(Adds details, background, share movement)
June 30 (Reuters) - Merck & Co Inc said its drug for treating chemotherapy-induced nausea and vomiting, Emend, was shown to be more effective than a placebo in a late-stage trial in children.
The company said it plans to file for marketing approval for Emend in the U.S. for the new pediatric formulation in the second half of 2014.
Merck said 51 percent of patients getting Emend showed no vomiting, no retching and no use of rescue medication for nausea and vomiting 25 to 120 hours following the beginning of chemotherapy, compared to 26 percent of those on a placebo.
More than 70 percent of cancer patients undergoing chemotherapy suffer from nausea and vomiting that may result in a delay or discontinuation of treatment.
Prolonged nausea and vomiting can also lead to weight loss, dehydration and malnutrition.
Emend is already approved for treating chemotherapy-induced nausea and vomiting in adults and had global sales of $507 million in 2013.
Tesaro Inc's experimental drug Rolapitant, if approved, will compete with Emend. (Reporting by Shailesh Kuber and Esha Dey in Bangalore; Editing by Saumyadeb Chakrabarty and Joyjeet Das)