Pharmaceutical Business review

Sanofi to acquire Synthorx for $2.5bn to strengthen immuno-oncology pipeline

Sanofi to acquire US biotechnology company Synthorx. Photo: courtesy of Sanofi de/Wikimedia Commons.

Headquartered in California, Synthorx is focused on developing therapies for cancer and autoimmune disorders. Sanofi is offering to buy the biotechnology company at $68 per share.

THOR-707, the company’s lead immuno-oncology product candidate, is currently in clinical development in multiple solid tumour types. The interleukin-2 (IL-2) variant is being assessed as a single agent and also in combination with immune checkpoint inhibitors.

According to Sanofi, THOR-707 can potentially become the best IL-2 therapeutic for the treatment of solid tumours and deliver improved pharmacology, therapeutic superiority and also less frequent dosing when compared to other IL-2 compounds.

Synthorx’s Expanded Genetic Alphabet platform technology is said to expand the genetic code by introducing a new DNA base pair.

The technology is claimed to have been designed to create biologics known as Synthorins which are protein optimised by the incorporation of amino acids encoded by the new DNA base pair.

Synthorx president and CEO Laura Shawver said: “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.

“Importantly, Sanofi has a portfolio of therapeutics that holds incredible promise for combining with our cytokine Synthorins to benefit patients around the world.”

Synthorx’s platform technology on its own and in combination with Sanofi’s Nanobody technology and other platforms is expected to help in developing a wide variety of drug conjugates, protein fusions, and multi-specific biologics, having applications in oncology and also in other therapeutic areas.

Sanofi said that it expects IL-2 to become a foundation of future IO-IO combinations apart from giving scope to multiple combinations with its own clinical and pre-clinical oncology assets. Some of the assets the French pharma company is looking to combine with Synthorx’s IL-2 variant are PD-1, CD-38, and molecules that regulate effector T-cells and natural killer cells.

Sanofi research and development global head John Reed said: “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.”

The French pharma company expects to close the deal in the first quarter of 2020, which will be subject to the satisfaction or waiver of customary closing conditions.