Nd then validated in the clinic. Two anti TLA-4 blocking mAbs--ipilimumab (Bristol-Myers Squibb, Princteon, NJ) and tremelimumab (Pfizer, New York, NY)-- demonstrated similar properties in early-phase clinical trials in patients with advanced solid tumors, mediating objective response rates of 10 to 15 in patients with metastatic melanoma and RCC.66-68 Response characteristics included delayed o