OTO-201 for the Treatment of Acute Otitis Externa: Results from a Phase 3 Randomized Clinical Study

OTO-201 is a ciprofloxacin otic suspension previously approved by the US Food and Drug Administration to treat children with bilateral otitis media with effusion requiring tympanostomy tube placement. In this phase 3, double-blind, randomized, prospective, sham-controlled, multicenter study, a single dose of OTO-201 was administered to the external auditory canal in subjects with unilateral or bilateral acute otitis externa.

Two hundred sixty-two subjects, 3 to 83 years of age, were randomized, and 260 subjects were included in the intent-to-treat analysis population: OTO-201 (0.2 mL, 12 mg, n = 130) or sham (air injection, n = 130). The primary efficacy measure was clinical cure (CC) on day 8, judged by blinded assessor for erythema, edema, otorrhea, and tenderness. Subjects were monitored over 28 days for efficacy and safety.

OTO-201 demonstrated a significant increase in CC compared with sham at day 8 (69.2% vs 46.1%, P < .001). Higher CC was also noted on day 4 ( P = .028), day 15 ( P < .001), and day 29 ( P < .001). A similar effect was observed in the pathogen-positive population. Single OTO-201 administration in the office setting was well tolerated by subjects.

In this study in subjects with acute otitis externa, a single administration of 12 mg OTO-201 to the external auditory canal demonstrated a significantly higher proportion of subjects with CC and bacterial eradication compared with sham starting on day 4 and on all other observation days through day 29, with no safety or tolerability concerns identified. OTO-201 is the first agent in a randomized phase 3 study to demonstrate the efficacy and safety of a single-dose, health care professional-administered topical antibiotic for the treatment of acute otitis externa.