AnaptysBio's IL-33 antibody stumbles in midphase eczema trial

After clearing a midstage study in asthma last fall, AnaptysBio’s anti-IL-33 antibody missed the mark in a phase 2b trial testing it in atopic dermatitis, or eczema. The drug, etokimab, did worse than placebo at easing symptoms such as itch and skin inflammation after 16 weeks of treatment. 

AnaptysBio’s stock tanked more than 70% in premarket trading. 

The ATLAS study pitted four doses of etokimab against placebo in 300 adults with moderate to severe eczema, according to All four doses missed the primary endpoint of the study, which was to show “statistically greater improvement” in eczema symptoms, as measured by the Eczema Area and Severity Index (EASI), after 16 weeks.

“We are surprised and very disappointed by the topline results of the ATLAS trial,” said AnaptysBio CEO Hamza Suria, in a statement. “We would like to thank all involved in the participation and support of the ATLAS study, including the patients, the investigators, their staff and our employees.  We look forward to continuing our strategy of advancing our wholly-owned clinical and preclinical pipeline programs.” 

RELATED: Pfizer's JAK inhibitor hits the mark in another phase 3 eczema trial 

The ripples of these data extend beyond the company’s eczema program. On the strength of the phase 2a data, AnaptysBio had planned to take etokimab into a phase 2b study of 300 to 400 patients with eosinophilic asthma. Now, it is postponing that trial until it’s analyzed the full data from the eczema study, the company said in the statement. 

That said, AnaptysBio is going full steam ahead on a phase 2 study of etokimab in about 100 adults with chronic rhinosinusitis with nasal polyps. It expects to reveal topline data in the first quarter of next year. The drug put up proof-of-concept data in peanut allergy in early 2018, but questions arose about the size of the study and the company’s decision to exclude a couple of patients from the analysis, which improved the results. That indication has since been removed from the company’s pipeline page. 

Beyond etokimab, the San Diego biotech is developing ANB019, an anti-IL-36R drug, for pustular psoriasis and palmoplantar pustulosis, an autoimmune condition that causes blister-like sores to form on the palms of the hands and soles of the feet. It also plans to file an IND for a PD-1 agonist it's developing for inflammatory diseases. 

AnaptysBio also has a number of partnered programs, including a suite of cancer programs it’s working on with GlaxoSmithKline and a pair of pacts with Celgene.