Boston — PureTech Health plc announced that the U.S. Food and Drug Administration has granted Fast Track designation to LYT-200 in combination with a hypomethylating agent for the treatment of relapsed or refractory high-risk myelodysplastic syndromes.
The company also said it completed an End-of-Phase 1 meeting with the FDA that supports advancing LYT-200 into a Phase 2 trial.
LYT-200 targets galectin-9, which PureTech describes as an oncogenic driver and immunosuppressor. The therapy is being developed by Gallop Oncology, a PureTech-founded company.
“Our productive End-of-Phase 1 meeting with the U.S. FDA provides a clear path to advance LYT-200 into Phase 2 development,” said Eric Elenko, Ph.D., Acting Chief Executive Officer of Gallop Oncology and Co-Founder of PureTech. “The STRIDE-MDS trial will seek to confirm the unprecedented clinical activity observed in Phase 1b, while its randomized, double-blind design will enable a clear assessment of the contribution of effect of LYT-200.”
The planned STRIDE-MDS Phase 2 trial will enroll about 125 patients with relapsed or refractory high-risk MDS. Participants will be randomized to receive LYT-200 at either 12 mg/kg or 7.5 mg/kg in combination with a hypomethylating agent, or placebo plus a hypomethylating agent.
The study will evaluate complete and partial response rates and is intended to support dose selection.
The regulatory meeting was supported by topline results from a completed Phase 1b study of LYT-200 in combination with azacitidine or decitabine in heavily pretreated patients whose disease had relapsed or become refractory to prior hypomethylating agent therapy.
Among 11 efficacy-evaluable patients receiving the 12 mg/kg dose of LYT-200 with a hypomethylating agent, the company reported a 27.3% complete response rate, a 36.3% combined complete and partial response rate and a 45.5% overall response rate. PureTech also reported no dose-limiting toxicities or myeloid suppression.
“R/R HR-MDS remains an area of profound unmet need, particularly for the vast majority of patients without an actionable mutation,” said Aleksandra Filipovic, M.D., Ph.D., Chief Medical Officer of Gallop Oncology. “Galectin-9 represents a compelling therapeutic target because of its role as both an oncogenic driver and potent immunosuppressor, and its elevated expression in HR-MDS is associated with shorter survival.”
Amer Zeidan, MBBS, MHS, Professor of Medicine at Yale University and Chief of the Division of Hematologic Malignancies at Yale Cancer Center, will serve as Global Principal Investigator of the Phase 2 trial.
PureTech said it intends to secure external capital in the first half of 2027 to support development of LYT-200 through completion of the Phase 2 study.
FDA Fast Track designation is intended to facilitate development and expedite review of drugs targeting serious conditions with unmet medical needs.
