Pieris Pharmaceuticals Announces Milestone Achievement for Boston Pharmaceuticals' Initiation of Phase 1/2 Study of BOS-342, a 4-1BB/GPC3 Immuno-Oncology Bispecific

BOSTON, MA / ACCESSWIRE / August 17, 2023 / Pieris Pharmaceuticals, Inc. (NASDAQ:PIRS), a clinical-stage biotechnology company focused on novel biotherapeutics through its proprietary Anticalin^® technology platform for respiratory diseases and cancer, today announced that the Company has achieved an undisclosed milestone payment from Boston Pharmaceuticals. The milestone is based on dosing the first patient in a Boston Pharmaceutical-sponsored phase 1/2 study of BOS-342 (formerly PRS-342), a 4-1BB/GPC3 immuno-oncology antibody-Anticalin fusion (Mabcalin™) bispecific protein, which was discovered by Pieris and licensed to Boston Pharmaceuticals and designed to provide a potent costimulatory bridge to exert tumor killing activity through the recruitment of T-cells.

The open-label phase 1/2 study is designed to evaluate the safety, tolerability, pharmacokinetics, and efficacy of BOS-342. The Phase 1 dose escalation portion of the study is expected to enroll adults with hepatocellular carcinoma (HCC) that progressed on at least one prior treatment and establish a recommended Phase 2 dose. If pursued, the Phase 2 portion of the study will evaluate efficacy, as measured by overall response rate.

The study is funded and conducted by Boston Pharmaceuticals, who exclusively licensed worldwide rights to BOS-342 in April 2021. In addition to the milestone announced today, Pieris could potentially be entitled to receive up to approximately $350 million in development, regulatory and sales-based milestone payments, and tiered royalties on sales of BOS-342.

"We are delighted with Boston Pharmaceuticals' commitment to BOS-342, now having initiated clinical development of yet another promising 4-1BB bispecific Mabcalin program originating from our platform and representing the fourth 4-1BB-targeted therapy that has entered clinical stage development," said Stephen S. Yoder, President and CEO of Pieris. "4-1BB is a highly promising target for cancer immunotherapy, and our multiple partnerships in this area validate the potential that 4-1BB-based bispecific therapies may play in advancing cancer therapeutics."

"Dosing of the first patient with BOS-342 represents an important milestone for the BOS-342 program and, more importantly, for patients with HCC, many of whom often do not achieve durable benefit from current available treatment regimens," said Sophie Kornowski, CEO of Boston Pharmaceuticals. "Preclinical data strongly support our belief that BOS-342 has the potential to address a significant unmet need as a treatment for patients with GPC3+ HCC."

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 has historically focused on 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 www.pieris.com.

Forward-Looking Statements:

This press release contains forward-looking statements as that term is defined in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Statements in this press release that are not purely historical are forward-looking statements. Such forward-looking statements include, among other things, the potential for Pieris' development programs including BOS-342 to address immuno-oncology diseases; the goals and advancement of our partnered programs, including BOS-342, into and through the clinic; making IND filings or achieving other milestones related to our programs, including BOS-342; the therapeutic potential, safety profile, and market opportunity of our Anticalin platform and our drug candidates; our continued progress in the area of co-stim bispecifics and inhaled therapeutics; the receipt of royalty and/or milestone payments provided for in our collaboration agreements; and the advancement and funding of our developmental programs generally. Actual results could differ from those projected in any forward-looking statement due to numerous factors. Such factors include, among others, potential partnering and strategic transactions or alternatives; our workforce reduction and related restructuring activities; our ability to successfully identify and implement any strategic transaction or strategic transactions that we may consummate in the future, on attractive terms or at all; our ability to realize the anticipated benefits of any strategic transaction; including in collaboration with other parties, the inherent uncertainties associated with developing new products or technologies and operating as a development stage company; our partners' ability to develop, complete clinical trials for, obtain approvals for and commercialize any of product candidates, including our and our partners' ability to recruit and enroll patients in clinical studies; our reliance on collaborative partners and other third parties for development of product candidates; competition in the industry in which we operate; the fact that data and results from clinical studies may not necessarily be indicative of future results; delays or disruptions due to COVID-19 or geopolitical issues, including the conflict in Ukraine; and market conditions. These forward-looking statements are made as of the date of this press release, and we assume no obligation to update the forward-looking statements, or to update the reasons why actual results could differ from those projected in the forward-looking statements, except as required by law. Investors should consult all of the information set forth herein and should also refer to the risk factor disclosure set forth in the reports and other documents we file with the Securities and Exchange Commission, or the SEC, available at www.sec.gov, including, without limitation, the Company's most recent Annual Report on Form 10-K, the Company's Quarterly Reports on Form 10-Q, and subsequent filings with the SEC.

Investor Relations Contact:

Pieris Pharmaceuticals, Inc.
Investors@pieris.com

SOURCE: Pieris Pharmaceuticals, Inc.