H.C. Wainwright analyst Debjit Chattopadhyay sees "fresh challenges" for bulls of Nektar Therapeutics' bempeg following competitive updates this weekend in urothelial cancer and triple-negative breast cancer. The EV-103 study, which evaluated the combination of enfortumab vedotin plus pembrolizumab in previously untreated, locally advanced or metastatic urothelial cancer, who were ineligible for cisplatin-based chemotherapy, delivered an overall response rate of 71%, Chattopadhyay tells investors in a research note. This is well above the 48% ORR reported for the bempeg plus nivolumab combination in a potentially similar patient population, adds the analyst, who keeps a Neutral rating on Nektar shares with a $24 price target.