It has been announced that the U.S. Food and Drug Administration (FDA) granted orphan drug designation for the Company’s WT1 cancer vaccine for the treatment of patients with Malignant Pleural Mesothelioma (MPM). SELLAS recently reported positive results of a Phase 2 trial of its WT1 vaccine in MPM patients, showing that overall survival improved and progression-free survival doubled. Based on these findings, SELLAS intends to initiate a pivotal Phase 2b/3 trial of its product candidate in patients with MPM by the third quarter of 2016.
“We are thrilled with the progress of our WT1 vaccine program, which has received two orphan designations in the last two months and is advancing into pivotal studies in AML and in MPM patients in 2016, as well as further Phase 2 studies including in multiple myeloma, ovarian cancer, glioblastoma multiforme, and a series of genetically defined cancers in a basket-trial design,” said Angelos M. Stergiou, M.D., Chairman and Chief Executive Officer of SELLAS.
Miltiadis Sougioultzoglou, M.D., SELLAS’s Executive Vice President, commented, “MPM is a difficult-to-treat and aggressive cancer, and fewer than five percent of patients survive beyond five years. There is a significant need for new treatment options, and we look forward to the commencement of the pivotal Phase 2b/3 trial.”
The FDA Office of Orphan Products Development grants orphan designation to drugs and biologics intended for treatment of rare diseases or conditions that affect fewer than 200,000 people in the United States. Orphan drug designation provides certain benefits to sponsors planning to test a product for use in a rare disease or condition. These benefits include tax credits for qualified clinical trials costs, and exemption from FDA user fees, and upon approval, the product may qualify for seven years of market exclusivity.
Andres Gutierrez, M.D., Ph.D., SELLAS’s Chief Medical Officer, further noted, “Our WT1 cancer vaccine, also known as SLS-001, has demonstrated promising safety and efficacy data in clinical trials enrolling a total of 100 patients. We have been carefully proceeding with our development work in hematological malignancies (AML and Multiple Myeloma), as well as a solid tumor (MPM), and we will broaden the indications this year to advance our cancer vaccine in other unmet medical needs.”
WT1 Cancer Vaccine Clinical Program in MPM
SELLAS’s randomized, double-blind, placebo-controlled Phase 2 study in MPM patients enrolled a total of 40 patients at Memorial Sloan Kettering Cancer Center and M.D. Anderson Cancer Center. As reported in November 2015 at the International WT1 Conference, the study findings showed a median overall survival of 21.4 months for WT1 vaccine-treated patients versus 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. Further, SELLAS’s WT1 vaccine demonstrated a favorable safety and tolerability profile.
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.
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 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 year-end 2016 and reporting initial data in 2017.