Subsequent Events

6 Months Ended

Jun. 30, 2018

Subsequent Events [Abstract]

Subsequent Events

11. Subsequent Events

TTR License Agreement Regulatory Milestone

On July 11, 2018, we received marketing authorization, or MA, approval for TEGSEDI from the European Commission, or EC, for the treatment of stage 1 or stage 2 polyneuropathy in adult patients with hereditary transthyretin amyloidosis, or hATTR amyloidosis, in Europe, or EU. As a result of the MA approval in the EU, we issued on August 3, 2018, 1,597,571 of common stock shares to Ionis as payment of the $40.0 million regulatory milestone for TEGSEDI, increasing Ionis' ownership percentage to slightly above 75 percent.

PTC Therapeutics

On August 1, 2018, we entered into an exclusive license agreement with PTC Therapeutics to commercialize TEGSEDI and WAYLIVRA in Latin America. Under the license agreement, we will receive an $18 million upfront payment, $12 million which is due in the third quarter of 2018 and $6 million which will be paid on the earlier of FDA or EMA approval of WAYLIVRA. We have the potential to earn $8 million of additional regulatory milestone payments for the approval of each drug. We will receive royalties from PTC in the mid-twenty percent range on net sales in Latin America for each drug. PTC's obligation to pay us royalties begins on the earlier of 12 months after the first commercial sale of a product in Brazil or the date that PTC recognizes revenue of at least $10 million in Latin America. Consistent with the agreements between us and Ionis, we will share all payment with Ionis, including royalties.