Ardelyx's constipation drug succeeds in late-stage trial

(Reuters) - Ardelyx Inc said a second late-stage trial of its drug for irritable bowel syndrome with constipation (IBS-C) met the main goal of reducing abdominal pain and increasing bowel movement, sending its shares up sharply in extended trading.

The company’s shares, which jumped nearly 60 percent, were up 33.3 percent at $7.20 on Wednesday.

IBS-C, which affects more than 11 million in the United States, is a type of irritable bowel syndrome in which patients experience abdominal pain and severe constipation.

The drug developer said on Wednesday it intends to file for marketing approval for the drug tenapanor with the U.S. Food and Drug Administration in the second half of 2018.

The study showed abdominal pain in tenapanor-treated patients reduced by at least 30 percent with more frequent bowel movement, when compared to a placebo group.

The trial results come five months after the company reported data from the first of its two late-stage studies, which failed to impress investors.

Cantor Fitzgerald analyst Mara Goldstein said investors are likely to re-evaluate tenapanor as a viable commercial drug for IBS-C after the positive data.

The occurrence of diarrhea was 16 percent for tenapanor-treated patients, slightly higher than the previous trial.

However, this is not high enough to make the drug commercially unsuccessful, according to Goldstein.

Tenapanor is likely to compete with Ironwood Pharmaceuticals Inc’s Linzess.

Synergy Pharmaceuticals Inc’s Trulance, which was approved for chronic idiopathic constipation in January, is also being tested in patients with IBS-C.

“The IBS-C market, in spite of new drugs, is still underserved and we believe tenapanor will be able to gain share,” Goldstein said.

Tenapanor is also being tested as a treatment for elevated levels of phosphorus in the blood in patients suffering from end stage renal disease, Ardelyx said on a conference call.

Reporting by Tamara Mathias in Bengaluru; Editing by Shounak Dasgupta