Sanofi, Regeneron chase 4th Dupixent approval with rare esophageal disease data

dupixent
Dupixent could score $11 billion in annual sales, according to Sanofi CEO Paul Hudson's estimates. (Sanofi)

Sanofi and Regeneron's immunology superstar Dupixent is well on its way to world domination with a flood of new indications in the pipeline. To support one of those, a rare esophageal disease, the partners released new data backing up Dupixent's case for a fourth FDA approval. 

Dupixent improved patients' ability to swallow and cut levels of targeted white blood cells over placebo in patients with eosinophilic esophagitis, a rare disease characterized by inflammation in the esophagus, according to late-breaking science presented this weekend at two gastroenterology virtual meetings. 

In Part A of a planned three-part clinical program, Dupixent improved patients' ability to swallow after four weeks of treatment and maintained that benefit through six months, the drugmakers said. The drug also pared back eosinophil levels, reduced disease symptoms and changed patients' gene expression for the disease at the 24-week mark. 

The newest data followed up on top-line data released in May showing Dupixent reduced disease symptoms over placebo after 24 weeks of therapy. Dupixent received the FDA's orphan drug designation in the disease back in 2017.

Dupixent, a blockbuster seller with three approvals under its belt, would become the first approved therapy for eosinophilic esophagitis. Sanofi and Regeneron are currently enrolling a Part B study in the disease, with a 28-week follow-up study planned. 

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A key growth driver for both Sanofi and Regeneron, Dupixent could snare $11 billion in sales each year as the drugmakers look to a bustling clinical pipeline for growth.

In June, the partners outlined the next clinical steps for Dupixent, including trials in eosinophilic esophagitis, chronic obstructive pulmonary disease (COPD), prurigo nodularis, chronic spontaneous urticaria and bullous pemphigoid. Sanofi and Regeneron hope to submit Dupixent data for approvals in eosinophilic esophagitis and chronic spontaneous urticaria—aka hives—in 2022. For hives, the drugmakers enrolled a 240-patient registrational trial earlier this year.

The partners are also awaiting data from two phase 3 trials in prurigo nodularis, a condition that causes hard, itchy lumps on the skin and has no FDA-approved therapies. Top-line data from those studies could read out as soon as the second half of 2021, with a regulatory submission to follow by year-end, Regeneron said.

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Sanofi and Regeneron are also plotting a 2023 regulatory filing for bullous pemphigoid, a rare autoimmune disease characterized by fluid-filled blisters. The partners will then follow that up with a COPD filing, planned for 2024.

While Sanofi and Regeneron rework their newly profitable immunology partnership, the companies will keep their 50-50 revenue split on Dupixent. In February, Sanofi CEO Paul Hudson predicted Dupixent could eventually turn in annual sales of $10.97 billion in sales after posting $2.56 billion in sales in 2019.

And despite the massiveness of those growth forecasts, some analysts figure Dupixent could be on track to hit them. In February, SVB Leerink pegged sales of Dupixent at $3.84 billion this year and $10 billion in 2026. That long-term forecast was 10% to 15% higher than the consensus estimate.