Following Incyte's (INCY) epacadostat failure and the recent, "relatively underwhelming" Bristol-Myers (BMY) lung cancer dataset, there has been a negative shift in investor sentiment towards pure immuno-oncology combination approaches, Piper Jaffray analyst Tyler Van Buren tells investors in a research note. The analyst believes there is now increased scrutiny towards uncontrolled trials with low patient numbers, and thinks investors will require a more significant margin of improvement when compared to standard of care until definitively proven in Phase III. As such, he expects investors to be increasingly critical of early IO combination data. Nevertheless, he continues to believe that Nektar Therapeutics' (NKTR) NKTR-214 data at ASCO in early June will be "confirmatory of the already positive data in existing tumor types and supportive of new indications." He keeps an Overweight rating on Nektar shares with a $125 price target.