Why Sanofi (SNY) Is Buying Principia Biopharma (PRNB) In A $3.68 Billion Deal

By Dan Anderson ● August 17, 2020
  • Sanofi SA (NASDAQ: SNY) and Principia Biopharma Inc (NASDAQ: PRNB) announced it entered into a definitive agreement under which Sanofi will buy all of the outstanding shares of Principia. These are the details.

Sanofi SA (NASDAQ: SNY) and Principia Biopharma Inc (NASDAQ: PRNB) — which is a late-stage biopharmaceutical company focused on developing treatments for immune-mediated diseases — announced it entered into a definitive agreement under which Sanofi will buy all of the outstanding shares of Principia for $100 per share in cash. This represents an aggregate equity value of about $3.68 billion (on a fully diluted basis). The Sanofi and Principia Boards of Directors have unanimously approved the transaction already.

Principia’s Bruton tyrosine kinase (BTK) inhibitors are adding to Sanofi’s efforts to accelerate and build a portfolio of the next generation of transformative treatments for autoimmune diseases. BTK is present in the signaling pathways of key innate and adaptive cell types of the immune system. And being able to block or disrupt these signaling processes can help in stopping inflammation and tissue destruction related to autoimmune diseases and target some of the underlying pathophysiology. 

BTK inhibitor ‘168: 

In a Phase 2b study in patients with multiple sclerosis, ‘168 had reduced Gd-enhancing T1 hyperintense lesions by 85% compared to placebo. And in June, Sanofi announced the first multiple sclerosis patient was enrolled in the Phase 3 program for the BTK inhibitor, comprising four pivotal clinical trials across the disease spectrum.

This acquisition will provide an opportunity to expand the development program to evaluate indications beyond central nervous system diseases.  


This oral BTK inhibitor is currently being evaluated in a Phase 3 program for patients with moderate to severe pemphigus, which is a rare debilitating autoimmune disease that causes blistering of the skin and mucous membranes. A Phase 3 program for immune thrombocytopenia, a disease that causes high risk for bleeding events, is expected to be initiated by the end of 2020, assuming no COVID-19 related impact. And the company also has an ongoing Phase 2 program for IgG4-related diseases, which is driven by chronic inflammation, immune cell infiltration, and fibrosis within organs that can lead to severe morbidity.

PRN473 Topical: 

This BTK inhibitor is a topical agent currently in Phase 1 trials and is being developed for immune-mediated diseases that could benefit from localized application to the skin. The Principia BTK inhibitor franchise is based on its proprietary Tailored Covalency platform that has generated potential best-in-class clinical candidates. 

The platform allows the design of both reversible covalent and irreversible covalent small molecule inhibitors that are more selective with less off-target effects. And the optimized target residence time has potential to deliver a desired efficacy with a stronger safety profile.

In 2017, Sanofi formed a collaboration with Principia under which Principia granted Sanofi an exclusive worldwide license to develop and commercialize BTK inhibitor ‘168 in multiple sclerosis and other central nervous system diseases.

Deal Terms:

As part of the merger agreement, Sanofi will commence a cash tender offer to acquire all outstanding shares of Principia common stock for $100 per share in cash for a total enterprise value of approximately $3.36 billion. And the consummation of the tender offer is subject to customary closing conditions, including the tender of at least a majority of the outstanding shares of Principia common stock, the expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, and other customary conditions.

Upon the successful completion of the tender offer, a wholly owned subsidiary of Sanofi will merge with Principia and the outstanding Principia shares not tendered in the tender offer will be converted into the right to receive the same $100 per share in cash paid in the tender offer. 

The tender offer is expected to commence later this month. And Sanofi plans to finance the transaction with cash on hand. The deal is expected to close in the fourth quarter of 2020. 

Evercore is acting as financial advisor to Sanofi and Weil, Gotshal & Manges LLP is acting as legal counsel. And Centerview Partners LLC and BofA Securities are acting as financial advisors to Principia and Cooley LLP is acting as its legal counsel.


“This acquisition advances our ongoing R&D transformation to accelerate development of the most promising medicines that will address significant patient needs. The addition of multiple BTK inhibitors to our pipeline demonstrates our commitment to strategic product acquisitions in our priority therapeutic areas. Full ownership of our brain-penetrant BTK inhibitor ‘168 removes complexities for this priority development program and simplifies future commercialization.”

– Sanofi Chief Executive Officer Paul Hudson

“The Phase 2b data in relapsing multiple sclerosis showed the strong potential of ‘168 to address disability and disease progression, and triggered the start of Phase 3 studies across the full spectrum of MS. Through this acquisition, we will be able to expand and accelerate development of BTK inhibitors across multiple indications. Both ‘168 and rilzabrutinib, have ‘pipeline in a product’ potential, and we look forward to unlocking their full treatment benefits across an array of diseases.”

– John Reed, M.D., Ph.D., Global Head of Research & Development at Sanofi

“Principia’s successful design and development of a whole portfolio of BTK inhibitors for immunology is aimed to transform the treatment for patients with immune-mediated diseases. By combining with Sanofi, we will bring significant resources to expand and accelerate the potential benefits of these therapies. The benefit of developing several BTK inhibitors will allow us to target specific organ systems for optimal patient benefit. The merger will provide global resources to get these novel therapies to patients faster.”

– Martin Babler, President and CEO at Principia Biopharma