French Authorities Advance Phase 3 Trial Testing Sellas’ GPS Cancer Vaccine

French Authorities Advance Phase 3 Trial Testing Sellas’ GPS Cancer Vaccine

French regulatory authorities have approved an investigational medicinal product dossier (IMPD) from Sellas Life Sciences, granting permission to advance in France a Phase 3 clinical trial testing the cancer vaccine galinpepimut-S (GPS) in people with acute myeloid leukemia (AML).

The REGAL trial, already recruiting participants in the U.S., will evaluate the GPS vaccine in AML patients who have achieved complete remission after second-line anti-leukemic therapy (CR2).

“This clearance marks an important milestone for Sellas, as the IMPD allows us to expand AML patient enrollment for our pivotal Phase 3 REGAL study of GPS in France,” Angelos M. Stergiou, MD, president and CEO of Sellas, said in a press release.

“Obtaining IMPD clearance is a stringent process, and includes submission of information related to the quality, manufacture and controls of GPS as well as data from non-clinical and clinical studies,” Stergiou added.

Galinpepimut-S, or GPS, is a cancer vaccine originally developed by researchers at Memorial Sloan Kettering Cancer Center. Like other vaccines, it works by stimulating an immune response. Specifically, this vaccine is designed to “train” the immune system to attack cells that express the protein Wilms Tumor 1 (WT1). This protein is commonly expressed by cancer cells; as such, the conceptual aim of GPS is to program the body’s immune system to find and destroy cancer cells.

The results from a pilot Phase 1/2 trial (NCT00665002), which enrolled 16 participants with AML, showed that galinpepimut-S significantly extended survival compared with conventional therapies (median 21 vs. 5.4 months). The therapy continued to be well tolerated throughout the study.

The European Medicines Agency has designated GPS an orphan drug for the treatment of AML, as well as for malignant pleural mesothelioma and multiple myeloma. The U.S. Food and Drug Administration has given GPS fast track and orphan drug designations for the same indications.

The open-label Phase 3 REGAL study (NCT04229979) seeks to enroll about 116 participants with AML who are in complete remission after a second-line treatment and who are ineligible for or unable to undergo an allogeneic stem-cell transplant.

The trial will be conducted at roughly 50 clinical sites in the United States and Europe. More information, including contacts and locations, can be found here.

The participants will be randomly selected for treatment with GPS or the physicians’ choice of the best available treatment.

Those receiving GPS will receive injections of the vaccine every two weeks. The patients will be given six doses over the first 10 weeks of the trial, followed by a break of four weeks. The participants then will receive another six doses followed by a three-week break, and a final three doses over six weeks. The last dose will be given at 52 weeks (one year).

Two days before each dose of GPS, and on the day after each dose, the participants will be given sargramostim, a medication that stimulates the growth of immune cells. The aim of this treatment, and of the multiple doses spread out over time, is to generate a strong and sustained immune response.

The study’s main goal is to determine whether galinpepimut-S extends patients’ lives compared with standard approaches. Remission — the time patients live without their leukemia returning — and immunological parameters also will be assessed. Interim data is expected by late 2021.

“We look forward to advancing our REGAL study in France and, upon the receipt of requisite approvals, other countries in Europe, particularly given the previously obtained orphan drug designation for GPS in AML by the European Medicines Agency,” Stergiou said.