SOUTH SAN FRANCISCO, CA, USA I May 14, 2019 I Principia Biopharma Inc. (Nasdaq: PRNB), a late-stage biopharmaceutical company dedicated to bringing transformative oral therapies to patients with significant unmet medical needs in immunology and oncology, today announced that the first patient has been dosed in its partner Sanofi’s Phase 2b clinical trial of SAR442168 in patients with relapsing multiple sclerosis (MS), triggering a $30 million milestone payment to Principia. SAR442168, formerly known as PRN2246, is a Bruton’s tyrosine kinase (BTK) inhibitor that crosses the human blood-brain barrier and modulates immune cell function in both the periphery and in the brain, which shows promise for the potential treatment of central nervous system (CNS) diseases.

“We are delighted that the first patient has been dosed in Sanofi’s Phase 2b dose-finding trial in patients with relapsing multiple sclerosis,” said Martin Babler, president and chief executive officer of Principia. “One challenge in developing medicines for CNS disorders has been achieving sufficient blood–brain barrier penetration. We are very enthusiastic about the potential of our CNS-penetrating BTK inhibitor, especially because in a Phase 1 clinical trial, we demonstrated exposure of SAR442168 in the CNS as well as BTK occupancy in peripheral blood.”

About the Phase 2b Clinical Trial of SAR442168
Sanofi is conducting a global, randomized, double-blind, placebo-controlled, Phase 2b clinical trial that will enroll approximately 120 patients with MS to evaluate SAR442168. The trial will include adult patients diagnosed with relapsing MS (RMS) with at least 1 relapse during the previous year, or 2 or more relapses during the previous 2 years, or 1 or more active Gadolinium (Gd)-enhancing brain lesion on magnetic resonance imaging (MRI) scan in the past 6 months prior to screening. The trial will evaluate the dose response of SAR442168, once daily, for the treatment of RMS based on MRI assessments.

About SAR442168
SAR442168, formerly known as PRN2246, is being developed to potentially treat MS and other CNS diseases, in part by penetrating the blood-brain barrier and modulating B cells and other immune cells in the CNS. During neuro-inflammation, the number of B cells in the brain increases, which is thought to play a central role in the pathology of MS and other CNS diseases. This provides the potential of targeting the adaptive and innate immunity in both the periphery and also within the CNS. In late 2017, Principia formed a collaboration with Sanofi under which Principia granted Sanofi an exclusive, worldwide license to develop and commercialize SAR442168.  Principia completed Phase 1 activities. Key findings from the Phase 1 trial included confirming that SAR442168 was well tolerated in the trial, that BTK occupancy increased in a dose dependent manner, and that cerebral spinal fluid exposure was achieved in all subjects who underwent lumbar puncture. Phase 2b and any further development will be conducted by Sanofi, a global biopharmaceutical company committed to discovering and developing new treatment options for people living with serious diseases, including MS.

About Principia Biopharma
Principia is a late-stage biopharmaceutical company dedicated to bringing transformative oral therapies to patients with significant unmet medical needs in immunology and oncology. Principia’s proprietary Tailored Covalency® platform enables the Company to design and develop reversible and irreversible covalent, small molecule inhibitors with potencies and selectivities that have the potential to rival those of injectable biologics yet maintain the convenience of a pill. PRN1008, a reversible covalent BTK inhibitor, is being evaluated in a Phase 3 clinical trial in patients with pemphigus, an orphan autoimmune disease, and in a Phase 2b clinical trial in patients with immune thrombocytopenia, a rare hematological disease. SAR442168 (formerly PRN2246), a covalent BTK inhibitor which crosses the blood-brain barrier, is in a Phase 2b clinical trial in patients with multiple sclerosis, and has been partnered with Sanofi for development in multiple sclerosis and, potentially, for other diseases of the central nervous system . PRN1371, a covalent inhibitor of Fibroblast Growth Factor Receptor (FGFR) is being evaluated in a Phase 1 trial in patients with bladder cancer. For more information, please visit www.principiabio.com.

SOURCE: Principia Biopharma