Priovant Therapeutics Announces Positive Phase 2 NEPTUNE Study Results for Brepocitinib in Non-Infectious Uveitis (NIU), Showing Strongest Efficacy Data in NIU Observed to Date

• On the pre-specified primary efficacy endpoint of Treatment Failure at week 24, 29% of subjects receiving brepocitinib 45 mg and 44% of subjects receiving brepocitinib 15 mg met Treatment Failure criteria (lower failure rates reflect greater treatment benefit). The Treatment Failure rate from disease activity (discontinuations censored) was 18% in the brepocitinib 45 mg arm.
• Brepocitinib 45 mg results represent the best Treatment Failure rates observed to date among active NIU studies measuring this registrational endpoint.
• All secondary efficacy endpoints were also positive and dose responsive, including measurements of potential benefit on prevention and treatment of uveitic macular edema.
• NEPTUNE represents the seventh positive Phase 2 study for brepocitinib with over 1,400 subjects and patients treated with brepocitinib in clinical trials. Brepocitinib was generally safe and well-tolerated in the study; no new safety and tolerability signals were identified.
• Brepocitinib is well positioned to support a potential multi-blockbuster franchise in specialty autoimmunity with an ongoing pivotal study in dermatomyositis on track to read out in calendar year 2025 and expected initiation of a pivotal program in NIU by the end of calendar year 2024.

NEW YORK and DURHAM, N.C., April 2, 2024 /PRNewswire/ -- Priovant Therapeutics today announced positive results from the Phase 2 study (NEPTUNE) evaluating brepocitinib in non-anterior non-infectious uveitis.

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.

Additional safety and efficacy data will be presented at a future medical conference. 

"Non-infectious uveitis is a devastating disease that can lead to severe visual impairment and contribute to tens of thousands of cases of legal blindness in the United States each year, including many instances of irreversible blindness," said Quan Dong Nguyen, MD, MSc, FARVO, FASRS, NEPTUNE investigator and Professor of Ophthalmology at the Byers Eye Institute, and Professor of Medicine and Pediatrics at Stanford University School of Medicine. "Current treatment options provide inadequate benefits to many patients; thus, novel pharmacotherapeutic agents with better efficacy and more convenient methods of administration are urgently needed. Brepocitinib's striking results on multiple endpoints of clinical significance position the drug to become a potentially transformative once-daily oral therapy for this debilitating disease and reinforce the distinctive mechanistic benefits of dual TYK2/JAK1 inhibition for highly inflammatory autoimmune diseases with multiple pathogenic cytokines, such as non-infectious uveitis."

"The NEPTUNE study was designed to minimize likelihood of false signals of benefit, by tapering patients with active disease from 60 mg/day of prednisone to 0 mg/day in just six weeks, more than twice as fast as steroid tapers in precedent studies," said Ben Zimmer, CEO of Priovant. "Against that backdrop, we are thrilled to see a failure rate of only 29% in the brepocitinib 45 mg arm, better than any precedent study was able to achieve even with more lenient tapers. The magnitude and consistency of dose-dependent benefit across multiple independent measurements of inflammation, visual acuity, and macular edema give us high confidence heading into Phase 3. The results further point to a potentially highly differentiated product profile for brepocitinib in NIU—an orphan indication with high prevalence, severe morbidity, and few other therapies approved or in development."

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.

About Priovant

Priovant Therapeutics is a biotechnology company dedicated to developing novel therapies for autoimmune diseases with high morbidity and few available treatment options. The company's lead asset is brepocitinib, a dual selective inhibitor of TYK2 and JAK1. Through dual TYK2/JAK1 inhibition, brepocitinib is able to distinctively suppress key cytokines linked to autoimmunity—including type I IFN, type II IFN, IL6, IL12, and IL23—with a single, targeted therapy. Brepocitinib has generated positive data in seven Phase 2 studies with oral once-daily administration. Brepocitinib is currently being evaluated in a Phase 3 program for dermatomyositis and is entering a Phase 3 program for non-infectious uveitis.

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Contact:
Daniel Herz-Roiphe
Priovant Therapeutics
[email protected] 

SOURCE Priovant Therapeutics