Protagonist Therapeutics Inc. continues having a tough time. The latest is a steep stock drop after a phase II trial in ulcerative colitis (UC) missed its primary endpoint, but the company insists the data are good enough to move into phase III. Top-line data showed a 450-mg BID dose of PN-943 in treating moderate to severe UC missed its primary endpoint, which was the number of participants achieving clinical remission at week 12 compared to placebo.