CTLA4 and melanoma: This trial established significant survival advantages with a median overall survival rate of 10.0 months on ipilimumab, an IgG1 antibody targeting CTLA‐4, compared to 6.4 months in patients receiving gp100 peptide vaccine alone.37 These findings led to US Food and Drug Administration (FDA) approval of ipilimumab as a first‐line therapy for advanced melanoma in 2011.