Ipilimumab is a fully human monoclonal antibody that indirectly enhances T-cell mediated responses by blocking the inhibitory signal of cytotoxic T-lymphocyte antigen-4 (CTLA-4). This results in T-cell activation, proliferation and lymphocyte infiltration into tumours, leading to tumour cell death.1
A randomised, double-blind, multicentre phase III study (n=676) to establish the efficacy of ipilimumab was conducted using an experimental melanoma peptide vaccine (gp100) as control. Patients with unresectable stage III/IV melanoma were randomised to receive ipilimumab, ipilimumab plus vaccine or vaccine alone (3:1:1). Ipilimumab, alone or in combination with the peptide, produced a significantly longer median overall survival of approximately 10 months compared with 6.4 months for patients receiving gp100 monotherapy (p<0.001). There was no significant difference in overall survival between the two ipilimumab groups.2
The most common adverse events were immune-related reactions, which occurred in approximately 60% of the treatment groups and 32% of the control group. Although ipilimumab-related adverse events can be severe, long-lasting or both, most are reversible with treatment. A total of 14 deaths related to study drugs were reported (with 7 from immune-related adverse events).2
- Yervoy Summary of Product Characteristics, July 2011.
- Hodi FS et al. N Engl J Med 2010; 363: 711-23.
Further Information: Bristol–Meyers Squibb Pharmaceuticals Ltd