Pieris stock deflates as AstraZeneca stops trials of asthma drug in response to toxicology signal

AstraZeneca has pulled the plug on clinical trials of its asthma candidate elarekibep after seeing data from a toxicology study. Pieris Pharmaceuticals, which licensed the inhaled IL-4 receptor alpha inhibitor to AstraZeneca, attributed the decision to “lung findings” from a 13-week nonclinical assessment.

According to Pieris, the nonhuman primate study generated no clinical observations across any of the three doses but did reveal “respiratory tract pathology findings” including inflammation-mediated lung tissue damage. The damage in primates that received a dry powder inhaler formulation of elarekibep did not appear to be dose related, Pieris said in a statement. 

The biotech added that the findings from the nonclinical tests “are not a concern for the active clinical studies but do not support long-term use and progression to later-stage development.” AstraZeneca responded to the data by discontinuing and stopping dosing in ongoing clinical studies of elarekibep, also known as AZD1402.

While Pieris is still considering its response, investors wasted no time in reacting. Shares in the company fell 58% to 37 cents in premarket trading Wednesday from a Tuesday closing price of 89 cents.

“Pieris will expedite a review of the implications of the data and AstraZeneca's decision on the program and will review its overall corporate priorities prior to sharing a further update,” the biotech said. 

The cessation of the clinical program was unrelated to the results of a phase 2a trial, which AstraZeneca was running to study the effect of elarekibep on the lung function of adults with asthma. Subjects in the study had uncontrolled asthma on medium-to-high doses of inhaled corticosteroids.

AstraZeneca paid $45 million to partner with Pieris in 2017 in an agreement that gave it rights to the then-preclinical elarekibep. Interest in the drug candidate was underpinned by evidence that Pieris had solved the puzzle of how to develop an inhaled antagonist for IL-4Ra, which is highly expressed in airways and implicated in type 2 endotype asthma. Antibodies against the target have low lung bioavailability.