On 4 April, Sanofi and Regeneron announced that the US Food and Drug Administration (FDA) had accepted a Priority Review of the supplemental Biologics License Application (sBLA) for Dupixent (dupilumab) in patients aged 12 years and older with eosinophilic oesophagitis (EoE). This follows February’s news that Sanofi and Regeneron had filed with the FDA. The target action date for the FDA decision on this investigational use is 3 August. If it is approved, Dupixent will be the first medicine available in the US for EoE.

EoE is a chronic, immune-mediated, atopic inflammatory condition of the oesophagus that has gained increased recognition over the past two decades. In EoE, oeosinophils infiltrate the oesophagus, contributing to tissue damage and chronic inflammation. The current treatment options for EoE patients are off-label symptomatic treatments such as proton pump inhibitors (omeprazole and pantoprazole) and corticosteroids (budesonide and fluticasone propionate).

In December 2020, Takeda ‘s Eohilia, a reformulation of budesonide for EoE, was the first drug to receive Priority Review for FDA approval. But after a delay by the FDA, Eohilia received a complete response letter (CRL) in December last year indicating that the drug could not be approved in its present form and that the FDA recommended an additional clinical study for further consideration. In February this year, during Takeda’s quarterly earnings call, the company announced its decision to cease further support to launch Eohilia for patients aged 11 years and older in the EoE market. Key opinion leaders (KOLs) interviewed by GlobalData had been hopeful that this drug would become the first to market, but unfortunately, its journey came to an end.

Takeda’s exit from the market opened the field for other manufacturers, including Sanofi/Regeneron’s Dupixent, Ellodi’s APT-1011 (a reformulation of fluticasone propionate), Bristol-Myers Squibb ’s cendakimab (RPC-4046), and AstraZeneca’s Fasenra (benralizumab). In addition, Dupixent is the only pipeline agent being studied in Phase III for a younger population, specifically patients aged 1–11 years old. As a result, Dupixent has the potential to receive a label expansion for the paediatric population in the near future.

Dupixent is a blockbuster drug for several allergic disorders such as asthma and atopic dermatitis. It is also used in children with asthma and eczema, and is very well-known among physicians. Although it is a first-in-class drug for EoE, KOLs believed that it will likely be effective for a small patient population who are not responsive to off-label proton pump inhibitors and corticosteroids in the first and second lines of therapy respectively. Despite this, the launch of high-price Dupixent for adolescents and adults is expected to increase the sales in this space significantly, representing the most impactful driver of growth for the EoE market.