Background: MDX010-020 was a phase III comparison of ipilimumab (Ipi), gp100 vaccine or the combination for advanced melanoma. A subset of patients (pts) received other immunotherapy (IM) for advanced disease prior to receiving Ipi, providing the opportunity to evaluate safety and efficacy of Ipi following IM. A prior analysis has shown that pts receiving prior IL-2 had a similar overall survival (OS) to pts who had not received prior IL-2 [Hodi et al NEJM2010]; we now report expanded results for pts receiving any prior IM (interferons and/or interleukin). Methods: Eligible pts (n=676) had unresectable stage III/IV melanoma and were randomized 3:1:1 to q3 wks x 4 doses of Ipi + gp100 or Ipi + placebo or gp100 + placebo. All Ipi doses were 3 mg/kg i.v. OS was retrospectively analyzed for pts receiving any prior IM; immune-related adverse events (irAEs) during induction were evaluated for pts who received any prior IM (322 pts, 48%) and for pts who received prior IL-2 (154 pts, 23%). Results: Demography and OS are summarized below. irAEs of any grade were reported for 60% (Ipi) and 54% (Ipi + gp100) of pts receiving any prior IM. Those receiving prior IL-2 specifically had 73% (Ipi) and 58% (Ipi + gp100) incidence of any grade irAEs. Incidence was similar for those not receiving prior IM or prior IL-2. Diarrhea, rash, and pruritus were the most common events in all groups. Conclusions: Results for OS in this subgroup analysis were similar for both those receiving any prior IM and those who did not receive prior IM and to the overall 020 population. In addition, safety profiles were similar irrespective of prior immunotherapy. Clinical trial information: NCT00094653.