Cancer therapy biotech Salarius Pharmaceuticals announced this week that it would be voluntarily pausing enrollment on its phase 1/2 trial of seclidemstat due to the death of a participant.
The drug — a differentiated inhibitor of the LSD1 enzyme — is being investigated as treatment for Ewing sarcoma and FET-rearranged sarcomas. Following the death of a metastatic FET-rearranged sarcoma patient, which was classified as suspected unexpected serious adverse reaction (SUSAR), the company’s independent Safety Review Committee decided that patients currently receiving the treatment may choose to continue being dosed but future enrollment would be paused until further notice.
The Texas-based biotech is now in talks with the FDA to determine how to proceed and restart enrollment. According to the recent statement, the phase is currently in its dose-expansion stage, which includes three cohorts: one enrolling up to 30 patients with Ewing sarcoma and will evaluate seclidemstat in combination with other drugs; one with up to 15 patients with myxoid liposarcoma; and one with up to 15 patients with FET-rearranged sarcomas. The study’s primary endpoints are to evaluate the safety and efficacy of the treatment with advanced disease.
Ewing sarcomas are rare, pediatric, deadly cancer that affect about 500 children and teens in the U.S. each year. Seclidemstat is an LSD1 inhibitor that regulates the methylation of histone 3 lysine 4 and 9 (H3K4/9), providing a promising epigenetic target for cancer therapies according to recent research.