Shares of Merck (MRK) and Bristol-Myers Squibb (BMY) rose after both rolled out new cancer drugs at a major medical society meeting in Chicago. Both presented results of trials of new melanoma cancer drugs. Merck's lambrolizumab induced major tumor shrinkage in 52% of patients on the highest dose. Bristol-Myers combined its cancer drug nivolumab with its Yervoy, which it sells now. About half of patients responded. Of those, tumors shrank an average 80%. Merck shares rose 3.8% to 48.45. Bristol-Myers rose 3.4% to 47.59 .