Exhibit 99.1

IMMUTEP LIMITED

ABN 90 009 237 889

Appendix 4D

Half-Year Financial Report

For the Half-Year Ended

31 December 2022

(previous corresponding period: half-year ended 31 December 2021)

To be read in conjunction with the 30 June 2022 Annual Report.

In compliance with Listing Rule 4.2A.

ABN 90 009 237 889    

ASX/Media Release (ASX: IMM)

24 February 2023

Appendix 4D Half-Year Financial Report

Results for Announcement to the Market

Current Reporting Period – Half-year Ended 31 December 2022

Previous Reporting Period – Half-year Ended 31 December 2021

The loss after tax for the half-year ended 31 December 2022 of A$20,623,250 was higher compared to A$16,270,213 for the half-year ended 31 December 2021. The increase in loss after tax for the period ended 31 December 2022 was mainly attributable to the following:

The above increases in loss were offset slightly by the following:

Contents

This half-year financial report does not include all the notes of the type normally included in an annual financial report. Accordingly, this report should be read in conjunction with the annual report for the year ended 30 June 2022 and any public announcements made by Immutep Limited during the half-year reporting period in accordance with the continuous disclosure requirements of the Corporations Act 2001.

Immutep Limited is a company limited by shares, incorporated and domiciled in Australia. Its registered office and principal place of business is at Level 33, 264 George Street, Australia Square, SYDNEY, NSW 2000. Its shares are listed on the Australian Securities Exchange (ASX) and NASDAQ Global Market (NASDAQ).

Directors’ Report

Your directors present their report on the group consisting of Immutep Limited and the entities it controlled at the end of, or during (referred to hereafter as the “Group” or “Immutep” and or the “Company”) the half-year ended 31 December 2022.

PRINCIPAL ACTIVITIES

Immutep is a globally active biotechnology company and a leader in the development of LAG-3 related immunotherapeutic products for the treatment of cancer and autoimmune disease. It is dedicated to leveraging its technology and expertise to bring innovative treatment options to market for patients.

Immutep has more product candidates and programs focused on LAG-3 immune control mechanism than any other drug development company. Its four product candidates in development have different mechanisms of action. Immutep’s lead product candidate is eftilagimod alpha (“efti” or “IMP321”), a soluble LAG-3 fusion protein (LAG-3Ig). It is a first-in-class antigen presenting cell (APC) activator being explored in late-stage cancer trials. Immutep is also developing an agonist of LAG-3 (IMP761) for autoimmune diseases. The Company also has two further LAG-3 products, including antibodies for immune response modulation, being developed by Immutep’s large pharmaceutical partners, and is conducting ongoing research activities for potential new candidates.

Immutep is listed on the Australian Securities Exchange (IMM), and on the NASDAQ (IMMP) in the United States.

REVIEW OF OPERATIONS AND ACTIVITIES

Throughout the half year and prior, Immutep has continued to progress its active trials of efti, building on the consistently compelling data reported across three key cancer indications and supporting the broad therapeutic potential of efti for non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) and metastatic breast cancer (MBC). Immutep has received US FDA Fast Track designation for two of these indications, 1st line NSCLC and 1st line HNSCC, enabling e.g. expedited review of potential regulatory submissions.

This promising data, coupled with the large market opportunity and high unmet need for more durable and tolerable options for patients, has informed Immutep’s late-stage clinical development strategy for efti which was announced during the period. The Company has determined to focus its late-stage development efforts on 1st line NSCLC in combination with anti-PD-1 therapy. The NSCLC program (see planned late-stage trial in 1st line NSCLC) will be shaped by the maturing data from the Company’s TACTI-002 and INSIGHT-003 trials, along with feedback from regulatory authorities and other stakeholders.

Immutep will also continue to advance its late-stage programs in HNSCC (see TACTI-003 trial) and MBC (see Late-Stage Phase II/III Trial in MBC). It is also actively expanding efti into additional indications and combination therapies, with a new trial in soft tissue sarcoma and a new trial in urothelial cancer announced during the half year. This clinical development strategy strongly positions Immutep, or a potential partner, to fully exploit efti’s broad potential.

Immutep was pleased to appoint its Chief Scientific Officer and Chief Medical Officer, Professor Frédéric Triebel, M.D. Ph.D. as Executive Director on its Board in the half year, recognising his role as driving force in the strategic development of Immutep’s LAG-3 product candidates. Professor Triebel pioneered the recently validated LAG-3 field of immuno-oncology, having discovered the LAG-3 gene in his early career.

Directors’ Report (Continued)

Immutep continues to exercise prudent cash management and remains well-funded with a cash balance of $68.38 million as at 31 December 2022. This provides a cash runway to the end of June, 2024.

Clinical Trials with Eftilagimod Alpha - Three Late-Stage Trials in Key Cancer Indications

Planned late-stage trial with Fast Track designation in 1^st line NSCLC

Aligned with its strategy to advance the clinical development of efti in three key indications, Immutep progressed preparatory work for its planned late-stage registrational trial evaluating efti in combination with anti-PD-1 for the treatment of 1^st line NSCLC. The trial is being designed to obtain sufficient data to support a potential application for regulatory approval for efti in this indication.

A key achievement in this strategy was the grant of Fast Track designation for this combination therapy for treatment of 1^st line NSCLC by the United States Food and Drug Administration (US FDA) in October 2022. Fast Track designation offers the Company the potential for expedited development and review by the FDA. The designation was granted based on the encouraging Phase II clinical data in 1L NSCLC from the TACTI-002 all-comer trial (see page TACTI-002 section). It is the second Fast Track designation issued by the FDA for efti (the first is for 1^st line HNSCC, see TACTI-003 section). In addition, the INSIGHT-003 study combining efti with anti-PD-1 and chemotherapy will help further inform our next steps in 1st line NSCLC.

Late-stage trial with Fast Track designation in 1st line HNSCC

TACTI-003 - Phase IIb

TACTI-003 is a Phase IIb multicentre, open label, randomised and controlled trial evaluating efti in combination with pembrolizumab for the treatment of 1st line HNSCC. It was granted Fast Track designation for 1st line HNSCC by the US FDA in 2021.

Initial safety data from the first 47 patients in the study was reviewed by the trial’s Independent Data Monitoring Committee (IDMC) in October 2022, with the IDMC recommending the trial continue with no modifications. The IDMC also reviewed initial efficacy data, although this was not the primary focus of the analysis. The recommendation validates Immutep’s strategy to evaluate efti in the 1st line HNSCC setting, following an encouraging Overall Response Rate (ORR) of 29.7% regardless of PD-L1 expression (a predictive biomarker for effective treatment by immune checkpoint inhibitors such as pembrolizumab) and five complete responses (CR) reported in the 2nd line HNSCC setting in TACTI-002.

A Trial in Progress poster on TACTI-003 was presented at the Society for Immunotherapy of Cancer (SITC) Annual Meeting 2022 in early November in Boston, US.

Recruitment into the trial is ongoing, with more than 50% of the planned 154 patients enrolled in December 2022 across 25 active trial sites. TACTI-003 is expected to be fully recruited by mid-2023.

Planned Late-Stage Phase II/III Trial in Metastatic Breast Cancer

For the evaluation of efti in MBC, Immutep continued engagement with regulatory authorities throughout the half year, including with the US FDA for its planned late-stage trial. In December 2022, Immutep received a positive outcome from its follow-up Type C meeting with the FDA. The Company and the FDA have agreed to an integrated Phase II/III trial design to help inform a potential Biologics License Application (a request for permission to sell a biologic product in the US).

Based on the encouraging efficacy, favourable safety and learnings from Immutep’s completed Phase IIb trial (AIPAC, which administered efti in conjunction with a standard-of-care chemotherapy on different days and ceased chemotherapy at six months), patients in the new MBC trial will receive efti and paclitaxel chemotherapy on the same day and treatment will continue until disease progression. In addition to HER2–/HR+ metastatic breast cancer, the patient population has also been expanded to include triple-negative breast cancer, an aggressive form of breast cancer with limited treatment options.

Directors’ Report (Continued)

Subject to regulatory and ethics committee feedback, the Phase II portion of the trial is expected to begin in 1^st quarter of calendar year 2023 with a safety lead in of 6 to 12 patients, followed by up to 58 patients for the randomised Phase II portion of the trial, testing also a higher dose of efti (30 mg vs 90 mg). Depending on the Phase II results, regulatory interactions and Immutep’s resources, the Phase III portion will commence.

TACTI-002 (also designated KEYNOTE-798) - Phase II

TACTI-002 is Immutep’s Phase II trial being conducted in collaboration with Merck & Co. (“MSD”). This all-comer trial in terms of PD-L1 status is evaluating the combination of efti with MSD’s KEYTRUDA^® (pembrolizumab) in NSCLC in 1st and 2nd line, and in HNSCC in 2nd line (Parts A, B and C, respectively). The trial is fully recruited (189 patients).

Part A – 1st line NSCLC – Immutep reported compelling new clinical data from 114 1st line NSCLC patients via a prestigious late-breaking abstract oral presentation at the SITC Annual Meeting in November 2022. Immutep’s abstract was selected as one of just nine to be showcased at the SITC 2022 press briefing, out of more than 1,500 abstract submissions.

The results showed an ORR of 40.4% in the all-comer PD-L1 trial, meeting the primary endpoint for Part A (1st line NSCLC) of the TACTI-002 trial. The ORR improved across all PD-L1 status groups by central assessment compared with data reported at an earlier cancer conference, ASCO 2022. Additionally, the interim median Duration of Response (DoR) of 21.6 months compares favourably to historical controls.

Promising results were also reported in Part A’s secondary endpoint of interim median Progression Free Survival (PFS). Efti in combination with pembrolizumab has received Fast Track designation after achieving an overall PFS of 6.6 months along with 9.3 months in patients with a PD-L1 Tumour Proportion Score (TPS) >1%.

Part B – 2nd line PD-X Refractory NSCLC – In August 2022, Immutep reported positive interim data from patients with 2nd line PD-X-refractory NSCLC at the 2022 World Conference on Lung Cancer (WCLC 2022) in Austria. The median Overall Survival (OS) reported was 9.7 months in the all-comer PD-L1 patient population, and mOS was not yet reached in patients with PD-L1 TPS of >50%. 25% of patients were progression free at the key 6-month mark and 36.5% were alive at 18 months. Importantly, the combination treatment continues to be safe and well-tolerated. It also compares favourably to standard of care chemotherapy-based options. In total 36 patients have been recruited.

Part C 2nd line HNSCC – Encouraging antitumor activity was reported in previous reporting periods, including an ORR of 29.7% and favourable duration and depth of responses, with five Complete Responses and a minimum duration of response extended to more than 9 months across all responding patients. The responses were reported in both high and low PD-L1 expressors. In total 39 patients have been recruited.

Immutep will report updated clinical results from TACTI-002 during calendar year 2023.

Phase II trial in Soft Tissue Sarcoma

During the half year, Immutep announced further expansion of its efti clinical development pipeline into a new cancer setting with a new investigator-initiated Phase II clinical trial. This trial will be conducted in collaboration with the Maria Skłodowska-Curie National Research Institute in Poland and will evaluate efti in combination with pembrolizumab and radiotherapy, prior to surgery, in up to 40 patients with soft tissue sarcoma. The Maria Skłodowska-Curie National Research Institute of Oncology will primarily fund the study with a grant from the Polish government of € 1.5M (~A$2.2M), with Immutep providing efti at no cost.

Preparations are ongoing to commence the trial in H1 of calendar year 2023.

Institute of Clinical Cancer Research (IKF) INSIGHT Clinical Trial Platform

INSIGHT is an investigator-initiated Phase I clinical trial platform investigating efti in different combination treatments. INSIGHT consists of five different arms from strata A to E, with active arms outlined below. The trial is being conducted by the Institute of Clinical Cancer Research (IKF) at Northwest Hospital, Frankfurt, Germany.

Directors’ Report (Continued)

INSIGHT-003 (Stratum C) - Phase I triple combination with standard-of-care anti-PD-1 therapy and chemotherapy

First interim data from the INSIGHT-003 clinical trial was reported in a poster presentation at the SITC Annual Meeting 2022 in November 2022. The data included initial efficacy results from the 11 of the 14 patients with metastatic NSCLC adenocarcinomas, along with safety data on all 14 patients. The data shows the triple combination approach is well-tolerated and provides promising early signals of therapeutic activity with an ORR of 72.7% (8/11) and a Disease Control Rate (DCR) of 90.9% (10/11). The trial reached its enrolment target of 20 patients with 1L NSCLC following the close of the period, in February 2023.

INSIGHT-005 (Stratum E) - New Phase I trial with Merck KGaA, Darmstadt, Germany, and Pfizer

Immutep entered into a new Clinical Trial Collaboration and Supply Agreement with large pharma partners, Merck KGaA, Darmstadt, Germany and Pfizer, during the half year. It is the second agreement Immutep has signed with Merck KGaA and Pfizer and builds on the encouraging clinical data reported from the completed INSIGHT-004 study of efti and avelumab (BAVENCIO^®) in multiple solid tumour indications.

The collaboration enables a new Phase I clinical study of efti and avelumab in patients with urothelial cancer that will be conducted under the INSIGHT platform. Under the Agreement, Immutep and Merck KGaA will jointly fund the study, which is expected to start in mid-2023.

EOC Pharma - Phase II (China)

Immutep’s Chinese development partner for efti, EOC Pharma, is continuing to progress it’s plans for the development of efti (designated EOC202) in China.

EOC holds the exclusive development and commercialisation rights of efti in China, Hong Kong, Macau and Taiwan. These rights are retained by Immutep in all other territories.

Commercial Scale Achieved in Manufacturing of Efti

Immutep successfully scaled-up the manufacturing process for efti during the half year, with the completion of its first 2,000L manufacturing run by the Company’s manufacturing partner, WuXi Biologics. This large-scale manufacturing capability is a significant achievement and subject to feedback from competent authorities, Immutep plans to introduce the material manufactured into ongoing and future Phase II/III clinical trials.

This represents an important step towards potential commercial production of efti and supports Immutep’s potential registrational trials of efti in multiple indications.

Preclinical Research & Development

IMP761

Immutep continued to progress the preclinical development steps for its autoimmune disease candidate, IMP761, including successfully establishing a GMP-compliant manufacturing process for IMP761. The 200L scale manufacturing process was developed by the Company’s manufacturing partner, Northway Biotech and will provide supply of IMP761 for Investigational New Drug (IND)-enabling studies and clinical trials.

IMP761 is Immutep’s immunosuppressive agonist antibody to LAG-3 which will be tested to treat the causes of autoimmune diseases, such as inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis, rather than merely treating the symptoms.

Out-licensed Programs

Novartis - Ieramilimab

Novartis is Immutep’s partner for the development of ieramilimab (Novartis code: LAG525), a humanised LAG-3 antagonist antibody derived from Immutep’s IMP701 antibody.

Directors’ Report (Continued)

Novartis continues to evaluate ieramilimab in clinical trials in multiple cancer indications in combination with its PD-1 inhibitor, spartalizumab.

GlaxoSmithKline (GSK) - IMP731

GSK is Immutep’s partner for GSK2831781, a LAG-3 depleting antibody derived from Immutep’s IMP731 antibody.

Immutep’s exclusive license with GSK remains in place for GSK2831781 while the pharma company determines their options for this program.

LabCorp

Laboratory Corporation of America Holdings, known as LabCorp (NYSE: LH), is Immutep’s US-based collaboration partner for the development of immuno-oncology products or services, a field of growing importance since the validation of the first LAG-3 product. Immutep was selected by LabCorp for its in-depth LAG-3 expertise and knowledge.

Beyond its initial fees from LabCorp, Immutep may be eligible to receive further revenues from commercial milestones under its Licence and Collaboration Agreement with LabCorp as the collaboration progresses.

Strengthening Intellectual Property

Immutep continued to build its intellectual property portfolio throughout the half year and was granted five new patents for efti and two patents for IMP761 and IMP731.

Eftilagimod Alpha

Two patents, filed as divisional applications, were granted by the Japanese and South Korean Patent Offices, respectively. These patents protect combination preparations comprising efti and a chemotherapy agent which is oxaliplatin, carboplatin, or topotecan. They follow the grant of the Japanese parent patent and corresponding patents in the United States, Europe, China and Australia, as announced in 2019 through 2021.

The Company was granted another patent by the South Korean Patent Office relating to a potency assay for release testing of efti. The assay is used in Immutep’s commercial-scale (2,000L) manufacturing process.

Immutep was also granted another patent by the Japanese Patent Office directed to combined therapeutic preparations comprising efti and an anti-PD-(L)1 antibody, and methods of use in the treatment of cancer and infection. Additionally, the Russian Patent Office granted a similar patent directed to combined therapeutic preparations comprising efti and an anti-PD-(L)1 antibody. These new patents in Japan and Russia build on corresponding patents granted in Australia, Europe, United States and China, as announced in 2018 through 2022.

IMP731

Immutep was granted a new patent by the Chinese Patent Office protecting IMP731 in the territory of mainland China. The patent is co-owned by Immutep with the French Institute of Health and Medical Research (INSERM) and exclusively licensed to GSK, Immutep’s development partner for IMP731.

IMP761

Immutep was granted a new patent by the Japanese Patent Office protecting IMP761, pharmaceutical compositions comprising IMP761, and the use of the compositions in the treatment of T-cell mediated inflammatory and autoimmune diseases. It follows the grant of a similar European patent announced in October 2020.

Directors’ Report (Continued)

Financial Performance

During the current half-year reporting period, total revenue and other income decreased from A$2.85 million to A$2.58 million. This was mainly as a result of a decrease of A$400k in grant income which was partly offset by an increase of A$174k in interest income.

Immutep recognised A$1.66 million of grant income of which A$1.17 million was attributable to the Company’s French subsidiary which receives grant from the French Crédit d’Impôt Recherche scheme for expenditure incurred on eligible research and development activities conducted during the reporting period. Approximately A$484k was recognized in the parent entity from the Australian Federal Government’s R&D tax incentive program, which was provided mainly in respect of expenditure incurred on eligible research and development activities conducted in the reporting period for the TACTI-002 and TACTI-003 trials. Total grant income in the current half-year reporting period is A$1.66 million compared to A$2.06 million in the half year ended 31 December 2021.

Interest income increased from A$130K to A$304k in the current half-year reporting period mainly due to the increase in interest rate.

Research and development and intellectual property expenses increased from A$14.63 million in the half-year ended 31 December 2021 to A$18.97 million in the current half-year reporting period. The increase is mainly attributable to an increase of A$3.80 million in manufacturing costs.

Whilst clinical trial costs related to TACTI-002 declined significantly, clinical trial costs relating to TACTI-003 rose substantially.

Corporate administrative expenses for the current half-year reporting period were A$4.13 million compared to A$4.30 million in the previous comparative period. This was mainly as a result of a decrease in share-based payment expenses.

The loss after tax for the half-year ended 31 December 2022 of A$20,623,250 was higher compared to A$16,270,213 for half-year ended 31 December 2021. This increase was mainly attributable to increase in manufacturing activities and clinical trial activities undertaken during the half year period.

In the half-year ended 31 December 2022, the Company recognized a non-cash gain of A$132K from the net change in fair value of warrants, whilst in half-year ended 31 December 2021 a gain of A$185k in the net change in fair value of warrants was recognized.

Outlook

With a clear clinical development strategy for efti based on compelling data from across three key cancers, and an expanding pipeline of trials in new indications such as soft tissue sarcoma, Immutep is strongly positioned to fully exploit efti’s potential.

We look forward to building on the promising clinical results reported with further data from our TACTI-002 trial and our late-stage TACTI-003 study in 1^st line HNSCC in calendar year 2023, as well as potentially commencing new late-stage trials in 1^st line NSCLC and MBC.

Directors’ Report (Continued)

Auditor’s independence declaration

A copy of the auditor’s independence declaration as required under section 307C of the Corporations Act 2001 is set out on page 10. This report is made in accordance with a resolution of directors.

Yours sincerely,

Auditor’s Independence Declaration

As lead auditor for the review of lmmutep Limited for the half-year ended 31 December 2022, I declare that to the best of my knowledge and belief, there have been:

This declaration is in respect of lmmutep Limited and the entities it controlled during the period.

PricewaterhouseCoopers, ABN 52 780 433 757

One International Towers Sydney, Watermans Quay, Barangaroo, GPO BOX 2650, SYDNEY NSW 2001

T: +61 2 8266 0000, F: +61 2 8266 9999, www.pwc.com.au

Level 11, 1PSQ, 169 Macquarie Street, Parramatta NSW 2150, PO Box 1155 Parramatta NSW 2124

T: +61 2 9659 2476, F: +61 2 8266 9999, www.pwc.com.au

Liability limited by a scheme approved under Professional Standards Legislation.

The above consolidated statement of comprehensive income should be read in conjunction with the accompanying notes.

Consolidated Balance Sheet

As at 31 December 2022

The above consolidated balance sheet should be read in conjunction with the accompanying notes.

Consolidated Statement of Changes in Equity

For the Half-year Ended 31 December 2022

The above consolidated statement of changes in equity should be read in conjunction with the accompanying notes.

Consolidated Statement of Cash Flows

For the Half-year Ended 31 December 2022

The above consolidated statement of cash flows should be read in conjunction with the accompanying notes.