Roivant and Priovant Therapeutics announced positive results from the Phase 2 study (NEPTUNE) evaluating brepocitinib in non-anterior non-infectious uveitis (NIU), showing the strongest efficacy data in NIU observed to date. The NEPTUNE study enrolled 26 subjects with active NIU who were randomized 2:1 to brepocitinib 45 mg once daily or brepocitinib 15 mg once daily. Patients, physicians, and the study team were blinded to dose.

All subjects received a 60 mg/day prednisone burst at study entry for two weeks and were tapered off prednisone per protocol by week 8 (six-week steroid taper). Subjects were evaluated for Treatment Failure, a registrational composite endpoint comprising multiple measures of ocular inflammation and visual acuity, as well as discontinuation due to intercurrent events or initiation of rescue therapy. The study?s primary efficacy endpoint was the Treatment Failure rate at week 24.

At week 24, 29% (5/17) of subjects in the brepocitinib 45 mg arm and 44% (4/9) of subjects in the brepocitinib 15 mg arm met Treatment Failure criteria, with lower failure rates reflecting greater treatment benefit. The Treatment Failure rate from disease activity (discontinuations censored) was 18% in the brepocitinib 45 mg arm. These observed results represent approximately twice the observed benefit as seen in the corresponding registrational study for the only approved non-steroidal therapy in NIU.

All week 24 secondary efficacy endpoints, including haze grades, visual acuity, and macular thickness, were also positive and dose responsive. Of patients in the brepocitinib 45 mg arm who met the threshold for uveitic macular edema at baseline, 43% achieved resolution of macular edema by week 24. No patients in the brepocitinib 45 mg arm who entered the study without macular edema developed macular edema by week 24.

Safety and tolerability were consistent with prior clinical studies of brepocitinib, with no new safety or tolerability signals identified. Brepocitinib has been dosed in over 1,400 subjects and patients with a safety profile that appears consistent with approved and widely prescribed JAK inhibitors. Priovant intends to initiate a Phase 3 program in NIU in the second half of calendar year 2024.

The company would like to thank all of the investigators and patients who participated in the NEPTUNE study. The ongoing Phase 3 study evaluating brepocitinib in dermatomyositis is expected to be fully enrolled in the third calendar quarter of 2024, with data expected in calendar year 2025.