– Trial Will Evaluate Galinpepimut-S Combined with Nivolumab to Treat Patients with Advanced-Stage Disease –

– Combination Therapy Builds on Previous Promising Results of WT1 Vaccine Monotherapy in Blood Cancers and Solid Tumors –

ZUG, Switzerland and NEW YORK, April 29, 2016 /PRNewswire/ — SELLAS Life Sciences Group (SELLAS), a development-stage biopharmaceutical company with its main focus on developing innovative products to treat cancers and central nervous system (CNS) diseases, today announced the initiation of a Phase 1 clinical trial to evaluate the safety and efficacy of SELLAS’s galinpepimut-S in combination with nivolumab (Opdivo®), Bristol- Myers Squibb’s PD-1 immune checkpoint inhibitor. The Phase 1 study is expected to enroll at least ten patients with recurrent ovarian cancer who are in second or greater clinical remission at Memorial Sloan Kettering Cancer Center. Ovarian cancer is one of the most common gynecologic malignancies and the fifth most frequent cause of cancer death in women in the United States. Over 22,000 cases are diagnosed annually, and there are an estimated 15,500 deaths per year.

Patients enrolled in the Phase 1 study will receive the combination therapy during the trial’s 14-week treatment period. Individuals who have not progressed by the end of this period will also receive a maintenance course of the WT1 vaccine. Pending the successful progress of the trial a larger, follow-on, randomized study may be planned.

“For patients with advanced-stage ovarian cancer, the five-year survival rate is less than 30%, and there is a substantial and urgent need for new treatments that can prolong remission and survival in patients,” said Roisin O’Cearbhaill, MD, MBBCh, BAO at Memorial Sloan Kettering and principal investigator for the trial. “Galinpepimut- S is a promising treatment for this disease because of WT1 showing an expression in ovarian cancer, and we believe T-cells, by combining galinpepimut-S and nivolumab, may specifically be directed towards the WT1 target and supports the rationale for its use in cancer immunotherapy approaches. In fact, studies have confirmed that ovarian cancer patients can exhibit immunologic competence even after multiple courses of chemotherapy, and immune activation has been shown to portend a better prognosis for these patients. We are excited to initiate clinical studies of galinpepimut-S in this cancer immunotherapy application and look forward to the progress of the program.”

Promising clinical results for SELLAS’s WT1 vaccine as monotherapy have been reported in peer-reviewed forums in both solid tumors (malignant pleural mesothelioma (MPM)) and hematological cancers (acute myeloid leukemia (AML) and multiple myeloma (MM)). Based on this progress, SELLAS is commencing pivotal Phase III clinical trials of galinpepimut-S in AML patients and MPM patients this year. Angelos M. Stergiou, M.D., Chairman and Chief Executive Officer of SELLAS, commented, “We are advancing a broad clinical program with galinpepimut-S to expand potential indications and develop in parallel applications for monotherapy and combined therapy in hematologic cancers and solid tumors. By the end of this year, we expect to have two pivotal trials and additional mid-stage studies in diverse indications, including a series of genetically defined Mismatch Repair cancers in a basket-trial design.”

Dr. Stergiou added, “We are very pleased to further broaden our successful clinical trials program with our collaborator MSK, and by extension to now integrate the leading anti-PD-1 product in our trial in ovarian cancer.”

About SELLAS’s WT1 Cancer Vaccine

SELLAS’ WT1 vaccine is a late clinical-stage cancer immunotherapy being developed to target hematologic cancers and solid tumors, including acute myeloid leukemia (AML), mesothelioma (MPM), multiple myeloma, ovarian cancer, and multiple other cancers. The WT1 antigen is a transcription factor that is not generally expressed in normal adult cells, but appears in a large number of cancers, as well as in certain cancer stem cells. WT1 has been ranked by the National Cancer Institute (NCI) as the Number 1 target for cancer immunotherapy. While WT1 has not been druggable by traditional approaches, it can be targeted by the immune system. Specifically, a number of different peptide sequences from the WT1 antigen have been identified as immunogenic and capable of stimulating cytotoxic T-cells that can target and kill WT1-expressing cancer cells. Studies also have shown that WT1 does not provoke tolerization and that patients’ T-cells can remain reactive to the antigen over time.

The WT1 vaccine, originally developed by Memorial Sloan Kettering Cancer Center and licensed to SELLAS, comprises four modified peptide chains that induce a strong innate immune response (CD4+/CD8+ T-cells) against the WT1 antigen. The WT1 vaccine is administered in combination with an adjuvant and an immune modulator to improve the immune response to the target. Based on its mechanism and the accumulating evidence of activity in mid-stage trials, the WT1 vaccine may have the potential to complement currently available therapies by destroying residual tumor cells of cancers in remission and providing ongoing immune surveillance for recurrent tumors. Overall, SELLAS’ WT1 vaccine could target over 20 cancers that over-express WT1, many of which are associated with relapse rates of up to 80% or more, as seen in patients with AML and MPM.

About SELLAS Life Sciences Group

SELLAS Life Sciences is a development-stage biopharmaceutical company focused on innovative products to treat cancer and central nervous system (CNS) diseases. SELLAS has two Phase 2b- and 3-ready products poised to enter trials in Europe and the US in 2016, across multiple indications in cancer and CNS diseases, as well as an earlier-stage highly innovative cancer therapeutic. The company recently received orphan drug designations by the US FDA for its WT1 cancer vaccine in Acute Myeloid Leukemia and Malignant Pleural Mesothelioma which will enter into pivotal clinical trials in 2016.

SELLAS’s WT1 vaccine, licensed from Memorial Sloan Kettering Cancer Center, is a cancer immunotherapeutic agent targeting a broad spectrum of hematologic cancers and solid tumor indications. This program will advance into Phase 3 trials in 2016 in AML and MPM as well as other indications in various development phases, including ovarian cancer, glioblastoma multiforme, and others with WT1 vaccine alone or in combination with other immunooncology agents. SELLAS is also advancing a proprietary formulation of high-dose Zolpidem under the 505(b)(2) pathway to treat basal ganglia disorders, including Parkinson’s disease and Progressive Supranuclear Palsy (PSP), which is the lead orphan indication. Zolpidem’s mechanism of action and therapeutic effects in such CNS-related diseases have been demonstrated in several studies. SELLAS expects to initiate a Phase 2b study of high-dose Zolpidem for PSP in 1H 2016. A third program is focused on SELLAS’s TR1 product candidate, a novel fusion protein that supplies the normal wild type p53/p21 protein to cancer cells to trigger innate cell death mechanisms (apoptosis). The Company is advancing its TR1 program toward IND-enabling studies, with the goal of commencing Phase 1 testing by early 2017.

SELLAS was founded in 2012 and is headquartered in Zug, Switzerland, with additional offices in New York, USA.

Contact:

For Investors:
Ami Bavishi, Burns McClellan, +1 (212) 213-0006, abavishi@burnsmc.com

For Media:
David Moser, J.D., + 1 (813) 864-2571, dmoser@sellaslife.com
Justin Jackson, Burns McClellan, +1 (212) 213-0006, jjackson@burnsmc.com