Principia Biopharma Inc. 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. 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.