Fennec Pharmaceuticals Inc. announced the results of the investigator-initiated Phase 2 STS-J01 clinical study of its drug PEDMARK in a filing dated September 17, 2026. The study evaluated the use of PEDMARK to reduce cisplatin-induced hearing loss in pediatric and adolescent and young adult patients with non-metastatic solid tumors in Japan.
The primary endpoint of the study was met. Among the 25 patients in the primary efficacy population, American Speech-Language-Hearing Association (ASHA)-defined hearing loss occurred in 24.0 percent of patients. This figure was significantly lower than the prespecified historical benchmark of 56.4 percent (P=0.001). By Brock criteria, 84 percent of patients had Grade 0 hearing loss, and no patients experienced Grade 3 or Grade 4 hearing loss.
The study enrolled 33 patients across 11 institutions in Japan, including 27 patients in the primary cohort and six in exploratory cohorts. Objective tumor responses were observed in 23 of 24 evaluable patients (95.8 percent). The safety profile was consistent with the known tolerability of PEDMARK, with no serious adverse events attributed to the drug and no Grade 4 PEDMARK-related toxicity observed.
The company stated that the data will be presented during the 58th Annual International Society of Pediatric Oncology (SIOP) Annual Meeting in San Antonio, Texas. Fennec indicated it is pursuing registration in Japan and is currently exploring partnering or licensing opportunities for PEDMARK.
