NEW YORK, Sept. 22, 2022 (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 its upcoming poster presentation related to its highly selective CDK9 inhibitor, GFH009, at the Tenth Annual Meeting of the Society of Hematologic Oncology (SOHO) being held on September 28 through October 1, 2022, in Houston, Texas and virtually. The poster presentation characterizes the preclinical pharmacokinetic (PK) profiles of two different formulations of GFH009 maleate, pH 4.5 and pH 6.0. Additional presentation details can be found below: Title: “Pharmacokinetics and Bioequivalence of Two Formulations of GFH009 Maleate Injection in Sprague Dawley Rats” Abstract #: AML-259 Date/Time: Wednesday, September 28, 2022 at 6:05 PM ET Presenter: Dragan Cicic, MD, Senior Vice President, Clinical Development, of SELLAS About SELLAS Life Sciences Group, Inc. SELLAS Life Sciences Group, Inc. (NASDAQ: SLS) 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, galinpepimut-S (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 potential as a monotherapy or in combination with other therapies to address a broad spectrum of hematologic malignancies and solid tumor indications. The Company is also developing GFH009, a small molecule, highly selective CDK9 inhibitor, which is licensed from GenFleet Therapeutics (Shanghai), Inc., for all therapeutic and diagnostic uses in the world outside of Greater China. 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 preclinical data for GFH009, plans for further development of GFH009, and the potential for GFH009 as a drug development candidate. 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 associated with the COVID-19 pandemic and its impact on the Company’s clinical plans and business strategy, risks and uncertainties associated 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 31, 2022 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 Allison Soss KCSA Strategic Communications Email: SELLAS@kcsa.com Phone: 212.896.1267 Media Contacts Raquel Cona / Michaela Fawcett KCSA Strategic Communications Email: SELLAS@kcsa.com Phone: 212.896.1276