Bristol-Myers Squibb Co said a late-stage trial of its drug, Opdivo, was stopped early after the immunotherapy was found to be effective in patients with the most common form of kidney cancer. The U.S. drugmaker said on Monday the study, Checkmate-025, was stopped early after an independent data monitoring committee concluded that Opdivo provided a survival advantage over the cancer drug, everolimus, among patients with advanced or metastatic renal cell carcinoma.