SELLAS To Present Data from Phase 2b Trial of NeuVax + Herceptin® at Upcoming European Society for Medical Oncology (ESMO) 2018 Meeting

Oral Presentation of NeuVax + Herceptin in the Adjuvant Treatment of Triple-Negative Breast Cancer

Conference Scheduled for October 19-23, 2018 in Munich, Germany

NEW YORK, July 23, 2018 (GLOBE NEWSWIRE) — SELLAS Life Sciences Group, Inc. (Nasdaq:SLS) (“SELLAS” or the “Company”), a clinical-stage biopharmaceutical company focused on the development of novel cancer immunotherapies for a broad range of cancer indications, today announced that data on the adjuvant treatment of women with triple-negative breast cancer (TNBC) with the combination of trastuzumab (Herceptin®) +/-nelipepimut-S (NeuVax™) will be presented as a Proffered Paper in an oral presentation at the 2018 Annual Meeting of the European Society for Medical Oncology October 19-23 in Munich, Germany.

The abstract, “Pre-specified interim analysis of a randomized phase 2b trial of trastuzumab + nelipepimut-S (NeuVax) vs trastuzumab for the prevention of recurrence demonstrates benefit in triple negative (HER2 low-expressing) breast cancer patients,” describes research undertaken at Cancer Insight, LLC by a team of clinicians-scientists led by COL (ret) George E. Peoples, MD, FACS, the principal investigator for the study.

Data will be presented from a prospective, randomized, single-blinded, controlled Phase 2b independent investigator-sponsored clinical trial (IST) of Herceptin® +/- NeuVax in HER 1+/2+ breast cancer patients in the adjuvant setting to prevent recurrences. As previously announced, a pre-specified interim analysis of safety and efficacy conducted by the study independent data safety monitoring board (DSMB), demonstrated a clinically meaningful and statistically significant difference between the TNBC cohort of patients and the control arm with a hazard ratio of 0.26, p-value = 0.023, in favor of the NeuVax + Herceptin combination compared to Herceptin alone. The analysis also showed an adverse event profile with no notable differences between treatment arms and no additional cardiotoxicity in the NeuVax + Herceptin arm. Based on these positive results, the DSMB recommended to expeditiously seek regulatory guidance from the U.S. Food and Drug Administration for further development of the combination of NeuVax + Herceptin in TNBC, a population with a large unmet medical need.

Herceptin® is a registered trademark of Genentech, Inc. and is not a trademark of SELLAS. The manufacturer of this brand is not affiliated with and does not endorse SELLAS or its products.

About ESMO

The European Society for Medical Oncology (ESMO) is Europe’s leading non-profit medical oncology organization. ESMO is a membership-based society, comprising of 500 expert committee members and 18,000 oncology professionals. ESMO organizes a large number of meetings to provide its members and the community with the resources they need and also plays a major role in public policy and European affairs. The ESMO 2018 Annual Meeting represents a multi-professional platform for oncology education and exchange, and for immense international visibility for scientific research, and will be held under the tagline “Securing access to optimal cancer care”.

About SELLAS Life Sciences Group, Inc.

SELLAS is a clinical-stage biopharmaceutical company focused on novel cancer immunotherapeutics 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 Wilms Tumor 1 (WT1) protein, which is present in an array of tumor types.  GPS has potential as a monotherapy or in combination to address a broad spectrum of hematologic malignancies and solid tumor indications.  SELLAS has Phase 3 clinical trials planned (pending funding availability) for GPS in two indications, acute myeloid leukemia (AML) and malignant pleural mesothelioma (MPM) and is also developing GPS as a potential treatment for multiple myeloma (MM) and ovarian cancer.  SELLAS plans to study GPS in up to four additional indications.  SELLAS has received Orphan Drug designations for GPS from the U.S. Food & Drug Administration (FDA) for AML, MPM, and MM, as well as from the European Medicines Agency, for AML and MPM; GPS also received Fast Track designation for AML and MPM from the FDA. SELLAS’ second product candidate, NeuVax™ (nelipepimut-S), is a HER2-directed cancer immunotherapy being investigated for the prevention of the recurrence of breast cancer after standard of care treatment in the adjuvant setting. NeuVax™ has received Fast Track status designation by FDA for the treatment of patients with early stage breast cancer with low to intermediate HER2 expression, otherwise known as HER2 1+ or 2+, following standard of care.

For more information on SELLAS, please visit

Forward-Looking Statements

This press release contains forward-looking statements, including, but not limited to, statements related to the results of clinical studies and as to further development of GPS for ovarian cancer as well as for a broad range of cancer indications, including the timing of clinical trials. 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 immune-oncology product development and clinical success thereof, the uncertainty of regulatory approval, and other risks and uncertainties affecting SELLAS and its development programs. These risks and uncertainties are described more fully in SELLAS’ Annual Report on Form 10-K and other filings with the Securities and Exchange Commission. Other risks and uncertainties of which SELLAS is not currently aware may also affect SELLAS’ forward-looking statements. 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:

Will O’Connor

Stern Investor Relations, Inc.


David Moser, JD

Sellas Life Sciences Group