(Reuters) - Amgen Inc said its experimental ovarian cancer drug did not show statistically significant improvement in overall survival rate in a late-stage trial. Patients given the drug, trebananib, along with a chemotherapy agent paclitaxel, experienced overall survival of 19.3 months, compared with 18.3 months for the placebo group. Statistically significant improvement in overall survival was the secondary goal of the trial. The trial, TRINOVA-1, is the first of three late-stage studies to evaluate safety and effectiveness of the drug in ovarian cancer patients. The company in 2013 reported results on the main goal of trial, where patients survived longer without the disease getting worse when compared with a placebo. Jefferies analysts in a note published on Oct. 20 said oncologists expect the drug to have little or no benefits in terms of overall survival. "Thus, FDA approval is unlikely in our view," they wrote. Data from the other late-stage trials are expected in the fourth-quarter of 2014 and 2015. The company's shares were marginally down in morning trading on the Nasdaq.