Salarius Pharmaceuticals voluntarily paused enrollment of its Phase I/II trial of seclidemstat for Ewing sarcoma and FET-rearranged sarcomas after a patient’s death.
Houston-based Salarius Pharmaceuticals voluntarily paused enrollment of its Phase I/II trial of seclidemstat for Ewing sarcoma and FET-rearranged sarcomas after a patient’s death, the company announced Tuesday.
Company shares dropped 27% at the news.
A patient with metastatic FET-rearranged sarcoma died during the trial. The death was classified as a suspected unexpected serious adverse reaction (SUSAR).
An independent Safety Review Committee analyzed the available data and suggested the company pause enrollment pending further investigation. Patients currently receiving the drug could continue treatment after discussing it with their physician.
“Patient safety is our primary concern, and this is reflected in the design of our clinical trial protocol, which automatically paused enrollment based upon this SUSAR,” David Arthur, CEO at Salarius, stated.
The company has informed the FDA and plans to continue analyzing the data to understand better how to proceed and restart enrollment. Salarius hopes to still release interim data from the trial later this year.
The trial is a multi-arm study. The first arm enrolls up to 30 patients with Ewing sarcoma and evaluates seclidemstat in combination with topotecan and cyclophosphamide, often used as second and third-line chemotherapy.
The second patient arm assesses seclidemstat as monotherapy in up to 15 patients with myxoid liposarcoma. The third arm evaluates the drug as a monotherapy in up to 15 patients with FET-rearranged or Ewing-related sarcomas. The clinical trial is being run across the U.S.
The drug is a differentiated inhibitor of the LSD1 enzyme, which is a well-validated target in hematological and solid tumors.
Seclidemstat inhibits LSD1’s demethylation and scaffolding properties. It has received Fast Track Designation, Orphan Drug Designation and Rare Pediatric Disease Designation for Ewing sarcoma from the FDA.
It is also being developed for several cancers with a high unmet medical need, including a second Phase I/II trial initiated by MD Anderson Cancer Center in hematologic cancers.
Salarius presented promising early-stage trial data on seclidemstat at the American Society of Clinical Oncology (ASCO) meeting in June 2021.
The data indicated a manageable safety profile, favorable pharmacokinetics that supported a twice-a-day dosage and indications of anti-tumor activity in an advanced, heavily pre-treated patient population. No significant hematological toxicities, which are known to be a limiting factor for other LSD1 inhibitors, were reported.
