SELLAS Life Sciences Announces Positive WT1 Cancer Vaccine (galinpepimut-S) Clinical Results at the 13th International Conference of the International Mesothelioma Interest Group (iMig)

ZUG, Switzerland and NEW YORK, May 4, 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 that results from a Phase 2 trial of the Company's WT1 cancer vaccine in patients with malignant pleural mesothelioma (MPM) were presented at the plenary session of the iMig 2016 Conference, being held May 1-4, 2016, in Birmingham, UK. SELLAS's galinpepimut-S is a late clinical-stage cancer immunotherapy being developed to target hematologic cancers and solid tumors, including MPM, acute myeloid leukemia (AML), multiple myeloma, ovarian cancer, and multiple other cancers. As reported in an oral plenary session presentation at this week's iMig Conference, treatment with galinpepimut-S in a randomized, double-blind, placebo-controlled Phase 2 trial conducted at Memorial Sloan Kettering Cancer Center (MSK) and M.D. Anderson Cancer Center resulted in improved overall survival in patients with MPM and doubling of progression-free survival:

• The trial showed a median overall survival of 21.4 months for WT1 vaccine-treated patients versus a median 16.6 months overall survival for patients in the placebo control arm.
• The WT1 cancer vaccine also resulted in a median progression-free survival of 11.4 months, double that of the control arm, 5.7 months, in patients with MPM.
• The WT1 vaccine demonstrated a favorable safety and tolerability profile in MPM patients.
• Patients with a complete tumor resection and subsequent treatment with galinpepimut-S showed a significant survival benefit
• Patients who mounted an immune-response with galinpepimut-S had a significant survival benefit
• Galinpepimut-S was very well tolerated by patients in this trial

Based on these results, SELLAS is preparing to initiate a pivotal Phase 2b/3 trial of its WT1 vaccine in patients with MPM by the third quarter of 2016.

"The results of the WT1 cancer vaccine clinical program have been encouraging, demonstrating enhanced survival and a favorable safety profile in patients," said Marjorie G. Zauderer, M.D., a medical oncologist at MSK and principal investigator for the trial. "Our goal in this approach is to ensure that patients can stay longer in complete remission by activating the body's own immune response against their cancer cells expressing the WT1 antigen. We believe that in a larger trial, as anticipated, we will gain a clearer picture of the potential impact of this promising therapy in a patient population with few treatment options."

David A. Scheinberg, M.D., Ph.D., an inventor of the WT1 vaccine, as well as Chair of the Molecular Pharmacology Program and Director of the Experimental Therapeutics Center at MSK, commented, "We have built a large body of laboratory data and clinical evidence demonstrating that the WT1 vaccine can have a clinically significant impact on patients with MPM, as well as individuals with other cancers, such as AML. We look forward to entry of this program into pivotal testing in MPM patients, as well as a second pivotal study anticipated in AML patients in the first half of this year."

"We are very pleased with the continuing progress of our lead programs," said Miltiadis Sougioultzoglou, M.D., Executive Vice President and Vice Chairman of the Board of SELLAS. "WT1 is one of the most widely expressed cancer antigens in multiple malignancies, and indeed we are seeing positive results for our WT1 vaccine against a broad range of cancers. Importantly, we have demonstrated responses in high-risk patients, and these findings are very exciting given that these patients typically relapse in less than one year, and we have shown we can extend their state of remission and survival."

Andres Gutierrez, M.D., Ph.D., SELLAS's Chief Medical Officer, stated, "In preparation for the pivotal trial of our WT1 vaccine in mesothelioma patients, we have had the opportunity to meet with key opinion leaders while at iMig 2016. We have seen a great deal of excitement about the study, which, in addition to the US, will enroll patients at sites internationally. The clinicians have been very pleased as we've started to roll out our careful and scientifically rigorous clinical plan, which will ultimately provide the foundations for a strong regulatory path forward."

Dr. Sougioultzoglou added, "In addition to the upcoming Phase 3 pivotal studies in AML and MPM, SELLAS has a broad program that includes multiple Phase 1b and 2 studies we have already started and others are expected to commence this year in additional solid tumors and hematological malignancies. We are excited to fully explore these diverse indications and anticipate a steady flow of clinical trial readouts over the next two years."

Additional Presentation Details:

About the Phase 2 Trial in Mesothelioma

The double-blind, randomized (1:1) study compared the WT-1 analog peptides vaccine in combination with Montanide-adjuvant + Granulocyte-macrophage colony-stimulating factor (GM-CSF), versus Montanide-adjuvant + GM-CSF in patients with MPM who had previously completed combined modality therapy. Thirty-nine patients were to be enrolled in each arm at two centers, MSK and M.D. Anderson Cancer Center. However, in May 2015, the trial's independent Data Monitoring Committee requested discontinuation of the control arm due to futility while leaving open the WT1 cancer vaccine arm. This change led to unblinding the study earlier than planned; total enrollment has reached 40 patients, with 19 patients in the WT1 cancer vaccine arm and 21 in the control arm.

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, [email protected]

For Media:
David Moser, J.D., + 1 (813) 864-2571, [email protected]
Justin Jackson, Burns McClellan, +1 (212) 213-0006, [email protected]

SOURCE SELLAS Life Sciences Group

Related Links

http://sellaslifesciences.com