Stifel analyst Stephen Willey said he believes the magnitude of the median progression free survival and overall survival benefits observed in MacroGenics' Phase 3 SOPHIA trial in margetuximab-treated patients - particularly in those carrying the CD16A-158F polymorphism - is "very encouraging" and eliminates the overhang of a "statistically-significant but potentially not clinically-meaningful" scenario. Feedback from knowledge leader physicians also suggests a product label potentially restricted to CD16A-158F patients does not pose a barrier to adoption, Willey tells investors. The analyst, who said he is incrementally more positive on the prospects of a PFS-based approval, even in the absence of mature overall survival data, keeps a Buy rating on MacroGenics shares, which are up 15% in pre-market trading.