AnaptysBio’s lead IL-33 antibody clears midstage test in asthma

Next-generation antibody company AnaptysBio has positive data for its lead pipeline drug etokimab in a third indication, adding asthma to its earlier wins in peanut allergy and atopic dermatitis.

The phase 2a trial in severe eosinophilic asthma gives the San Diego company another proof-of-concept study for the interleukin-33 (IL-33) inhibitor, setting up a third phase 2b program that it says will start early next year. Shares in the company were down marginally after the announcement.

The study was small—involving just 25 patients who received a single intravenous dose of etokimab (ANB020)—but according to the company showed that the anti-IL-33 drug had a rapid impact on lung function that lasted for around two months.

Using the forced exhalation in one second (FEV1) measure, the trial showed an 8% improvement for the antibody compared to placebo the second day after dosing, and this rose to 11% by day 64, although the difference fell back to 4% and 6% at timepoints in between.

Blood biomarkers supported the proposed mechanism of the drug, with eosinophil levels down 31% at day two and 46% at day 64 versus control, though once again with dips in the interim. All the patients were also taking inhaled steroids and beta agonist bronchodilators.

The trial’s principal investigator—University of Oxford respiratory specialist Professor Ian Pavord—said the data shows “the potential for IL-33 inhibition in treating severe eosinophilic asthma” but will need to be investigated further in additional studies.

Earlier this year, AnaptysBio reported proof-of-concept data with etokimab in peanut allergy, once again with some questions about study in terms of its size and the San Diego biotech’s decision to exclude a couple of patients from the analysis, which improved the results.

In 2017, it reported data in atopic dermatitis which CEO Hamza Suria said were “a solid foundation for the continued development of [the drug] across a number of atopic diseases”—and helped the company complete a $195 million public offering to help fund its phase 2 programs, which will use a new subcutaneous formulation of the drug.

The company has two phase 2b trials on the go—ATLAS in atopic dermatitis and ECLIPSE in chronic rhinosinusitis with nasal polyps—that are due to read out in the second half of 2019, said Suria on a conference call.

With three separate studies now showing an impact on inflammatory diseases, the biotech is becoming increasingly confident that IL-33 is a target worth pursuing. Etokimab is pitching at increasingly competitive indications with atopic dermatitis and severe asthma however, as both diseases have new biologic therapies in the rollout phase.

“We are thrilled to have demonstrated proof-of-concept in this single dose Phase 2a trial and look forward to advancing the development of etokimab for patients suffering from eosinophilic asthma,” commented Suria, who says the biotech is out in front in the anti-IL-33 category.

“Genotypic studies have validated the key role played by IL-33 in asthma, and we believe etokimab’s upstream mechanism has the potential for a broad therapeutic benefit across multiple atopic disorders.”