Principia Announces Data Presentations of Rilzabrutinib in Patients with Immune Thrombocytopenia (ITP) at Two Upcoming Virtual Medical Meetings

SOUTH SAN FRANCISCO, Calif., May 26, 2020 (GLOBE NEWSWIRE) -- Principia Biopharma Inc. (Nasdaq: PRNB), a late-stage biopharmaceutical company focused on developing treatments for immune-mediated diseases, today announced upcoming presentations at the European Hematology Association (EHA) and the International Society on Thrombosis and Haemostasis (ISTH) congresses from Principia’s clinical program evaluating rilzabrutinib in patients with immune thrombocytopenia (ITP), a rare autoimmune disease that causes high risk for bleeding, excessive bruising, fatigue and potential for life threatening intracranial bleeding due to destruction of platelets.

David Kuter, M.D., Director of Clinical Hematology at Massachusetts General Hospital and Professor of Medicine at Harvard Medical School, will present updates on efficacy and safety, including durability of effect, from the ongoing open-label Phase 1/2 clinical trial in patients with ITP. Presentation dates are outlined below. Following the presentations, the slides and poster will be available on the Principia website.

• 25^th Congress of the European Hematology Association
  Session: ITP: What’s new in 2020 -- Abstract S316
  All oral presentations will be made available on the on-demand Virtual Congress platform as of Friday, June 12 at 8:30 am CEST and will be accessible until October 15, 2020 -- https://ehaweb.org/
  
• International Society on Thrombosis and Haemostasis Congress
  Poster session: Platelet Disorders and von Willebrand Disease Abstracts
  The ePoster will be available on the ISTH 2020 Virtual Congress Platform on July 12, 2020 -- https://www.isth.org/

About ITP and Rilzabrutinib
Immune thrombocytopenia (ITP) is characterized by immune-mediated platelet destruction and impairment of platelet production, leading to downstream thrombocytopenia, a predisposition to bleeding, and adverse impact on patient quality of life. Unmet needs in relapsed or refractory ITP are to improve remission rates and durability by targeting underlying disease mechanisms. Rilzabrutinib is an oral, small molecule, reversible covalent inhibitor of Bruton’s tyrosine kinase (BTK) that modulates immune-mediated processes in ITP. Rilzabrutinib was designed based on Principia’s proprietary Tailored Covalency^® platform to optimize rilzabrutinib’s safety and efficacy profile, resulting in prolonged and reversible action at the target site while being rapidly eliminated from the body. Principia believes this approach limits systemic exposure of rilzabrutinib and enables rapid clinical reversibility of effects on the immune system and is thus designed for use as a chronic therapy in immune-mediated diseases.

About Principia Biopharma
Principia is a late-stage biopharmaceutical company dedicated to bringing transformative therapies to patients with significant unmet medical needs in immune-mediated diseases. Through Principia’s proprietary Tailored Covalency^® platform, our strategy is to build and advance a pipeline of best-in-class drug candidates with significant therapeutic benefits, limit unintended side effects, improve quality of life and over time modify the course of disease. This highly reproducible approach enables the company to pursue multiple programs efficiently, having discovered three drug candidates. Rilzabrutinib, a reversible covalent BTK inhibitor, is being evaluated in a global Phase 3 clinical trial in participants with pemphigus, a Phase 1/2 clinical trial in participants with immune thrombocytopenia (ITP), and the company plans to initiate a Phase 2 clinical trial in participants with IgG4-Related Diseases. PRN2246/SAR442168 is a covalent BTK inhibitor which crosses the blood-brain barrier and is partnered with Sanofi. Sanofi has announced that PRN2246/SAR442168 will be evaluated in four Phase 3 clinical trials in participants with relapsing and progressive forms of multiple sclerosis. PRN473 Topical, a topical reversible covalent BTK inhibitor designed for immune mediated diseases that could benefit from localized application to the skin, is being evaluated in a Phase 1 trial. For more information, please visit www.principiabio.com.

Forward-Looking Statements
This press release contains forward-looking statements. These forward-looking statements reflect the current beliefs and expectations of management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to, Principia’s expectations regarding the Principia pipeline of product candidates, the initiation, progress of, and timing of, its clinical trials, the timing, scope and success of additional clinical results, and the planned presentation of rilzabrutinib efficacy and safety datain its ongoing Phase 1/2 clinical trial in ITP at the virtual EHA and ISTH congresses. Such forward-looking statements involve known and unknown risks, uncertainties, and other important factors that may cause Principia’s actual results, performance, or achievements to be materially different from those expressed or implied by the forward-looking statements. For a description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to Principia’s business in general, see the risk factors set forth in Principia’s reports filed with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and Principia specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.

Investor Contact: Christopher Chai, CFO ir@principiabio.com Media Contact: Paul Laland media@principiabio.com 415.519.6619