22 May 2013 - 22 May 2013 - French Sanofi (EPA:SAN) and US Regeneron Pharmaceuticals (NASDAQ:REGN) unveiled Tuesday positive findings from a Phase IIa proof-of-concept trial of their investigational monoclonal antibody, dupilumab (SAR231893/REGN668), in moderate to severe allergic asthma.

Dupilumab targets the alpha subunit of the interleukin 4 receptor (IL-4R alpha), which modulates signaling of both IL-4 and IL-13, drivers of Th2 (Type 2 helper T cell) immune response.

The trial evaluated weekly dupilumab 300 mg versus placebo for 12 weeks in 104 patients with moderate to severe, persistent asthma that was not well controlled with inhaled glucocorticosteroids (ICS) and long-acting beta agonist (LABA) therapy, and who had elevated blood or sputum eosinophils (immune cells used as a marker of Th2 asthma in this study). The participants also received ICS and LABA therapy for the first four weeks of the trial. The primary endpoint was experience of a protocol-defined asthma exacerbation.

The results showed that 5.8% of the patients treated with dupilumab experienced an asthma exacerbation versus 44.2% of the patients who received placebo. This means the incidence of asthma exacerbations was decreased by 87% for the dupilumab arm compared to placebo.

In addition, clinically meaningful and statistically significant improvements were demonstrated for lung function and forced expiratory volume over one second (FEV1) (difference from baseline to week 12 between dupilumab and placebo of 0.27 L, p < 0.001), the partners noted.

The most frequent side effects for both placebo and dupilumab groups included injection-site reaction, nasopharyngitis, upper respiratory tract infection, headache and nausea.

Looking ahead, Sanofi and Regeneron will launch a Phase IIb trials of dupilumab in asthma and atopic dermatitis.