Sanofi's $1.1B eczema drug hits midphase goal, spurring talk of phase 3 and new indications

One of Sanofi’s priority assets has hit the primary endpoint in a phase 2b clinical trial. The candidate, which Sanofi snagged in its $1.1 billion Kymab buyout, improved outcomes in eczema patients, clearing the French drugmaker to push into phase 3 and boosting its prospects of targeting other diseases. 

Sanofi previously added the drug candidate, the anti-OX40-ligand monoclonal antibody amlitelimab, to its list of prospects that receive additional funding to accelerate development. A phase 2b trial in atopic dermatitis, the most common form of eczema, represented the first test of whether Sanofi’s belief in the molecule is justified. The antibody passed the test, although key details remain under wraps for now. 

The phase 2b trial randomized 390 people with moderate to severe atopic dermatitis to receive one of four subcutaneous doses of amlitelimab or placebo. After 16 weeks, Sanofi saw a significant change on an eczema scale from baseline, causing the study to hit its primary endpoint.

Sanofi is yet to share the data underpinning the primary endpoint success, or any numbers from the trial, but did provide a few more high-level findings. The improvements on the eczema scale continued out to Week 24, a key secondary endpoint, and the antibody was well tolerated in all dose arms. No new safety concerns were identified. 

“We believe that the results from this phase 2b study with amlitelimab support our perspective that targeting OX40-ligand has the potential to provide a first and best-in-class treatment option that addresses type 2 and non-type 2 inflammation to meet the individual needs of people living with atopic dermatitis and other chronic inflammatory diseases,” Naimish Patel, M.D., head of global development, immunology and inflammation at Sanofi, said in the release.

Sanofi sees targeting OX40-ligand as a way to restore immune homeostasis between pro-inflammatory and regulatory T cells. Hitting OX40-ligand rather than OX40 could increase the antibody’s effect on T-cell stimulation while maintaining regulatory T cells. Sanofi now has evidence the mechanism helps atopic dermatitis patients failed by topical drugs. A midphase asthma trial has a 2024 primary completion date.

Talking to investors earlier this month, Bill Sibold, executive vice president specialty care at Sanofi, said the first step is to collect data in atopic dermatitis and asthma, but “assuming that works, you would expect that we would look at other indications as well.” The strategy echoes Sanofi’s approach to Dupixent, development of which expanded quickly beyond its initial focus on eczema and asthma.