Priovant wins FDA approval for dermatomyositis treatment, first targeted therapy

Priovant Therapeutics has received US Food and Drug Administration (FDA) approval for brepocitinib, a dual TYK2/JAK1 inhibitor. The once-daily oral drug is for adults with dermatomyositis (DM) and is the company’s first approved product.

According to Fierce Pharma on the 28th (local time), Priovant said brepocitinib was approved under the brand name Rislaya to treat adults with dermatomyositis. Dermatomyositis is an autoimmune disease characterized by progressive muscle weakness and widespread, painful and itchy skin lesions.

Rislaya is the first targeted therapy approved for dermatomyositis. The disease has traditionally been treated with chronic, high-dose steroids. In an announcement on the 27th, Priovant said dermatomyositis substantially reduces patients’ quality of life through physical disability, skin and muscle pain, skin disfigurement, and sensitivity to light and touch.

The approved indication is also broad. It can be used in adults with dermatomyositis without restrictions based on disease activity, clinical presentation or previous treatment history. The company added that it can be used either as a replacement for existing nontargeted therapies or as an add-on combination treatment.

The approval was based on data from the late-stage VALOR trial. Priovant described it as the largest dermatomyositis study conducted to date.

In the trial, which compared two doses of Rislaya with placebo in 241 patients with dermatomyositis, the high-dose group had a mean Total Improvement Score (TIS) of 46.5 after 1 year of treatment, exceeding the placebo group’s 31.2 and meeting the primary endpoint.

In its approval announcement, Priovant said improvements in TIS among patients receiving Rislaya appeared as early as week 4, increased over time and were maintained through the end of the trial. At the end of the trial, 55% of patients receiving Rislaya achieved moderate or greater improvement on the TIS while using minimal or no steroids, compared with 30% in the control group.

The company also emphasized changes perceived by patients themselves. In response to a question about overall disease activity, patients receiving Rislaya reported more than four times the improvement reported by patients receiving placebo.

Priovant also noted the possibility that Rislaya could help patients with dermatomyositis regain some independence in their daily lives.

As a JAK-class drug, Rislaya is expected to carry boxed warnings for serious infections, death, malignancies, major adverse cardiovascular events and thrombosis. Common adverse events recorded in the VALOR trial included upper respiratory tract infection, headache, fatigue, urinary tract infection, nausea and influenza.

Ben Zimmer, Priovant’s chief executive officer (CEO), called the approval of Rislaya “a historic moment for the dermatomyositis community” in a statement on the 27th.

“We are pleased that adults with dermatomyositis finally have a fundamentally new treatment option,” he said. “It was designed to target the biology of the disease and has been shown to meaningfully improve how patients feel and function in their daily lives.”

This is Priovant’s first approval. Priovant was established by Roivant in 2022 after a deal with Pfizer secured brepocitinib and the TYK2 inhibitor ropsacitinib.

The company designated dermatomyositis as a key indication for the drug as it entered phase 3 development, but a failed phase 2 lupus trial in 2023 also blemished its clinical record.

Priovant is seeking additional indications for the molecule. A phase 3 trial in noninfectious uveitis is underway, and the company recently began enrolling patients in a late-stage trial for cutaneous sarcoidosis.