The Committee for Orphan Medicinal Products (COMP) of the European Medicines Agency (EMA) has given a positive opinion in support of orphan drug designation for the WT1 cancer vaccine (galinpepimut-S), which SELLAS Life Sciences is advancing in clinical studies as a treatment for malignant pleural mesothelioma (MPM) and acute myeloid leukemia (AML).
The vaccine was granted a similar designation as a potential MPM and AML therapy by the U.S. Food and Drug Administration (FDA) earlier this year.
“The orphan designations for galinpepimut-S, both in the US and now the European Union, underscore the important unmet needs in treating patients with MPM and with AML,” Angelos M. Stergiou, MD, chairman and chief executive officer of SELLAS, said in a recent press release. “SELLAS is dedicated to advancing novel therapies that we believe can make a significant difference in the lives of desperately ill patients. We are proud of the progress of our WT1 vaccine program, and we expect to initiate pivotal studies of the WT1 vaccine in both MPM and AML later this year, as well as additional mid-stage studies in diverse indications.”
SELLAS recently released positive Phase 2 data on the WT1 vaccine in patients with MPM, demonstrating an improvement in overall survival and doubled rates of progression-free survival. These results formed the basis for a new Phase2b/3 clinical trial of the vaccine in MPM patients, expected to begin in the third quarter of 2016.
SELLAS is also planning to soon start a Phase 3 clinical trial of its vaccine in AML patients.
A Phase 2 study in AML adult patients reported that those treated with the WT1 vaccine achieved a median overall survival of around four years. Data from a previous Phase 1 trial in this patient group showed that treatment resulted in a median overall survival of more than three years. Combined trial results demonstrated a two-year overall survival in adult AML patients of 79 percent. Historical two-year overall survival data in identical patient populations range from 30 percent to 45 percent.
“Given a favorable opinion for both indications despite them being submitted a month a part is truly unique,” said Gregory M. Torre, PhD, JD, the company’s chief regulatory officer and VP, Operations. “It speaks not only to the strength of the data but the interest of the COMP in these serious and life threatening indications.”
The WT1 vaccine, originally developed by Memorial Sloan Kettering Cancer Center, is licensed to SELLAS. It targets the WT1 antigen, and is administered in combination with an adjuvant and an immune modulator to boost the immune response against WT1.
WT1 is a transcription factor not usually present in adult cells. Since it appears in a multitude of cancers, and in some cancer stem cells, the antigen has been ranked the No. 1 target for cancer immunotherapy by the National Cancer Institute.