Mixed Results for Sanofi and Regeneron's COPD Drug Itepekimab Cast Doubt on Approval Timeline

Sanofi and Regeneron Pharmaceuticals have reported mixed results from two Phase III trials of their investigational drug itepekimab for chronic obstructive pulmonary disease (COPD), potentially derailing plans for regulatory submission this year. The outcome has sent shares of both companies tumbling and raised questions about the drug's future in COPD treatment.

AERIFY Trial Results: A Tale of Two Outcomes

The AERIFY-1 and AERIFY-2 trials, each enrolling approximately 1,000 former smokers with moderate-to-severe COPD, were designed to evaluate itepekimab's efficacy in reducing moderate or severe COPD exacerbations. While AERIFY-1 met its primary endpoint, AERIFY-2 failed to demonstrate a statistically significant benefit.

In AERIFY-1, itepekimab showed a 27% reduction in the annualized rate of moderate or severe COPD attacks compared to placebo when administered every two weeks, and a 21% reduction when given monthly. Both results were statistically significant.

However, AERIFY-2 painted a different picture. The biweekly dosing regimen only reduced exacerbations by 2%, while monthly dosing showed a 12% reduction. Neither outcome in AERIFY-2 reached statistical significance.

Market Impact and Future Prospects

The disappointing results have had immediate repercussions in the market. Regeneron's shares plummeted by over 17%, while Sanofi experienced a 6% decline. Analysts, who had high expectations for itepekimab, are now reassessing the drug's potential.

Brian Skorney of Baird noted, "COPD usually requires two positive Phase 3 results for regulatory approval, so we think one hit and one miss is unlikely to pave the way for commercialization." This sentiment was echoed by Brian Abrahams of RBC Capital Markets, who suggested that "at the very least" an additional late-stage study would be necessary.

The setback is particularly significant for Regeneron, which faces increasing pressure from biosimilar competition to its eye drug Eylea and an impending patent expiration for Dupixent, its blockbuster inflammatory disease treatment.

Sanofi and Regeneron are now reviewing the data and plan to discuss the results with health regulators. They noted that the overall number of COPD attacks in the studies was lower than anticipated, potentially due to enrollment occurring during the COVID-19 pandemic. This lower exacerbation rate decreased the statistical power of both trials.