KANSAS CITY, Kan. and BOSTON, Nov. 20, 2013 /PRNewswire/ -- Aratana Therapeutics, Inc. (NASDAQ: PETX), a biopharmaceutical company focused on the licensing, development and commercialization of innovative medications for pets, today announced positive results from its dose-ranging study of AT-001, the company's innovative drug for treating pain in dogs with osteoarthritis. In the study, dogs receiving AT-001 demonstrated improvements in pain assessment scores that were statistically significant compared to placebo (p<0.05) at a once-daily dose. Aratana expects to move AT-001 forward into the pivotal field effectiveness study in 2014, and then, if the results of the pivotal effectiveness study are favorable, into commercialization upon approval, which is anticipated to be in 2016. The blinded, placebo-controlled, multi-center dose-ranging study of AT-001 enrolled in excess of 300 client-owned dogs with osteoarthritis. Dogs were randomized equally into three groups treated with AT-001 (two once per day dose groups and one twice per day dose group) and one group treated with placebo. Dogs were dosed for 28 days, and effectiveness was determined by a standard protocol utilizing a validated owner-assessed pain score. Aratana has selected a once-daily dose for further development. Ernst Heinen, DVM, Ph.D., Head of Drug Evaluation and Development for Aratana Therapeutics, stated, "We are very pleased with these results, which allow us to move forward confidently with a dose of AT-001 that appears safe at therapeutic levels for dogs with osteoarthritis pain." Steven St. Peter, M.D., President and Chief Executive Officer of Aratana Therapeutics, added, "We believe AT-001 has the potential to be an important product in the well-established $260 million pain market in the U.S. alone. We look forward to continuing our dialogue with the Center for Veterinary Medicine regarding the AT-001 program." Aratana will discuss these results in more detail when the final study reports are available.