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Pieris Pharmaceuticals Presents IND-enabling Data for Bispecific Immuno-Oncology Drug Candidate, PRS-343, in Poster Session at the 2017 Meeting of the American Association for Cancer Research (AACR)

BOSTON, MA--(Marketwired - April 04, 2017) - Pieris Pharmaceuticals, Inc. (PIRS), a clinical-stage biotechnology company advancing novel biotherapeutics through its proprietary Anticalin® technology platform, announced today the presentation of data informing the design of a first-in-patient clinical trial for PRS-343, a first-in-class 4-1BB/HER2 bispecific in a poster session at the 2017 Annual Meeting of the American Association for Cancer Research (AACR).

Complementing previously disclosed preclinical data demonstrating that PRS-343 elicits robust T cell expansion in the tumor microenvironment while avoiding unwanted peripheral T cell activation in HER2-positive cancer models, the data presented today demonstrate:

  • PRS-343 elicited robust T cell activation when engaging HER2 on cell lines derived from tumors resistant to trastuzumab therapy, as well as tumor cell lines with elevated HER2 expression in the IHC 2+ range
  • 4-1BB-mediated T cell activation by PRS-343 resulted in the expression of a broad spectrum of inflammatory cytokines associated with anti-tumor immune responses
  • PRS-343 was well tolerated and led to no significant findings in IND-enabling preclinical safety and non-human primate toxicology studies

Today's presented data suggest the clinical potential of PRS-343 in a broad population of patients with HER2-expressing cancers," commented Louis Matis, MD, Chief Development Officer of Pieris. "Moreover, the preclinical pharmacokinetic and safety profile of PRS-343 supports the initiation of clinical development, which we anticipate during the first half of this year." A copy of the poster can be viewed here.

About PRS 343:
PRS-343 is a bispecific monoclonal antibody/Anticalin fusion protein comprised of a HER2 tumor-targeting mAb genetically linked to a potent Anticalin specific for the immune costimulatory TNF family receptor 4-1BB (CD137). PRS-343 is being developed as the first 4-1BB based therapeutic to mediate the activation of tumor-specific T lymphocytes selectively within the tumor microenvironment (TME). 4-1BB is a potent costimulatory immunoreceptor and an established marker for tumor-specific infiltrating T lymphocytes (TILs), and is, therefore, an attractive target for cancer immunotherapy. In in vivo preclinical tumor models, PRS-343 has demonstrated potent T lymphocyte activation localized to the TME of established HER2-positive tumors, indicating the potential for both enhanced safety and efficacy.

About Pieris Pharmaceuticals:
Pieris is a clinical stage biotechnology company that discovers and develops Anticalin-based drugs to target validated disease pathways in a unique and transformative way. Our pipeline includes immuno-oncology multi-specifics tailored for the tumor micro-environment, an inhaled Anticalin to treat uncontrolled asthma and a half-life-optimized Anticalin to treat anemia. Proprietary to Pieris, Anticalins are a novel class of protein therapeutics validated in the clinic and by partnerships with leading pharmaceutical companies. Anticalin®, is a registered trademark of Pieris. Pieris has partnerships with Servier, ASKA, Roche, Sanofi, Daiichi Sankyo and Zydus. For more information visit www.pieris.com.

Forward Looking Statements
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