Shares of Flexion Therapeutics (FLXN) soared 28% in after-hours trade on Tuesday after it had announced that its phase 3 trial hit the primary endpoint of the study. The phase 3 trial recruited 486 patients and split them up into three different dose groups. One group of patients took a single IA injection of 40 mg of Zilretta, one group of patients took saline — a placebo– and the last set of patients took 40 mg of an active drug known as immediate-release TCA. 

Zilretta has already received FDA Fast Track Designation, which gives it a faster track for approval. If all goes well with filings and communications between the FDA, Flexion expects to file a New Drug Application — NDA — by the second half of 2016.