Sanofi’s plans to submit itepekimab to regulators for approval this year have been thrown into doubt after the Regeneron-partnered drug failed one of a pair of phase 3 chronic obstructive pulmonary disease (COPD) trials.
Both of the studies, dubbed Aerify-1 and Aerify-2, evaluated administering the IL-33 drug itepekimab subcutaneously every two weeks or four weeks across a combined total of more than 2,000 former smokers with moderate to severe COPD. Both trials were designed to demonstrate a statistically significant reduction in moderate or severe exacerbations of COPD compared to placebo after 52 weeks.
Aerify-1 hit this endpoint by demonstrating a 27% relative reduction in exacerbations among patients who received itepekimab every two weeks and a 21% reduction among those who received the drug every four weeks.
But Aerify-2 was less successful, producing just a 2% reduction at two-week dosing and a 12% reduction at four-week dosing.
Sanofi partly blamed the results on the lower total number of exacerbations “than prospectively anticipated,” which the company said had “decreas[ed] the power of both trials.”
“Enrollment largely occurred during the time of the global COVID pandemic, which could have contributed to the overall lower exacerbation rates,” the pharma explained.
Adverse events were “generally comparable” between the itepekimab and placebo cohorts, Sanofi said in its May 30 release. In the failed Aerify-2 trial, adverse events that led to death were 3% for each of the itepekimab cohorts compared to 2% for the placebo group.
The failure of that trial is a significant setback for a drug that was listed in Sanofi’s most recent earnings presentation in April as being lined up for a regulatory filing in the second half of this year. At the time, Houman Ashrafian, Ph.D., Sanofi’s head of R&D, described the COPD readouts as “significant” and told analysts they could potentially lead to itepekimab’s market launch in 2026.
In a statement attached to this morning’s data, Ashrafian sounded more muted on the drug’s near-term plans.
“While we are encouraged by the results of AERIFY-1, the results of both studies merit further exploration to have a full understanding of the data and the role that IL-33 plays in this complex disease,” Ashrafian said. “Certain people with COPD are in desperate need of new treatment options, especially those who continue to experience exacerbations despite being on maximal therapy, and we remain committed to discussing these data with regulatory agencies to evaluate our path forward.”
Sanofi declined to confirm to Fierce Biotech that its previous FDA timeline remains on track.
The French Big Pharma had been developing itepekimab in collaboration with Regeneron. The two companies have seen blockbuster success with their immunology drug Dupixent and had previously evaluated the two therapies in combination as an asthma treatment in a phase 2 trial before halting that work in 2021.
Separate phase 2 and 3 trials of itepekimab in COPD remain ongoing. Even if today’s unimpressive results mark the end of the road for itepekimab in that respiratory indication, the drug is still being evaluated in trials for rhinosinusitis with nasal polyps and bronchiectasis.
“We are encouraged by the initial results from AERIFY-1 and are carefully reviewing the results from both itepekimab trials to inform next steps,” Regeneron Chief Scientific Officer George Yancopoulos, M.D., Ph.D., said in today’s release.
“We remain committed to our broader itepekimab development program,” Yancopoulos added. “The learnings will be invaluable as we continue to advance itepekimab in respiratory diseases with unmet need.”
The Aerify-2 fail continues a run of bad luck for Sanofi this year. The Paris-based pharma has also seen its psoriasis drug balinatunfib, its asthma hopeful amlitelimab and its Johnson & Johnson-sourced E. coli vaccine all underwhelm in the clinic in 2025.