The following discussion and analysis of our financial condition and results of operations should be read together with our consolidated financial statements and related notes appearing elsewhere in this Quarterly Report on Form 10-Q and our consolidated financial statements and related notes for the year ended December 31, 2025 included in our Annual Report on Form 10-K, which was filed with the SEC on March 6, 2026. This Quarterly Report on Form 10-Q contains forward-looking statements that involve substantial risks and uncertainties. The words “expect,” “anticipate,” “intend,” “plan,” “believe,” “estimate,” “may,” “will,” “should,” “could,” “target,” “strategy,” “project,” “guidance,” “likely,” “usually,” “potential,” or the negative of these words or variations of such words, similar expressions, or comparable terminology are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. There are a number of important risks and uncertainties that could cause our actual results to differ materially from those indicated by forward-looking statements. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. These forward-looking statements are based on current expectations, estimates, forecasts and projections about the industry and markets in which we operate, and management’s beliefs and assumptions. These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict and may cause our actual results, performance or achievements to be materially different from future results, performance or achievements expressed or implied by any forward-looking statements. A further list and description of risks, uncertainties and other factors that could cause actual results or events to differ materially from the forward-looking statements that we make is included in the cautionary statements herein and in our other filings with the SEC, including those set forth under Part I, Item 1A, Risk Factors in our Annual Report on Form 10-K for the year ended December 31, 2025. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments that we may make. We have based the forward-looking statements included in this Quarterly Report on Form 10-Q on information available to us on the date of this quarterly report, and we assume no obligation to update any such forward-looking statements, other than as required by law. Although we undertake no obligation to revise or update any forward-looking statements, whether as a result of new information, future events or otherwise, you are advised to consult any additional disclosures that we may make directly to you or through reports that we, in the future, may file with the SEC, including Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. Overview Altimmune, Inc. is a late clinical-stage biopharmaceutical company developing novel therapies for serious liver diseases. Our lead product candidate, pemvidutide (formerly known as ALT-801), is a balanced 1:1 glucagon/GLP-1 dual receptor agonist in development for the treatment of MASH, AUD and ALD. We may also pursue additional indications for pemvidutide that leverage its differentiated clinical profile. Except where the context indicates otherwise, references to “we,” “us,” “our,” “Altimmune”, or the “Company” refer to the company and its subsidiaries. Recent Business Update Underwritten Public Offering On April 24, 2026, we completed an underwritten public offering pursuant to which we raised approximately $211.1 million in net proceeds from the issuance of a combination of common stock, common stock warrants and pre-funded warrants. The common stock and pre-funded warrants were sold in combination with an accompanying common stock warrant to purchase one share of common stock (or pre-funded warrant in lieu thereof) issued for each share of common stock or pre-funded warrant sold. The gross proceeds could increase by another $225 million if all the warrant holders exercise their common stock warrants. See Note 7. Stockholders’ Equity for additional information. 17 Table of Contents Headquarters Relocation On June 16, 2026, we announced plans to relocate our corporate headquarters from Gaithersburg, Maryland to Morristown, New Jersey later this year. The new headquarters is in a region with a strong presence of biopharmaceutical companies, which is expected to support our ability to attract top-tier talent in our hybrid business model, as we continue our growth as a late-stage development company. Accordingly, we have entered into a lease agreement for office space in Morristown, New Jersey, which will serve as our new headquarters upon facility occupancy and lease commencement. We will make monthly rental payments aggregating approximately $0.3 million annually for the 5-year lease term. The relocation of our headquarters is expected to help us achieve cost efficiencies over the long term. Ongoing Clinical Trials MASH In January 2026, we announced that the U.S. Food and Drug Administration (“FDA”) granted Breakthrough Therapy Designation to pemvidutide for the treatment of MASH based on the data from the IMPACT Phase 2b trial at 24 weeks in which we observed statistically significant MASH resolution and positive trends in fibrosis improvement. In December 2025, the Company announced positive 48-week data from the IMPACT trial, including statistically significant improvements observed in key non-invasive markers of fibrosis and inflammation, such as Enhanced Liver Fibrosis (“ELF”) and Liver Stiffness Measurement (“LSM”), which are strongly associated with MASH histologic changes, and noted continued reductions from 24-week timepoint. Additional weight loss was observed from 24 weeks to 48 weeks at the 1.8 mg dose with no evidence of plateauing. We also observed greater adherence to treatment in the pemvidutide arms, as shown by lower discontinuation rates than the placebo group which may be attributable to the favorable safety and tolerability profile of pemvidutide. With the positive 48-week data from the IMPACT trial, FDA designation and having secured the necessary financing, we began preparing for our PERFORMA Phase 3 trial in MASH. We have aligned with the FDA following an End of Phase 2 Meeting, and submitted the final study protocol to the FDA. Further, we received scientific advice from the European Medicines Agency and Medicines and Healthcare products Regulatory Agency (UK) and selected a global Contract Research Organization with deep experience running global MASH pivotal trials. The global pivotal PERFORMA Phase 3 trial will test two doses of pemvidutide over an estimated duration of approximately 60 months for liver-related events supporting final approval, including an interim analysis after 52 weeks with biopsy-based endpoints to support an accelerated approval. On August 3, 2026, we announced that we have begun enrolling patients in the PERFORMA Phase 3 trial, evaluating the efficacy and safety of pemvidutide in patients with MASH. The PERFORMA trial is a global, Phase 3, randomized, double-blind, placebo-controlled study evaluating the efficacy, safety and clinical outcomes of pemvidutide in MASH patients with moderate to advanced fibrosis. PERFORMA is our registrational study for pemvidutide in MASH and will assess the effects of treatment on fibrosis improvement and MASH resolution as well as clinical outcomes. The 52-week data readout from the PERFORMA trial to support the accelerated approval of pemvidutide is anticipated in 2029. AUD RECLAIM, a Phase 2 trial evaluating the efficacy and safety of pemvidutide in subjects with AUD, is a randomized, placebo-controlled trial conducted across approximately 15 sites in the United States, targeting enrollment of approximately 100 subjects. Subjects will be randomized 1:1 to receive either 2.4 mg pemvidutide or placebo weekly for 24 weeks. The trial’s primary endpoint is a change in alcohol consumption, measured by the change from baseline in the average number of heavy drinking days (“HDD”) per week measured at Week 24, with the key secondary endpoints including the proportion of subjects achieving a 2-level reduction in World Health Organization (“WHO”) risk drinking level and the absolute change from baseline in average levels of phosphatidylethanol (“PEth”), a serum biomarker of alcohol intake. In August 2025, the FDA granted Fast Track designation to pemvidutide for the treatment of AUD. Enrollment in the RECLAIM Phase 2 trial in AUD was completed in November 2025, several months ahead of schedule. 18 Table of Contents On July 28, 2026, we announced the positive topline results from the RECLAIM Phase 2 trial evaluating the 2.4 mg dose of pemvidutide, in patients with moderate to severe AUD. The trial met its primary endpoint with a highly statistically significant reduction in HDD per week versus placebo, with positive results across important secondary endpoints, including a two-level reduction in the WHO risk drinking level and zero HDDs, both of which are FDA registrational endpoints, as well as a reduction in PEth levels. A generally favorable safety and tolerability profile was observed in the trial. We plan to request an End-of-Phase 2 meeting with the FDA based on the results of the trial. ALD RESTORE, a Phase 2 trial evaluating the efficacy and safety of pemvidutide in subjects with ALD, is a randomized, placebo-controlled trial enrolling approximately 100 patients across 34 sites in the United States. Subjects will be randomized 1:1 to receive either 2.4 mg pemvidutide or placebo weekly for 48 weeks. The trial’s primary endpoint is the change from baseline in LSM by vibration-controlled transient elastography and will be assessed in a hierarchical manner at Week 48 and then at Week 24. Main secondary endpoints include changes in ELF score at Weeks 24 and 48, and changes in alcohol consumption and body weight at the same time points. In July 2026, we completed enrollment in the RESTORE Phase 2 trial in ALD. Recent Global Events Tariffs and Inflation The United States recently imposed reciprocal and additional tariffs on many countries around the world. Such tariffs and counter-tariffs by other countries against the U.S. have been causing uncertainties in the global markets. If the tariffs and counter-tariffs continue or escalate, they could have a significant negative effect on the global economy or on our operations, including continued inflationary pressures on raw materials, supply chain and logistics disruptions, and volatility in the capital markets, foreign exchange rates and interest rates. Inflation generally affects us by increasing our employee-related costs and clinical trial expenses, as well as other operating expenses. Our financial condition and results of operations may also be impacted by other factors we may not be able to control, such as public health crises, global supply chain disruptions, uncertain global economic conditions, global trade disputes or political instability as further discussed in the section “Risk Factors” in our 2025 Annual Report on Form 10-K. Conflict in Middle East We are closely monitoring the impact of the ongoing military conflict in the Middle East, including the recent conflict involving the U.S., Israel and Iran, on our business as the conflict has caused increased economic uncertainty and operational complexity globally. While we have no direct exposure to the Middle East, and do not currently believe the situation will have a material impact on our operating results, we are monitoring any broader economic impact from the situation. Should the conflict continue or escalate, it could have a significant negative effect on the global economy or on our operations, including continued inflationary pressures on raw materials, oil and energy prices and clinical trial costs, supply chain and logistics disruptions, volatility in foreign exchange rates and interest rates and heightened cybersecurity threats. 19 Table of Contents Results of Operations Comparison of the three months ended June 30, 2026 and 2025 The following table summarizes our results of operations for the three months ended June 30, 2026 and 2025 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ $ Change ​ % Change Revenues ​ $ — ​ $ 5 ​ $ (5) (100) % Operating expenses: ​ ​ ​ ​ ​ ​ ​ ​ Research and development ​ 18,655 ​ 17,236 ​ 1,419 8 % General and administrative ​ 7,574 ​ 5,691 ​ 1,883 33 % Total operating expenses ​ 26,229 ​ 22,927 ​ 3,302 14 % Loss from operations ​ (26,229) ​ (22,922) ​ (3,307) 14 % Other income (expense): ​ ​ ​ ​ ​ ​ ​ ​ Interest expense ​ (1,097) ​ (264) ​ (833) 316 % Interest income ​ 4,526 ​ 1,132 ​ 3,394 300 % Other income (expense), net ​ (25) ​ (92) ​ 67 (73) % Total other income (expense), net ​ 3,404 ​ 776 ​ 2,628 339 % Net loss ​ $ (22,825) ​ $ (22,146) ​ $ (679) 3 % ​ Research and development expenses Research and development expenses for the three months ended June 30, 2026 and 2025 consisted primarily of expenses related to product candidate development, summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ (in thousands) ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ $ Change ​ % Change Pemvidutide ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MASH ​ $ 3,795 ​ $ 5,446 ​ $ (1,651) (30) % ALD ​ ​ 4,604 ​ ​ 1,538 ​ ​ 3,066 199 % AUD ​ ​ 723 ​ ​ 1,097 ​ ​ (374) (34) % Other pemvidutide expenses ​ ​ 2,454 ​ ​ 3,032 ​ ​ (578) (19) % Total pemvidutide expenses ​ ​ 11,576 ​ ​ 11,113 ​ ​ 463 ​ 4 % Non-project costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Labor ​ ​ 3,067 ​ ​ 3,206 ​ ​ (139) (4) % Stock compensation ​ ​ 1,091 ​ ​ 1,553 ​ ​ (462) (30) % Shared service and infrastructure ​ 2,921 ​ ​ 1,364 ​ ​ 1,557 114 % Total research and development expenses ​ $ 18,655 ​ $ 17,236 ​ $ 1,419 8 % ​ The increase in research and development expenses was due primarily to the ongoing ALD trial as well as the startup costs for PERFORMA Phase 3 trial in MASH and the non-project costs to support these activities, partially offset by the decrease in expenses related to completion of the RECLAIM Phase 2 trial in AUD and IMPACT Phase 2b trial in MASH, which were ongoing in the second quarter of 2025. General and administrative expenses General and administrative expenses increased by $1.9 million, or 33%, for the three months ended June 30, 2026, as compared to the three months ended June 30, 2025, primarily due to a $0.6 million increase in compensation expenses and a $1.1 million increase in expenses for professional services. 20 Table of Contents Total other income (expense), net Total other income (expense), net increased by $2.6 million, or 339%, for the three months ended June 30, 2026, as compared to the three months ended June 30, 2025. The net increase was primarily due to a $3.4 million increase in interest income earned on our cash equivalents and investments in marketable securities, partially offset by a $0.8 million increase in interest expense related to our Term Loan. Comparison of the six months ended June 30, 2026 and 2025 The following table summarizes our results of operations for the six months ended June 30, 2026 and 2025 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ $ Change ​ % Change Revenues ​ $ — ​ $ 10 ​ $ (10) (100) % Operating expenses: ​ ​ ​ ​ ​ ​ ​ ​ Research and development ​ 34,847 ​ 33,063 ​ 1,784 5 % General and administrative ​ 15,626 ​ 11,684 ​ 3,942 34 % Total operating expenses ​ 50,473 ​ 44,747 ​ 5,726 13 % Loss from operations ​ (50,473) ​ (44,737) ​ (5,736) 13 % Other income (expense): ​ ​ ​ ​ ​ ​ ​ ​ Interest expense ​ (2,165) ​ (265) ​ (1,900) 717 % Interest income ​ 7,427 ​ 2,677 ​ 4,750 177 % Other income (expense), net ​ (177) ​ (77) ​ (100) 130 % Total other income (expense), net ​ 5,085 ​ 2,335 ​ 2,750 118 % Net loss before income taxes ​ ​ (45,388) ​ ​ (42,402) ​ ​ (2,986) 7 % Income tax expense (benefit) ​ — ​ (681) ​ 681 (100) % Net loss ​ $ (45,388) ​ $ (41,721) ​ $ (3,667) 9 % ​ Research and development expenses Research and development expenses for the six months ended June 30, 2026 and 2025 consisted primarily of expenses related to product candidate development, summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ (in thousands) ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ $ Change ​ % Change Pemvidutide ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MASH ​ $ 7,492 ​ $ 11,763 ​ $ (4,271) ​ (36) % ALD ​ ​ 7,239 ​ ​ 1,596 ​ ​ 5,643 354 % AUD ​ ​ 2,280 ​ ​ 1,413 ​ ​ 867 ​ 61 % Other pemvidutide expenses ​ ​ 4,096 ​ ​ 5,572 ​ ​ (1,476) ​ (26) % Total pemvidutide expenses ​ ​ 21,107 ​ ​ 20,344 ​ ​ 763 ​ 4 % Non-project costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Labor ​ ​ 6,555 ​ 6,551 ​ 4 0 % Stock compensation ​ ​ 2,323 ​ 3,329 ​ (1,006) (30) % Shared service and infrastructure ​ 4,862 ​ 2,839 ​ 2,023 71 % Total research and development expenses ​ $ 34,847 ​ $ 33,063 ​ $ 1,784 5 % ​ The increase in research and development expenses was due primarily to the ongoing ALD and AUD trials as well as the startup costs for PERFORMA Phase 3 trial in MASH and the non-project costs to support these activities, partially offset by the decrease in expenses related to completion of the IMPACT Phase 2b trial in MASH, which was ongoing in the first six months of 2025. 21 Table of Contents General and administrative expenses General and administrative expenses increased by $3.9 million, or 34%, for the six months ended June 30, 2026, as compared to the six months ended June 30, 2025, primarily due to a $1.4 million increase in compensation expenses and $1.6 million increase in professional services. Total other income (expense), net Total other income (expense), net increased by $2.8 million, or 118%, for the six months ended June 30, 2026, as compared to the six months ended June 30, 2025. The net increase was primarily due to a $4.8 million increase in interest income earned on our cash equivalents and investments in marketable securities, partially offset by a $1.9 million increase in interest expense related to our Term Loan. Liquidity and Capital Resources Overview Our primary sources of cash during the six months ended June 30, 2026 were from equity transactions, interest from our money market funds and investments in marketable securities, and proceeds from maturity of our investments. Our cash, cash equivalents, restricted cash and short-term investments were $326.3 million as of June 30, 2026. In addition, we had $192.3 million in long-term investments. We believe, based on the operating cash requirements and capital expenditures expected for 2026 and 2027, our cash on hand as of June 30, 2026 is sufficient to fund operations for at least a twelve-month period from the issuance date of our June 30, 2026 consolidated financial statements. ​ We have not generated any revenues from the sale of any products to date and there is no assurance of any future revenues from product sales. We have incurred significant losses since we commenced operations. As of June 30, 2026, we had an accumulated deficit of $694.9 million. In addition, we have not generated positive cash flows from operations. We have relied on a variety of financing sources, including the issuance of debt and equity securities. As capital resources are consumed to fund our research and development activities, we may require additional capital beyond our currently anticipated amounts. In order to address our capital needs, including our planned clinical trials, we must continue to actively pursue additional equity or debt financing, and monetization of our existing programs through partnership arrangements or sales to third parties. Sources of Liquidity Loan Financing On May 13, 2025 (“Closing Date”), we entered into a Loan and Security Agreement (“Loan Agreement”) with Hercules Capital, Inc. (“Hercules”) and the lenders party thereto, pursuant to which the lenders will make available up to four tranches of term loans in an aggregate principal amount of $100.0 million (the “Term Loan”), subject to certain terms and conditions. The first Term Loan tranche was drawn down on the Closing Date in an aggregate principal amount of $15.0 million. On November 5, 2025, (the “Amendment Closing”), we entered into an amendment to the Loan Agreement with Hercules and the lenders party thereto, pursuant to which the lenders will, subject to certain terms and conditions, increase the availability under the Term Loan from an aggregate principal amount of $100.0 million to $125.0 million. The Term Loan, as amended, is structured in four tranches. As disclosed above, the first Term Loan tranche was drawn down on the Closing Date in an aggregate principal amount of $15.0 million. The second Term Loan tranche was drawn down on the Amendment Closing in an aggregate principal amount of $20.0 million. Upon the achievement of certain milestones and subject to other terms and conditions set out in the Loan Agreement, as amended, the third Term Loan tranche will be made available in an aggregate principal amount of up to $10.0 million. The fourth Term Loan tranche will be made available in an aggregate principal amount of up to $80.0 million subject to the approval of the lenders. The Term Loan, as amended, bears interest equal to the greater of (a) 9.70% per annum and (b) the prime rate as reported in The Wall Street Journal plus 2.45% per annum. The interest-only period has been extended to 30 months from May 13, 2025. 22 Table of Contents Shelf Registrations On November 13, 2025, we filed a shelf registration statement on Form S-3, as amended, which was declared effective on December 5, 2025. This shelf registration allows us to offer and sell up to $400.0 million of our common stock, preferred stock, debt securities, warrants, rights and units (the “November 2025 Shelf”) for a period of 3 years from effectiveness. On April 22, 2026, we filed a registration statement on Form S-3MEF which was declared effective immediately. This shelf registration allowed us to increase the aggregate amount under the November 2025 Shelf by an additional $65.0 million. On February 27, 2025, we filed a shelf registration statement on Form S-3, which was declared effective on March 13, 2025. This shelf registration allows us to offer and sell up to $400.0 million of our common stock, preferred stock, debt securities, warrants, rights and units (the “February 2025 Shelf”) for a period of 3 years from effectiveness. On February 28, 2023, we filed a shelf registration statement on Form S-3ASR, which was declared effective immediately. This shelf registration allowed us to offer and sell any amount of our common stock, preferred stock, debt securities, warrants, rights and units (the “2023 Shelf”). The 2023 Shelf expired on February 27, 2025. ATM Offerings On November 6, 2025, we entered into an Equity Distribution Agreement (the “November 2025 Agreement”) with Leerink Partners LLC serving as sales agent, with respect to an ATM offerings program under which we may offer and sell shares of our common stock having an aggregate offering price of up to $200.0 million through the sales agent from the February 2025 Shelf. Since inception through June 30, 2026, we raised approximately $34.2 million in net proceeds, with $165.3 million remaining available to be sold under the November 2025 Agreement. On February 27, 2025, we entered into an Equity Distribution Agreement (the “February 2025 Agreement”) with Leerink Partners LLC, Piper Sandler & Co. and Stifel, Nicolaus & Company, Incorporated, serving as sales agents, with respect to an ATM offerings program under which we offered and sold shares of our common stock having an aggregate offering price of up to $150.0 million through the sales agents from the February 2025 Shelf. Since inception, through the termination of the February 2025 Agreement in November 2025, we raised approximately $118.3 million in net proceeds. On February 28, 2023, we entered into an Equity Distribution Agreement (the “2023 Agreement”) with Evercore Group L.L.C., JMP Securities LLC and B. Riley Securities, Inc., serving as sales agents, with respect to an ATM offerings program under which we offered and sold shares of our common stock having an aggregate offering price of up to $150.0 million through the sales agents from the 2023 Shelf. Since inception through the termination of the 2023 Agreement in February 2025, we raised approximately $126.8 million in net proceeds. January 2026 RDO On January 27, 2026, we entered into a securities purchase agreement with a new fundamental institutional investor pursuant to a registered direct offering under the November 2025 Shelf for the purchase and sale of 12,397,920 shares of our common stock and 4,647,534 pre-funded warrants for net proceeds of approximately $70.3 million. The pre-funded warrants were fully exercised on February 13, 2026, resulting in the issuance of 4,647,534 shares of our common stock. April 2026 Offering On April 22, 2026, we entered into an underwriting agreement with certain underwriters pursuant to which we offered and sold securities consisting of (i) 64,250,000 shares of our common stock and accompanying common stock warrants to purchase an aggregate of 64,250,000 shares of common stock (or pre-funded warrants in lieu thereof) and (ii) in lieu of common stock, to certain investors that so choose, pre-funded warrants to purchase an aggregate of up to 10,750,000 shares of its common stock and accompanying common stock warrants to purchase an aggregate of 10,750,000 shares of common stock (or pre-funded warrants in lieu thereof), at an exercise price of $0.001 per pre-funded warrant. The common stock and pre-funded warrants were sold in combination with an accompanying common stock warrant to 23 Table of Contents purchase one share of common stock (or pre-funded warrant in lieu thereof) issued for each share of common stock or pre-funded warrant sold. The accompanying common stock warrant has an exercise price of $3.00 per share and is immediately exercisable from the date of issuance. The combined offering price of each share of common stock and accompanying common stock warrant is $3.00. The combined offering price of each pre-funded warrant and accompanying common stock warrant is $2.999. The net proceeds of the April 2026 Offering were approximately $211.1 million, after deducting the underwriting discount and estimated offering expenses. If all of the common stock warrants sold in the April 2026 Offering were to be exercised in cash at their exercise price, we would receive additional gross proceeds of $225 million. All shares of common stock, pre-funded warrants and common stock warrants offered and sold in the April 2026 Offering were issued pursuant to the February 2025 Shelf, the November 2025 Shelf and a related registration statement that was filed with the SEC on April 22, 2026 pursuant to Rule 462(b) under the Securities Act of 1933, as amended, and became automatically effective upon filing as permitted under Rule 429. Cash Flows The following table provides information regarding our cash flows for the six months ended June 30, 2026 and 2025: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, (in thousands) ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ Increase (Decrease) Net cash (used in) provided by: ​ ​ ​ ​ ​ ​ Operating activities ​ $ (45,163) ​ $ (36,190) ​ $ 8,973 Investing activities ​ (225,133) ​ 96,006 ​ (321,139) Financing activities ​ 289,544 ​ 86,363 ​ 203,181 Net increase in cash and cash equivalents and restricted cash ​ $ 19,248 ​ $ 146,179 ​ $ (126,931) ​ Operating Activities Net cash used in operating activities was $45.2 million for the six months ended June 30, 2026 compared to $36.2 million during the six months ended June 30, 2025. The primary uses of cash from our operating activities included payments for labor and labor-related costs, professional fees, research and development costs associated with our clinical trials, and other general corporate expenditures. The increase in cash used in operations of $9.0 million year over year was due to changes in working capital accounts of $5.9 million and an increase in net loss as adjusted for non-cash items of $3.1 million. Investing Activities Net cash used in investing activities was $225.1 million for the six months ended June 30, 2026 compared to $96.0 million net cash provided by investing activities during the six months ended June 30, 2025. The net cash used in investing activities during the six months ended June 30, 2026 was primarily due to a $332.4 million purchase of investments in marketable securities, partially offset by a $107.3 million in proceeds from sales and maturities of these investments. The net cash provided by investing activities during the six months ended June 30, 2025 was primarily due to a $143.6 million in proceeds from sales and maturities of investments in marketable securities, partially offset by a $47.6 million purchase of investments in marketable securities. Financing Activities Net cash provided by financing activities was $289.5 million during the six months ended June 30, 2026 compared to $86.4 million cash provided by financing activities during the six months ended June 30, 2025. The net cash provided by financing activities during the six months ended June 30, 2026 was primarily the result of the receipt of $211.1 million in net proceeds from the April 2026 Offering, $70.3 million in net proceeds from the January 2026 RDO, $8.7 million in net proceeds from the issuance of common stock from our ATM offerings program, net of deferred offering costs, $0.2 million in proceeds from the sale of shares under the ESPP, partially offset by $0.7 million net payments for tax withholding obligations related to share-based compensation. The net cash provided by financing activities during the six months ended June 30, 2025 was primarily the result of the receipt of $72.3 million in net proceeds from the issuance 24 Table of Contents of common stock from our ATM offerings program, $14.6 million in net proceeds from the term loan, and $0.2 million in proceeds from the sale of shares under the ESPP, partially offset by $0.7 million net payments for tax withholding obligations related to share-based compensation. Capital Resources We have financed our operations to date principally through our equity offerings, debt and proceeds from issuances of our preferred stock, common stock and warrants. As of June 30, 2026, we had $63.1 million of cash, cash equivalents and restricted cash and $455.5 million of investments in marketable securities, of which $263.3 million is in short-term investments. Accordingly, management believes that we have sufficient capital to fund our plan of operations for at least a twelve-month period from the issuance date of our June 30, 2026 consolidated financial statements. In order to address our long-term capital needs, including our planned clinical trials, in April 2026, we raised approximately $211.1 million in net proceeds from the April 2026 Offering. If all of the common stock warrants issued in the April 2026 Offering are exercised, we would receive an additional $225 million in gross proceeds. Critical Accounting Estimates Management’s Discussion and Analysis of Financial Condition and Results of Operations is based upon our unaudited consolidated financial statements, which have been prepared in accordance with U.S. GAAP and the rules and regulations of the SEC for interim financial reporting. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues, expenses, and the disclosure of contingent liabilities in our consolidated financial statements. We base our estimates and judgments on historical experience, knowledge of current conditions, and expectations of what could occur in the future given available information. Stock-based Compensation We calculated the fair value of stock option awards using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the input of subjective assumptions, including stock price volatility and the expected life of stock options. The application of this valuation model involves assumptions that are highly subjective, judgmental and sensitive in the determination of compensation cost. Having achieved sufficient historical data on our own stock, effective January 1, 2026, the expected stock price volatility for stock option awards is based on the historical volatility of our stock price volatility. The average expected life of stock options was determined according to the “simplified method” as described in SAB 107, which is the midpoint between the vesting date and the end of the contractual term. The risk-free interest rate was determined by reference to implied yields available from U.S. Treasury securities with a remaining term equal to the expected life assumed at the date of grant. We have not paid and do not anticipate paying cash dividends. Therefore, the expected dividend rate is assumed to be 0%. Except as disclosed above, there have been no changes in our critical accounting policies and significant judgment and estimates as disclosed in our Annual Report on Form 10-K for the year ended December 31, 2025.