• As lead candidate mipletamig continues to outperform efficacy and safety benchmarks in AML trials, APVO711 exemplifies emerging innovation from Aptevo's proprietary ADAPTIR® platform
• In preclinical studies, APVO711 demonstrates dual anti-cancer functionality with broad solid tumor potential and developability

SEATTLE, WASHINGTON / ACCESS Newswire / May 8, 2025 / Aptevo Therapeutics Inc. (Nasdaq:APVO), a clinical-stage biotechnology company focused on developing novel immune-oncology therapeutics based on its proprietary ADAPTIR® and ADAPTIR-FLEX® platform technologies, today provided a program update for APVO711, a dual mechanism bispecific utilizing the PD-L1 arm to block the PD-1/PD-L1 pathway and the CD40 arm to enhance T cell priming through activation of the stimulatory receptor CD40 on antigen presenting cells. This update highlights the depth and scientific versatility of Aptevo's existing pipeline and reinforces the Company's ability to advance differentiated candidates for solid tumors with significant unmet need. Currently in preclinical development, APVO711 reflects the potential of Aptevo's platform-based strategy to generate bispecific therapeutics with novel mechanisms and broad clinical relevance.

"With APVO711, we're advancing an innovative dual-mechanism approach to immunotherapy-one that not only boosts the immune system through PD-L1 blockade but also facilitates T-cell priming via CD40 activation. This is important in the development of new therapeutics for cancers that have proven resistant to standard checkpoint therapies. We believe APVO711 has the potential to unlock deeper, more sustained responses, and ultimately expand the reach of immunotherapy to patients who need it most," said Marvin White, President and CEO of Aptevo.

About APVO711

• Novel Mechanism: APVO711 is a bispecific antibody targeting PD-L1 × CD40-combining checkpoint inhibition with immune activation in a single molecule.

• Designed for Potency: Unlike traditional checkpoint inhibitors, APVO711 simultaneously blocks immune suppression and primes antigen presenting cells to trigger robust T-cell responses.

• Targeting the Unmet Need: Developed to address a wide variety of tumor types and augment the anti-tumor responses achieved with PD-1/PD-L1 blockade alone.

• Pipeline Synergy: Represents a key part of Aptevo's novel immuno-oncology platform, with strong potential for combination strategies across solid tumors.

• Momentum Building: Preclinical studies demonstrate dual anti-cancer functionality.

"APVO711 represents a novel immunotherapy approach - by targeting both PD-L1 and CD40, this bispecific candidate is designed to block tumor-driven immune suppression while simultaneously priming T cells for a stronger, more durable anti-tumor response. In a landscape where many patients fail to respond to checkpoint inhibitors alone, APVO711 offers a rational strategy to expand the benefits of immunotherapy to a broader range of cancers and patients," said Michelle H. Nelson, Ph.D., Director of Immunobiology at Aptevo Therapeutics.

About Aptevo Therapeutics

Aptevo Therapeutics Inc. (Nasdaq: APVO) is a clinical-stage biotechnology company focused on developing novel bispecific immunotherapies for the treatment of cancer. The Company has two clinical candidates. Mipletamig is currently being evaluated in RAINIER, a two-part Phase 1b/2 trial for the treatment of frontline acute myeloid leukemia in combination with standard-of-care venetoclax + azacitidine. Mipletamig has received orphan drug designation ("orphan status") for AML according to the Orphan Drug Act. ALG.APV-527, a bispecific conditional 4-1BB agonist, only active upon simultaneous binding to 4-1BB and 5T4, is being co-developed with Alligator Bioscience and is being evaluated in a Phase 1 clinical trial for the treatment of multiple solid tumor types likely to express 5T4. The Company has three pre-clinical candidates with different mechanisms of action designed to target a range of solid tumors. All pipeline candidates were created from two proprietary platforms, ADAPTIR®and ADAPTIR-FLEX®. The Aptevo mission is to improve treatment outcomes and transform the lives of cancer patients. For more information, please visit www.aptevotherapeutics.com.

Safe Harbor Statement

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including, without limitation, Aptevo's expectations about the activity, efficacy, safety, tolerability and durability of its therapeutic candidates and potential use of any such candidates, including in combination with other drugs, as therapeutics for treatment of disease, its expectations regarding the effectiveness of its ADAPTIR and ADAPTIR-FLEX platforms, whether pre-clinical studies of APVO711 will show the desired anti-tumor efficacy, mechanism of action and safety profile and whether APVO711 will function with new mechanisms of action compared to our previous candidates and synergistically induce a biological response, whether APVO711 will demonstrate the ability to fight a range of solid malignancies, statements related to the progress of Aptevo's clinical programs, including statements related to anticipated clinical and regulatory milestones, whether further study of mipletamig in a Phase 1b dose optimization trial focusing on multiple doses of mipletamig in combination with venetoclax + azacitidine on a targeted patient population will continue to show clinical benefit, whether Aptevo's final trial results will vary from its earlier assessment, the possibility and timing of interim data readouts for ALG.APV-527, statements related to Aptevo's ability to generate stockholder value, whether Aptevo will continue to have momentum in its business in the future, and any other statements containing the words "may," "continue to," "believes," "knows," "expects," "optimism," "potential," "designed," "promising," "plans," "will" and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based on Aptevo's current intentions, beliefs, and expectations regarding future events. Aptevo cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from Aptevo's expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement.

There are several important factors that could cause Aptevo's actual results to differ materially from those indicated by such forward-looking statements, including a deterioration in Aptevo's business or prospects; further assessment of preliminary or interim data or different results from later clinical trials; adverse events and unanticipated problems, adverse developments in clinical development, including unexpected safety issues observed during a clinical trial; and changes in regulatory, social, macroeconomic and political conditions. For instance, actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the uncertainties inherent in the results of preliminary or interim data and preclinical studies being predictive of the results of later-stage clinical trials, initiation, enrollment and maintenance of patients, and the completion of clinical trials, the availability and timing of data from ongoing clinical trials, the trial design includes combination therapies that may make it difficult to accurately ascertain the benefits of mipletamig, expectations for the timing and steps required in the regulatory review process, expectations for regulatory approvals, the impact of competitive products, our ability to enter into agreements with strategic partners or raise funds on acceptable terms or at all and other matters that could affect the availability or commercial potential of Aptevo's product candidates, business or economic disruptions due to catastrophes or other events, including natural disasters or public health crises such as the coronavirus (referred to as COVID-19), geopolitical risks, including the current war between Russia and Ukraine and the war between Israel and Hamas, and macroeconomic conditions such as economic uncertainty, rising inflation and interest rates, continued market volatility and decreased consumer confidence. These risks are not exhaustive, Aptevo faces known and unknown risks. Additional risks and factors that may affect results are set forth in Aptevo's filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and its subsequent reports on Form 10-Q and current reports on Form 8-K. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Aptevo's expectations in any forward-looking statement. Any forward-looking statement speaks only as of the date of this press release, and, except as required by law, Aptevo does not assume any obligation to update any forward-looking statement to reflect new information, events, or circumstances.

CONTACT:
Miriam Weber Miller
Head, Investor Relations & Corporate Communications
Aptevo Therapeutics
Email: This email address is being protected from spambots. You need JavaScript enabled to view it. or This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: 206-859-6628