SELLAS Life Sciences Enters Agreement with IMPACT-AML to Expand SLS009 Clinical Program into Europe

• Supports capital-efficient expansion of the SLS009 clinical program into frontline AML, enabling broader U.S. and European patient enrollment 
• U.S. enrollment evaluating SLS009 in combination with AZA/VEN in newly diagnosed AML with high-risk features is planned for Q1 2026, with European enrollment anticipated in Q2 2026 

NEW YORK, Jan. 14, 2026 (GLOBE NEWSWIRE) — SELLAS Life Sciences Group, Inc. (NASDAQ: SLS) (“SELLAS’’ or the “Company”), a late-stage clinical biopharmaceutical company focused on the development of novel therapies for a broad range of cancer indications, today announced that it has entered into an agreement with IMPACT-AML, a European collaborative initiative dedicated to advancing innovative treatments for patients with acute myeloid leukemia (AML). Under the agreement, the IMPACT-AML network will conduct a clinical study evaluating SLS009, a highly selective CDK9 inhibitor, enabling access to multiple European clinical sites and patients.

IMPACT-AML is a pan-European project and builds an inclusive clinical network (STREAM platform) that connects patients, clinicians, and researchers to test novel AML therapies and improve patient outcomes (https://impactaml.eu/). It is part of the prestigious EU Mission Cancer program and a top-tier scientific cluster. The IMPACT-AML project is led by a consortium of major research and clinical institutions in Europe, including IRST (IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori”), the University of Bologna, IIS LA FE (Health Research Institute Hospital La Fe), several European AML collaborative groups, and supranational organizations under the umbrella of the European Leukemia Net (ELN), as well as various university hospitals across Europe. By leveraging IMPACT-AML’s existing infrastructure and expertise, SELLAS expects to expand European patient access to SLS009 in a highly cost-efficient manner while supporting broader participation across the clinical program.

“This is a highly meaningful milestone for SELLAS and for the SLS009 program,” said Angelos Stergiou, M.D., Sc.D., President and Chief Executive Officer of SELLAS. “Gaining access to the IMPACT-AML framework represents strong external validation of SLS009 and reflects the growing recognition of SLS009’s potential in addressing critical unmet needs in AML. Importantly, this collaboration allows us to efficiently expand our clinical program into Europe by leveraging an established infrastructure, significantly improving capital efficiency while supporting broader and faster patient enrollment as we advance the program into frontline AML.”

The collaboration is expected to support the continued execution of the SLS009 clinical program as SELLAS advances into frontline AML. The study in Europe is planned to enroll approximately 40 patients to evaluate SLS009 in combination with azacitidine and venetoclax (AZA/VEN) in patients with newly diagnosed AML with high-risk features. Enrollment in the first part of the trial for newly diagnosed patients is expected to begin at U.S. sites in Q1 2026, followed by initiation at European sites in Q2 2026, subject to regulatory and site readiness.

“IMPACT-AML is committed to accelerating access to promising new therapeutic approaches for patients with AML who face limited treatment options,” said IMPACT-AML Scientific Coordinator, Dr. Giovanni Martinelli. “We are pleased to collaborate with SELLAS and support the evaluation of SLS009 within our European network, consistent with our mission to facilitate efficient, high-quality clinical research in AML.”

About SELLAS Life Sciences Group, Inc.

SELLAS is a late-stage clinical biopharmaceutical company focused on the development of novel therapeutics for a broad range of cancer indications. SELLAS’ lead product candidate, GPS, is licensed from Memorial Sloan Kettering Cancer Center and targets the WT1 protein, which is present in an array of tumor types. GPS has the potential as a monotherapy and combination with other therapies to address a broad spectrum of hematologic malignancies and solid tumor indications. The Company is also developing SLS009 (tambiciclib) – potentially the first and best-in-class differentiated small molecule CDK9 inhibitor with reduced toxicity and increased potency compared to other CDK9 inhibitors. Data suggests that SLS009 demonstrated a high response rate in AML patients with unfavorable prognostic factors including ASXL1 mutation, commonly associated with poor prognosis in various myeloid diseases. For more information on SELLAS, please visit www.sellaslifesciences.com.

Forward-Looking Statements

This press release contains forward-looking statements. All statements other than statements of historical facts are “forward-looking statements,” including those relating to future events. In some cases, forward-looking statements can be identified by terminology such as “plan,” “expect,” “anticipate,” “may,” “might,” “will,” “should,” “project,” “believe,” “estimate,” “predict,” “potential,” “intend,” or “continue” and other words or terms of similar meaning. These statements include, without limitation, statements related to the GPS clinical development program, including the REGAL study and the timing of future milestones related thereto. These forward-looking statements are based on current plans, objectives, estimates, expectations, and intentions, and inherently involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks and uncertainties with oncology product development and clinical success thereof, the uncertainty of regulatory approval, and other risks and uncertainties affecting SELLAS and its development programs as set forth under the caption “Risk Factors” in SELLAS’ Annual Report on Form 10-K filed on March 20, 2025 and in its other SEC filings. Other risks and uncertainties of which SELLAS is not currently aware may also affect SELLAS’ forward-looking statements and may cause actual results and the timing of events to differ materially from those anticipated. The forward-looking statements herein are made only as of the date hereof. SELLAS undertakes no obligation to update or supplement any forward-looking statements to reflect actual results, new information, future events, changes in its expectations, or other circumstances that exist after the date as of which the forward-looking statements were made.

Investor Contact

John Fraunces

Managing Director

LifeSci Advisors, LLC

jfraunces@lifesciadvisors.com