BOSTON, MA, USA and PARIS, France I November 8, 2021 I Pieris Pharmaceuticals, Inc. (NASDAQ:PIRS), a clinical-stage biotechnology company advancing novel biotherapeutics through its proprietary Anticalin® technology platform for respiratory diseases, cancer, and other indications, and Servier, a global pharmaceutical group, today announced that the first patient has been dosed in the phase 1/2 study of PRS-344/S095012, a next generation 4-1BB/PD-L1 Anticalin-based bispecific for the treatment of solid tumors, triggering an undisclosed milestone payment to Pieris. The global, open-label phase 1/2 dose escalation study will evaluate the safety, tolerability, potential optimal dosage, and potential anti-tumor activity of PRS-344/S095012 in patients with advanced solid tumors whose cancer progressed on standard-of-care treatment.

PRS-344/S095012 is a tetravalent bispecific fusion protein comprising 4-1BB-targeting Anticalin proteins and a PD-L1-targeting antibody. Preclinical studies showed that PRS-344/S095012 is superior to the combined administration of separate PD-L1- and 4-1BB- targeting molecules. Further, in anti-PD-L1-resistant mouse models, the bispecific induces a dose-dependent anti-tumor response and significantly extends survival. In vitro, PRS-344/S095012 enhances effective CD8+ T cell response and proinflammatory cytokine release. Furthermore, preclinical models reflect that PRS-344/S095012-mediated 4-1BB activation is PD-L1 dependent, reducing the risk of peripheral toxicity, and 4-1BB co-stimulation only occurs in combination with simultaneous TCR signaling, restricting its activity to antigen-specific T cells.

“This marks an important step in our development of PRS-344/S095012, our broader 4-1BB bispecifics franchise, and our strategic alliance with Servier. Our 4-1BB/PD-L1 bispecific has been designed to address localized 4-1BB agonism while driving PD-L1 antagonism benefit, thereby facilitating a meaningful therapeutic window,” said Tim Demuth, M.D., Ph.D., Chief Medical Officer of Pieris.

“PRS-344/S095012 has shown clear synergistic benefit in preclinical studies thanks to its bispecific format. We are excited to have begun clinical development of PRS-344/S095012, which may provide patients with a new treatment option and significant clinical impact. The dosing of the first patient in this study marks a meaningful step to developing a potential future treatment for cancer patients with limited options,” said Patricia Belissa-Mathiot, Director of Clinical Development and R&D Chief Medical Officer at Servier.

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 respiratory and immuno-oncology focused partnerships with leading pharmaceutical companies. For more information, visit

About Servier

Servier is a global pharmaceutical group governed by a Foundation. With a strong international presence in 150 countries and a total revenue of 4.7 billion euros in 2020, Servier employs 22,500 people worldwide. Servier is an independent group that invests over 20% of its brand-name revenue in Research and Development every year. To accelerate therapeutic innovation for the benefit of patients, the Group is committed to open and collaborative innovation with academic partners, pharmaceutical groups, and biotech companies. It also integrates the patient’s voice at the heart of its activities, from research to support beyond the pill.

A leader in cardiology, the ambition of the Servier Group is to become a renowned and innovative player in oncology. Its growth is based on a sustained commitment to cardiovascular and metabolic diseases, oncology, neuroscience and immuno-inflammatory diseases. To promote access to healthcare for all, the Servier Group also offers a range of quality generic drugs covering most pathologies.

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SOURCE: Pieris Pharmaceuticals