Priovant Therapeutics is exploring the potential of brepocitinib, a dual inhibitor of tyrosine kinase 2 (TYK2) and Janus kinase 1 (JAK1), across a spectrum of autoimmune diseases, encouraged by its performance in Phase II trials.
Benjamin Zimmer, CEO of Priovant, noted in an interview with Clinical Trials Arena that brepocitinib's unique mechanism allows for a broad cytokine suppression profile, potentially impacting various autoimmune conditions. The company is currently focusing on dermatomyositis and uveitis, citing the potential for brepocitinib to be transformative in these areas.
Clinical Development
Currently, brepocitinib is being evaluated in two Phase III trials. The VALOR trial (NCT05437263) is assessing its efficacy in dermatomyositis, a rare inflammatory muscle disorder, with 241 patients enrolled. Topline data is anticipated in 2025. The primary endpoint is the total improvement score at 52 weeks, a composite measure of dermatomyositis disease activity.
Additionally, the CLARITY trial (NCT06431373) is investigating brepocitinib in non-anterior non-infectious uveitis, with two sub-studies each enrolling 150 patients. Last month, the FDA granted Fast Track designation to brepocitinib for this indication, based on positive results from the Phase II NEPTUNE trial (NCT05523765).
Broader Potential
Beyond dermatomyositis and uveitis, brepocitinib has shown promise in Phase II trials for psoriasis, psoriatic arthritis, ulcerative colitis, and Crohn’s disease. According to Zimmer, these results warrant further investigation into other autoimmune conditions.
Competitive Landscape
The autoimmune disease treatment landscape is largely dominated by monoclonal antibodies, such as AbbVie's adalimumab (Humira). However, there is growing interest in TYK2/JAK1 inhibitors. GlobalData estimates that there are currently 58 TYK2/JAK1 inhibitors in development for autoimmune indications like inflammatory bowel disease, psoriasis, psoriatic arthritis, and atopic dermatitis.
Mechanism of Action
Brepocitinib's dual inhibition of TYK2 and JAK1 sets it apart, potentially offering a unique cytokine suppression profile compared to other JAK inhibitors. This mechanism could allow the therapy to modulate multiple cytokines implicated in various autoimmune diseases.
