Aptevo Therapeutics Inc.

Previous wording

We are a clinical-stage, research and development biotechnology company focused on developing novel immunotherapy candidates for the treatment of different forms of cancer. We have developed two versatile and enabling platform technologies for rational design of precision immune modulatory drugs and have two clinical candidates and six preclinical candidates currently in development. Clinical candidate mipletamig is a CD123xCD3 T cell engager that is currently being evaluated in the RAINIER study, a Phase 1b/2 program evaluating mipletamig in combination with standard of care venetoclax + azacitidine for the treatment of frontline acute myelogenous leukemia (AML) patients who are unfit for intensive chemotherapy. The ongoing Phase 1b trial was initiated in August 2024. Results from cohorts 1, 2 and 3 to date were highly favorable for both safety and efficacy. Clinical candidate ALG.APV-527 targets 4-1BB (co-stimulatory receptor) and 5T4 (tumor antigen). The compound is designed to reactivate antigen-primed T cells to specifically kill tumor cells and is currently being evaluated for the treatment of multiple solid tumor types in a dose escalation trial.

Current wording

We are a clinical-stage, research and development biotechnology company focused on developing novel immunotherapy candidates for the treatment of different forms of cancer. We have developed two versatile and enabling platform technologies for rational design of precision immune modulatory drugs and have two clinical candidates and six preclinical candidates currently in development. Clinical candidate mipletamig is a CD123xCD3 T cell engager currently being clinically evaluated in the RAINIER trial, part one of a Phase 1b/2 program initiated in August 2024 for the treatment of frontline acute myelogenous leukemia (AML) in combination with standard of care venetoclax + azacitidine. Clinical candidate ALG.APV-527 targets 4-1BB (co-stimulatory receptor) and 5T4 (tumor antigen). The compound is designed to reactivate antigen-primed T cells to specifically kill tumor cells and is currently being evaluated for the treatment of multiple solid tumor types.

Previous wording

Our ADAPTIR and ADAPTIR-FLEX platforms are designed to generate monospecific, bispecific, and multi-specific antibody candidates capable of enhancing the human immune system against cancer cells. ADAPTIR and ADAPTIR-FLEX are both heterodimer platforms, which gives us the flexibility to potentially generate immunotherapeutic candidates with a variety of mechanisms of action. This flexibility in design allows us to generate novel therapeutic candidates that may provide effective strategies against difficult to treat, as well as advanced forms of cancer. We have successfully designed and constructed numerous investigational-stage product candidates based on our ADAPTIR platform. The ADAPTIR platform technology is designed to generate monospecific and bispecific immunotherapeutic proteins that specifically bind to one or more targets, for example, bispecific therapeutic molecules, which may have structural and functional advantages over monoclonal antibodies. We have also developed a preclinical candidate based on the ADAPTIR-FLEX platform which is advancing in our pipeline. The structural differences of ADAPTIR and ADAPTIR FLEX molecules over monoclonal antibodies allow for the development of immunotherapies that are designed to engage immune effector cells and disease targets to produce signaling responses that modulate the immune system to kill tumor cells. We believe we are skilled at candidate generation, validation, and subsequent preclinical and clinical development.

Current wording

Our ADAPTIR and ADAPTIR-FLEX platforms are designed to generate monospecific and multi-specific antibody candidates capable of enhancing the human immune system against cancer cells. Both are modular platforms, which give us the flexibility to potentially generate immunotherapeutic candidates with a variety of mechanisms of action. This flexibility in design allows us to generate novel therapeutic candidates that may provide effective strategies against difficult to treat, as well as advanced forms of cancer. We have successfully designed and constructed numerous clinical-stage product candidates based on our ADAPTIR platform, which is designed to generate monospecific and bispecific immunotherapeutic proteins that specifically bind to one or more targets. This allows for the development of therapeutic molecules which may have structural and functional advantages over monoclonal antibodies. We have also developed a preclinical candidate based on the ADAPTIR-FLEX platform which is advancing in our pipeline. The structural differences of ADAPTIR and ADAPTIR FLEX molecules over monoclonal antibodies allow for the development of immunotherapies that are designed to engage immune effector cells and disease targets to produce signaling responses that modulate the immune system to kill tumor cells. We believe we are skilled at candidate generation, validation, and subsequent preclinical and clinical development.

Previous wording

No cytokine release syndrome (CRS) observed among evaluable frontline patients to date — a meaningful distinction in a category where CRS is a common and often dose-limiting toxicity

Current wording

No cytokine release syndrome (CRS), a common and often dose-limiting toxicity associated with similar therapies, has been observed in frontline patients to date

Previous wording

Comparison of the three and nine months ended September 30, 2025 and 2024

Current wording

Comparison of the three months ended March 31, 2026 and 2025

Previous wording

consulting costs related to our clinical and pre-clinical programs;

Current wording

consulting costs related to our clinical and preclinical programs;

Previous wording

Our research and development expenses by program for the three and nine months ended September 30, 2025 and 2024 are shown in the following table:

Current wording

Our research and development expenses by program for the three months ended March 31, 2026 and 2025 are shown in the following table:

Previous wording

Research and development expenses increased by $0.9 million, from $3.1 million for the three months ended September 30, 2024 to $4.0 million for the three months ended September 30, 2025. Research and development expenses increased by $0.5 million, from $10.5 million for the nine months ended September 30, 2024 to $11.0 million for the nine months ended September 30, 2025. The increase was primarily due to increased Mipletamig and employee costs and was offset by lower costs on ALG.APV- 527 as we wrapped up the dose escalation trial. As of September 30, 2025 and December 31, 2024, we had $1.1 million and $1.4 million in accounts payable and other accrued liabilities related to accrued clinical expenses.

Current wording

Research and development expenses increased by $0.3 million, from $3.6 million for the three months ended March 31, 2025 to $3.9 million for the three months ended March 31, 2026. The increase was primarily due to increased mipletamig and employee costs. This was offset by lower expenses for ALG.APV-527 as we concluded the dose escalation trial.

Previous wording

Other income, net consists primarily of interest income from our cash equivalents and short term rental income. Other income, net was $0.06 million and $0.1 million for the three and nine months ended September 30, 2025, respectively. Other income, net was $0.1 million and $0.4 million for the three and nine months ended September 30, 2024, respectively. The change in other income, net is primarily due to lower interest income from our money market accounts.

Current wording

Other income, net consists primarily of interest income from our cash equivalents and short term rental income. Other income, net was $0.1 million for each of the three months ended March 31, 2026 and 2025.

Previous wording

The following table provides information regarding our cash flows for the nine months ended September 30, 2025 and 2024:

Current wording

The following table provides information regarding our cash flows for the three months ended March 31, 2026 and 2025:

Previous wording

Net cash used in operating activities of $20.4 million for the nine months ended September 30, 2025 was primarily due to our net loss of $20.2 million for the period and changes in working capital accounts. Net cash used in operating activities of $18.0 million for the nine months ended September 30, 2024 was primarily due to our net loss of $17.8 million for the period and changes in working capital accounts.

Current wording

Net cash used in operating activities of $8.0 million for the three months ended March 31, 2026 was primarily due to our net loss of $6.7 million for the period and changes in working capital accounts. Net cash used in operating activities of $6.6 million for the three months ended March 31, 2025 was primarily due to our net loss of $6.4 million for the period and changes in working capital accounts.

Previous wording

Net cash provided by financing activities of $32.7 million and $8.9 million for the three and nine months ended September 30, 2025 and 2024, respectively, were primarily due to exercise of warrants and issuance of common stock, including common stock issued pursuant to the SEPA (as defined below) and the ATM Agreement (as defined below).

Current wording

Net cash provided by financing activities of $0.9 million for the three months ended March 31, 2026 was primarily due to the issuance of common stock pursuant to the SEPAs. Net cash provided by financing activities was $0 million for the three months ended March 31, 2025.

Previous wording

On June 16, 2025, we entered into a Standby Equity Purchase Agreement (the “SEPA”) with YA II PN, LTD., a Cayman Islands exempt limited company (“Yorkville”). Pursuant to the SEPA, the Company has the right, but not the obligation, to issue and sell to Yorkville from time to time up to $25.0 million (the “Commitment Amount”) of the Company’s common stock during the 36 months following the execution of the SEPA, subject to the restrictions and satisfaction of the conditions in the SEPA. As consideration for Yorkville’s irrevocable commitment to purchase the shares of common stock up to the Commitment Amount, the Company paid a structuring fee in the amount of $25,000 to Yorkville, and the Company has agreed to pay a commitment fee to Yorkville in an amount equal to 2.00% of the Commitment Amount in five equal installments. Pursuant to the SEPA, we will not sell shares of our common stock to Yorkville that would result in the beneficial ownership of Yorkville and its affiliates (on an aggregated basis) exceeding 9.99% of our then outstanding common stock. For the nine months ended September 30, 2025, the Company issued 8.3 million shares of common stock to Yorkville under the SEPA for aggregate gross proceeds of $15.0 million. As of September 30, 2025, the remaining availability under the SEPA is $10.0 million. We filed Form S-1 for 6.9 million shares under the SEPA on October 1, 2025. The filing is currently pending SEC review and approval, which has been delayed due to the U.S. federal government shutdown. We believe that our existing cash resources will be sufficient to meet our projected operating requirements for at least twelve months from the date of issuance of these financial statements.

Current wording

On June 16, 2025, we entered into the First SEPA with Yorkville. Pursuant to the First SEPA, the Company has the right, but not the obligation, to issue and sell to Yorkville from time to time up to $25.0 million of the Company’s common stock during the 36 months following the execution of the First SEPA, subject to the restrictions and satisfaction of the conditions in the First SEPA. As consideration for Yorkville’s irrevocable commitment to purchase the shares of common stock up to the First Commitment Amount, the Company paid a structuring fee in the amount of $25,000 to Yorkville, and the Company has agreed to pay a commitment fee to Yorkville in an amount equal to 2.00% of the First Commitment Amount in five equal installments. Pursuant to the First SEPA, we will not sell shares of our common stock to Yorkville that would result in the beneficial ownership of Yorkville and its affiliates (on an aggregated basis) exceeding 9.99% of our then outstanding common stock. For the three months ended March 31, 2026, the Company issued 0.1 million shares of common stock to Yorkville under the First SEPA for aggregate gross proceeds of $0.7 million. As March 31, 2026, the remaining availability under the First SEPA was $7.9 million. We filed a Registration Statement on Form S-1 for 6.9 million shares under the First SEPA on October 1, 2025. A subsequent Form S-1 may be needed to access additional shares under First SEPA.

Previous wording

On April 28, 2025, we entered into an At The Market Offering Agreement (the “ATM Agreement”) with Roth Capital Partners, LLC, as sales agent (“Roth”) for an aggregate offering price of $50 million, pursuant to which the Company may offer and sell shares of its common stock from time to time through Roth. The compensation to Roth for the shares sold pursuant to the ATM Agreement will be an amount equal to 3.0% of the gross sales price of the shares sold under the ATM Agreement. The sale of such shares of common stock by Roth will be effected under the Company’s existing shelf Registration Statement on Form S-3, which was declared effective on February 26, 2025 (the “Registration Statement”). For the nine months ended September 30, 2025, we issued 2.8 million shares of our common stock at an average price of $2.74 per share under the ATM Agreement. We received $7.6 million less issuance costs of $0.23 million in proceeds from the issuance of these shares. In addition, $4.1 million in net proceeds was raised during the subsequent events period. There is currently no remaining availability under the ATM Agreement due to the limitations of General Instruction I.B.6.

Current wording

On April 28, 2025, we entered the ATM Agreement with Roth, pursuant to which the Company may offer and sell up to $50 million of its common stock from time to time through Roth. The compensation to Roth for the shares sold pursuant to the ATM Agreement will be an amount equal to 3.0% of the gross sales price of the shares sold under the ATM Agreement. The sale of such shares of common stock by Roth will be effected under the Company’s existing shelf Registration Statement on Form S-3, which was declared effective on February 26, 2025. We did not sell any shares under the ATM Agreement during the three months ended

Previous wording

On February 14, 2025, we filed a Registration Statement on Form S-3 covering the offering, issuance, and sale up to $100 million in common stock, preferred stock, and various series of debt securities and/or warrants to purchase any of such securities, which included the unsold securities from the prior registration statement. On June 20, 2025, we filed the latest amendment to the prospectus supplement to the Registration Statement on Form S-3 filed on February 14, 2025 pursuant to General Instruction I.B.6 of Form S-3 (General Instruction I.B.6), which updates the amount of shares that we are eligible to sell under the ATM Agreement to $8.0 million. So long as the aggregate market value of our common stock held by non-affiliates is less than $75 million, we will not sell shares under the ATM

Current wording

On February 14, 2025, we filed a Registration Statement on Form S-3 covering the offering, issuance, and sale up to $100 million in common stock, preferred stock, and various series of debt securities and/or warrants to purchase any of such securities, which included the unsold securities from the prior registration statement. On June 20, 2025, we filed the latest amendment to the prospectus supplement to the Registration Statement on Form S-3 filed on February 14, 2025 pursuant to General Instruction I.B.6 of Form S-3, which updates the amount of shares that we are eligible to sell under the ATM Agreement to $8.0 million. So long as the aggregate market value of our common stock held by non-affiliates is less than $75 million, we will not sell shares under the ATM Agreement with a value of more than one-third of the aggregate market value of our common stock held by non-affiliates in any 12-month period due to the limitations of General Instruction I.B.6 of Form S-3 and the current public float of our common stock. If our public float increases such that we may sell additional amounts under the ATM Agreement and the prospectus, we will file another amendment to the prospectus supplement prior to making additional sales. The limitations of General Instruction I.B.6 do not apply to sales of our shares under the SEPAs with Yorkville as the sales of such shares were registered under a separate registration statement on Form S-1.

Previous wording

On February 28, 2020, Aptevo entered into an LLC Purchase Agreement with Medexus, pursuant to which we sold all of the issued and outstanding limited liability company interests of Aptevo BioTherapeutics LLC, a wholly owned subsidiary of Aptevo. On March 29, 2023, we entered into and closed a Purchase Agreement with XOMA pursuant to which we sold to XOMA our right, title, and interest to all future deferred payments from Medexus and a portion of potential milestones. As consideration, we received $9.6 million at closing from XOMA and an additional $0.05 million post-closing payment. Aptevo continues to be eligible to receive up to $5.8 million in milestone payments from Medexus upon achievement of certain regulatory and IXINITY net sales threshold.

Current wording

On February 28, 2020, Aptevo entered into the LLC Purchase Agreement with Medexus, pursuant to which we sold all of the issued and outstanding limited liability company interests of Aptevo BioTherapeutics LLC, a wholly owned subsidiary of Aptevo. On March 29, 2023, we entered into and closed a Purchase Agreement with XOMA pursuant to which we sold to XOMA our right, title, and interest to all future deferred payments from Medexus and a portion of potential milestones. As consideration, we received $9.6 million at closing from XOMA and an additional $0.05 million post-closing payment. Aptevo continues to be eligible to receive up to $5.8 million in milestone payments from Medexus upon achievement of certain regulatory and IXINITY net sales threshold. These milestone payment opportunities must be achieved by February 2035, after which any unachieved milestones will expire.

Previous wording

We have financed our operations to date primarily through royalty and purchase agreements with various partners, sale of business products and segments, public offerings of our common stock, loan proceeds, milestone payments, research and development funding from strategic partners, revenue generated from our previously owned commercial products, and funds received at the date of our spin-off from Emergent. We had cash and cash equivalents of $21.1 million and an accumulated deficit of $269.2 million as of September 30, 2025.

Current wording

We have financed our operations to date primarily through royalty and purchase agreements with various partners, sale of business products and segments, public offerings of our common stock, loan proceeds, milestone payments, research and development funding from strategic partners, revenue generated from our previously owned commercial products, and funds received at the date of our spin-off from Emergent. We had cash and cash equivalents of $14.5 million and an accumulated deficit of $281.9 million as of March 31, 2026.

Previous wording

For the nine months ended September 30, 2025, net cash used in our operating activities was $20.4 million.

Current wording

For the three months ended March 31, 2026, net cash used in our operating activities was $8.0 million.

Previous wording

the effects of macroeconomic conditions, including rising and fluctuating inflation and supply chain constraints as well as political events such as the U.S. federal government shutdown and evolving healthcare policies;

Current wording

the effects of macroeconomic conditions, including rising and fluctuating inflation and supply chain constraints as well as political events such as the U.S. federal government shutdown, evolving healthcare policies, ongoing conflicts in Europe and the Middle East and military actions;

Previous wording

our future ability to continue as a going concern.

Current wording

our ability to continue as a going concern.