SELLAS Life Sciences Announces Achievement of Development Milestone for Approval of IND for Galinpepimut-S in China

SELLAS to Receive $1 Million Milestone Payment in Second Quarter 2022

NEW YORK, April 06, 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 that an Investigational New Drug (“IND”) application to initiate the first clinical trial in China for 3D189, also known as SELLAS’ galinpepimut-S (GPS), has been approved by China’s National Medical Products Administration (“NMPA”).

SELLAS’ partner in China, 3D Medicines Inc. (“3D Medicines”), submitted the IND, for a small Phase I clinical trial investigating safety, earlier this year. 3D Medicines expects to initiate the trial by mid-2022 and will be responsible for all expenses related to executing the trial in China. The approval of the IND by the NMPA triggered a $1 million milestone payment to SELLAS, which the Company expects to receive in the second quarter of 2022. 3D Medicines’ current clinical development plan provides for initiation of a Phase II clinical trial following receipt of satisfactory safety data from the Phase I study; the initiation of the Phase II study will also trigger a milestone payment to SELLAS. Total remaining potential milestone payments to SELLAS under the license agreement between the two companies could total $191.5 million, not including future royalties.

“We are pleased that the 3D Medicines’ IND application filed earlier this year is now approved by China’s NMPA which allows 3D Medicines to move forward with their planned Phase 1 clinical trial. This marks the beginning of development of GPS in China which is an important milestone for SELLAS,” said Dragan Cicic, MD, Senior Vice President, Clinical Development, of SELLAS.

About 3D189
3D189, also known as SELLAS’ lead product candidate, GPS, is an immunotherapeutic that targets the Wilms Tumor 1 (WT1) protein which is present and over-expressed in an array of hematological malignancies and solid tumors. When administered to a patient as a monotherapy or in combination with standard treatments, GPS’ induced immune response has the potential to recognize and destroy cancer cells and provide ongoing support to the immune system so that it can continue to target and destroy recurring tumors and residual cancer cells. The immunotherapy has the potential to be a highly effective approach to prolonging survival by delaying or preventing recurrence in patients in complete remission or with minimal residual disease.

3D Medicines holds the exclusive license from SELLAS to develop, manufacture and commercialize 3D189 in China, Hong Kong, Macau and Taiwan region for all therapeutic and other diagnostic uses.

About 3D Medicines Inc.
3D Medicines Inc. is a commercial-stage biopharmaceutical company with a mission to help people with cancer live longer and better. Envisioning a future when cancer is managed as a chronic disease, 3D Medicines focuses on the development of differentiated next-generation immuno-oncology drugs, helping cancer patients live with prolonged survival time and a better quality of life. 3D Medicines has established a pipeline with both next-generation biological macromolecule and chemotherapeutic small-molecule drugs, as well as a professional team capable of global development, registration and commercialization operation.

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 potential both as a monotherapy and in combination 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 the clinical development of GPS, the potential for GPS as a drug development candidate, the achievement of future milestones, and the potential receipt of milestone payments. 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, risks and uncertainties associated with immune-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 Contact
Raquel Cona
KCSA Strategic Communications
Email: SELLAS@kcsa.com
Phone: 212.896.1276