Dupixent is first FDA-approved drug for rare skin disease

The long list of therapeutic uses for Sanofi and Regeneron's Dupixent has been lengthened, after the drug became the first FDA-approved therapy for rare and debilitating skin disease bullous pemphigoid (BP).

BP primarily affects elderly patients and causes reddening of the skin and the formation of painful and intensely itchy chronic lesions and blisters, in some cases spreading across a majority of the body. It is estimated to affect around 27,000 people in the US, mainly aged 60 to 80, who can have their daily activities drastically compromised and become prone to infections.

IL-4 and IL-13 inhibitor Dupixent (dupilumab) is the first biologic drug to show an improvement in remission and symptoms in BP, and the first to allow patients to reduce the use of steroids, which are the standard therapy for the disorder, but can have serious long-term side effects.

The FDA approval is based mainly on the ADEPT study reported last year, which showed that the drug achieved a five-fold greater sustained remission rate at 36 weeks – 20% versus 4% – compared to placebo, without the need for steroid rescue therapy.

In addition, 41% of Dupixent-treated patients achieved a 90% or greater reduction in disease severity, compared to 10% of the control group, while "clinically meaningful" itch reduction was recorded in 40% and 11%, respectively. Itch is often reported to be one of the most damaging symptoms to BP patients' quality of life.

The approval has been hailed by the International Pemphigus and Pemphigoid Foundation (IPPF), whose executive director – Patrick Dunn – said: "Dupixent is the first targeted medicine to allow patients the potential to achieve sustained remission and reduce itch."

He added: "This approval in the US is important for the thousands of patients living with bullous pemphigoid, and we look forward to working with regulators around the world to bring this innovative medicine to more patients in need."

Additional applications for Dupixent as a treatment for BP are also under review around the world, including in the EU, Japan, and China, said Sanofi and Regeneron, which also have trials of the drug on the go in additional indications, including chronic pruritus of unknown origin and lichen simplex chronicus.

Dupixent is now approved to treat eight diseases characterised by type 2 inflammation in the US, including atopic dermatitis and asthma, and has grown into a huge product with sales topping $14 billion last year. Recent approvals in chronic obstructive pulmonary disease (COPD) and now BP suggest there is still plenty of growth left in the tank for the product.