Japan clears Dupixent for bullous pemphigoid

Regeneron Pharmaceuticals (REGN) and Sanofi (SANp) announced that Japan’s Ministry of Health, Labour and Welfare has approved Dupixent (dupilumab) for the treatment of adults with bullous pemphigoid (BP). The decision makes Dupixent the first targeted medicine approved in Japan for this patient population.

Dupixent is now listed in Japan as a 300 mg pre-filled syringe or pre-filled pen for adults with BP, according to Sanofi product materials. The treatment is administered as a subcutaneous injection every two weeks following an initial loading dose and can be given in a clinic or at home after appropriate training by a healthcare professional.

In Japan, Dupixent was already approved for certain patients with atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyposis, prurigo nodularis, chronic spontaneous urticaria and chronic obstructive pulmonary disease. The new BP indication broadens its use in diseases driven in part by type 2 inflammation.

The Japanese approval is based on data from the pivotal LIBERTY‑BP‑ADEPT Phase 2/3 trial (also referred to as ADEPT), according to Sanofi and Regeneron. The randomized, double-blind, placebo-controlled study evaluated the efficacy and safety of Dupixent in 106 adults with moderate-to-severe BP over a 52‑week treatment period.

Patients were randomized to receive Dupixent 300 mg (n=53) or placebo (n=53), added to standard-of-care oral corticosteroids (OCS). All participants followed a protocol-defined OCS tapering regimen once disease activity was controlled, with tapering intended to be completed by Week 16 if control was maintained.

The primary endpoint was the proportion of patients achieving sustained disease remission at Week 36. In the core dataset used for the regulatory submission in Japan, more than four times as many patients on Dupixent achieved this endpoint compared with placebo, at 18% versus 4%, with a p-value of 0.0250.

Sustained disease remission was defined as complete clinical remission with completion of OCS taper by Week 16, no relapse after taper completion and no use of rescue therapy through Week 36. Relapse criteria included the appearance of at least three new lesions a month or at least one large lesion or urticarial plaque over 10 cm that did not heal within a week.

Bullous pemphigoid is described in the releases as a rare, chronic, and often relapsing skin disease that primarily affects elderly patients. It is characterized by intense itch, painful blisters and lesions, and reddening of the skin, with underlying type 2 inflammation and an increased susceptibility to infection due to skin breakdown.

Existing treatment options are noted as limited and can add to disease burden by suppressing the immune system. Dupixent is described as a fully human monoclonal antibody that inhibits interleukin‑4 and interleukin‑13 signaling and is not an immunosuppressant. The broader Dupixent program has shown decreased type 2 inflammation in Phase 3 trials across several indications.

Globally, more than 1.4 million patients are being treated with Dupixent across approved indications in over 60 countries, according to the companies. Dupilumab is being jointly developed by Sanofi (SANp) and Regeneron under a global collaboration agreement and has been studied in more than 60 clinical trials involving over 12,000 patients.

Separately, Sanofi announced the availability of its Q1 2026 aide-mémoire on the Investors section of its website. The document is prepared each quarter to support financial modelling of results.

The aide-mémoire covers non-comparable items, foreign currency impact and share count for the quarter. Sanofi stated that its first-quarter 2026 results will be published on April 23, 2026.

Sanofi describes itself as an R&D-driven, AI-powered biopharma company listed on Euronext and Nasdaq, focused on medicines and vaccines that leverage its understanding of the immune system. Regeneron is described as a biotechnology company that develops and commercializes medicines using proprietary platforms such as VelocImmune and VelociSuite.