Incidence, overall grades, and overall response of acute GVHD that required treatment. (A) Among the 3542 patients who met the criteria for inclusion, 1601 and 256 were diagnosed with classic and late acute GVHD of any grade, respectively. Of patients with classic and late acute GVHD, 1245 of 1601 (77.8%) and 193 of 256 (75.4%), respectively, received systemic GVHD treatment. (B) The cumulative incidence of classic and late acute GVHD that required systemic treatment were 35.2% (95% CI, 33.6-36.8) and 5.7% (95% CI, 4.9-6.5), respectively. (C) The rates of grades 3/4 acute GVHD were 17.7% in classic and 36.3% in late acute GVHD (P < .001). (D) Overall response rate (CR or PR) on day 28 was 72.0% in classic vs 55.4% in late acute GVHD (P < .001). CR rate on day 28 was 59.3% in classic and 46.6% in late acute GVHD (P < .001). Dx, diagnosis; CR, complete response; PR, partial response; Tx, treatment.