Ironwood's constipation drug meets main goal in late-stage study

(Reuters) - Ironwood Pharmaceuticals Inc said a lower dose of its constipation drug met the main goal of improving bowel movements of patients in a late-stage study. The company's shares rose as much as 4.2 percent in extended trading on Tuesday, before giving up almost all of those gains. The drug developer said a 72 micrograms (mcg) dose of the drug, linaclotide, fared better than a placebo when tested in adults with chronic idiopathic constipation (CIC), a type of gastrointestinal disorder. Two higher doses of linaclotide are already on the market: a 145 mcg capsule for patients with CIC and a 290 mcg capsule for adults who have irritable bowel syndrome with constipation. Ironwood along with its partner Allergan Plc said they plan to submit a supplemental new drug application (sNDA) for the 72 mcg dose of the drug in the first half of 2016. An sNDA is required to make any changes the packaging, labeling, dosages, ingredients or new indications for a drug that is already approved by the FDA. CIC, a type of gastrointestinal disorder where individuals have infrequent bowel movements, affects about 15 percent of the U.S. population, according to the National Institutes of Health. It is called idiopathic because the cause is unknown. Ironwood's shares were up 0.19 percent at $10.74 in extended trading. They closed at $10.72 on the Nasdaq, down 30 percent this year. (Reporting by Rosmi Shaji in Bengaluru; Editing by Savio D'Souza)