The pharma giant pulled out of its partnership with Sangamo, signalling unsteady waters for the latter company and the future of gene therapies.

Pfizer gave Sangamo Therapeutics coal for Christmas, terminating a hemophilia A gene therapy pact to deprive the cash-strapped biotech of up to $220 million in milestones.

Sangamo, a gene therapy pioneer, loses a financial lifeline as Pfizer drops a gene therapy program for hemophilia.

Sangamo Therapeutics said on Monday that partner Pfizer has terminated their hemophilia A gene therapy co-development agreement, sending its shares down nearly 64% in extended trade. Sangamo added that it has now regained the rights to the therapy's development and would explore all options to advance the program,

Sangamo Therapeutics Inc.’s stock tumbled 56% on Tuesday for its second-biggest one-day percentage decline ever, after Pfizer Inc. terminated a hemophilia A gene-therapy partnership.

The biotech company intends to explore ways to move ahead with developing the treatment, including seeking a new collaborator.

Sangamo Therapeutics, Inc. (NASDAQ:SGMO) regained the development and commercialization rights to giroctocogene fitelparvovec, an investigational gene therapy product candidate for moderately severe to severe hemophilia A that it has co-developed with and licensed to Pfizer Inc (NYSE:PFE).