PTC Therapeutics plans to buy a drug candidate from Sangamo Therapeutics for up to $211 million.

Under the agreement, PTC will pay $111 million upfront, plus up to an additional $100 million in contingent milestone payments, according to a filing with the Securities and Exchange Commission on Friday.

The milestone payments include $80 million upon accelerated approval by the Food and Drug Administration for a biologics license application and $20 million upon full approval by the FDA.

The deal is for ST-920, a gene therapy product candidate aimed at treating Fabry disease, a rare genetic disorder.