BOSTON, MA, USA I June 21, 2023 I Pieris Pharmaceuticals, Inc. (NASDAQ:PIRS), a clinical-stage biotechnology company advancing novel biotherapeutics through its proprietary Anticalin® technology platform for respiratory diseases and cancer indications, announced that partner AstraZeneca yesterday communicated to Pieris its decision to discontinue and cease dosing in the ongoing clinical studies of elarekibep, an inhaled IL-4 receptor alpha inhibitor under development for the treatment of asthma. This decision was based on lung findings from a non-clinical 13-week GLP toxicology study with dry powder inhaler-formulated elarekibep, which are not a concern for the active clinical studies but do not support long-term use and progression to later-stage development. AstraZeneca’s decision was made independent of any data from the Phase 2a study. 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 13-week non-human primate study included three active dose cohorts. AstraZeneca concluded that there were no clinical observations across any of the doses but that there were respiratory tract pathology findings. These findings included inflammation-mediated lung tissue damage, which did not appear to be dose related.

“We are disappointed with these non-clinical study results. Although elarekibep had begun enrolling in the efficacy portion of the Phase 2a study, later-stage development of this program requires supportive longer-term non-clinical toxicology data,” stated Stephen Yoder, Pieris’ President and CEO. “We will now reassess our priorities and communicate a corporate update as quickly as possible following a thorough review of our options. We have greatly valued the expertise and resources AstraZeneca committed to elarekibep and are grateful to the many physicians, patients and caregivers who have supported this study.”

About Pieris Pharmaceuticals:

Pieris is a clinical-stage biotechnology company that combines leading protein engineering capabilities and deep understanding into molecular drivers of disease to develop medicines that drive local biology to produce superior clinical outcomes for patients. Our pipeline includes inhalable Anticalin proteins to treat respiratory diseases and locally-activated bispecifics for immuno-oncology. Proprietary to Pieris, Anticalin proteins are a novel class of therapeutics validated in the clinic and by strong partnerships with leading pharmaceutical companies. For more information, visit

SOURCE: Pieris Pharmaceuticals