This looks...interesting? It looks like McCarthy's going for a dramatic role, although this still looks a tad more comedic, just not in her usual raunchy way. It's from Marielle Heller, the director of Diary of a Teenage Girl, so I assume it's more of a drama (plus it's based on a Lee Israel's actual memoir, so the true story factor comes into play) and the presence of Richard E. Grant would suggest the same thing, but l would guess it falls more into the "dramedy" vein.
Melissa McCarthy stars in the adaptation of the memoir CAN YOU EVER FORGIVE ME?, the true story of best-selling celebrity biographer (and friend to cats) Lee Israel (Melissa McCarthy) who made her living in the 1970's and 80's profiling the likes of Katharine Hepburn, Tallulah Bankhead, Estee Lauder and journalist Dorothy Kilgallen.