WT1 Vaccine Helped High-Risk Multiple Myeloma Patients After Stem Cell Transplant

WT1 Vaccine Helped High-Risk Multiple Myeloma Patients After Stem Cell Transplant

High-risk multiple myeloma patients may benefit markedly from galinpepimut-S, an experimental immunotherapy from SELLAS Life Sciences, following autologous stem cell transplant (ASCT), according to recent data from a Phase 2 clinical trial showing that the agent nearly doubles the progression-free survival rates compared to historical controls who received ASCT alone.

Galinpepimut-S, which is a late clinical-stage immunotherapy, is being developed for a number of hematologic and solid cancers, including acute myeloid leukemia, mesothelioma, multiple myeloma and ovarian cancer. It comprises four small proteins that induce a strong immune response against the WT1 protein, which is highly expressed in certain tumor cells, but not usually found in healthy cells.

“We have previously demonstrated that Wilms’ tumor antigen 1 (WT1) is selectively overexpressed on malignant plasma cells, and immunotherapeutic strategies targeting this antigen could improve key outcomes in patients with multiple myeloma,” Guenther Koehne, MD, PhD, said in a press release. Koehne is attending physician, Adult Bone Marrow Transplantation Service at Memorial Sloan Kettering Cancer Center in in New York, and principal investigator on this phase 2 clinical trial.

The randomized Phase 2 trial (NCT01827137) was designed to evaluate the safety and efficacy of galinpepimut-S in myeloma patients who received ASCT. The study enrolled 19 patients and showed an 18-month overall survival rate of 86%, with 17 of the 18 evaluable patients still alive 28 months after the beginning of the study.

Importantly, the study included 15 high-risk cytogenetics patients, who also had additional unfavorable characteristics, which often result in low progression-free survival rates that do not exceed 12-15 months following ASCT. Compared to the results obtained in a cohort of high-risk myeloma patients assessed in a MD Anderson Cancer Center study, galinpepimut-S treatment nearly doubled the 18-month progression-free survival of these patients, and induced a 43% increase in overall survival.

The Phase 2 study still has not reached median overall survival or progression-free survival, but  researchers estimate the latter will be greater than 18 months.

“We are now witnessing promising responses in these high-risk patients, who typically relapse within 12-15 months of autotransplant,” said Nicholas Sarlis, MD, PhD, and SELLAS’ chief medical officer.

“Treatments for high-risk multiple myeloma have remained a clinical challenge,” Koehne, who also is associate professor of medicine, Weill Cornell Medical College. “Now, for the first time, galinpepimut-S has provided strong indication of a meaningful clinical benefit, following autotransplantation in patients with high-risk multiple myeloma, particularly those with an adverse cytogenetic profile. We are encouraged by these positive results and planning further studies to expand upon and confirm our observations,” he said.

Inês Martins holds a BSc in Cell and Molecular Biology from Universidade Nova de Lisboa and is currently finishing her PhD in Biomedical Sciences at Universidade de Lisboa. Her work has been focused on blood vessels and their role in both hematopoiesis and cancer development.

Leave a Comment

Your email address will not be published. Required fields are marked *