Treatment with dupilumab resulted in significant clinical improvements in adults with inadequately controlled moderate to-severe atopic dermatitis, in two phase III studies evaluating the biologic agent, according to Regeneron and Sanofi.

The phase III results of the two 16-week studies, SOLO 1 and SOLO 2 , in nearly 1,400 adults with baseline Investigator’s Global Assessment (IGA) scores of 3 (moderate disease) or 4 (severe), were announced by Regeneron and Sanofi. The companies are codeveloping dupilumab, which inhibits signaling of interleukin-4 and IL-13, “two key cytokines required for the T helper 2 (Th2) immune response,” according to Regeneron.

In the studies, patients were randomized to treatment with 300 mg subcutaneously of dupilumab once a week or every 2 weeks (after a 600-mg loading dose) or placebo, for 16 weeks.

At 16 weeks, significantly more of those in the two treatment groups achieved clearing or near clearing of skin lesions – a primary endpoint – compared with placebo: In SOLO 1 and SOLO 2, respectively, an IGA score of 0 (clear) or 1 (almost clear) was achieved by 37% and 36% of those treated with 300 mg weekly, and 38% and 36% of those treated every 2 weeks, compared with 10% and 8.5% of those on placebo (P less than .0001).

Improvement from baseline in the Eczema Area and Severity Index ( EASI ) score in the SOLO 1 and SOLO 2 studies, respectively, were 72% and 69% of those treated with 300 mg weekly and 72% and 67% of those treated every 2 weeks, compared with 38% and 31% of those on placebo (P less than .0001).

The rates of adverse events ranged from 65% to 73% for those on dupilumab, and from 65% to 72% for those on placebo. The rates of serious adverse events were 1%-3% among those on dupilumab and 5%-6% for placebo; serious and severe infections were more common among those on placebo. Compared with placebo, injection site reactions were higher among those on dupilumab (10%-20% vs. 7%-8%). Conjunctivitis was more common among dupilumab-treated patients (7%-12% vs. 2% for placebo). One patient stopped treatment because of conjunctivitis.

The phase III results, which were announced in an April 1 press release , will be presented at a future medical meeting, and the companies plan to file for approval with the Food and Drug Administration in the third quarter of 2016.