Promising asthma trial prompts Regeneron, Sanofi to push dupilumab into PhIII

Regeneron ($REGN) and its close partner Sanofi ($SNY) have cleared the final mid-stage hurdle for dupilumab in asthma patients, with several doses hitting the trial endpoint both for a subset of patients as well as the broad population. And the ambitious development team at Regeneron now plans to hustle into a pivotal late-stage program as they continue to make swift progress with a drug that promises to tackle a trio of conditions that share a core inflammatory trigger.

Dupilumab is designed to block two proteins, interleukin-4 and interleukin-13, that play a key role in the inflammatory process. A slate of studies has demonstrated that the drug has been effective in treating severe eczema, chronic sinusitis and asthma, and the development partners clearly see a blockbuster market waiting at the end of late-stage studies.

In the Phase IIb that read out today, investigators in the development team said that the three highest doses of dupilumab combined with standard of care significantly improved the breathing of patients with high eosinophils--a key biomarker for a large group of patients--with two doses showing promise for the subset as well as the broad population. The drug also was linked to a drop in asthma attacks.

Dupilumab emerged from Regeneron's development platform, which has also produced a closely-watched PCSK9 cholesterol drug that is also partnered with Sanofi. While the pharma giant has struggled to develop new drugs--recently bidding its CEO Chris Viehbacher goodbye after an internal squabble with the board--its partnership with Regeneron has produced most of its most promising late-stage drugs.

A win here would be big for Regeneron and huge for Sanofi. Leerink Swann analyst Joseph Schwartz has projected peak annual sales potential for dupilumab at $2.8 billion for two indications--asthma and atopic dermatitis indication. And the partners could be setting the stage for even more.

Regeneron and Sanofi face some competition which is even further advanced in the clinic. Just days ago GlaxoSmithKline ($GSK) filed for an approval of its IL-5 asthma drug mepolizumab, with Teva (reslizumab) and AstraZeneca (benralizumab) trailing along the IL-5 pathway. AstraZeneca ($AZN) has posted a peak sales estimate for its drug--which has had mixed results in mid-stage trials--at $2 billion. And they all expect that their drugs can also hit the mark for COPD.

"Many have thought that targeting the Th2 pathway in asthma would limit benefit to a subset of asthmatics, such as those with high eosinophils. In this study, blocking IL-4/IL-13 signaling with dupilumab improved lung function and reduced severe exacerbations in the broader study population," said Elias Zerhouni, who heads R&D for Sanofi. "Based on these results, we plan to move dupilumab into Phase III clinical development in patients with moderate-to-severe uncontrolled asthma."

- here's the release