The US FDA has started its review of Sanofi and Regeneron’s dupilumab for atopic dermatitis, setting the clock ticking on a possible approval by 29 March next year.
Dupilumab is an inhibitor of interlukin-4 (IL-4) and IL-13 and according to the companies is the first systemic therapy to show efficacy in moderate-to-severe atopic dermatitis, a chronic inflammatory skin disease also known as eczema.
There are estimated to be between 18 million and 25 million people in the US alone with eczema and seems to be on the increase in children, according to Centers for Disease Control and Prevention (CDC) data. Sanofi and Regeneron maintain there is a huge unmet medical need among patients at the upper end of the symptoms spectrum, with around 1.6 million people uncontrolled on current therapies.
Most patients on prescription therapies are treated with topical steroids, which are generally used sparingly to avoid side effects and should not be applied to some areas of the body such as the face.
More severe cases are treated with calcineurin inhibitors such as cyclosporine and methotrexate, but these drugs have toxicities that impede long-term use so even in responders symptoms generally come back.
Dupilumab showed efficacy as a monotherapy in this indication in two trials – SOLO 1 and SOLO 2 – while a follow-up trial called CHRONOS looked at its use in combination with corticosteroids was also positive, showing that adding the antibody to therapy raised the response rate from 23% to around 75%.
Sanofi and Regeneron are also developing dupilumab for other allergic diseases such as asthma, nasal polyps and eosinophilic esophagitis.
“The data really suggests that we have hit upon here – with blocking both IL-4 and IL-13 – the critical drivers of allergic disease in general,” said Regeneron chief scientific officer George Yancopoulos on a recent investor call.
Regeneron and Sanofi are the only companies with a drug blocking both those targets in late-stage development, so will have a sizeable lead time if the FDA approves the marketing application.
Analysts at Leerink Swann have previously suggested that dupilumab could reach $2.8 bn in sales per year if it gets a green light in both atopic dermatitis and asthma.