLA approval, the FDA may require a risk evaluation and mitigation strategy (“REMS”), to help ensure that the benefits of the drug or biologic outweigh the potential risks. REMS can include medication guides, communication plans for healthcare professionals, and elements to assure safe use (“ETASU”). ETASU can include, but are not limited to, special training or certification for prescribing or dispensing, dispensing only under certain circumstances, special monitoring, and

23

the use of patient registries. The requirement for a REMS can materially affect the potential market and profitability of the product. Moreover, product approval may require substantial post-approval testing and surveillance to monitor the product’s safety or efficacy. Once granted, product approvals may be withdrawn if compliance with regulatory standards is not maintained or problems are identified following initial marketing.

Changes to some of the conditions established in an approved application, including changes in indications, labeling, or manufacturing processes or facilities, require submission and FDA approval of a new NDA or BLA or NDA or BLA supplement before the change can be implemented. An NDA or BLA supplement for a new indication typically requires clinical data similar to that in the original application, and the FDA uses the same procedures and actions in reviewing NDA or BLA supplements as it does in reviewing NDAs or BLAs.

Post-Approval Requirements

Once an NDA or BLA is approved, a product will be subject to certain post-approval requirements. For instance, the FDA closely regulates the post-approval marketing and promotion of drugs and biologics, including standards and regulations for direct-to-consumer advertising, off-label promotion, industry-sponsored scientific and educational activities and promotional activities involving the internet. Drugs and biologics may be marketed only for the approved indications and in accordance with the provisions of the approved labeling.

Adverse event reporting and submission of periodic reports is required following FDA approval of an NDA or BLA. The FDA also may require post-marketing testing, known as Phase 4 testing, REMS, and surveillance to monitor the effects of an approved product, or the FDA may place conditions on an approval that could restrict the distribution or use of the product. In addition, quality control, drug manufacture, packaging, and labeling procedures must continue to conform to cGMPs after approval. Drug and biologic manufacturers and certain of their subcontractors are required to register their establishments with the FDA and certain state agencies. Registration with the FDA subjects entities to periodic unannounced inspections by the FDA, during which the agency inspects manufacturing facilities to assess compliance with cGMPs. Accordingly, manufacturers must continue to expend time, money, and effort in the areas of production and quality-control to maintain compliance with cGMPs. Regulatory authorities may withdraw product approvals or request product recalls if a company fails to comply with regulatory standards, if it encounters problems following initial marketing, or if previously unrecognized problems are subsequently discovered.

FDA Expedited Review Programs

The FDA administers a number of programs to facilitate the development, and expedite the review, of drugs or biologics that are intended for the treatment of serious or life-threatening diseases or conditions. For instance, a sponsor may seek the FDA’s designation of its product candidate as a “fast track” product. Fast track products are those products intended for the treatment of a serious or life-threatening disease or condition and which demonstrate the potential to address unmet medical needs for such disease or condition. Drugs that qualify as a qualified infectious disease product (“QIDP”), under the Generating Antibiotic Incentives Now (“GAIN”) Act, are also eligible for fast track designation. Biologics, such as lysins, are not currently eligible for QIDP designation.

Under the fast track program, the sponsor of a new drug or biologic candidate may request that the FDA designate the candidate for a specific indication as a fast track drug or biologic concurrent with, or after, the filing of the IND for the candidate. The FDA must determine if the drug or biologic candidate qualifies for fast track designation within 60 days of receipt of the sponsor’s request. If fast track designation is obtained, the FDA may initiate review of sections of the marketing application before the application is complete. This “rolling review” is available if the applicant provides and the FDA approves a schedule for the remaining information. However, the FDA’s time period goal for reviewing an application does not begin until the last section of the NDA or BLA is submitted. Additionally, the fast track designation may be withdrawn by the FDA if the FDA believes that the designation is no longer supported by data emerging in the clinical trial process. In addition, a product candidate that receives fast track designation is eligible for more frequent meetings with the FDA to

24

discuss the product’s development plan and ensure collection of appropriate data needed to support approval and more frequent communications from FDA regarding such things as the design of the proposed clinical trials and use of biomarkers, as applicable. In August 2015, the FDA granted fast track designation to exebacase for the treatment of Staph aureus bacteremia, including endocarditis.

In some cases, a product may be eligible for accelerated approval. Drug or biological products intended to treat serious or life-threatening diseases or conditions may be eligible for accelerated approval upon a determination that the product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. In clinical trials, a surrogate endpoint is a measurement of laboratory or clinical signs of a disease or condition that substitutes for a direct measurement of how a patient feels, functions, or survives. Surrogate endpoints can often be measured more easily or more rapidly than clinical endpoints.

A drug or biologic candidate approved on this basis is subject to rigorous post-marketing compliance requirements, including the completion of Phase 4 or post-approval clinical trials to confirm the effect on the clinical endpoint. Failure to conduct required post-approval studies, or confirm a clinical benefit during post-marketing studies, will allow the FDA to withdraw the drug or biologic from the market on an expedited basis. All promotional materials for drug candidates approved under accelerated regulations are subject to prior review by the FDA.

The Food and Drug Administration Safety and Innovation Act established a category of drugs and biologics referred to as “Breakthrough Therapies” that may be eligible to receive Breakthrough Therapy designation. A sponsor may seek FDA designation of a product candidate as a “Breakthrough Therapy” if the product is intended, alone or in combination with one or more other products, to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that the product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. Under the Breakthrough Therapy program, the sponsor of a new drug candidate may request that the FDA designate the drug candidate for a specific indication as a breakthrough therapy concurrent with, or after, the filing of the IND for the drug candidate. The designation includes all of the fast track program features, as well as more intensive FDA interaction and guidance. The Breakthrough Therapy designation is a distinct status from both accelerated approval and priority review, which can also be granted to the same drug if relevant criteria are met. If a product is designated as Breakthrough Therapy, the FDA will work to expedite the development and review of such drug. The FDA may also rescind Breakthrough Therapy designation for a product candidate if the FDA determines the product candidate no longer meets the criteria for Breakthrough Therapy designation. In February 2020, the FDA granted breakthrough therapy designation to exebacase for the treatment of MRSA bacteremia, including right-sided endocarditis, when used in addition to SOC anti-staphylococcal antibiotics in adult patients.

Fast track designation, priority review and accelerated approval do not change the standards for approval but may expedite the development or approval process.

Guidance for Industry: “Antibacterial Therapies for Patients with an Unmet Medical Need for the Treatment of Serious Bacterial Diseases” – Potential for Streamlined Development

The FDA issued guidance for the industry in August 2017, which among other things, discusses the potential for antibacterial drug candidates intended to treat serious bacterial infections in patients who have few or no available therapies to be candidates for a streamlined development pathway. According to the guidance, candidates for a streamlined process would be likely to have (1) a new mechanism of action that preserves antibacterial activity against bacteria that have mechanisms of resistance to other available antibacterial drugs; (2) an added inhibitor that neutralizes a mechanism of resistance; (3) an alteration in the structure of the molecule

25

that makes the drug candidate no longer susceptible to the mechanisms of resistance to existing drugs; or (4) some other characteristic that has a potential to lead to enhanced effectiveness.

Draft Guidance for Industry: “Limited Population Pathway for Antibacterial and Antifungal Drugs” (LPAD)

As part of the 21^st Century Cures Act of 2016, LPAD is intended to permit the approval of new antibiotics on the basis of relatively small clinical data sets studying patients with rare, serious, or life-threatening infections in whom large-scale trials would be infeasible. The FDA issued draft guidance for the industry regarding LPAD in June 2018 which defines the potential for antibacterial and antifungal drug candidates to be approved under a limited population development pathway. According to the draft guidance, candidates for this pathway are agents intended to treat a serious or life-threatening infection in a limited population with unmet needs, have substantial evidence of effectiveness for the drug’s intended use and sufficient information to conclude that the drug is safe for use under the conditions prescribed, recommended, or suggested in the proposed labeling which is expected to define the limited population for intended use. The FDA’s determination of safety and effectiveness must reflect the benefit-risk profile of the antibiotic in the limited population and must take into account the severity, rarity, or prevalence of the infection the drug is intended to treat and the availability or lack of alternative treatments for that limited population.

Pediatric Information

Under the Pediatric Research Equity Act (“PREA”), NDAs or BLAs or supplements to NDAs or BLAs must contain data to assess the safety and effectiveness of the drug for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the drug is safe and effective. The FDA may grant full or partial waivers, or deferrals, for submission of data. Unless otherwise required by regulation, PREA does not apply to any drug for an indication for which orphan designation has been granted.

Additional Controls for Biologics

To help reduce the increased risk of the introduction of adventitious agents, the PHSA emphasizes the importance of manufacturing controls for products whose attributes cannot be precisely defined. The PHSA also provides authority to the FDA to immediately suspend licenses in situations where there exists a danger to public health, to prepare or procure products in the event of shortages and critical public health needs, and to authorize the creation and enforcement of regulations to prevent the introduction or spread of communicable diseases in the United States and between states.

After a BLA is approved, the product may also be subject to official lot release as a condition of approval. As part of the manufacturing process, the manufacturer is required to perform certain tests on each lot of the product before it is released for distribution. If the product is subject to official release by the FDA, the manufacturer submits samples of each lot of product to the FDA together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer’s tests performed on the lot. The FDA may also perform certain confirmatory tests on lots of some products, such as viral vaccines, before releasing the lots for distribution by the manufacturer. In addition, the FDA conducts laboratory research related to the regulatory standards on the safety, purity, potency, and effectiveness of biological products. As with drugs, after approval of biologics, manufacturers must address any safety issues that arise, are subject to recalls or a halt in manufacturing, and are subject to periodic inspection after approval.

Biosimilars

The Biologics Price Competition and Innovation Act of 2009 (“BPCIA”), created an abbreviated approval pathway for biological products shown to be highly similar to or interchangeable with an FDA-licensed reference biological product. Biosimilarity sufficient to reference a prior FDA-approved product requires that there be no

26

differences in conditions of use, route of administration, dosage form, and strength, and no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency. Biosimilarity must be shown through analytical studies, animal studies, and at least one clinical study, absent a waiver by the Secretary. A biosimilar product may be deemed interchangeable with a prior approved product if it meets the higher hurdle of demonstrating that it can be expected to produce the same clinical results as the reference product and, for products administered multiple times, the biologic and the reference biologic may be switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic. To date, few biosimilars have been licensed under the BPCIA, and no interchangeable products have been approved under the BPCIA to date. Complexities associated with the larger, and often more complex, structures of biological products, as well as the process by which such products are manufactured, pose significant hurdles to implementation which are still being evaluated by the FDA.

Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing that company’s own preclinical and clinical data from adequate and well-controlled trials to demonstrate the safety, and efficacy of their product. The first biologic product submitted under the abbreviated approval pathway that is determined to be interchangeable with the reference product may also enjoy a period of exclusivity. At this juncture, it is unclear whether products deemed “interchangeable” by the FDA will, in fact, be readily substituted by pharmacies, which are governed by state pharmacy law.

Disclosure of Clinical Trial Information

Sponsors of clinical trials of FDA-regulated products, including drugs, are required to register and disclose certain clinical trial information. Information related to the product, patient population, phase of investigation, study sites and investigators, and other aspects of the clinical trial is then made public as part of the registration. Sponsors are also obligated to discuss the results of their clinical trials after completion. Disclosure of the results of these trials can be delayed until the new product or new indication being studied has been approved. Competitors may use this publicly available information to gain knowledge regarding the progress of development programs.

Other Domestic Regulatory Requirements

In the United States, the research, manufacturing, distribution, sale, and promotion of drug and biological products are potentially subject to regulation by various federal, state, and local authorities in addition to the FDA, including the Centers for Medicare and Medicaid Services, other divisions of the United States Department of Health and Human Services (e.g., the Office of the Inspector General), the United States Department of Justice and individual United States Attorneys’ offices within the Department of Justice, and state and local governments. For example, sales, marketing, and scientific/educational grant programs must comply with the anti-fraud and abuse provisions of the Social Security Act, the False Claims Act, the privacy and security provisions of the Health Insurance Portability and Accountability Act, or “HIPAA”, as amended by the Health Information Technology and Clinical Health Act, or “HITECH”, and similar state laws, each as amended. Pricing and rebate programs must comply with the Medicaid rebate requirements of the Omnibus Budget Reconciliation Act of 1990 and the Veterans Health Care Act of 1992, each as amended. If products are made available to authorized users of the Federal Supply Schedule of the General Services Administration, additional laws and requirements apply. All of these activities are also potentially subject to federal and state consumer protection, unfair competition, and other laws, and violations of these laws may result in imprisonment, criminal fines, civil monetary penalties and exclusion from participation in federal healthcare programs.

27

In addition to FDA restrictions on marketing of pharmaceutical products, several other types of state and federal laws have been applied to restrict certain marketing practices in the pharmaceutical industry in recent years. These laws include anti-kickback statutes and false claims statutes. The federal healthcare program Anti-Kickback Statute prohibits, among other things, knowingly and willfully offering, paying, soliciting or receiving remuneration to induce or in return for purchasing, leasing, ordering or arranging for the purchase, lease or order of any healthcare item or service reimbursable under Medicare, Medicaid or other federally financed healthcare programs. This statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on the one hand and prescribers, purchasers and formulary managers on the other. In addition, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation. Violations of the Anti-Kickback Statute are punishable by imprisonment, criminal fines, civil monetary penalties and exclusion from participation in federal healthcare programs. Although there are a number of statutory exemptions and regulatory safe harbors protecting certain common activities from prosecution or other regulatory sanctions, the exemptions and safe harbors are drawn narrowly, and practices that involve remuneration intended to induce prescribing, purchases or recommendations may be subject to scrutiny if they do not qualify for an exemption or safe harbor.

Federal false claims laws prohibit any person from knowingly presenting, or causing to be presented, a false claim for payment to the federal government, or knowingly making, or causing to be made, a false statement to have a false claim paid. Recently, several pharmaceutical and other healthcare companies have been prosecuted under these laws for allegedly inflating drug prices they report to pricing services, which in turn were used by the government to set Medicare and Medicaid reimbursement rates, and for allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product. In addition, certain marketing practices, including off-label promotion, may also violate false claims laws. The majority of states also have statutes or regulations similar to the federal anti-kickback law and false claims laws, which apply to items and services reimbursed under Medicaid and other state programs, or, in several states, apply regardless of the payor.

HIPAA also created new federal criminal statutes that prohibit among other actions, knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program, including private third-party payors, knowingly and willfully embezzling or stealing from a healthcare benefit program, willfully obstructing a criminal investigation of a healthcare offense, and knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation.

There has also been a recent trend of increased federal and state regulation of payments made to physicians and other healthcare providers. The Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act (collectively, the “Affordable Care Act”), among other things, imposes new reporting requirements on drug manufacturers for payments made by them to physicians and teaching hospitals, as well as ownership and investment interests held by physicians and their immediate family members. Failure to submit required information may result in civil monetary penalties of up to an aggregate of $165,786 per year (or up to an aggregate of $1,105,241 per year for “knowing failures”), for all payments, transfers of value or ownership or investment interests that are not timely, accurately and completely reported in an annual submission. Drug manufacturers are required to submit reports to the government by the 90th day of each calendar year. Certain states also mandate implementation of compliance programs, impose restrictions on drug manufacturer marketing practices and/or require the tracking and reporting of gifts, compensation and other remuneration to physicians.

We may also be subject to data privacy and security regulation by both the federal government and the states in which we conduct our business. HIPAA, HITECH, and their respective implementing regulations, impose specified requirements relating to the privacy, security and transmission of individually identifiable

28

health information. Among other things, HITECH makes HIPAA’s privacy and security standards directly applicable to “business associates,” defined as independent contractors or agents of covered entities that create, receive, maintain or transmit protected health information in connection with providing a service for or on behalf of a covered entity. HITECH also increased the civil and criminal penalties that may be imposed against covered entities, business associates and possibly other persons, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorney’s fees and costs associated with pursuing federal civil actions. In addition, state laws govern the privacy and security of health information in certain circumstances, many of which differ from each other in significant ways, thus complicating compliance efforts.

Moreover, ContraFect is now, and in the future may become, subject to additional federal, state, and local laws, regulations, and policies relating to safe working conditions, laboratory practices, the experimental use of animals, and/or the use, storage, handling, transportation, and disposal of human tissue, waste, and hazardous substances, including radioactive and toxic materials and infectious disease agents used in conjunction with our research work.

Physician Drug Samples

As part of the sales and marketing process, pharmaceutical companies frequently provide samples of approved drugs to physicians. The Prescription Drug Marketing Act, or the PDMA, imposes requirements and limitations upon the provision of drug samples to physicians, as well as prohibits states from licensing distributors of prescription drugs unless the state licensing program meets certain federal guidelines that include minimum standards for storage, handling and record keeping. In addition, the PDMA sets forth civil and criminal penalties for violations.

New Legislation and Regulations

From time to time, legislation is drafted, introduced and passed in Congress that could significantly change the statutory provisions governing the testing, approval, manufacturing and marketing of products regulated by the FDA. In addition to new legislation, FDA regulations and policies are often revised or interpreted by the agency in ways that may significantly affect our business and our products. It is impossible to predict whether further legislative changes will be enacted or whether FDA regulations, guidance, policies or interpretations changed or what the effect of such changes, if any, may be.

For example, in December 2016, the 21st Century Cures act, or Cures Act, was signed into law. The Cures Act, among other things, is intended to modernize the regulation of drugs and biologics and spur innovation, but its ultimate implementation remains unclear. Among other things, the Cures Act provides a new “limited population” approval pathway for antibacterial and antifungal drugs intended to treat serious or life-threatening infections.

Foreign Regulation

In addition to regulations in the United States, we may become subject to widely varying foreign regulations, which may be quite different from those of the FDA, governing clinical trials, manufacture, product registration and approval, and pharmaceutical sales. Whether or not FDA approval has been obtained, we must obtain a separate approval for a product by the comparable regulatory authorities of foreign countries prior to the commencement of product marketing in these countries. The approval process varies from country to country, and the time may be longer or shorter than that required for FDA approval. In certain countries, regulatory authorities also establish pricing and reimbursement criteria. In addition, under current United States law, there are restrictions on the export of products not approved by the FDA, depending on the country involved and the status of the product in that country.

29

European Medicines Agency (“EMA”) – Small and Medium Enterprise (“SME”) Designation

The SME designation was established by EMA to promote innovation and the development of new medicinal products by smaller companies. Companies with SME status are eligible to receive financial incentives as well as administrative and regulatory support through national and regional level programs. These benefits include access to dedicated EMA personnel during the clinical development process as well as reductions in fees associated with regulatory procedures such as Scientific Advice, Marketing Authorizations, and inspections. Companies with SME status are also eligible for early application (prior to proof of concept) to the priority medicines (“PRIME”) scheme. PRIME provides enhanced support for the development of medicines that target an unmet medical need. In August 2016, the EMA granted SME designation to ContraFect. We continue to meet the requirements for the designation and have maintained our SME status.

Data Privacy and Security Laws

We are also subject to data privacy and security laws in jurisdictions outside of the U.S. For example, in the E.U. and the European Economic Area (“E.E.A.”) we are subject to Regulation (EU) 2016/679 (General Data Protection Regulation or “GDPR”) in relation to our collection, control, processing, sharing, disclosure and other use of personal data (i.e. data relating to an identifiable living individual). The GDPR is directly applicable in each E.U. and E.E.A. Member State, however, it provides that E.U. and E.E.A. Member States may introduce further conditions, including limitations, which could limit our ability to collect, control, process, share, disclose and otherwise use personal data (including health and medical information), and/or could cause our compliance costs to increase, ultimately having an adverse impact on our business. The GDPR imposes a strict data protection compliance regime including: providing detailed disclosures about how personal data is collected and processed (in a concise, intelligible and easily accessible form); demonstrating that valid consent or another an appropriate legal basis is in place or otherwise exists to justify data processing activities; appointing data protection officers in certain circumstances; granting new rights for data subjects in regard to their personal data (including the right to be “forgotten” and the right to data portability), as well as enhancing current rights (e.g., data subject access requests); introducing the obligation to notify data protection regulators or supervisory authorities (and in certain cases, affected individuals) of significant data breaches; imposing limitations on retention of personal data; maintaining a record of data processing; defining for the first time pseudonymized (i.e., key-coded) data; and complying with principal of accountability and complying with the obligation to demonstrate compliance through policies, procedures, training and audit.

We are also subject to E.U. rules with respect to cross-border transfers of personal data out of the E.U. and E.E.A. These rules are under scrutiny from time to time. For example, there is ongoing litigation challenging the E.U. Commission approved model clauses (also called standard contractual clauses), which is a commonly used transfer mechanism under the GDPR. It is uncertain whether the model clauses will be invalidated by the European courts. In addition, Brexit will mean that at some point that the United Kingdom (“U.K.”) will become a “third party” for the purposes of data transfers under the GDPR.

We depend on a number of third parties in relation to the operation of our business (including clinical research organizations), a number of which process personal data on our behalf. There is no assurance that our own privacy and security-related safeguards and/or any contractual measures that we enter into with these providers will protect us from the risks associated with the third-party processing, storage and transmission of such information. Any violation of data or security laws by our third-party processors could have a material adverse effect on our business and result in the fines and penalties outlined below.

We are subject to the supervision of local data protection authorities in those E.U. and E.E.A. jurisdictions where we are established or otherwise subject to the GDPR. Fines for certain breaches of the GDPR are significant: up to the greater of EUR 20 million or 4% of total global annual turnover. In addition to the foregoing, a breach of the GDPR could result in regulatory investigations, reputational damage, orders to cease/ change our processing of our data, enforcement notices, assessment notices (for a compulsory audit), as well potential civil claims including class action type litigation where individuals suffer harm.

30

We are also subject to evolving E.U. privacy laws on cookies, and e-marketing. The E.U. is in the process of replacing the e-Privacy Directive with a new set of rules taking the form of a regulation. The draft e-Privacy Regulation imposes strict opt-in marketing rules with limited exceptions for business-to-business communications, alters rules on third-party cookies, web beacons and similar technology and significantly increases fining powers to the same levels as the GDPR (i.e. the greater of 20 million Euros or 4% of total global annual revenue). While the e-Privacy Regulation was originally intended to be adopted on May 25 2018 (alongside the GDPR), it is still going through the European legislative process and commentators now expect it to be adopted during the second half of 2020 or during 2021 following a transition period. We are likely to be required to expend further capital and other resources to ensure compliance with these changing laws and regulations.

Pharmaceutical Coverage, Pricing and Reimbursement

Our ability to commercialize our product candidates successfully will depend in part on the extent to which the United States and foreign governmental authorities, private health insurers and other third-party payors establish appropriate coverage and reimbursement levels for our product candidates and related treatments. In many of the markets where we would commercialize a product following regulatory approval, the prices of pharmaceutical products are subject to direct price controls (by law) and to drug reimbursement programs with varying price control mechanisms. Public and private health care payors control costs and influence drug pricing through a variety of mechanisms, including through negotiating discounts with the manufacturers and through the use of tiered formularies and other mechanisms that provide preferential access to certain drugs over others within a therapeutic class. Payors also set other criteria to govern the uses of a drug that will be deemed medically appropriate and therefore reimbursed or otherwise covered. In particular, many public and private health care payors limit reimbursement and coverage to the uses of a drug that are either approved by the FDA or that are supported by other appropriate evidence (for example, published medical literature) and appear in a recognized drug compendium. Drug compendia are publications that summarize the available medical evidence for particular drug products and identify which uses of a drug are supported or not supported by the available evidence, whether or not such uses have been approved by the FDA.

Healthcare Reform

In the United States, there have been a number of legislative and regulatory changes to the healthcare system in ways that could affect our future revenues and profitability and the future revenues and profitability of our potential customers. For example, the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (the “MMA”) revised the payment methodologies for many drugs, which resulted in reduced reimbursement to providers. Additionally, the MMA created an outpatient prescription drug benefit which became effective on January 1, 2006. This benefit is administered by private pharmacy benefit managers and other managed care organizations and is putting increased pressure on the pharmaceutical industry to reduce prices.

In March 2010, the Affordable Care Act was passed, which substantially changes the way health care is financed by both governmental and private insurers, and significantly impacts the U.S. pharmaceutical industry. The Affordable Care Act, among other things, subjects biologic products to potential competition by lower-cost biosimilars, addresses a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected, increases the minimum Medicaid rebates owed by manufacturers under the Medicaid Drug Rebate Program and extends the rebate program to individuals enrolled in Medicaid managed care organizations, establishes annual fees and taxes on manufacturers of certain branded prescription drugs, and a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 50% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D.

31

The current presidential administration and U.S. Congress have attempted to repeal or “repeal and replace” the Affordable Care Act. Although those efforts did not succeed, the presidential administration may continue to seek to modify, repeal, or otherwise invalidate all, or certain provisions of, the Affordable Care Act. There is still uncertainty with respect to the impact the President’s administration and the U.S. Congress may have, if any, on the Affordable Care Act, and any changes will likely take time to unfold. Additionally, since its enactment, there have been judicial and Congressional challenges to certain aspects of the Affordable Care Act. For example, on December 14, 2018, a U.S. District Court Judge in the Northern District of Texas, or Texas District Court Judge, ruled that the entire Affordable Care Act is invalid based primarily on the fact that the Tax Cuts and Jobs Act of 2017 repealed the tax-based shared responsibility payment imposed by the Affordable Care Act, on certain individuals who fail to maintain qualifying health coverage for all or part of a year, which is commonly referred to as the “individual mandate”. On December 18, 2019, the U.S. Court of Appeals for the 5th Circuit upheld the District Court’s decision that the individual mandate was unconstitutional but remanded the case back to the District Court to determine whether the remaining provisions of the Affordable Care Act are invalid as well. It is unclear how these decisions, subsequent appeals, if any, or other efforts to challenge, repeal or replace the Affordable Care Act will impact the law, or our business or financial condition.

In addition, other legislative changes have been proposed and adopted in the United States since the Affordable Care Act was enacted. For example, the Budget Control Act of 2011 among other things, resulted in aggregate reductions of Medicare payments to providers of 2% per fiscal year, which went into effect in April 2013 and due to subsequent legislative amendments to the statute, will remain in effect through 2029 unless additional Congressional action is taken. Further, on January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, further reduced Medicare payments to several types of providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. Recently there has also been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted legislation designed to, among other things, reform government program reimbursement methodologies. For example, the Cures Act changes the reimbursement methodology for infusion drugs and biologics furnished through durable medical equipment in an attempt to remedy over- and underpayment of certain drugs.

If additional state and federal healthcare reform measures are adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, we could expect such measures to result in reduced demand for our product candidates or additional pricing pressures.

Segment Reporting

We are engaged solely in the discovery and development of therapeutic protein and antibody products for life-threatening, drug-resistant infectious diseases. Accordingly, we have determined that we operate in one operating segment.

Employees

As of March 9, 2020, we had 24 full-time employees, including 13 employees with advanced degrees. Of these full-time employees, 13 employees are engaged in research and development activities. None of our employees is represented by a labor union or covered by a collective bargaining agreement. We consider our relationship with our employees to be good.

Our Corporate Information

We were incorporated under the laws of the State of Delaware in March 2008. Our executive offices are located at 28 Wells Avenue, 3rd Floor, Yonkers, NY 10701, and our telephone number is (914) 207-2300. Our website address is www.contrafect.com. References to our website are inactive textual references only and the content of our website should not be deemed incorporated by reference into this Form 10-K.

32

Available Information

Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and any amendments to these reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, are available free of charge on our website located at www.contrafect.com as soon as reasonably practicable after they are filed with or furnished to the Securities and Exchange Commission (the “SEC”). These reports are also available at the SEC’s Internet website at www.sec.gov.

A copy of our Corporate Governance Guidelines, Code of Ethics and Business Conduct, Whistleblower Policy and Procedures and the charters of the Audit & Finance Committee, Compensation Committee and Nominating and Corporate Governance Committee are posted on our website, www.contrafect.com, under “Corporate Governance” and are available in print to any person who requests copies by contacting us by calling (914) 207-2300 or by writing to ContraFect Corporation, Attn: General Counsel, 28 Wells Avenue, 3rd Floor, Yonkers, NY 10701.

33