(Reuters) - Cara Therapeutics Inc reported disappointing data from a key study testing its chronic pain treatment in patients with osteoarthritis, sending the drug developer's shares down about 32 percent after the bell on Thursday.
The company was testing three dosages of its drug, CR845, in 476 patients with osteoarthritis of the hip or knee experiencing moderate-to-severe pain, against a placebo.
Two dosages of the drug - 1 mg and 2.5 mg - failed to meet the main goal of reducing pain intensity in patients, while the 5 mg dose exhibited a statistically significant reduction in joint pain in patients with osteoarthritis of the hip, Cara said.
However, the 5 mg dose did not demonstrate reduction in joint pain of the combined patient group.
Cara is also evaluating CR845 for the treatment of pruritus, a condition which causes severe itching of the skin.
Shares of the Stamford, Connecticut-based Cara plunged about 32 percent to $17.40 after-market.
(Reporting by Divya Grover in Bengaluru; Editing by Shounak Dasgupta and Martina D'Couto)