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.

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 is on course to run out of money within months and has now lost access to up to $220 million in milestone payments from Pfizer.

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

Sangamo Therapeutics (SGMO) stock plunged as Pfizer (PFE) ends collaboration on hemophilia A gene therapy. Find out the reasons for the selloff.