Fennec Pharmaceuticals Announces Positive Topline Results From Investigator-Initiated Clinical Study of PEDMARK(TM) in Japan to Reduce Cisplatin-Induced Hearing Loss

Executive Summary

• Fennec Pharmaceuticals announced topline results from the investigator‑initiated Phase 2/3 STS‑J01 trial in Japan showing a marked reduction in cisplatin‑induced hearing loss among pediatric and AYA patients treated with PEDMARK® (24% vs. historical 56–63%).
• The study confirmed that PEDMARK® does not diminish cisplatin’s antitumor activity, with an overall tumor response rate of ~95%.
• Fennec plans to seek Japanese regulatory approval for PEDMARK® and will explore partnering or licensing opportunities in Japan.

Key Details

• Study Design: Open‑label, single‑arm Phase 2/3 trial; 33 patients total (27 aged 3–18 y primary cohort, 6 exploratory infants).
• Primary Endpoint: Incidence of hearing impairment at end of treatment in the 3‑ to 18‑year cohort (ASHA criteria).
• Results – Hearing Loss:
• ASHA‐defined loss: 24% (primary cohort) vs. historical 56% (ACCL0431).
• Brock grade ≥ 1 loss: 16% vs. historical 63% (SIOPEL‑6).
• Sub‑group (7–18 y): 19% ASHA, 14.3% Brock.
• Antitumor Efficacy: Approximate overall response rate of 95%; no reduction in cisplatin exposure observed.
• Safety: >200 treatment‑emergent adverse events reported; none attributed to PEDMARK®. No new safety signals identified.
• Pharmacokinetics: No evidence of interaction or attenuation of cisplatin activity; PK data support six‑hour post‑cisplatin dosing window.
• Regulatory Intent: Fennef will file for registration in Japan and seek partnership/licensing arrangements to commercialize PEDMARK® locally. Full data to be presented at a future scientific meeting and submitted for peer‑reviewed publication.
• Quotes:
• Pierre S. Sayad, CMO – highlighted the consistency of protective effect across continents and emphasized that PEDMARK® does not interfere with cisplatin’s mechanism.
• Eiso Hiyama, MD – stressed the unmet need in Japan and expressed confidence in PEDMARK®’s safety and efficacy profile.

Notable Quotes

• “Seeing such low rates of hearing loss in a real‑world, investigator‑initiated setting in Japan reinforces the consistency and magnitude of PEDMARK®’s protective effect… The high tumor response rate and the pharmacokinetic data show that PEDMARK® does not interfere with how cisplatin works.” – Pierre S. Sayad, PhD, CMO, Fennec Pharmaceuticals
• “These encouraging results … demonstrate that PEDMARK® can protect hearing without compromising cisplatin’s efficacy or introducing any concerning side effects.” – Eiso Hiyama, MD, Lead Investigator

Materiality Assessment: Material – Positive (significant clinical data supporting expanded indication and potential new market entry).