Feasibility and Safety of Intratympanic Administration of Sustained-Exposure Dexamethasone Thermosensitive Gel (OTO-104) for Prevention of Cisplatin-Induced Hearing Loss in Children: A Multisite Phase 2 Randomized Clinical Trial

Background: Cisplatin-induced hearing loss (CIHL) remains a significant complication of pediatric cancer treatment. We evaluated the feasibility, safety, and trends of the efficacy of intratympanic injections of sustained-exposure dexamethasone thermosensitive gel (OTO-104) for otoprotection. Procedure: In this multisite randomized phase 2 trial (NCT02997189), patients aged 0.5–21 years with newly diagnosed cancer treated with cisplatin were eligible. Participants’ ears were randomized to receive up to three intratympanic injections of 0.2 mL OTO-104 in one ear and no treatment contralaterally. OTO-104 was administered by an otolaryngologist within 72 hours preceding each cisplatin cycle. Feasibility was determined by the successful administration of intended doses. Treatment-emergent adverse events (TEAEs) and outcomes were monitored by physical examination, concurrent medications, otoscopy, tympanometry, and audiometry. Results: From January 6 to September 26, 2017, 18 doses of OTO-104 were administered to 11 evaluable participants across 5 centers (range, 1–14 years; 9 neuroblastoma and 2 osteosarcoma) via intratympanic injection (9) or tympanostomy tube (2). Sixteen injections were paired with other procedural sedations and two were performed awake; all injections were successfully delivered. The median interval between OTO-104 and cisplatin was 14 hours (range, 7–64). Clinically insignificant tympanic scabs were noted in five participants; no middle ear changes were observed. There were three otologic TEAEs (two transient mild-moderate otalgia [related] and one hypoacusis [unrelated]) and no related non-otologic TEAEs. CIHL developed similarly in treated versus untreated ears; the trial was terminated early. Conclusions: Although dexamethasone at this dose was not otoprotective, these results suggest that intratympanic injection may be safe, feasible, and a viable delivery platform for testing other otoprotectants.