Principia Announces Expansion of its BTK Franchise with PRN473 Topical

Company expands focus on immune-mediated diseases and suspends FGFR program

Company outlines anticipated key corporate milestones

SOUTH SAN FRANCISCO, Calif., Jan. 09, 2020 (GLOBE NEWSWIRE) -- Principia Biopharma Inc. (Nasdaq: PRNB), a late-stage biopharmaceutical company focused on developing treatments for immune-mediated diseases, today announced an expansion of its Bruton tyrosine kinase (BTK) franchise with PRN473 Topical. The company also announced suspension of PRN1371, an FGFR inhibitor for bladder cancer to focus the portfolio on immune-mediated diseases.

“PRN473 Topical broadens Principia’s portfolio of purpose-designed BTK inhibitors, with the goal of expanding the options for patients and the knowledge of BTK’s role across immune-mediated diseases,” said Martin Babler, Principia’s president and chief executive officer. “Principia remains at the forefront of BTK immune therapy with three separate molecules and approaches (systemic, topical, and CNS), each with distinctive rationales and potential future commercial opportunities.”

By commencing clinical development of PRN473 Topical, a reversible covalent BTK inhibitor, Principia believes topical administration will be an important addition to the expected utility of systemic BTK inhibition (rilzabrutinib) and CNS-penetrant BTK therapy (SAR442168/PRN2246).  Each of the three programs were discovered by Principia and have separate intellectual property estates.

About PRN473 Topical
PRN473 Topical, an investigational drug, is entering into a Phase 1, randomized, double blind, placebo-controlled, single and multiple dose trial to evaluate its safety, tolerability and pharmacokinetics. The trial will be conducted in Australia and is expected to be completed in 2020.

BTK is involved in innate and adaptive immune responses and is a critical signaling molecule in immune-mediated diseases. BTK inhibitors have demonstrated an ability to block inflammatory immune cells, eliminate autoantibody destructive signaling, and prevent new autoantibody production without depleting B cells. Given the abundance of immune cells in skin and their role in immune-mediated diseases, PRN473 Topical is being developed for localized skin applications. PRN473 Topical is the company’s third BTK inhibition molecule to enter the clinic, joining rilzabrutinib, an oral, reversible covalent BTK inhibitor designed to treat systemic diseases (pemphigus, immune thrombocytopenia, and IgG4-RD) and SAR442168/PRN2246, the company’s partnered central nervous system (CNS) penetrating BTK inhibitor that targets immune and inflammatory diseases of the CNS (multiple sclerosis).