Sangamo strikes TxCell takeover to gain CAR-Treg pipeline

TxCell CEO Stéphane Boissel. (TxCell)

Sangamo Therapeutics is set to acquire TxCell for its CAR-Treg platform and pipeline. The €72 million ($84 million) takeover will position Sangamo to move a CAR-carrying regulatory T cell candidate into testing in solid organ transplant patients next year.

TxCell switched its focus to CAR-Tregs across 2015 and 2016, combining its background in regulatory T cells and autoimmune disorders with CAR targeting. The idea is to insert chimeric antigen receptors into the T cells that control how the immune system responds to foreign particles. When delivered into the patient, these CAR-modified cells should zero in on inflammation sites and bind to target antigens, activating cells that maintain immune homeostasis and prevent autoimmune disease. 

France’s TxCell has worked on the concept for the past few years, accuring preclinical evidence its CAR-Tregs deliver potent, local immunosuppression. That could enable TxCell to stop organ rejection and treat conditions such as Crohn's disease and multiple sclerosis without causing the side effects associated with systemic immunosuppression by the anti-TNF alpha drugs and antibodies used today.

TxCell is yet to test the idea in the clinic but Sangamo thinks there is already enough supporting evidence to justify a small acquisition. Sangamo has persuaded key investors in TxCell to accept its €72 million cash offer and expects to close the deal in the fourth quarter.

The takeover will give Sangamo ownership of a CAR-Treg designed to stop the rejection of solid organ transplants that is set to enter the clinic. Data in that relatively risk tolerant population will inform Sangamo’s attempts to move into chronic autoimmune diseases. TxCell is exploring the use of its T cells in multiple sclerosis, rheumatoid arthritis and inflammatory diseases of the bowel and skin. Further down the line, Sangamo will apply its zinc finger gene editing technology to TxCell’s cells. 

“We believe Sangamo's ZFN editing technology will facilitate the precise genetic modifications needed to create a new class of Treg-based antigen and tissue specific immunosuppressive medicines," TxCell CEO Stephane Boissel said in a statement. "Progressing such CAR-Treg products in clinical development and towards commercialization would require expertise and financial resources that were impossible for us to get as a stand-alone business at a reasonable cost." 

Shares in TxCell increased 150% following news of the deal.