Sanofi, Regeneron ditch Dupixent trial in patients who failed Novartis and Roche's Xolair for hives condition

Despite sales of $6.2 billion last year for their eczema and asthma treatment Dupixent, Sanofi and Regeneron still believe they are scratching the surface of what they can accomplish with the autoimmune superstar.

These days, the companies are all about piling on indications for the monoclonal antibody. Friday, however, Sanofi and Regeneron revealed a rare setback for Dupixent, halting a trial in people with chronic spontaneous urticaria (CSU).

The phase 3 study assessed Dupixent in those who haven’t had success with the lone therapy approved for the condition—Novartis and Roche’s Xolair. Because Dupixent failed to significantly reduce symptoms, the trial was stopped for futility, despite numerical improvements observed for all the main evaluation criteria including itching.

CSU is a severe inflammatory condition that causes hives on the skin or deep swelling under the skin. Antihistamines are the first-line treatment, but some patients need more help.

RELATED: Sanofi's Dupixent, amid €10B sales push, posts positive data in chronic spontaneous urticaria

Sanofi and Regeneron are far from finished in their attempts to crack the large CSU market. In a previously reported phase 3 study, which evaluated patients who had not been treated with Xolair, Dupixent plus antihistamines significantly reduced itch and hives compared to antihistamines alone.

The companies remain committed to advancing Dupixent and are evaluating their next steps, they said.  

“While Dupixent did not show a significant benefit in the most difficult-to-treat patients who remain refractory to all approved medicines, we are carefully assessing the potential role of Dupixent in CSU based on the success of the first phase 3 trial in biologic-naïve patients, where Dupixent nearly doubled the reduction in itch and urticaria activity,” George Yancopoulos, M.D., Ph.D., Regeneron’s chief scientific officer, said in a release.

The news comes two months after Novartis reported the same in a pair of trials of its ligelizumab in CSU patients. The drug is effective when paired with antihistamines but couldn’t top its predecessor, Xolair.

The potential market is significant. Last July, during a quarterly earnings call, Bill Sibold, executive vice president of Sanofi’s Genzyme unit, said that about 15% of the 300,000 patients eligible for biologics are taking Xolair. He said then that Sanofi believed biologic treatments could eventually reach about 30% of this group.

RELATED: How to get to $11B? For Sanofi and Regeneron's Dupixent, 5 new approvals would help

Analysts at ODDO BHF believe today's news is a minor setback for Dupixent.

“Initial positive results at an earlier stage of the disease mean that hopes are maintained for CSU,” they wrote in a note to clients. “With annualized sales of €6 billion, we have not changed our sales momentum for Dupixient and maintain our peak of €10 billion in 2026.”