NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS

MARCH 31, 2016

1. Nature of Operations and Business Activities

Nature of Operations and Basis of Presentation

Sorrento Therapeutics, Inc. (NASDAQ: SRNE), together with its subsidiaries (collectively, the “Company”) is a biopharmaceutical company focused on the discovery, acquisition, development and commercialization of proprietary drug therapeutics for addressing significant unmet medical needs worldwide. The Company’s primary therapeutic focus is oncology, including the treatment of chronic cancer pain, but is also developing therapeutic products for other indications, including immunology and infectious diseases. The Company currently has multiple clinical development programs underway: (i) Chimeric Antigen Receptor-T Cell (“CAR-T”) programs for solid tumors, (ii) resiniferatoxin, or RTX, a non-opiate, ultra-potent and selective agonist of the TRPV-1 receptor for intractable pain in end-stage disease, and (iii) its clinical development programs for its biosimilar/biobetter antibodies.

The Company’s pipeline also includes preclinical fully human therapeutic monoclonal antibodies (mAbs), including its biosimilars/biobetters, its fully human anti-PD-L1 and anti-PD-1 checkpoint inhibitors derived from its proprietary G-MAB ^® library platform, antibody drug conjugates (ADCs), bispecific antibodies (BsAbs), as well as Chimeric Antigen Receptor-T Cell (CAR-T) and Chimeric Antigen Receptor Natural Killer (NK) cells (CAR.NK™) for adoptive cellular immunotherapy. The Company’s objective is to develop its antibody drug products and adoptive cellular immunotherapies as: (i) First in Class (FIC), and/or (ii) Best in Class (BIC), which may offer greater efficacy and/or fewer adverse events or side effects as compared to existing drugs, as well as fully human therapeutic antibodies derived from its proprietary G-MAB ^® antibody platform and ADCs.  

Through March 31, 2016, the Company had devoted substantially all of its efforts to research and product development, raising capital and building infrastructure, and had not realized revenues from its planned principal operations.

The accompanying interim consolidated financial statements have been prepared by the Company, without audit, in accordance with the instructions to Form 10-Q and, therefore, do not necessarily include all information and footnotes necessary for a fair statement of its financial position, results of operations and cash flows in accordance with United States generally accepted accounting principles (GAAP). The accompanying consolidated financial statements include the accounts of the Company’s wholly-owned subsidiaries and those of a variable interest entity where the Company is the primary beneficiary. For consolidated entities where the Company owns or are exposed to less than 100% of the economics, the Company records net income (loss) attributable to noncontrolling interests in its consolidated statements of operations equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties.  Sorrento Therapeutics, Inc. Hong Kong Limited had no operating activity through March 2016.  All intercompany balances and transactions have been eliminated in consolidation.

In determining whether the Company is the primary beneficiary of an entity, the Company applies a qualitative approach that determines whether it has both (i) the power to direct the economically significant activities of the entity and (ii) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity. These considerations impact the way the Company accounts for its existing collaborative relationships and other arrangements. The Company continuously assesses whether it is the primary beneficiary of a variable interest entity as changes to existing relationships or future transactions may result in the Company consolidating or deconsolidating one or more of its collaborators or partners.

The balance sheet at December 31, 2015 is derived from the audited consolidated financial statements at that date which are not presented herein.

In the opinion of management, the unaudited financial information for the interim periods presented reflects all adjustments, which are only normal and recurring, necessary for a fair statement of financial position, results of operations and cash flows. These consolidated financial statements should be read in conjunction with the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015. Operating results for interim periods are not expected to be indicative of operating results for the Company’s 2016 fiscal year.    

Liquidity

The Company anticipates that it will continue to incur net losses in the foreseeable future as it (i) advances clinical stage product candidates such as biosimilar/biobetter antibodies, CAR-T programs and RTX in the clinic and potentially pursues other development, (ii) continues to identify a number of potential mAb and ADC drug candidates and further advances various preclinical and

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development activitie s, (iii) advances its product candidates into the clinic, (iv) invests in additional joint ventures or third party collaboration or acquisition agreements, and (v) expands corporate infrastructure, including the costs associated with being a NASDAQ listed public company. Based on currently available resources, the Company believes it has the ability to meet all obligations due over the course of the next twelve months.

On April 3, 2016, the Company entered into a Securities Purchase Agreement (the “ABG Purchase Agreement”) with ABG SRNE Limited and Ally Bridge LB Healthcare Master Fund Limited (collectively, “Ally Bridge”), pursuant to which, among other things, the Company agreed to issue and sell to Ally Bridge and other purchasers that may be designated by Ally Bridge (collectively, the “ABG Purchasers”), in a private placement transaction (the “ABG Private Placement”), up to $50 million in shares of common stock of the Company (“Common Stock”) and warrants to purchase shares of Common Stock. Upon the closing of the ABG Private Placement, the Company will issue to each ABG Purchaser (1) such number of shares (the “ABG Shares”) of Common Stock as is equal to the amount of such ABG Purchaser’s investment divided by $5.55, and (2) a warrant to purchase such number of shares of Common Stock as is equal to 30% of the ABG Shares sold and issued to such ABG Purchaser (each, an “ABG Warrant”); provided that , following the consummation of the ABG Private Placement, Ally Bridge and its affiliates will not beneficially own more than 9.99% of the outstanding shares of Common Stock. Each ABG Warrant will have an exercise price of $8.50 per share, will be immediately exercisable upon issuance, will have a term of three years and will be exercisable on a cash or cashless exercise basis.

Under the terms of the ABG Purchase Agreement, the Company is obligated to prepare and file with the Securities and Exchange Commission (the “SEC”), within 30 days of the closing date of the ABG Private Placement, a registration statement to register for resale the ABG Shares and the shares of Common Stock issuable upon exercise of each ABG Warrant (the “ABG Warrant Shares”), and may be required to effect certain registrations to register for resale the ABG Shares and the ABG Warrant Shares in connection with certain “piggy-back” registration rights granted to the ABG Purchasers.

On April 3, 2016, the Company also entered into a Securities Purchase Agreement (collectively, the “Additional Purchase Agreements”) with each of Beijing Shijilongxin Investment Co., Ltd. ( “Beijing Shijilongxin”), FREJOY Investment Management Co., Ltd. (“Frejoy”) and Yuhan Corporation (“Yuhan”), pursuant to which, among other things, the Company agreed to issue and sell, in separate private placement transactions: (1) to Beijing Shijilongxin, 8,108,108 shares of Common Stock, and a warrant to purchase 1,176,471 shares of Common Stock, for an aggregate purchase price of $45 million; (2) to Frejoy, 8,108,108 shares of Common Stock, and a warrant to purchase 1,176,471 shares of Common Stock, for an aggregate purchase price of $45 million; and (3) to Yuhan, 1,801,802 shares of Common Stock, and a warrant to purchase 235,294 shares of Common Stock, for an aggregate purchase price of $10 million. The warrants to be issued pursuant to each of the Additional Purchase Agreements (collectively, the “Additional Warrants” and, together with each ABG Warrant, the “Warrants”) will have an exercise price of $8.50 per share, will be immediately exercisable upon issuance, will have a term of three years and will be exercisable on a cash or cashless exercise basis.

Under the terms of the Additional Purchase Agreements, each of Beijing Shijilongxin, Frejoy and Yuhan has the right to demand, at any time beginning six months after the closing of the transactions contemplated by the applicable Additional Purchase Agreement, that the Company prepare and file with the SEC a registration statement to register for resale such investor’s shares of Common Stock purchased pursuant to the applicable Additional Purchase Agreement and the shares of Common Stock issuable upon exercise of such investor’s Additional Warrant. In addition, the Company may be required to effect certain registrations to register for resale such shares in connection with certain “piggy-back” registration rights granted to Beijing Shijilongxin, Frejoy and Yuhan.

The closing of the transactions contemplated by the ABG Purchase Agreement and each of the Additional Purchase Agreements are each subject to customary closing conditions, including obtaining clearance for the issuance of the applicable shares of Common Stock and the Warrants in accordance with the listing requirements of The Nasdaq Stock Market LLC and the completion of due diligence by Ally Bridge, Beijing Shijilongxin, Frejoy and Yuhan, respectively. The Company expects that the closings of the transactions will occur by the end of May 2016.

On May 2, 2016 the Company announced that it has closed its previously announced private placement of common stock and warrants with Yuhan Corporation for gross proceeds of $10 million.  Yuhan purchased 1,801,802 shares of common stock at $5.55 per share and a warrant to purchase 235,294 shares of common stock.  The warrant is exercisable for three years at an exercise price of $8.50 per share.

The Company plans to continue to fund its operating losses and capital funding needs through public or private equity or debt financings, strategic collaborations, licensing arrangements, asset sales, government grants or other arrangements. The Company filed a universal shelf registration statement on Form S-3 with the Securities and Exchange Commission (“SEC”), which was declared effective by the SEC in July 2013 (the “2013 Shelf Registration Statement”). The 2013 Shelf Registration Statement provides the Company the ability to offer up to $100 million of securities, including equity and other securities as described in the registration statement. After the May 2014 underwritten offering the Company has the ability to offer up to $36.6 million of additional securities under the 2013 Shelf Registration Statement. In November 2014, the Company filed a universal shelf registration statement on Form

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S-3 with the SEC, which was declared effective by the SEC in December 2014 (the “2014 Shelf Registra tion Statement”). The 2014 Shelf Registration Statement provides the Company with the ability to offer up to $250 million of securities, including equity and other securities as described in the registration statement. Included in the 2014 Shelf Registrati on Statement is a sales agreement prospectus covering the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $50.0 million of the Company’s common stock that may be issued and sold under a sales agreement with MLV & C o. LLC (the “ATM Facility”).   During the three months ended March 31, 2016 the Company sold approximately $3.6 million under the ATM Facility.  After the first quarter 2016 sales activities the Company has the ability to offer up to $46.4 million of additi onal securities under the ATM Facility.  The Company cannot be sure that such additional funds will be available on reasonable terms, or at all. If the Company is unable to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, and/or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations, and future prospects.

If the Company raises additional funds by issuing equity securities, substantial dilution to existing stockholders would result. If the Company raises additional funds by incurring debt financing, the terms of the debt may involve significant cash payment obligations as well as covenants and specific financial covenants that may restrict the Company’s ability to operate its business.

2. Significant Accounting Policies

Use of Estimates

The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period.  On an ongoing basis, the Company evaluates its estimates, including those related to the valuation of warrants, stock-based compensation and the valuation allowance for deferred tax assets. The Company bases its estimates on historical experience and on various other market-specific and relevant assumptions that it believes to be reasonable under the circumstances. Management believes that these estimates are reasonable; however, actual results may differ from these estimates.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with original maturities of three months or less to be cash equivalents. The Company minimizes its credit risk associated with cash and cash equivalents by periodically evaluating the credit quality of its primary financial institution. The balance at times may exceed federally insured limits. The Company has not experienced any losses on such accounts.

Fair Value of Financial Instruments

The Company follows accounting guidance on fair value measurements for financial instruments measured on a recurring basis, as well as for certain assets and liabilities that are initially recorded at their estimated fair values. Fair value is defined as the exit price, or the amount that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company uses the following three-level hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs to value its financial instruments:

Financial instruments measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires it to make judgments and consider factors specific to the asset or liability. The use of different assumptions and/or estimation methodologies may have a material effect on estimated fair values. Accordingly, the fair value estimates disclosed or initial amounts recorded may not be indicative of the amount that the Company or holders of the instruments could realize in a current market exchange.

The carrying amounts of cash equivalents and marketable securities approximate their fair value based upon quoted market prices. Certain of our financial instruments are not measured at fair value on a recurring basis, but are recorded at amounts that

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approximate their fair value due to their liquid or short-term nature, such as cash, accounts receivable and payable, and other financial instruments in current assets or current liabilities.

Marketable Securities

Marketable securities are designated as available-for-sale securities and are accounted for at fair value. Marketable securities are classified as short-term or long-term based on the nature of the securities and their availability to meet current operating requirements. Marketable securities that are readily available for use in current operations are classified as short-term available-for-sale securities and are reported as a component of current assets in the accompanying consolidated balance sheets. Marketable securities that are not considered available for use in current operations are classified as long-term available-for-sale securities and are reported as a component of long-term assets in the accompanying consolidated balance sheets.

Securities that are classified as available-for-sale are carried at fair value, with temporary unrealized gains and losses reported as a component of stockholders' equity until their disposition. The cost of securities sold is based on the specific identification method.

All of the Company’s marketable securities are subject to a periodic impairment review. The Company recognizes an impairment charge when a decline in the fair value of its investments below the cost basis is judged to be other-than-temporary.  For the three months ended March 31, 2016, no other-than-temporary impairment charges were recorded.

Grants and Accounts Receivable

Grants receivable at March 31, 2016 and December 31, 2015 represent amounts due under several federal contracts with the National Institute of Allergy and Infectious Diseases, or NIAID, a division of the National Institutes of Health, or NIH, collectively, the NIH Grants. The Company considers the grants receivable to be fully collectible; accordingly, no allowance for doubtful amounts has been established. If amounts become uncollectible, they are charged to operations.

Accounts receivable at March 31, 2016 and December 31, 2015 consists of trade receivables from sales and services provided to certain customers, which are generally unsecured and due within 30 days. Estimated credit losses related to trade accounts receivable are recorded as general and administrative expenses and as an allowance for doubtful accounts within grants and accounts receivable, net. The Company reviews reserves and makes adjustments based on historical experience and known collectability issues and disputes. When internal collection efforts on accounts have been exhausted, the accounts are written off by reducing the allowance for doubtful accounts. As of March 31, 2016 and December 31, 2015, the allowance for doubtful accounts was $30,000 and $4,000, respectively.

Property and Equipment

Property and equipment are carried at cost less accumulated depreciation. Depreciation of property and equipment is computed using the straight-line method over the estimated useful lives of the assets, which are generally three to five years. Leasehold improvements are amortized over the lesser of the life of the lease or the life of the asset. Repairs and maintenance are charged to expense as incurred.

Acquisitions and Intangibles

The Company has engaged in business combination activity. The accounting for business combinations requires management to make judgments and estimates of the fair value of assets acquired, including the identification and valuation of intangible assets, as well as liabilities assumed. Such judgments and estimates directly impact the amount of goodwill recognized in connection with each acquisition, as goodwill presents the excess of the purchase price of an acquired business over the fair value of its net tangible and identifiable intangible assets.

Goodwill and Other Long-Lived Assets

Goodwill, which has an indefinite useful life, represents the excess of cost over fair value of net assets acquired. Goodwill is reviewed for impairment at least annually during the fourth quarter, or more frequently if events occur indicating the potential for impairment. During its goodwill impairment review, the Company may assess qualitative factors to determine whether it is more likely than not that the fair value of its reporting unit is less than its carrying amount, including goodwill. The qualitative factors include, but are not limited to, macroeconomic conditions, industry and market considerations, and the overall financial performance of the Company. If, after assessing the totality of these qualitative factors, the Company determines that it is not more likely than not that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company proceeds to perform the two-step test for goodwill impairment. The first step involves comparing the estimated fair

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value of the reporting unit with its carrying value, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, the Company performs the second step of the goodwill impairment test to deter mine the amount of loss, which involves comparing the implied fair value of the goodwill to the carrying value of the goodwill. The Company may also elect to bypass the qualitative assessment in a period and elect to proceed to perform the first step of th e goodwill impairment test. The Company performed its annual assessment for goodwill impairment in the fourth quarter of 2015, noting no impairment.  There have not been any triggering events through March 31, 2016.

The Company evaluates its long-lived assets with definite lives, such as property and equipment, acquired technology, customer relationships, patent and license rights, for impairment by considering competition by products prescribed for the same indication, the likelihood and estimated future entry of non-generic and generic competition with the same or similar indication and other related factors. The factors that drive the estimate of the life are often uncertain and are reviewed on a periodic basis or when events occur that warrant review. Recoverability is measured by comparison of the assets’ book value to future net undiscounted cash flows that the assets are expected to generate. There have not been any impairment losses of long-lived assets through March 31, 2016.

Derivative Liability

Derivative liabilities are recorded on the consolidated balance sheets at fair value on the date of issuance and are revalued on each balance sheet date until such instruments are exercised or expire, with changes in the fair value between reporting periods recorded as other income or expense.  The Company estimates the fair value of derivative liabilities using the Black-Scholes option pricing model.

Investments in Other Entities

The Company holds a portfolio of investments in equity securities that are accounted for under either the equity method or cost method. Investments in entities over which the Company has significant influence but not a controlling interest are accounted for using the equity method, with the Company’s share of earnings or losses reported in other income (expense), net.

The Company’s cost method investments are included in investments in common stock on the consolidated balance sheets.  The Company’s equity method investments are included in equity method investments on the consolidated balance sheets.

All investments are reviewed on a regular basis for possible impairment. If an investment's fair value is determined to be less than its net carrying value and the decline is determined to be other-than-temporary, the investment is written down to its fair value. Such an evaluation is judgmental and dependent on specific facts and circumstances. Factors considered in determining whether an other-than-temporary decline in value has occurred include: market value or exit price of the investment based on either market-quoted prices or future rounds of financing by the investee; length of time that the market value was below its cost basis; financial condition and business prospects of the investee; the Company’s intent and ability to retain the investment for a sufficient period of time to allow for recovery in market value of the investment; issues that raise concerns about the investee's ability to continue as a going concern; any other information that we may be aware of related to the investment. The Company does not report the fair value of its equity investments in non-publicly traded companies because it is not practical to do so.

Research and Development Costs and Collaborations

All research and development costs are charged to expense as incurred. Such costs primarily consist of lab supplies, contract services, stock-based compensation expense, salaries and related benefits.

Acquired In-Process Research and Development Expense

The Company has acquired and may continue to acquire the rights to develop and commercialize new drug candidates. The up-front payments to acquire a new drug compound, as well as future milestone payments, are immediately expensed as acquired in-process research and development provided that the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, have no alternative future use.

Income Taxes

The provisions of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 740-10, Uncertainty in Income Taxes, address the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the financial statements. Under ASC 740-10, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by taxing authorities, based on the technical merits of the position. The Company has determined that it has uncertain tax positions.

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The Company accounts for income taxes using the asset and liability method to compute the differences between the tax basis of assets and liabilities and the related financial amounts, using currently enacted tax rates.

The Company has deferred tax assets, which are subject to periodic recoverability assessments. Valuation allowances are established, when necessary, to reduce deferred tax assets to the amount that more likely than not will be realized. As of March 31, 2016 and December 31, 2015, the Company maintained a full valuation allowance against its deferred tax assets, with the exception of an amount equal to its deferred tax liabilities, which can be expected to reverse over a definite life.

Revenue Recognition

The Company’s revenues are generated primarily from various NIH grant awards, and from the sale of customized reagents and the provision of contract development services. The revenue from the NIH grant awards is based upon subcontractor and internal costs incurred that are specifically covered by the grant, and where applicable, a facilities and administrative rate that provides funding for overhead expenses. These revenues are recognized when expenses have been incurred by subcontractors or when the Company incurs internal expenses that are related to the grant.

Revenues from sales are generated from the sale of customized reagents which include industrial standard cytotoxins, linkers, and linker-toxins used for preparing ADCs.  Contract development services include providing synthetic expertise to customer’s synthesis by delivering proprietary cytotoxins, linkers and linker-toxins and ADC service using industry standard toxin and antibodies provided by customers. Revenue is recognized when, (i) persuasive evidence of an arrangement exists, (ii) the product has been shipped or the services have been rendered, (iii) the price is fixed or determinable, and (iv) collectability is reasonably assured.

License fees for the licensing of product rights are recorded as deferred revenue upon receipt of cash and recognized as revenue on a straight-line basis over the license period.

The Company is obligated to accept from customers the return of products sold that are damaged or do not meet certain specifications. The Company may authorize the return of products sold in accordance with the terms of its sales contracts, and estimates allowances for such amounts at the time of sale. The Company has not experienced any sales returns.

Stock-based Compensation

The Company accounts for stock-based compensation in accordance with FASB ASC Topic 718, which establishes accounting for equity instruments exchanged for employee services. Under such provisions, stock-based compensation cost is generally measured at the grant date, based on the calculated fair value of the award and an estimate of forfeitures, and is recognized as an expense, under the straight-line method, over the employee’s requisite service period (generally the vesting period of the equity grant).

The Company accounts for equity instruments, including restricted stock or stock options, issued to non-employees in accordance with authoritative guidance for equity based payments to non-employees. Stock options issued to non-employees are accounted for at their estimated fair value determined using the Black-Scholes option-pricing model. The fair value of options and restricted stock granted to non-employees is re-measured over the vesting period, and the resulting changes in fair value are recognized as expense in the period of the change in proportion to the services rendered to date.

Net Earnings (Loss) per Share

Basic net earnings (loss) per share is computed by dividing net income (loss) for the period by the weighted average number of common shares outstanding during the period. Diluted net earnings (loss) per share reflects the additional dilution from potential issuances of common stock, such as stock issuable pursuant to the exercise of stock options or the exercise of outstanding warrants. The treasury stock method and if-converted method are used to calculate the potential dilutive effect of these common stock equivalents. Potentially dilutive shares are excluded from the computation of diluted net earnings (loss) per share when their effect is anti-dilutive. In periods where a net loss is presented, all potentially dilutive securities are anti-dilutive and are excluded from the computation of diluted net loss per share.

Comprehensive Income (Loss )

Comprehensive income (loss) is comprised of net income (loss) and adjustments for the change in unrealized gains and losses on our investments in available-for-sale marketable securities, net of taxes. The Company displays comprehensive income (loss) and its components in its consolidated statements of comprehensive income (loss).

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Segment Information

The Company is engaged primarily in the discovery and development of innovative therapies focused on oncology and the treatment of chronic cancer pain as well as immunology and infectious diseases based on its platform technologies. Accordingly, the Company has determined that it operates in one operating segment.

Recent Accounting Pronouncements

In January 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”)  2016-01, “Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities” . The new standard principally affects accounting standards for equity investments, financial liabilities where the fair value option has been elected, and the presentation and disclosure requirements for financial instruments. Upon the effective date of the new standard, all equity investments in unconsolidated entities, other than those accounted for using the equity method of accounting, will generally be measured at fair value through earnings. There will no longer be an available-for-sale classification and therefore, no changes in fair value will be reported in other comprehensive income for equity securities with readily determinable fair values. The new guidance on the classification and measurement will be effective for public business entities in fiscal years beginning after December 15, 2017, including interim periods within those fiscal years and early adoption is permitted. The Company is currently evaluating the impact this standard may have on its financial position, results of operations, or cash flows.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , to improve financial reporting for leasing transactions. The new standard requires lessees to recognize on the balance sheet a right of use asset and related lease liability for all leases with terms greater than twelve months. The ASU also requires disclosures about the amount, timing, and uncertainty of cash flows arising from leases. The effective date for public entities is fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted for all entities. The Company is currently evaluating any impact this standard may have on its financial position, results of operations, or cash flows .  

In March 2016, the FASB issued ASU 2016-09, Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting. The ASU includes multiple provisions intended to simplify various aspects of the accounting for share-based payments. While aimed at reducing the cost and complexity of the accounting for share-based payments, the amendments are expected to significantly impact net income, earnings per share, and the statement of cash flows. The effective date for public entities is for fiscal years beginning after December 15, 2016. Early adoption is permitted in any interim period provided that the entire ASU is adopted. The Company is currently evaluating any impact this standard may have on its financial position, results of operations, or cash flows .

3. Fair Value Measurements

The Company measures the fair value of financial assets and liabilities based on authoritative guidance that defines fair value, establishes a framework consisting of three levels for measuring fair value, and requires disclosures about fair value measurements.  Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date.

The Company’s marketable securities are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets.  The Company’s derivative liability was classified within Level 3 of the fair value hierarchy because the value was calculated using significant judgment based on the Company’s own assumptions in the valuation of this liability.

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The following table presents the Company’s financial assets and liabilities that are measured at fair value on a recurring basis.  (in t housands):

The following table includes a summary of the derivative liability measured at fair value using significant unobservable inputs (Level 3) during the three months ended March 31, 2016 (in thousands): 

4 . Marketable Securities

Marketable securities consisted of the following as of March 31, 2016 (in thousands):

On July 27, 2015, NantKwest, Inc., or NantKwest, completed its initial public offering (“IPO”).  Prior to the IPO the Company’s investment in NantKwest was accounted for using the cost method and the total investment of $10.0 million was classified as part of investments in common stock on the Company’s consolidated balance sheets.  The common shares were subject to restrictions in a lock-up agreement through December 27, 2015 as well as limitations under Rule 144 of the Securities Act of 1933. As these were short term restrictions, the Company did not apply a marketability discount.  For the three months ended March 31, 2016, the

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Company recorded an unrealized loss of $36.9 million, representing the difference between t he $10.0 million cost basis and the estimated fair value net of tax of $0 as of March 31, 2016, as accumulated other comprehensive income in the stockholder's equity section of the Company’s consolidated balance sheet and as a change in unrealized gains an d losses on marketable securities in the Company’s consolidated statements of comprehensive income (loss).   The tax effect of $ 14.3 million on the unrealized gain on marketable securities as of December 31, 2015 was reversed during the three months ended M arch 31, 2016 due to the decrease in the value of the marketable securities as of March 31, 2016.   The Company’s investment in NantKwest, Inc. will be revalued on each balance sheet date.  The fair value of the Company’s holdings in NantKwest at March 31, 2016 is a Level 1 measurement.

5. Investments  

As of March 31, 2016 and December 31, 2015, the aggregate carrying amount of the Company’s cost-method investments in non-publicly traded companies was $112.0 million and included an ownership interest in NantCell, Inc., NantBioScience, Inc., Brink Biologics, Inc., Coneksis, Inc., and Globavir Biosciences, Inc. The Company’s cost-method investments are assessed for impairment quarterly. The Company has determined that it is not practicable to estimate the fair value of its cost-method investments on a regular basis and does not reassess the fair value of cost-method investments if there are no identified events or changes in circumstances that may have a significant adverse effect on the fair value of the investments.  No impairment losses were recorded during the three months ended March 31, 2016 and 2015.

CARgenix

I n August 2015,  the Company and TNK Therapeutics, Inc. (“TNK”), its subsidiary entered into a Membership Interest Purchase Agreement (the “Membership Interest Purchase Agreement”) with CARgenix Holdings LLC (“CARgenix”) and the members of CARgenix (the “Members”) pursuant to which the Members sold all of their membership interests in CARgenix to TNK for: (1) a cash payment of $100.00, and (2) $6.0 million in shares of TNK Class A common stock, subject to adjustment in certain circumstances, to be issued to the Members upon a financing resulting in gross proceeds (individually or in the aggregate) to TNK of at least $50.0 million (a “Qualified Financing”). In the event a Qualified Financing does not occur by March 15, 2016 or TNK does not complete an initial public offering of shares of its capital stock by March 31, 2016, in lieu of receiving shares of TNK pursuant to the acquisition, the Members shall receive an aggregate of 309,917 shares of Company common stock, subject to adjustment in certain circumstances. The Membership Interest Purchase Agreement further provides that 20% of the shares of TNK or the Company’s, as applicable, issuable to the Members shall be held in escrow to secure certain post-closing adjustment and indemnification rights of TNK for a period of 12 months following the closing of the transaction.  The aggregate purchase price of $6.0 million was recognized as acquired in-process research and development expense in the consolidated statement of operations during the three months ended September 30, 2015.  The corresponding acquisition liability will remain until settlement.  On March 7, 2016, the Company entered into Amendment No. 1 to the Membership Purchase Agreement to extend the Qualified Financing Date to September 15, 2016 and the IPO Date to October 15, 2016.

BDL

In August 2015, the Company and TNK entered into a Stock Purchase Agreement (the “Stock Purchase Agreement”) with BDL Products, Inc. (“BDL”) and the stockholders of BDL (“Stockholders”) pursuant to which the Stockholders sold all of their shares of capital stock in BDL to TNK for: (1) a cash payment of $100.00, and (2) $6.0 million in shares of TNK Class A common stock, subject to adjustment in certain circumstances, to be issued to the Stockholders upon a Qualified Financing. In the event a Qualified Financing does not occur by March 15, 2016 or TNK does not complete an initial public offering of shares of its capital stock by March 31, 2016, in lieu of receiving shares of TNK pursuant to the acquisition, the Stockholders shall receive an aggregate of 309,917 shares of Company common stock, subject to adjustment in certain circumstances. The Stock Purchase Agreement further provides that 20% of the shares of TNK or the Company’s, as applicable, issuable to the Stockholders shall be held in escrow to secure certain post-closing adjustment and indemnification rights of TNK for a period of 12 months following the closing of the transaction.  The aggregate purchase price of $6.0 million was recognized as acquired in-process research and development expense in the consolidated statement of operations during the three months ended September 30, 2015.  The corresponding acquisition liability will remain until settlement.  On March 7, 2016, the Company entered into Amendment No. 1 to the Stock Purchase Agreement to extend the Qualified Financing Date to September 15, 2016 and the IPO Date to September 30, 2016.

6 . Equity Method Investments

NANTibody

In April 2015, the Company and NantCell, Inc., or NantCell, a wholly-owned subsidiary of NantWorks, Inc., a private company owned by Dr. Patrick Soon-Shiong, an affiliate of the Company, established a new joint venture called Immunotherapy NANTibody, LLC, or NANTibody, as a stand-alone biotechnology company with $100.0 million initial joint funding.  NantCell owns 60% of the

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equity interest of NANTibody and agreed to contribute $60.0 million to NANTibody.  The Company owns 40% o f NANTibody and in July 2015, the Company had NantPharma, LLC, or NantPharma, contribute its portion of the initial joint funding of $40.0 million to NANTibody from the proceeds of the sale of IgDraSol.  NANTibody will focus on accelerating the development of multiple immuno-oncology monoclonal antibodies (mAbs) for the treatment of cancer, including but not limited to anti-PD-1, anti-PD-L1, anti-CTLA4 mAbs, and other immune-check point antibodies as well as antibody drug conjugates (ADCs) and bispecific an tibodies.

The Company is accounting for its interest in NANTibody as an equity method investment, due to the significant influence the Company has over the operations of NANTibody through its board representation and 40% voting interest.  The Company’s investment in NANTibody is reported in equity method investments on its consolidated balance sheets and its share of NANTibody’s loss is recorded in loss on equity investments on its consolidated statement of operations.  The financial statements of NANTibody are not received sufficiently timely for the Company to record its portion of earnings or loss in its current financial statements and therefore reports its portion of earnings or loss on a quarter lag.  As of March 31, 2016, the carrying value of the Company’s investment in NANTibody was approximately $39.6 million.

NANTibody recorded a total net loss of $964,000 for the three months ended December 31, 2015.  The Company recorded its portion of loss from NANTibody in loss on equity investments on its consolidated statement of operations for the three months ended March 31, 2016. As of December 31, 2015, NANTibody had $99.4 million in current assets and $506,000 in current liabilities.

NantStem

In July 2015, the Company and NantBioScience, Inc., or NantBioScience, a wholly-owned subsidiary of NantWorks, established a new joint venture called NantCancerStemCell, LLC, or NantStem, as a stand-alone biotechnology company with $100.0 million initial joint funding.  As initially organized, NantBioScience was obligated to make a $60.0 million cash contribution to NantStem for a 60% equity interest in NantStem, and the Company was obligated to make a $40.0 million cash contribution to NantStem for a 40% equity interest in NantStem.  Fifty percent of these contributions were funded in July 2015 and the remaining amounts were to be made by no later than September 30, 2015. The Company had NantPharma contribute its portion of the initial joint funding of $20.0 million to NantStem from the proceeds of the sale of IgDraSol.   Pursuant to a Side Letter dated October 13, 2015, the NantStem joint venture agreement was amended to relieve the Company of the obligation to contribute the second $20.0 million payment, and its ownership interest in NantStem was reduced to 20%.  NantBioScience’s funding obligations were unchanged.  The Side Letter was negotiated at the same time the Company issued a call option on shares of NantKwest that it owned to Cambridge Equities, LP, a related party to the Company and to NantBioScience.  (See Note 13).

The Company is accounting for its interest in NantStem as an equity method investment, due to the significant influence the Company has over the operations of NantStem through its board representation and 20% voting interest.  The Company’s investment in NantStem is reported in equity method investments on its consolidated balance sheets and its share of NantStem’s loss is recorded in loss on equity investments on its consolidated statement of operations.  The financial statements of NantStem are not received sufficiently timely for the Company to record its portion of earnings or loss in its current financial statements and therefore reports its portion of earnings or loss on a quarter lag.  As of March 31, 2016, the carrying value of the Company’s investment in NantStem was approximately $18.0 million.

NantStem recorded a total net loss of $566,000 for the three months ended December 31, 2015.  The Company recorded its portion of loss from NantStem in loss on equity investments on its consolidated statement of operations for the three months ended March 31, 2016.  As of December 31, 2015, NantStem had $79.6 million in current assets and $139,000 in current liabilities.

Yuhan

In March 2016, the Company and Yuhan Corporation, or Yuhan, a South Korea company, entered into an agreement to form a joint venture company called ImmuneOncia Therapeutics, LLC, to develop and commercialize a number of immune checkpoint antibodies against undisclosed targets for both hematological malignancies and solid tumors.

Under the terms of the joint venture agreement, Yuhan will contribute an initial investment of $10.0 million to ImmuneOncia, and the Company will grant ImmuneOncia an exclusive license for one of its immune checkpoint antibodies for specified countries while retaining the rights for US, European, and Japanese markets, as well as global rights for ImmuneOncia to two additional antibodies that will be selected by ImmuneOncia from a group of pre-specified antibodies from the Company’s immuno-oncology antibody portfolio. Yuhan will own 51% of ImmuneOncia, while the Company will hold 49%. Yuhan’s Chief Scientific Officer Dr. Su Youn Nam will be appointed CEO of ImmuneOncia.   As of March 31, 2016, funding and operations of the joint venture had not yet begun, as a result no investment has been recorded as of March 31, 2016.

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7. Goodwill and Intangible Assets

As of both March 31, 2016 and December 31, 2015, the Company had goodwill of $20.6 million , respectively.  The Company performed a qualitative test for goodwill impairment as of December 31, 2015. Based upon the results of the qualitative testing the Company concluded that it is more-likely-than-not that the fair values of the Company’s goodwill was in excess of its carrying value and therefore performing the first step of the two-step impairment test was unnecessary. No goodwill impairment was recognized for the three months ended March 31, 2016 and 2015.

The Company’s intangible assets, excluding goodwill, include patent rights, core technologies and customer relationships. Amortization for the intangible assets that have finite useful lives is generally recorded on a straight-line basis over their useful lives.  A summary of the Company’s identifiable intangible assets is as follows (in thousands):

As of March 31, 2016, the remaining weighted average life for identifiable intangible assets is 15 years.

Patent rights are stated at cost and depreciated on a straight-line basis over the estimated useful lives of the assets, determined to be approximately 19 years from the date of transfer of the rights to the Company in April 2013. Amortization expense for both the three months ended March 31, 2016 and 2015 was $1,000, respectively, which has been included in intangibles amortization.

Acquired technology is stated at cost and depreciated on a straight-line basis over the estimated useful lives of the assets, determined to be approximately 19 years from the date of acquisition of the technology in December 2013. Amortization expense for both the three months ended March 31, 2016 and 2015 was $44,000, respectively, which has been included in intangibles amortization.

Customer relationships are stated at cost and depreciated on a straight-line basis over the estimated useful lives of the assets, determined to be approximately five years from the date of acquisition in December 2013. Amortization expense for both the three months ended March 31, 2016 and 2015 was $66,000, respectively, which has been included in intangibles amortization.

Estimated future amortization expense related to intangible assets at March 31, 2016 is as follows (in thousands):

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8 . Significant Agreements and Contracts

License Agreement with The Scripps Research Institute

In January 2010, the Company entered into a license agreement, or the TSRI License, with The Scripps Research Institute, or TSRI. Under the TSRI License, TSRI granted the Company an exclusive, worldwide license to certain TSRI patent rights and materials based on quorum sensing for the prevention and treatment of Staphylococcus aureus (“Staph”) infections, including Methicillin-resistant Staph. In consideration for the license, the Company: (i) issued TSRI a warrant for the purchase of common stock, (ii) agreed to pay TSRI a certain annual royalty commencing in the first year after certain patent filing milestones are achieved, (iii) agreed to pay a royalty on any sales of licensed products by the Company or its affiliates and a royalty for any revenues generated by the Company through its sublicense of patent rights and materials licensed from TSRI under the TSRI License. The TSRI License requires the Company to indemnify TSRI for certain breaches of the agreement and other matters customary for license agreements. The parties may terminate the TSRI License at any time by mutual agreement. In addition, the Company may terminate the TSRI License by giving 60 days’ notice to TSRI and TSRI may terminate the TSRI License immediately in the event of certain breaches of the agreement by the Company or upon the Company’s failure to undertake certain activities in furtherance of commercial development goals. Unless terminated earlier by either or both parties, the term of the TSRI License will continue until the final expiration of all claims covered by the patent rights licensed under the agreement. The warrant was exercised in February 2015.  For the three months ended March 31, 2016 and 2015, the Company recorded $20,000   and $25,000 in patent prosecution and maintenance costs associated with the TSRI License, respectively.  All such costs have been included in general and administrative expenses.

License Agreement with Mabtech Limited

I n August 2015, the Company entered into an exclusive licensing agreement to develop and commercialize multiple prespecified biosimilar and biobetter antibodies from Mabtech Limited.  Under the terms of the agreement, the Company will develop and market these four monoclonal antibodies (mAbs) for the North American, European and Japanese market. The Company made an initial license payment of $10 million which was recognized as acquired in-process research and development expense in the consolidated statements of operations.  The agreement includes additional milestone payments totaling up to $190 million payable over the next four years.  In February 2016, the Company paid an additional $10 million payment for the exclusive licensing agreement to Mabtech Limited which was recognized as acquired in-process research and development expense in the consolidated statements of operations.   

License Agreement with NantCell

In April 2015, the Company and NantCell entered into a license agreement. Under the terms of the agreement the Company granted an exclusive license to NantCell covering patent rights, know-how, and materials related to certain antibodies, anti-body drug conjugates (ADC) and two CAR-TNK products.  NantCell agreed to pay a royalty not to exceed five percent (5%) to the Company on any net sales of products (as defined) from the assets licensed by the Company to NantCell.  In addition to the future royalties payable under this agreement, NantCell paid an upfront payment of $10 million to the Company and issued 10 million shares of NantCell common stock to the Company valued at $100 million based on a recent equity sale of NantCell common stock to a third party.  As of March 31, 2016, the Company had not yet provided all of the items noted in the agreement and therefore has recorded the entire upfront payment and value of the equity interest received as deferred revenue.  The Company will recognize the upfront payment and the value of the equity interest received over the expected license period of approximately ten years on a straight line basis.  The Company’s ownership interest in NantCell does not provide the Company with control or the ability to exercise significant influence, therefore the $100 million investment will be carried at cost in the consolidated balance sheets and evaluated for other-than-temporary impairment on a quarterly basis.

NIH Grants

In June 2014, the NIAID awarded the Company a Phase II STTR grant to support the advanced preclinical development of human bispecific antibody therapeutics to prevent and treat Staphylococcus aureus ( S. aureus or Staph) infections, including methicillin-resistant S. aureus (MRSA), or the Staph Grant III award. The project period for this Phase II grant covers a two-year period which commenced in June 2014, with total funds available of approximately $1 million per year for up to 2 years. During the three months ended March 31, 2016 and 2015, the Company recorded $239,000 and $86,000 of revenue, respectively, associated with the Staph Grant III award.     

In June 2014, the NIAID awarded the Company a Phase I STTR grant entitled “Anti-Pseudomonas Immunotherapy and Targeted Drug Delivery”. This grant will support the preclinical development of novel anti- Pseudomonas aeruginosa mAb immunotherapy or an antibody-mediated targeted antibiotic delivery vehicle. Each modality may be an effective and safe stand-alone therapy and/or a component of a “cocktail” therapeutic option for prevention and treatment of P. aeruginosa infections. The project

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period for this Phase I grant covers a two-year period which commenced in July 2014, with total funds available of approximately $300,000 per year for up to 2 years. During the three months ended March 31, 2016 and 2015, the Company recorded $126,000 and $55,000 of revenue, re spectively, associated with the Phase I STTR grant award.     

In July 2014, the National Cancer Institute (NCI), a division of the NIH, awarded the Company a Phase I STTR grant, entitled “Targeting of Myc-Max Dimerization for the Treatment of Cancer”. This grant will support the preclinical development of the Myc inhibitor, which interferes with the protein-protein interaction (PPI) between Myc and its obligatory dimerization partner, Max, preventing sequence-specific binding to DNA and subsequent initiation of oncogenic transformation. The project period for this Phase I grant covers a one-year period which commenced in August 2014, with total funds available of approximately $225,000. During the three months ended March 31, 2016 and 2015, the Company recorded $0 and $74,000 of revenue, respectively, associated with the Phase I Myc grant award.     

In August 2014, the National Heart, Lung, and Blood Institute (NHBLI), a division of the NIH awarded the Company a Phase I Small Business Technology Transfer (SBIR) grant entitled “Human Anti-WISP-1 Antibodies for Treatment of Idiopathic Pulmonary Fibrosis”. This grant will advance the Company’s immunotherapy targeting WNT-1 Inducible Signaling Protein-1(WISP1) for the treatment of Idiopathic Pulmonary Fibrosis (IPF). WISP1 is a protein that has been shown to be upregulated in IPF, linked to key growth factors, cellular proliferation, hyperplasia and is correlated with late stage cancers. IPF is a fatal disease, which results in progressive loss of lung function due to fibrosis of the lungs. The project period for this Phase I grant covers a one-year period which commenced in August 2014, with total funds available of approximately $225,000.  During the three months ended March 31, 2016 and 2015, the Company recorded $52,000 and $10,000 of revenue, respectively, associated with the Phase I WISP1 grant award.     

9. Loan and Security Agreement

In September 2013, the Company entered into a $5.0 million loan and security agreement with two banks pursuant to which: (i) the lenders provided the Company a term loan which was funded at closing, (ii) the Company repaid its then outstanding equipment loan balance of $762,000, and (iii) the lenders received a warrant to purchase an aggregate 31,250 shares of the Company’s common stock at an exercise price of $8.00 per share exercisable for seven years from the date of issuance. The value of the warrants, totaling $215,000, was recorded as debt discount and additional paid-in capital.

In March 2014, the Company entered into an amended and restated loan and security agreement, increasing the September 2013 facility to $12.5 million from $5.0 million, with the same two banks. Such loan was funded at closing and is secured by a lien covering substantially all of the Company’s assets, excluding intellectual property, which is subject to a negative pledge. In October 2014, the Company entered into a second amendment to its amended and restated loan and security agreement to extend the interest only payments on the outstanding amount of the loan from October 1, 2014 to May 1, 2015, after which equal monthly payments of principal and interest are due until the loan maturity date of September 30, 2017. The amended and restated loan: (i) interest rate is 7.95% per annum, and (ii) provided the Lenders additional warrants to purchase an aggregate of 34,642 shares of the Company’s common stock at an exercise price of $12.99 per share, exercisable for seven years from the date of issuance. The value of the warrants, totaling $322,000, was recorded as debt discount and additional paid-in capital.

At the Company’s option, it may prepay all of the outstanding principal balance, subject to certain pre-payment fees ranging from 1% to 3% of the prepayment amount. In the event of a final payment of the loans under the loan agreement, either in the event of repayment of the loan at maturity or upon any prepayment, the Company is obligated to pay the amortized portion of the final fee of $781,000.

The Company is also subject to certain affirmative and negative covenants under the loan agreement, including limitations on its ability to: undergo certain change of control events; convey, sell, lease, license, transfer or otherwise dispose of any equipment financed by loans under the loan agreement; create, incur, assume, guarantee or be liable with respect to indebtedness, subject to certain exceptions; grant liens on any equipment financed under the loan agreement; and make or permit any payment on specified subordinated debt. In addition, under the loan agreement, subject to certain exceptions, the Company is required to maintain with the lender its primary operating, other deposit and securities accounts.

Long-term debt and unamortized discount balances are as follows (in thousands):

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Future minimum payments under the amended and restated loan and security agreement are as follows (in thousands):

10. Stockholders’ Equity

Common Stock

The Company has a Sales Agreement with MLV & Co. LLC, ("MLV") to permit the sale by MLV, acting as its sales agent, of up to $50.0 million in additional shares of the Company's common stock from time to time in an at-the-market offering under the Sales Agreement. All sales of shares have been and will continue to be made pursuant to an effective shelf registration statement on Form S-3 filed with the SEC. The Company pays MLV a commission of approximately 2% of the aggregate gross proceeds the Company receives from all sales of the Company's common stock under the Sales Agreement. There were net proceeds on sales of approximately $3.5 million at a weighted average price of $6.37 under the Sales Agreement during the three months ended March 31, 2016.  There was no sales activity under the Sales Agreement during the three months ended March 31, 2015.

11. Stock Incentive Plans

2009 Non-Employee Director Grants

In September 2009, prior to the adoption of the 2009 Stock Incentive Plan, the Company’s Board of Directors approved the reservation and issuance of 8,000 nonstatutory stock options to the Company’s non-employee directors. The outstanding options vested on the one year anniversary of the vesting commencement date in October 2010, and are exercisable for up to 10 years from the grant date. No further shares may be granted under this plan and, as of March 31, 2016, all options had been cancelled and no   options were outstanding.

2009 Stock Incentive Plan

In October 2009, the Company’s stockholders approved the 2009 Stock Incentive Plan. In June 2014, the Company’s stockholders approved, among other items, the amendment and restatement of the 2009 Stock Incentive Plan, or the Stock Plan, to increase the number of common shares authorized to be issued pursuant to the Stock Plan to 3,760,000. Such shares of the Company’s common stock are reserved for issuance to employees, non-employee directors and consultants of the Company. The Stock Plan provides for the grant of incentive stock options, non-incentive stock options, stock appreciation rights, restricted stock awards, unrestricted stock awards, restricted stock unit awards and performance awards to eligible recipients. Recipients of stock options shall be eligible to purchase shares of the Company’s common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The maximum term of options granted under the Stock Plan is ten years. Employee option grants will generally vest 25% on the first anniversary of the original vesting commencement date, with the balance vesting monthly over the remaining three years. The vesting schedules for grants to non-employee directors and consultants will be determined by the Company’s Compensation Committee.  

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The following table summarizes stock option activity as of Marc h 31, 2016 and the changes for the period then ended (dollar values in thousands):

The Company uses the Black-Scholes valuation model to calculate the fair value of stock options. The fair value of employee stock options was estimated at the grant date using the following assumptions:

The assumed dividend yield was based on the Company’s expectation of not paying dividends in the foreseeable future. Due to the Company’s limited historical data, the estimated volatility incorporates the historical and implied volatility of comparable companies whose share prices are publicly available. The risk-free interest rate assumption was based on the U.S. Treasury’s rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. The weighted average expected life of options was estimated using the average of the contractual term and the weighted average vesting term of the options.

The total employee stock-based compensation recorded as operating expenses was $1,038,000 and $982,000 for the three months ended March 31, 2016 and 2015, respectively.

The total unrecognized compensation cost related to unvested stock option grants as of March 31, 2016 was $7,186,000 and the weighted average period over which these grants are expected to vest is 2.8 years.

The Company records equity instruments issued to non-employees as expense at their fair value over the related service period as determined in accordance with the authoritative guidance and periodically revalues the equity instruments as they vest.  Stock-based compensation expense related to non-employee consultants recorded as operating expenses was $52,000 and $420,000 for the three months ended March 31, 2016 and 2015, respectively.

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Subsidiary Equity Grants

In May 2015, the Company’s subsidiary TNK Therapeutics, Inc., or TNK, adopted the TNK 2015 Stock Option Plan and reserved 10.0 million shares of TNK class A common stock.  During the three months ended March 31, 2016, TNK awarded 402,000 options with a weighted average grant date fair value of $0.84 per share to certain Company personnel, directors and consultants under such plan.  Stock options granted under this plan typically vest a portion immediately upon grant and the remaining options over two to four years or monthly over four years from the grant date and have a contractual term of ten years. As of March 31, 2016, 3.0 million options were outstanding.

In May 2015, TNK granted a warrant to the Company’s CEO to purchase 9.5 million shares of TNK class B common stock which have 10 to 1 voting rights.  Warrant shares totaling 4.0 million are exercisable evenly over forty months and the remaining warrant shares are exercisable if certain defined events occur within four years from date of issuance at an initial exercise price of $0.01 per share.  The exercise price of the warrant is subject to customary adjustment provisions for stock splits, stock dividends, recapitalizations and the like.  As of March 31, 2016, 9.5 million warrants were outstanding.

In May 2015, the Company’s subsidiary LA Cell, Inc., or LA Cell, adopted the LA Cell 2015 Stock Option Plan and reserved 10.0 million shares of LA Cell class A common stock.  During the three months ended March 31, 2016, LA Cell awarded 401,500 options with a weighted average grant date fair value of $0.20 per share to certain Company personnel, directors and consultants under such plan. Stock options granted under this plan typically vest a portion immediately upon grant and the remaining options over two to four years or monthly over four years from the grant date and have a contractual term of ten years. As of March 31, 2016, 2.1 million options were outstanding.

In May 2015, LA Cell granted a warrant to the Company’s CEO to purchase 9.5 million shares of LA Cell class B common stock which have 10 to 1 voting rights.  Warrant shares totaling 4.0 million are exercisable evenly over forty months and the remaining warrant shares are exercisable if certain defined events occur within four years from date of issuance at an initial exercise price of $0.01 per share.  The exercise price of the warrant is subject to customary adjustment provisions for stock splits, stock dividends, recapitalizations and the like.  As of March 31, 2016, 9.5 million warrants were outstanding.

In October 2015, the Company’s subsidiary Concortis Biosystems, Corp., or CBC, adopted the CBC 2015 Stock Option Plan and reserved 10.0 million shares of CBC class A common stock.  During the three months ended March 31, 2016, CBC awarded 9,750 options with a weighted average grant date fair value of $0.17 per share to certain Company personnel under such plan. Stock options granted under this plan typically vest a portion immediately upon grant and the remaining options over two to four years or monthly over four years from the grant date and have a contractual term of ten years. As of March 31, 2016, 1.8 million options were outstanding.

In October 2015, CBC granted a warrant to the Company’s CEO to purchase 9.5 million shares of CBC class B common stock which have 10 to 1 voting rights.  Warrant shares totaling 4.0 million are exercisable evenly over forty months and the remaining warrant shares are exercisable if certain defined events occur within four years from date of issuance at an initial exercise price of $0.25 per share.  The exercise price of the warrant is subject to customary adjustment provisions for stock splits, stock dividends, recapitalizations and the like.  As of March 31, 2016, 9.5 million warrants were outstanding.

In October 2015, the Company’s subsidiary Scintilla Pharmaceuticals, Inc., or Scintilla, adopted the Scintilla 2015 Stock Option Plan and reserved 10.0 million shares of Scintilla class A common stock.  During the three months ended March 1, 2016, Scintilla awarded 2,000 options with a weighted average grant date fair value of $0.01 per share to certain Company personnel under such plan.   Stock options granted under this plan typically vest a portion immediately upon grant and the remaining options over two to four years or monthly over four years from the grant date and have a contractual term of ten years. As of March 31, 2016, 1.0 million options were outstanding.

In October 2015, Scintilla granted a warrant to the Company’s CEO to purchase 9.5 million shares of Scintilla class B common stock which have 10 to 1 voting rights.  Warrant shares totaling 4.0 million are exercisable evenly over forty months and the remaining warrant shares are exercisable if certain defined events occur within four years from date of issuance at an initial exercise price of $0.01 per share.  The exercise price of the warrant is subject to customary adjustment provisions for stock splits, stock dividends, recapitalizations and the like.   As of March 31, 2016, 9.5 million warrants were outstanding.

In October 2015, the Company’s subsidiary Sorrento Biologics, Inc., or Biologics, adopted the Biologics 2015 Stock Option Plan and reserved 10.0 million shares of Biologics class A common stock.  No options were awarded during the three months ended March 31, 2016 under such plan. Stock options granted under this plan typically vest a portion immediately upon grant and the remaining options over two to four years or monthly over four years from the grant date and have a contractual term of ten years. As of March 31, 2016, 1.4 million options were outstanding.

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In October 2015, Biologics granted a warrant to the Company’s CEO to purchase 9.5 million shares of Biologics class B common stock which have 10 to 1 voting rights.  Warrant shares totaling 4.0 million are exercisable evenly over forty months and the remaining warrant shares are exercisable if certain defined events occur within four years from date of issuance at an initial exercise price of $0.01 per share.  The exercise price of the warrant is subject to customary adjustment provisions for stock splits, stock dividends, recapitalizations and the like .   As of March 31, 2016, 9.5 million warrants were outstanding.

The total director stock-based compensation recorded as operating expenses by the Company for TNK, LA Cell, CBC, Scintilla and Biologics for the three months ended March 31, 2016 and 2015 was $42,000 and $0, respectively.  Total unrecognized stock-based compensation expense related to unvested director stock option and warrant grants for these entities as of March 31, 2016 was $492,000, and the weighted-average period over which these grants are expected to vest is approximately 3.3 years.  The Company records equity instruments issued to non-employees as expense at their fair value over the related service period as determined in accordance with the authoritative guidance and periodically revalues the equity instruments as they vest.  Stock based compensation expense related to non-employee consultants recorded as operating expenses by the Company for TNK, LA Cell, CBC, Scintilla and Biologics for the three months ended March 31, 2016 and 2015 was $48,000 and $0, respectively.

The weighted-average assumptions used in the Black-Scholes option and warrant pricing model used by TNK, LA Cell, CBC, Scintilla and Biologics to determine the fair value of stock option grants for directors and non-employee consultants for the three months ended March 31, 2016 were as follows: expected dividend yield – 0%, risk-free interest rate – 1.39% to 1.89%, expected volatility – 76% to 77%, and expected term of 4.0 to 6.1 years.

In May 2014, the Company’s subsidiary Ark Animal Health, Inc., or Ark, adopted the Ark 2014 Stock Option Plan and reserved and awarded 600,000 options to certain directors and consultants under such plan. Stock options granted under such plan typically vest a portion immediately upon grant and the remaining options over one year from the grant date and will have a contractual term of ten years. As of March 31, 2016, 351,000 options were outstanding.

The total director and consultant stock-based compensation recorded as operating expenses by the Company for Ark for the three months ended March 31, 2016 and 2015 was $0 and $34,000, respectively.  No unrecognized stock-based compensation expense related to unvested stock option grants existed as of March 31, 2016.

12. Investment in Variable Interest Entity

The Company’s consolidated financial statements include the financial results of LA Cell, Inc. (LA Cell), a consolidated subsidiary of the Company and a variable interest entity in which the Company is the primary beneficiary.

In September 2015, LA Cell exclusively licensed certain technology from City of Hope.  The technology includes cell-penetrating antibody therapies that enables modified monoclonal antibodies (mAbs) to penetrate into cells and target disease-causing molecules.  Utilizing mAbs derived from the Company's antibody portfolio, LA Cell is focused on developing therapies against important oncology targets, including but not limited to c-MYC, mutated KRAS, STAT3, and FoxP3.  Pursuant to the license agreement, LA Cell made a $2.0 million upfront payment to City of Hope and has accrued an additional initial payment of $3.0 million to City of Hope as of March 31, 2016 .  The license agreement also provides for development and sales milestone payments and royalties based on net sales, as defined in the license agreement.

Upon the formation of LA Cell, the Company held all of the outstanding stock of LA Cell. As of March 31, 2016, the Company held an aggregate of approximately a 48% ownership of outstanding shares but which include a majority of the voting rights.  

For the three months ended March 31, 2016, LA Cell recognized $3.0 million in acquired in-process research and development expense in the Company’s consolidated statements of operations and incurred minimal general and administrative expenses.

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13. Derivative Liability

On October 13, 2015, the Company wrote a call option to Cambridge Equities, LP (Cambridge), a related party, on up to 2.0 million shares of NantKwest, Inc., (NantKwest) common stock held by the Company (the Option Agreement).  As of March 31, 2016, the Company holds approximately 5.6 million shares of common stock of NantKwest, par value $.0001 per share, which is classified as available-for-sale and reported in its consolidated financial statements as marketable securities.  The Option Agreement gave Cambridge the right to purchase up to 2.0 million shares at a price of $15.295 per share from time to time in the first quarter of 2016.  There is no contractual option premium associated with this Option Agreement.  The Option Agreement is a derivative as defined in ASC 815 and is recognized at fair value every reporting period the Option Agreement is in effect, with changes in fair value recognized in current operations.  The call option expired unexercised on March 31, 2016 and for the three months ended March 31, 2016 the Company recorded a gain of $5.5 million upon the cancelation of the derivative liability and as of March 31, 2016 no derivative liability was recorded on the Company’s consolidated balance sheets .

14. Income Taxes

The Company maintains deferred tax assets that reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. These deferred tax assets include net operating loss carryforwards, research credits and temporary differences. In assessing the Company's ability to realize deferred tax assets, management considers, on a periodic basis, whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. As such, management has determined that it is appropriate to maintain a full valuation allowance against the Company's U.S. federal and state deferred tax assets, with the exception of an amount equal to its deferred tax liabilities, which can be expected to reverse over a definite life.

The Company is subject to taxation in the U.S. and various state jurisdictions. The Company's tax years for 2007 and later are subject to examination by the U.S. and state tax authorities due to the existence of the NOL carryforwards.

As of the March 31, 2016, the Company had approximately $1.8 million of unrecognized tax benefits that, if recognized, would impact the effective income tax rate for continuing operations, subject to possible offset by an increase in the deferred tax asset valuation allowance. As of March 31, 2015, there were no unrecognized tax benefits.

The Company recognizes interest and penalties related to unrecognized tax benefits in its provision for income taxes. For the three months ended March 31, 2016 and 2015, no expense was recorded related to interest and penalties. The Company believes that no significant amount of the liabilities for uncertain tax positions will expire within twelve months of March 31, 2016.

15. Commitments and Contingencies

Litigation

In the normal course of business, the Company may be named as a defendant in one or more lawsuits. The Company is not a party to any outstanding material litigation and management is currently not aware of any legal proceedings that, individually or in the aggregate, are deemed to be material to its financial condition or results of operations.  On April 25, 2016, Wildcat Liquid Alpha, LLC (“WLA”) filed a complaint in the Court of Chancery of the State of Delaware seeking an order to compel the Company to provide WLA with certain documents, books and records for inspection and copying.  The Company believes that Wildcat’s demand for documents is deficient and without merit, and will defend itself against the demand and the requirement to furnish such documents, books and records to WLA.

Operating Leases

The Company currently leases in San Diego, California approximately 43,000 square feet of corporate office and laboratory space and approximately 6,350 square feet of laboratory and office space at a second location.  The Company’s lease agreements in San Diego, as amended, for its corporate office and laboratory space and its second laboratory and office space, expire in December 2025 and June 2018, respectively.  

For all leased properties the Company has provided a total security deposit of $381 to secure its obligations under the various leases, which has been included in prepaid and other assets.

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16. Related Party Agreements

During the three months ended March 31, 2016 and 2015, the Company purchased products totaling $117,000 and $65,000, respectively, from Levena Biopharma Co., LTD (Levena), a Chinese Corporation.  The Company’s former Senior Vice President and Head of Antibody Drug Conjugates was one of the owners of Levena.

In December 2014, the Company entered into a securities purchase agreement (the “Purchase Agreement”) with an affiliated entity of Dr. Patrick Soon-Shiong (the “Investor”) pursuant to which the Company agreed to issue and sell to the Investor an aggregate of approximately 7.2 million shares of the Company’s common stock at a price of $5.80 per share for an aggregate purchase price of $41.7 million. In connection with the Purchase Agreement, the Investor received a warrant to purchase approximately 1.7 million shares of the Company’s Common Stock. The warrant is exercisable for a period of three years from the date of issuance at an initial exercise price of $5.80 per share.

In December 2014, the Company entered into a joint development and license agreement with Conkwest Inc., which has changed its name to NantKwest, and of which Dr. Patrick Soon-Shiong is a majority owner.  In addition, the Company purchased approximately 5.6 million shares of NantKwest common stock for $10 million.

As described more fully in Notes 6 and 8, during 2015, the Company entered into a joint venture called Immunotherapy NANTibody, LLC, with NantCell, a wholly-owned subsidiary of NantWorks, a private company owned by Dr. Patrick Soon-Shiong.  In July 2015, the Company contributed its portion of the initial joint funding of $40 million to the Immunotherapy NANTibody joint venture.  The Company and NantCell have also entered into a license agreement pursuant to which the Company received a $10 million upfront license payment and $100 million of vested NantCell common stock.  

As described more fully in Notes 6 and 13, t he Company entered into a joint venture called NantCancerStemCell, LLC, or NantStem, with NantBioScience, a wholly-owned subsidiary of NantWorks.   In connection with negotiated changes to the structure of NantStem the Company issued a call option on shares of NantKwest that it owned to Cambridge Equities, LP (Cambridge), a related party to the Company and to NantBioScience.  The call option to Cambridge was on up to 2.0 million shares of NantKwest common stock held by the Company (the Option Agreement).  As of March 31, 2016, the Company holds approximately 5.6 million shares of common stock of NantKwest, which is classified as available-for-sale in the consolidated financial statements.  The Option Agreement gave Cambridge the right to purchase up to 2.0 million shares at a price of $15.295 from time to time in the first quarter of 2016.  There was no option premium associated with this Option Agreement.  The Option Agreement was a derivative as defined in ASC 815 and was marked to fair value every reporting period the Option Agreement was in effect, with changes in fair value recognized in earnings.  The call option expired unexercised on March 31, 2016 and for the three months ended March 31, 2016 the Company recorded a gain of $5.5 million upon the cancelation of the derivative liability.  As of March 31, 2016 no derivative liability was recorded on the Company’s consolidated balance sheets.  In April 2015, the Company purchased 1.0 million shares of NantBioScience common stock for $10 million.  

In May 2015, the Company entered into a stock sale and purchase agreement with NantPharma, a private company owned by NantWorks pursuant to which the Company sold its equity interests in IgDraSol, its wholly-owned subsidiary and holder of the rights to Cynviloq for an upfront payment of $90.05 million and potential regulatory and sales milestones of up to $1.2 billion.  

17. Subsequent Events

On April 3, 2016, the Company entered into a Securities Purchase Agreement (the “ABG Purchase Agreement”) with ABG SRNE Limited and Ally Bridge LB Healthcare Master Fund Limited (collectively, “Ally Bridge”), pursuant to which, among other things, the Company agreed to issue and sell to Ally Bridge and other purchasers that may be designated by Ally Bridge (collectively, the “ABG Purchasers”), in a private placement transaction (the “ABG Private Placement”), up to $50 million in shares of common stock of the Company (“Common Stock”) and warrants to purchase shares of Common Stock. Upon the closing of the ABG Private Placement, the Company will issue to each ABG Purchaser (1) such number of shares (the “ABG Shares”) of Common Stock as is equal to the amount of such ABG Purchaser’s investment divided by $5.55, and (2) a warrant to purchase such number of shares of Common Stock as is equal to 30% of the ABG Shares sold and issued to such ABG Purchaser (each, an “ABG Warrant”); provided that , following the consummation of the ABG Private Placement, Ally Bridge and its affiliates will not beneficially own more than 9.99% of the outstanding shares of Common Stock. Each ABG Warrant will have an exercise price of $8.50 per share, will be immediately exercisable upon issuance, will have a term of three years and will be exercisable on a cash or cashless exercise basis.

Under the terms of the ABG Purchase Agreement, the Company is obligated to prepare and file with the Securities and Exchange Commission (the “SEC”), within 30 days of the closing date of the ABG Private Placement, a registration statement to register for resale the ABG Shares and the shares of Common Stock issuable upon exercise of each ABG Warrant (the “ABG Warrant

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Shares”), and may be required to effect certain registrations to register for resale the ABG Shares and the ABG Warrant Shares in connection with certain “piggy-back” registration rights granted to the ABG Purchasers.

On April 3, 2016, the Company also entered into a Securities Purchase Agreement (collectively, the “Additional Purchase Agreements”) with each of Beijing Shijilongxin Investment Co., Ltd. ( “Beijing Shijilongxin”), FREJOY Investment Management Co., Ltd. (“Frejoy”) and Yuhan Corporation (“Yuhan”), pursuant to which, among other things, the Company agreed to issue and sell, in separate private placement transactions: (1) to Beijing Shijilongxin, 8,108,108 shares of Common Stock, and a warrant to purchase 1,176,471 shares of Common Stock, for an aggregate purchase price of $45 million; (2) to Frejoy, 8,108,108 shares of Common Stock, and a warrant to purchase 1,176,471 shares of Common Stock, for an aggregate purchase price of $45 million; and (3) to Yuhan, 1,801,802 shares of Common Stock, and a warrant to purchase 235,294 shares of Common Stock, for an aggregate purchase price of $10 million. The warrants to be issued pursuant to each of the Additional Purchase Agreements (collectively, the “Additional Warrants” and, together with each ABG Warrant, the “Warrants”) will have an exercise price of $8.50 per share, will be immediately exercisable upon issuance, will have a term of three years and will be exercisable on a cash or cashless exercise basis.

Under the terms of the Additional Purchase Agreements, each of Beijing Shijilongxin, Frejoy and Yuhan has the right to demand, at any time beginning six months after the closing of the transactions contemplated by the applicable Additional Purchase Agreement, that the Company prepare and file with the SEC a registration statement to register for resale such investor’s shares of Common Stock purchased pursuant to the applicable Additional Purchase Agreement and the shares of Common Stock issuable upon exercise of such investor’s Additional Warrant. In addition, the Company may be required to effect certain registrations to register for resale such shares in connection with certain “piggy-back” registration rights granted to Beijing Shijilongxin, Frejoy and Yuhan.

The closing of the transactions contemplated by the ABG Purchase Agreement and each of the Additional Purchase Agreements are each subject to customary closing conditions, including obtaining clearance for the issuance of the applicable shares of Common Stock and the Warrants in accordance with the listing requirements of The Nasdaq Stock Market LLC and the completion of due diligence by Ally Bridge, Beijing Shijilongxin, Frejoy and Yuhan, respectively. The Company expects that the closings of the transactions will occur by the end of May 2016.

On May 2, 2016 the Company announced that it has closed its previously announced private placement of common stock and warrants with Yuhan Corporation for gross proceeds of $10 million.  Yuhan purchased 1,801,802 shares of common stock at $5.55 per share and a warrant to purchase 235,294 shares of common stock.  The warrant is exercisable for three years at an exercise price of $8.50 per share.

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