Quarterly Report for Quarter Ending March 31, 2026 (Form 10-Q)

Management's Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion and analysis of our results of operations and financial condition should be read in conjunction with our financial statements and the notes to those financial statements that are included elsewhere in this report. Our discussion includes forward-looking statements based upon current expectations that involve risks and uncertainties, such as our plans, objectives, expectations and intentions. Actual results and the timing of events could differ materially from those anticipated in these forward-looking statements as a result of a number of factors, including those set forth under the "Business" section and elsewhere in this report. We use words such as "may," "will," "might," "could," "would," "should," "expect," "intend," "plan," "anticipate," "believe," "estimate," "predict," "project," "aim," "potential," "continue," "ongoing," "goal," "forecast," "guidance," "outlook," or the negative of these terms or other similar expressions to identify forward-looking statements, although not all forward-looking statements contain these words. All forward-looking statements included in this report are based on information available to us on the date hereof and, except as required by law, we assume no obligation to update any such forward-looking statements.

Overview

​

We are a commercial-stage biopharmaceutical company pioneering a transformational approach to treating cancer. Our mission is to be the global leader in innovating, developing, and delivering tumor infiltrating lymphocyte, or TIL, cell therapies for patients with solid tumor cancers. TIL cell therapies harness the individual immune system's ability to recognize and destroy diverse cancer cells that are unique to each patient. These individualized therapies are manufactured using centralized, scalable, and proprietary manufacturing processes which rejuvenate and multiply each patient's polyclonal T cells into the billions.

​

Iovance was founded to build upon the promise of TIL cell therapy initially developed at academic research centers, including the National Cancer Institute, or the NCI. Our multi-center trials, scalable manufacturing, regulatory approvals and commercial infrastructure have transformed TIL cell therapy from a research product available to only a small number of patients, into a commercially viable treatment that is accessible for thousands of cancer patients.

​

Our two commercial products include Amtagvi^® (lifileucel) and Proleukin^® (aldesleukin), an interleukin-2, or IL-2, product used in the Amtagvi^® treatment regimen and other applications.

​

Amtagvi^® is the first one-time, individualized T cell therapy for a solid tumor cancer and for the treatment of adult patients with previously treated advanced, or unresectable or metastatic melanoma, approved for use in the U.S. and Canada. Amtagvi^® is administered as part of a treatment regimen that includes lymphodepletion and a short course of Proleukin^®.

​

Globally, Amtagvi^® has the potential to address more than 30,000 previously treated advanced melanoma patients annually. We plan to launch into additional markets with a high prevalence of advanced melanoma. Potential approvals are pending in Australia in the first half of 2026 and Switzerland in 2027. In the European Union, or EU, we withdrew our initial marketing authorization application, or MAA, in July 2025. We are working with the European Medicines Agency, or EMA, to resubmit a centralized MAA in 2026. In the United Kingdom, or UK, we withdrew our initial MAA in May 2026 and will resubmit the MAA with additional information for expedited review in 2026.

​

Our development pipeline consists of TIL cell therapies in additional solid tumor cancer indications as monotherapy or in combination with standard of care, as well as next generation approaches. We are conducting two ongoing registrational trials in frontline advanced melanoma and previously treated advanced non-small cell lung cancer, or NSCLC. We have commenced a registrational trial in previously treated advanced undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma, and plan to engage with the FDA for an expedited path to accelerated approval.

​

Corporate Strategy

A global leader in innovating, developing, and delivering TIL cell therapy

Our mission is to be the global leader in innovating, developing, and delivering TIL cell therapy. Our vision is to pioneer this transformational approach to cure solid tumor cancers. We are committed to continuous innovation to develop TIL cell therapies and optimize TIL treatment regimens that may extend and improve life for patients with cancer.

Our top priority is to drive commercial success of Amtagvi^® for previously treated advanced melanoma across four primary areas:

​

U.S. Commercial Launch of the First TIL Cell Therapy in Advanced Melanoma

Amtagvi^®

Amtagvi^® (lifileucel) is the first one-time, individualized T cell therapy approved for a solid tumor cancer and for the treatment of adult patients with previously treated advanced melanoma. Amtagvi^® returns billions of individualized patient T cells back to the body to fight cancer and is administered as part of a treatment regimen.

Amtagvi^® is indicated for the treatment of adult patients with advanced melanoma previously treated with a PD-1 blocking antibody, and if BRAF V600 mutation positive, a BRAF inhibitor with or without a MEK inhibitor. The U.S. accelerated approval of Amtagvi^® is based on safety and efficacy results from the C-144-01 global, multicenter clinical trial. A global, randomized Phase 3 confirmatory trial, TILVANCE-301, is investigating Amtagvi^® in combination with pembrolizumab in frontline advanced melanoma.

Amtagvi^® has multiple growth drivers, including:

​

Proleukin^®

We sell Proleukin^® (aldesleukin), an interleukin-2, or IL-2, product to three main distributors in the U.S., distributors outside the U.S., and numerous third-party clients across the three revenue channels: 1) use in the Amtagvi^® treatment regimen, or other approved oncology uses, or the primary channel, 2) use in the manufacturing process for Amtagvi^® and other cell therapies and 3) use in clinical and research settings. Proleukin^® is approved in the U.S., and licensed in multiple international markets, for treatment of adults with metastatic renal cell carcinoma and/or metastatic melanoma.

In May 2023, we acquired the worldwide rights to Proleukin^® from Clinigen Holdings Limited, Clinigen Healthcare Limited, and Clinigen, Inc., which we refer to collectively as Clinigen.

​

Scalable TIL manufacturing for commercial and clinical demand

​

To date, more than 1,500 patients have been treated with commercial and investigational TIL cell therapies manufactured using Iovance processes. The Iovance Cell Therapy Center, or iCTC, in Philadelphia, Pennsylvania is the first FDA-approved facility to manufacture commercial TIL cell therapy. We believe that the iCTC is the only current Good Manufacturing Practice, or cGMP, facility with a centralized, scalable TIL manufacturing process. Facilitated by its proximity to multiple airports, the iCTC covers logistics and delivery of TIL cell therapies to treatment centers in North America, Europe, and Asia Pacific.

The current iCTC facility has the potential capacity to supply TIL cell therapies for more than 5,000 cancer patients annually. To utilize our internal manufacturing suites at greater scale, improve gross margin and reduce operating expenses, we transitioned all

manufacturing for clinical and commercial Iovance TIL cell therapies to the iCTC and terminated an agreement with a contract manufacturer in the first quarter of 2026 to manage and reduce long-term product manufacturing costs. We have full control of manufacturing capacity and product quality, supply and delivery logistics, cost efficiencies and process improvements, such as automation and next generation approaches that may further streamline timelines and costs. Certain clinical trials for our next-generation investigational TIL cell therapies will continue to be supported by contract manufacturing organizations, or CMOs. Details of related agreements are provided in Note 12 Licenses and Agreements section of this Quarterly Report on Form 10-Q of our condensed consolidated financial statements for the quarter ended March 31, 2026.

​

TIL Cell Therapy Platforms for Advanced, or Metastatic or Unresectable, Solid Tumor Cancers

​

Our T cell-based immunotherapy technology platform of TIL cell therapies leverages patient-specific cells to recognize and attack diverse cancer cells that are unique to each patient. We believe this approach is the emerging backbone for immuno-oncology approaches to treat solid tumor cancers.

We have investigated TIL cell therapy in global, multicenter Iovance-sponsored clinical trials in various treatment settings for patients with advanced melanoma, NSCLC, cervical cancer, endometrial cancer, and head and neck squamous cell carcinoma, or HNSCC. Through ongoing academic collaborations, as well as government and other partners, we are investigating additional solid tumor types and treatment settings. We have provided prior or ongoing support for investigator-sponsored clinical trials for patients with soft tissue sarcoma, osteosarcoma, pancreatic and colorectal cancer, platinum resistant ovarian cancer, anaplastic thyroid cancer, and triple negative breast cancer.

Applying our expertise in TIL cell therapy, our next-generation technology platforms are designed to optimize outcomes with TIL cell therapy across three key initiatives: genetic modifications, potency, and new treatment regimens using an improved IL-2.

Intellectual Property

We have established a leading intellectual property portfolio developed internally and licensed from third parties. We currently own more than 100 U.S. patents related to TIL cell therapy, including patents directed to compositions and methods of treatment in a broad range of cancers, such as U.S. Patent Nos. 10,130,659; 10,166,257; 10,272,113; 10,363,273; 10,398,734; 10,420,799; 10,463,697; 10,517,894; 10,537,595; 10,639,330; 10,646,517; 10,653,723; 10,695,372; 10,894,063; 10,905,718; 10,918,666; 10,925,900; 10,933,094; 10,946,044; 10,946,045; 10,953,046; 10,953,047; 11,007,225; 11,007,226; 11,013,770; 11,026,974; 11,040,070; 11,052,115; 11,052,116; 11,058,728; 11,083,752; 11,123,371; 11,141,434; 11,141,438; 11,168,303; 11,168,304; 11,179,419; 11,202,803; 11,202,804; 11,220,670; 11,241,456; 11,254,913; 11,266,694; 11,273,180; 11,273,181; 11,291,687; 11,293,009; 11,304,979; 11,304,980; 11,311,578; 11,337,998; 11,344,579; 11,344,580; 11,344,581; 11,351,197; 11,351,198; 11,351,199; 11,364,266; 11,369,637; 11,384,337; 11,401,507; 11,433,097; 11,517,592; 11,529,372; 11,541,077; 11,631,483; 11,713,446; 11,819,517; 11,857,573; 11,865,140; 11,866,688; 11,939,596; 11,969,444; 11,975,028; 11,981,921; 11,998,568; 12,023,355; 12,024,718; 12,031,157; 12,104,172; 12,121,541; 12,159,700; 12,170,134; 12,188,048; 12,194,061; 12,226,434; 12,226,522; 12,230,378; 12,230,379; 12,233,075; 12,280,140; 12,343,380; 12,453,697; 12,473,532; 12,485,145; 12,495,791; 12,553,029; 12,553,031; 12,558,375; 12,570,959; 12,570,961; 12,611,427; 12,611,428; and 12,611,429. More than 50 of these patents are related to our Gen 2 TIL manufacturing processes and have terms that we anticipate will extend to October 2037 or January 2038, not including any patent term extensions or adjustments that may be available. Our owned and licensed intellectual property portfolio also includes patents and patent applications relating to TIL, marrow-infiltrating lymphocytes, or MIL, and peripheral blood lymphocyte, or PBL, therapies; frozen tumor-based TIL technologies; remnant TIL and digest TIL compositions, methods, and processes; methods of manufacturing TIL, MIL, and PBL therapies; the use of costimulatory and T cell modulating molecules in TIL cell therapy and manufacturing; stable and transient genetically-modified TIL cell therapies, including genetic knockouts of immune checkpoints; cytokine-tethered TIL cell therapies; methods of using immune checkpoint inhibitor, or ICIs, in combination with TIL cell therapies; TIL selection technologies; and methods of treating patient subpopulations.

Components of Operating Results

​

Revenue

​

Revenue for the three months ended March 31, 2026 represents product sales of Amtagvi^®, as well as Proleukin^®, primarily driven from sales in the U.S. to support the ongoing commercial launch of Amtagvi^®, which received FDA approval in February 2024. Proleukin^®, which we acquired the worldwide rights to in May 2023, is also sold in markets outside the U.S., primarily in the EU and UK.

​

Amtagvi^® revenue is recognized upon patient infusion, while Proleukin^® revenue is recognized upon shipment or delivery to customers, which include specialty distributors, clinical manufacturers, research organizations, and ATCs. Revenue is reduced at the time of recognition for expected chargebacks, discounts, rebates, and sales allowances, collectively referred to as gross to net adjustments, or GTN adjustments. In the U.S., these GTN adjustments are attributable to various commercial arrangements and government programs. In addition, non-U.S. government programs may include different pricing schemes such as cost caps and volume discounts.

​

Costs and Expenses

​

Cost of sales

​

Cost of sales includes cost of inventories sold, including overhead and manufacturing costs of Amtagvi^®, reserves for excess and obsolete inventory, royalties payable on the sales of our products and other costs that are directly associated with the purchase and sales of Proleukin^®.

​

In the event that the manufactured product does not meet specifications, or a patient is unable to receive the infusion, the Amtagvi^® product is generally destroyed and the costs associated with manufacturing and inventory associated with the product is generally required to be expensed as cost of sales. However, if the out-of-specifications product can be administered as part of a clinical trial, in an expanded or early access program, or single-patient investigational new drug submission, as requested by the treating physician, the costs of the product are recorded as research and development expense based on the fact that we receive clinical data related to these infusions.

​

The manufacturing process for Amtagvi^® is highly complex and subject to stringent FDA guidelines and requirements, as well as internal specifications and quality guidelines. Our ability to successfully manufacture Amtagvi^® and deliver finished product to ATCs for infusion into patients is dependent on several factors, including patient selection and quality of tumors provided by the treatment centers for use in the manufacturing of Amtagvi^®. We focus significant effort and attention on working with the treatment centers regarding these matters, as well as on our internal manufacturing processes.

​

Research and development expense

​

Research and development expenses include personnel and facility-related expenses, outside contracted services including clinical trial costs, manufacturing and process development costs, research costs, and other consulting services. Research and development costs are expensed as incurred. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and amortized over the period that the goods are delivered, or the related services are performed, subject to an assessment of recoverability.

​

Clinical development costs are a significant component of research and development expenses. We have a history of contracting with third parties that perform various clinical trial activities on our behalf in connection with the ongoing development of our product candidates. The financial terms of these contracts are subject to negotiations and may vary from contract to contract and may result in an uneven payment flow. We accrue and expense costs for clinical trial activities performed by third parties based upon estimates of work completed to date of the individual trial in accordance with agreements established with contract research organizations and clinical trial sites. The duration, costs, and timing of our clinical trials and development of our product candidates will depend on a number of factors that include, but are not limited to, the number of patients that enroll in the trial, per patient trial costs, number of sites included in the trial, discontinuation rates of patients, duration of patient follow-up, efficacy and safety profile of the product candidate, and the length of time required to enroll eligible patients.

​

We expect to continue to incur research and development expenses for the foreseeable future as we continue to conduct our clinical trials for our various product candidates. However, it is difficult to determine with certainty the duration and completion costs of our current or future preclinical programs and clinical trials of our product candidates.

​

Selling, general and administrative expense

​

Selling, general, and administrative expenses consist primarily of salaries and other related costs, including facility costs not otherwise capitalized in inventory or included in research and development expenses, legal fees relating to corporate matters and intellectual property, insurance, public company expenses relating to maintaining compliance with Nasdaq listing rules and SEC requirements, investor relations costs, and fees for accounting and consulting services. Selling, general, and administrative costs are expensed as incurred, and we accrue for services provided by third parties related to the above expenses by monitoring the status of services provided and receiving estimates from its service providers and adjusting its accruals as actual costs become known.

​

We anticipate selling, general, and administrative expenses will increase as we expand the use of Amtagvi^® and market Proleukin^®, as well as expected growth in the internal general and administrative team to align with the overall growth in the business as we execute an expected expansion in both the U.S. market and outside of the U.S.

​

Depreciation and amortization

​

Depreciation and amortization includes depreciation and amortization expense for the property and equipment as well as non-cash amortization of intangible assets, including amortization expense for the fair value step-up of acquired Proleukin^® inventory which is recognized as the acquired inventory units are sold, the developed technology intangible asset and the milestone payment recorded as part of the Acquisition, and the intellectual property license intangible asset related to Amtagvi^®. These expenses are recorded on a straight-line basis over the estimated useful lives of the assets.

​

Restructuring charges

​

Restructuring charges consist primarily of employee severance payments and other postemployment benefit related expenses. The Company records restructuring charges based on whether the termination benefits are provided under an on-going benefit arrangement or under a one-time benefit arrangement. The Company recognizes charges related to restructuring plans when the liabilities have been incurred and can be reasonably estimated.

​

Interest and other income, net

​

Interest and other income, net is derived from our interest-bearing cash, cash equivalents and investment balances as well as other income associated with non-recurring activities such as lease terminations.

​

Income tax benefit

​

Income tax benefit pertains to the operations in the UK and realization of related deferred taxes.

​

Results of Operations for the Three Months Ended March 31, 2026 and 2025

Revenue

​

Revenue for the three months ended March 31, 2026 increased by $22.1 million, or 45%, compared to the same period in 2025. The increase in revenue as compared to the prior period was driven by an increase in Amtagvi^® infusions, correspondent increase in Proleukin^®, and price increases for both products.

​

As it relates to revenue timing for our products, Amtagvi^® infusions are expected to lag behind Amtagvi^® related Proleukin^® sales by 2-3 months, and we expect ATCs to utilize approximately 15 Proleukin^® vials per Amtagvi^® infusion. While such Proleukin^® sales are not directly indicative of future Amtagvi^® revenues because of the timing of stocking activities by specialty distributors and because of sales that are not related to Amtagvi^® infusions, such as sales of Proleukin^® utilized in clinical manufacturing or clinical trials, such sales are one indicator of future Amtagvi^® revenues.

Costs and expenses

The following table summarizes the period-over-period changes in our costs and expenses:

​

​
Cost of sales

Cost of sales, excluding depreciation and amortization, for the three months ended March 31, 2026 decreased by $0.2 million, or 1%, compared to the same period in 2025. The decrease was driven by a $5.3 million decrease in period costs primarily related to patient drop-off driven by patient health and ability to receive the Amtagvi^® treatment, as well as manufacturing results that did not meet required specifications, and were not otherwise utilized under an expanded access program or single-patient IND to generate clinical data. This decrease was partially offset by (i) a $3.8 million increase from sales of Amtagvi^® and Proleukin^® products as well as costs related to the manufacturing of Amtagvi^® and (ii) a $1.3 million increase in royalties payable related to the increase in sales of Proleukin.

​

Research and development expense

​

Research and development expense for the three months ended March 31, 2026 decreased by $13.5 million, or 18%, compared to the same period in 2025. The decrease was primarily attributable to (i) a $4.9 million decrease in outside services cost driven by a decrease in the number of consultants, (ii) a $4.8 million decrease in stock-based compensation expense primarily driven by a lower number of stock awards granted at lower average stock price, (iii) a $5.5 million decrease in clinical trial costs, driven primarily by completion of 144-01 and 144-05 clinical trials as well as other ongoing studies advancing into a late-stage of clinical trials, and (iv) a $0.7 million decrease in other costs, including travel and license cost. These decreases were partially offset by a $2.4 million increase in clinical manufacturing costs primarily driven by increased clinical production.

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. We separate our research and development expenses into two broad categories: direct and indirect. Additionally, with respect to direct research and development expenses, we further divide expenses into the following sub-categories: "TIL, including combination therapy," "Next Generation," and "Other clinical, preclinical and research programs under development." Lifileucel monotherapy includes our TIL monotherapy clinical trials, including clinical trials previously reported as LN-145. For direct research and development expenses, we track specific project research and development expenses that are directly attributable to our preclinical and clinical development candidates that have been selected for further development. Such direct research and development expenses include third-party contract costs relating to the manufacturing of TILs, as well as preclinical and clinical trial activities.

​

All remaining research and development expenses are categorized as indirect research and development expenses. Such indirect research and development expenses include employee salaries and benefits, stock-based compensation, consulting and contracted

services to supplement our in-house activities, and costs associated with our facilities. These expenses are not directly tied to any individual project and are generally deployed across multiple projects. As such, we do not maintain information regarding those costs incurred on a project specific basis.

​

The table below summarizes our research and development expenses by therapeutic area (in thousands):

​

​

Selling, general and administrative expense

​

Selling, general and administrative expenses for the three months ended March 31, 2026 decreased by $4.9 million, or 11%, compared to the same period in 2025. The decrease was primarily attributable to (i) a $5.4 million decrease in stock-based compensation expense primarily driven by a lower number of stock awards granted at lower average stock price, and (ii) a $1.4 million decrease in other costs, including costs associated with intellectual property legal costs, and software license costs related to our information technology infrastructure. This decrease was partially offset by (i) a $1.2 million increase in costs incurred in support of the marketing, advertising, and market research in rest of world of Amtagvi^®, and (ii) a $0.7 million increase in payroll and related expenses driven by an increase in the number of employees to support growth in the overall business.

Depreciation and amortization
​

Depreciation and amortization expense for the three months ended March 31, 2026 increased by $0.5 million, or 6% compared to the same period in 2025. The increase was primarily driven by the expansion of our iCTC manufacturing facility.

Interest and other income, net

​

Interest and other income, net for the three months ended March 31, 2026 decreased by $1.9 million, or 59%, compared to the same period in 2025. The decrease was primarily driven by a decrease in average investment balances and slightly lower rate of return on our investments.

Income tax (expense) benefit

​

Income tax benefit for the three months ended March 31, 2026 decreased by $1.2 million or 64%, compared to the same period in 2025. The decrease was mainly driven by the mix of income across jurisdictions that have varying effective tax rates.

Net loss

​

​

Net loss for the three months ended March 31, 2026 decreased by $37.1 million, or 32%, compared to the same period in 2025. The decrease in our net loss is primarily due to the increase in sales of Amtagvi^® and Proleukin^® products. We anticipate that we will continue to incur net losses in the future as we further invest in our clinical and internal research and development programs, as well as ongoing execution of the launch of Amtagvi^®.

Liquidity and Capital Resources

As of March 31, 2026, we had $319.4 million in cash, cash equivalents, short-term investments, and restricted cash ($196.5 million of cash and cash equivalents, $116.9 million in short-term investments, and $6.0 million in restricted cash). We have incurred losses and generated negative cash flows from operations since inception. Historically, we have funded our operations from various public and private offerings of our equity securities, both common stock and preferred stock, from option and warrant exercises, and from interest income. Since 2017, our primary source of funds has been from the public sale of our common stock. With the recent approval of our BLA, we expect to continue to generate revenue from the sale of our first internally developed product, Amtagvi^®. Furthermore, as Proleukin^® inventory that was previously with distributors in the U.S. market at the time of the acquisition of the worldwide rights to Proleukin^® in May 2023 has been substantially depleted, we also began to sell Proleukin^® into the U.S. market, where product margins are substantially higher than in other markets, to support ongoing and anticipated infusions related to the continued strong commercial launch of Amtagvi^®. However, such revenues for Amtagvi^® and Proleukin^® may not be material enough to generate positive operational cash flows during the 12 months from the date the condensed consolidated financial statements are issued and this Quarterly Report on Form 10-Q is filed.

We expect to continue to incur significant expenses to support our ongoing execution of the commercial launch of Amtagvi^®, fund ongoing clinical programs, including our NSCLC registrational study, IOV-LUN-202, and our frontline advanced melanoma Phase 3 confirmatory trial, TILVANCE-301, continue the development of our pipeline candidates, and for other general corporate purposes. Based on the funds we have available as of the date our condensed consolidated financial statements for the three months ended March 31, 2026 are issued, we believe that we have sufficient capital to fund our anticipated operating expenses and capital expenditures as planned for at least the twelve months following the issuance of our condensed consolidated financial statements included in this Quarterly Report on Form 10-Q.

In August 2025, we approved a strategic restructuring plan with an associated reduction in workforce as a result of a review of current strategic priorities, resource allocation, and cost reduction intended to reduce operating costs, streamline operations and extend our cash runway. The restructuring plan is expected to optimize business performance, prioritize key manufacturing and research and development efforts, as well as reduce headcount by approximately 19 percent.

Corporate Capitalization

As of March 31, 2026, we had outstanding 438,106,537 shares of our $0.000041666 par value common stock, 194 shares of our $0.001 par value Series A Convertible Preferred Stock, and 1,932,667 shares of our $0.001 par value Series B Convertible Preferred Stock. The outstanding shares of Series A Convertible Preferred Stock are currently convertible into 97,000 shares of our common stock, and the outstanding shares of Series B Convertible Preferred Stock are currently convertible into 1,932,667 shares of our

common stock. The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock do not have voting rights or accrue dividends.

On August 22, 2025, we entered into an Amended and Restated Open Market Sale Agreement, or the 2025 Sale Agreement, with Jefferies with respect to an "at the market" offering program. Under the terms of the 2025 Sale Agreement, we may, from time to time, in our sole discretion, issue and sell up to $350.0 million of shares of our common stock pursuant to the "at the market" offering program. The 2025 Sale Agreement superseded and replaced in its entirety the 2023 Sale Agreement. The issuance and sale, if any, of shares of our common stock under the Sale Agreement was or will be made pursuant to a prospectus supplement dated August 22, 2025 to our Registration Statement on Form S-3ASR, which became effective immediately upon filing with the U.S. Securities and Exchange Commission on June 16, 2023, or the Registration Statement.

Through the three months ended March 31, 2026, we received $98.5 million in proceeds, net of offering costs, through the sale of 24,918,834 shares of our common stock under the 2025 Sale Agreement.

In the future, we may periodically offer one or more of these securities in amounts, prices and terms to be announced when and if the securities are offered. If any of the securities covered by the Registration Statement are offered for sale, a prospectus supplement will be prepared and filed with the SEC containing specific information about the terms of such offering at that time.

Cash Flows

​

The following table summarizes our cash flows from operating, investing and financing activities for the periods indicated (in thousands):

​

​
Operating Activities

Net cash used in operating activities for the periods presented represents cash disbursements related to all activities other than investing and financing activities. Operating cash flow is derived by adjusting our net loss for non-cash items and changes in operating assets and liabilities. Net cash used in operating activities for the three months ended March 31, 2026 was $72.1 million as compared to $103.7 million for the same period in 2025. The $31.6 million decrease in cash used in operating activities was driven by a $37.1 million decrease in net loss resulting from an increase in revenues generated by sales of Amtagvi^® and Proleukin^®. The overall decrease in cash used in operating activities also includes a net decrease in non-cash charges of $10.1 million. The net decrease in non-cash charges was primarily driven by lower stock-based compensation expenses, and lower amortization of right-of-use assets related to operating leases, partially offset by a decrease in deferred tax benefits related to the operations in the UK, amortization of intangible assets and accretion of discounts and amortization of premiums on investments, net. In addition, net cash used in operating activities decreased by $4.6 million, primarily related to changes in operating assets and liabilities.

The $4.6 million decrease in net cash used in operating activities related to changes in operating assets and liabilities was driven by a $2.3 million decrease in trade accounts receivable, resulting from the collection of cash from the sale of our products, a net $9.5 million decrease in accounts payable and accrued expenses, resulting from timing of vendor invoicing and related payments, and a $11.8 million decrease in net cash used driven primarily by purchases of inventory and an increase in prepaid expenses and other assets that resulted from the timing of related payments.

Investing Activities

Net cash provided by investing activities for the periods presented primarily relates to the cash utilized to fund the purchase and maturity of investments, capital expenditures as well as the Acquisition. Net cash provided by investing activities for the three months ended March 31, 2026 was $11.4 million, compared to net cash provided by investing activities of $15.9 million for the same period in

2025. The decrease in cash provided of $4.5 million was primarily driven by a $4.1 million decrease associated with changes in the timing of maturities and purchases of investments.

Financing Activities

Net cash provided by financing activities for the three months ended March 31, 2026, was $94.3 million compared to net cash provided of $143.3 million for the same period in 2025. The decrease in net cash provided by financing activities of $49.0 million was primarily driven by a decrease in net proceeds of $50.5 million received through the sales of common stock through our "at the market" offering program during the three months ended March 31, 2026, as compared to the net proceeds received from our "at the market" offering program for the same period in 2025. In addition, a $1.5 million increase from tax payments related to shares withheld for vested restricted stock units contributed to the overall decrease in cash provided by financing activities.

Contractual Obligations

The following table summarizes our non-cancellable contractual obligations as of March 31, 2026, and the effects that such obligations are expected to have on our liquidity and cash flows in future periods (in thousands):

​

​

​

Off-Balance Sheet Arrangements

As of March 31, 2026, we had no obligations that would require disclosure as off-balance sheet arrangements.

Critical Accounting Policies and Significant Judgments and Estimates

Our accounting policies are more fully described in Note 2 of the condensed consolidated financial statements included in this Quarterly Report on Form 10-Q. As described in Note 2, the preparation of our condensed consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of our financial statements, as well as the reported revenues and expenses during the reported periods. We base our estimates on historical experience and on various market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Estimates are assessed each period and updated to reflect current information. Actual results may differ from these estimates under different assumptions or conditions.

We believe the following critical accounting policies reflect the more significant judgments and estimates used in the preparation of our condensed consolidated financial statements:

Asset Acquisitions

​

We make certain judgments to determine whether transactions should be accounted for acquisitions of assets or business combinations using the guidance in Accounting Standard Codification, or ASC, Topic 805, Business Combinations, by first applying a screen test to assess if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of assets. If the screen test is met, the transaction is accounted for as an asset acquisition. If the screen test is not met, further assessment is required to determine whether we have acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business.

If the assets acquired do not constitute a business, we account for asset acquisitions using the cost accumulation and allocation method. Under this method, the cost of the acquisition, including direct acquisition-related costs, is allocated to the assets acquired on a relative fair value basis. Goodwill is not recognized in an asset acquisition and any difference between consideration transferred and the fair value of the net assets acquired is allocated to the identifiable assets acquired based on their relative fair values.

Deferred tax liabilities arising from basis differences in assets acquired are calculated using the simultaneous equations method under ASC 740, Income Taxes and based on the effective tax rate. The resulting deferred tax liability is recorded against the carrying amount of the acquired intangible assets on a relative fair value basis.

Contingent consideration in the scope of ASC Topic 815, Derivatives and Hedging, is included in the cost of the asset acquisition at its acquisition date fair value. Contingent consideration in the scope of ASC Topic 450, Contingencies, is recognized when it is both probable and reasonably estimable.

Intangible Assets

​

Our acquired intangible assets are initially measured based on an allocation of the cost of the acquisition to the assets acquired on a relative fair value basis and are recorded net of accumulated amortization, while intangible assets recorded as the result of milestone or license payments are recorded at the amount paid. We amortize our intangible assets on a straight-line basis over their estimated useful lives.

When contingent consideration is a component of the cost of an asset acquisition, we capitalize the amount of incremental cost from the contingent consideration related to the intangible asset acquired in the period the underlying contingency is resolved. When this occurs, we will recognize a cumulative catch-up to reflect amortization on the intangible assets that would have been recognized had the incremental cost from the contingent consideration been recorded as of the acquisition date.

We review intangible assets for impairment at least annually and whenever events or changes in circumstances have occurred which could indicate that the carrying value of the assets are not recoverable. If such indicators are present, we assess the recoverability of affected assets by determining if the carrying value of the assets is less than the sum of the undiscounted future cash flows of the assets. If the assets are found to not be recoverable, we measure the amount of impairment by comparing the carrying value of the assets to their fair values. We determined that no indicators of impairment or impaired intangible assets existed as of March 31, 2026.

Inventory and Cost of Sales

​

Inventory is stated at the lower of cost or net realizable value on a first-in, first-out basis. Our assessment of net realizable value requires the use of estimates regarding the net realizable value of our inventory balances, including an assessment of excess or obsolete inventory. We determine excess or obsolete inventory based on multiple factors, including our most recent sales and manufacturing forecast compared to quantities on hand and the expiration date of the product and materials.

Revenue Recognition

We recognize revenue from product sales in accordance with ASC 606, Revenue from Contracts with Customers. Under ASC 606, revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To the extent the transaction price includes variable

consideration, we estimate the amount of variable consideration that should be included in the transaction price using the most likely method based on historical experience, as well as applicable information currently available.

In the U.S., products are sold principally to hospitals and clinics, as well as distributors and wholesalers, and outside of the U.S. to hospitals and clinics. Contractual performance obligations are usually limited to transfer of control of the product to the customer. In the case of Amtagvi^®, revenue is recognized upon infusion while for Proleukin^®, transfer of control occurs either upon shipment or upon receipt of product after considering when the customer obtains legal title to the product. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring our products and is generally based on a list of fixed prices less allowances for chargebacks, product returns, rebates and discounts. Our payment terms to customers range from 45 to 105 days; payment terms differ by customer and by product.

Revenue is reduced at the time of recognition for expected chargebacks, discounts, rebates, and sales allowances, collectively referred to as gross to net adjustments, or GTN adjustments. In the U.S., these GTN adjustments are attributable to various commercial arrangements and government programs. In addition, non-U.S. government programs may include different pricing schemes such as cost caps and volume discounts. Cash discounts are recorded as a reduction to receivables and settled through the issuance of credits, typically within one month. All other GTN adjustments are recorded as a liability and settled through cash payments to the customer.

Significant judgment is required in estimating GTN adjustments considering legal interpretations of applicable laws and regulations, historical experience, payer channel mix, current contract prices under applicable programs, processing time lags and inventory levels in the distribution channel.

Indirect taxes collected from customers and remitted to government authorities that are related to sales of our products, primarily in Europe, are excluded from revenues.

Accrued Research and Development Costs

​

Research and development costs are expensed as incurred. Clinical development costs compose a significant component of research and development costs. We have a history of contracting with third parties, including CROs, independent clinical investigators, and CMOs, that perform various clinical trial activities on our behalf in connection with the ongoing development of our product candidates. The financial terms of these contracts are subject to negotiations and may vary from contract to contract and may result in uneven payment flow. We accrue and expense costs for clinical trial activities performed by third parties based upon the work completed to date for each clinical trial in accordance with agreements established with CROs, hospitals, and clinical investigators. Accruals for CROs and CMOs are recorded based on services received and efforts expended pursuant to agreements established with CROs, CMOs, and other outside service providers. We determine our costs through discussions with internal clinical stakeholders and outside service providers as to the progress or stage of completion of clinical trials or services and the contracted fee to be paid for such services.

​

Included in our clinical development costs are investigator costs, which are costs associated with treatments administered at clinical sites as required under each clinical trial protocol. Our estimates for clinical investigator costs and timing of expense recognition will depend on a number of factors that include, but are not limited to, (i) the overall number of patients that enroll in the trial at each individual site, (ii) the length of clinical trial enrollment period, (iii) discontinuation and completion rates of patients, (iv) duration of patient safety follow-ups, (v) the number of sites included in the clinical trial, and (vi) the contracted fee of each participating site for patient treatment while on clinical trial, which can vary greatly for several reasons including, but not limited to, geographic region, medical center or physician costs, and overhead costs. In addition, our estimates for per patient trial costs will vary based on a number of factors that include, but are not limited to, the extent of additional treatments that may be administered by investigators as a result of patient health status, recoverability of patient costs through insurance carriers of patients, and unanticipated cost of injuries incurred as a result of the clinical trial treatment. We accrue estimated expenses resulting from obligations under investigator site agreements as the timing of payments does not always timely align with the periods over which the treatments are administered by the clinical investigators. These estimates are typically based on contracted amounts, patient visit data, discussions with internal clinical stakeholders and outside service providers, and historical look-back analysis of actual payments made to date.

​

We make judgments and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO, or other outside service provider, the payments are recorded within prepaid expenses and other current assets and subsequently recognized as research and development expense when the associated services have been performed. As

actual costs become known, we adjust our estimates, liabilities and assets. Inputs used in our determination of estimates discussed above may vary from actual, which will result in adjustments to research and development expense in future periods.

​