Sanofi to acquire Synthorx to bolster its immuno-oncology pipeline for $2.5 Billion

• Proprietary immuno-oncology (IO) platform synergistic with Sanofi’s existing therapeutic platforms  
• Lead asset THOR-707 (“not-alpha” IL-2) being explored across multiple solid tumor types alone and in combination with immune checkpoint inhibitors and other future IO combinations
• Pre-clinical pipeline for oncology and autoimmune disorders

PARIS and San Diego, California – December 9, 2019 – Sanofi and Synthorx, Inc. (NASDAQ: THOR), a clinical-stage biotechnology company focused on prolonging and improving the lives of people suffering from cancer and autoimmune disorders, entered into a definitive agreement under which Sanofi will acquire all of the outstanding shares of Synthorx for $68 per share in cash, which represents an aggregate equity value of approximately $2.5 billion (on a fully diluted basis). The transaction was unanimously approved by both the Sanofi and Synthorx Boards of Directors.

“This acquisition fits perfectly with our strategy to build a portfolio of high-quality assets and to lead with innovation, as you will hear at our Capital Markets Day tomorrow, December 10. Additionally, it is aligned with our goal to build our oncology franchise with potentially practice-changing medicines and novel combinations," says Paul Hudson, Chief Executive Officer, Sanofi.

“Synthorx’s exceptionally novel discovery platform has already produced a molecule that has the potential to become a foundation of the next generation of immuno-oncology combination therapies. By selectively expanding the numbers of effector T-cells and natural killer cells in the body, THOR-707 can be combined with our current oncology medicines and our emerging pipeline of immuno-modulatory agents for treating cancer. Moreover, Synthorx’s pipeline of engineered lymphokines has great promise not only for oncology but also for addressing many autoimmune and inflammatory diseases. ” says John Reed, M.D., Ph.D., Global Head of Research & Development at Sanofi.

“We are grateful that Sanofi has acknowledged the value of our Expanded Genetic Alphabet platform and the potential of our pipeline of optimized therapeutics for cancer and autoimmune disorders,” says Laura Shawver, Ph.D., President and Chief Executive Officer, Synthorx. “Importantly, Sanofi has a portfolio of therapeutics that holds incredible promise for combining with our cytokine Synthorins to benefit patients around the world. I want to thank our employees and the Sanofi organization for their relentless efforts on behalf of patients.”

Enhancing Sanofi’s Immuno-Oncology Franchise

Synthorx’s lead immuno-oncology product candidate, THOR-707, a variant of interleukin-2 (IL-2), is in clinical development in multiple solid tumor types as a single agent and in combination with immune checkpoint inhibitors. It has the potential to become the best-in-class IL-2 therapeutic for the treatment of solid tumors and demonstrate improved pharmacology, less frequent dosing, and therapeutic superiority when compared to other IL-2 compounds.

The addition of THOR-707 and Synthorx’s other earlier-stage cytokine programs to Sanofi’s pipeline will enhance Sanofi’s position in oncology, and in immuno-oncology. We expect IL-2 to become a foundation of future IO-IO combinations as well as offering multiple combination opportunities with Sanofi’s clinical and pre-clinical oncology assets, including with PD-1, CD-38, and molecules that modulate effector T-cells and natural killer cells.

Synergistic with Sanofi’s existing platforms

Synthorx’s Expanded Genetic Alphabet platform is expected to be a source for developing a differentiated therapeutic pipeline. Alone and in combination with other existing Sanofi platforms, including the Nanobody^® technology, it will enable the company to develop a wide range of novel biologics, including drug conjugates, protein fusions, and multi-specific biologics, with applications beyond oncology and extending to other therapeutic areas.

Transaction Terms

Under the terms of the merger agreement, Sanofi will commence a cash tender offer to acquire all of the outstanding shares of Synthorx common stock for $68 per share in cash for a total enterprise value of approximately $2.35 billion. The $68 per share acquisition price represents a 172% premium to Synthorx’s closing price on December 6, 2019.

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 Synthorx common stock, the expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, and other customary conditions. Following the successful completion of the tender offer, a wholly owned subsidiary of Sanofi will merge with Synthorx and the outstanding Synthorx shares not tendered in the tender offer will be converted into the right to receive the same $68 per share in cash paid in the tender offer. The tender offer is expected to commence in December 2019. Sanofi plans to finance the transaction with cash on hand. Subject to the satisfaction or waiver of customary closing conditions, Sanofi expects to complete the acquisition in the first quarter of 2020.

Morgan Stanley & Co. is acting as financial advisor to Sanofi and Weil, Gotshal & Manges LLP is acting as its legal counsel. Centerview Partners LLC is acting as exclusive financial advisor to Synthorx and Cooley LLP is acting as its legal counsel.

About Synthorx

Synthorx, Inc. is a clinical-stage biotechnology company focused on prolonging and improving the lives of people with cancer and autoimmune disorders. Synthorx’s proprietary, first-of-its-kind Expanded Genetic Alphabet platform technology expands the genetic code by adding a new DNA base pair and is designed to create optimized biologics, referred to as Synthorins. A Synthorin is a protein optimized through incorporation of novel amino acids encoded by the new DNA base pair that enables site-specific modifications, which enhance the pharmacological properties of these therapeutics. The company’s lead immuno-oncology (IO) product candidate, THOR-707, a variant of IL-2, is in development in multiple tumor types as a single agent and in combination with an immune checkpoint inhibitor. The company was founded based on important discoveries by Dr. Floyd Romesberg and The Scripps Research Institute. Synthorx is headquartered in La Jolla, Calif. For more information, visit www.Synthorx.com. 

About Sanofi

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