Sanofi/Regeneron's IL-33 blocker meets endpoint in POC study

The companies announced that REGN3500 (SAR440340) monotherapy significantly reduced loss of asthma control and improved lung function compared to placebo. In the trial, the greatest improvement was observed in patients with blood eosinophil levels ≥300 cells/microliter.

The results, however, do not show if REGN3500 is superior to Sanofi's IL-4R/IL13R antagonist dupilumab, which is approved to treat asthma and atopic dermatitis. In contrast, according to Sanofi/Regeneron, patients treated with dupilumab monotherapy did numerically better than REGN3500 across all endpoints. However, the trial was not powered to show differences between active treatment arms. The combination of REGN3500 and dupilumab also did not demonstrate increased benefit compared to dupilumab monotherapy in this trial.

Adverse events occurred in 61.6% of patients who received REGN3500, 66.2% of patients receiving both REGN3500 and dupilumab, 56.8% of patients who received dupilumab and 64.9% of patients who received placebo. According to the companies, the incidence of serious AEs and AEs leading to treatment discontinuations was low.

Regeneron‘s CSO George D. Yancopoulos suggested that "REGN3500 may provide an alternative targeted approach for patients suffering from asthma." The IL33-blocking antibody is currently being tested in
atopic dermatitis and chronic obstructive pulmonary disease. GlaxoSmithKline and Anaptysbio have already clinical programmes targeting IL-33

Despite standard-of-care treatment with inhaled corticosteroid (ICS) and long-acting beta-agonist (LABA) therapy, people with moderate-to-severe asthma often have inadequately controlled, persistent symptoms that may make them suitable for treatment with a biologic therapy. These people live with coughing, wheezing and difficulty breathing, and are at risk of severe asthma attacks that may require emergency room visits or hospitalizations.