Itepekimab Met Primary Endpoint in One of Two Chronic Obstructive Pulmonary Disease (COPD) Phase 3 Trials

Regeneron and Sanofi announced mixed results from Phase 3 trials of itepekimab for COPD in former smokers; the AERIFY-1 trial met its primary endpoint, demonstrating a statistically significant 27% reduction in moderate or severe exacerbations compared to placebo, while AERIFY-2 did not meet the primary endpoint despite some earlier benefits. Both companies are assessing the data and plan to discuss next steps with regulatory authorities, while continuing to evaluate itepekimab in other respiratory diseases.

Analysis

Regeneron and Sanofi reported mixed Phase 3 trial results for itepekimab in adults who were former smokers with inadequately controlled chronic obstructive pulmonary disease (COPD). The AERIFY-1 trial successfully met its primary endpoint, demonstrating a statistically significant reduction in moderate or severe acute exacerbations at 52 weeks by 27% with itepekimab every two weeks and 21% with itepekimab every four weeks, compared to placebo, both deemed clinically meaningful. Conversely, the AERIFY-2 trial failed to meet the same primary endpoint, showing only a 2% reduction with the bi-weekly dose and a 12% reduction with the four-week dose at 52 weeks, despite observing some benefit earlier in the trial (18% and 21% reductions respectively at week 24). A key confounding factor was the lower-than-anticipated total number of exacerbations, which decreased the statistical power of both trials, potentially influenced by enrollment occurring largely during the COVID-19 pandemic. The safety profile of itepekimab was generally consistent across both trials and with prior studies, with overall adverse event rates comparable between itepekimab (ranging 64-71%) and placebo (ranging 64-68%) groups. Regeneron and Sanofi are currently assessing the complete dataset and intend to discuss these divergent outcomes and potential next steps with regulatory authorities. Despite the setback in AERIFY-2, both companies remain committed to the broader itepekimab development program, which includes ongoing trials for other respiratory conditions such as chronic rhinosinusitis and non-cystic fibrosis bronchiectasis.

Key Decisions for Investors

• Investors should adopt a cautious stance regarding itepekimab's prospects in COPD due to the conflicting Phase 3 trial outcomes, which introduce significant uncertainty for regulatory approval and commercial viability in this indication.
• Closely monitor upcoming communications from Regeneron and Sanofi concerning their discussions with regulatory agencies, as these will be critical in determining the future development path and potential for itepekimab in COPD.
• Evaluate the potential impact on the broader itepekimab program, considering that the drug is still under investigation for other respiratory diseases where it might demonstrate a more consistent efficacy profile, thus retaining some value for the pipeline.