Ipilimumab improves the relapse-free survival of patients with advanced stage melanoma rendered free of disease surgically, but at high risk for relapse, according to a study published in The Lancet.
The prognosis for patients with metastatic melanoma remains poor, with 5-year survival rates of 63% in patients who have metastatic disease in regional lymph nodes, and only 17% in patients who have metastatic disease in distant sites.
Ipilimumab is approved for the treatment of melanoma that cannot be surgically removed or that has metastasised.
Researchers at Moffitt Cancer Center, Tampa, Florida, wanted to determine if ipilimumab could improve the survival of patients with advanced-stage melanoma if it was given after the surgical removal of both their primary melanoma tumours and their regional lymph nodes.
The study, which included researchers from 19 countries, compared ipilimumab treatment (n = 476) with placebo (n = 475).
Patients who received ipilimumab survived longer without experiencing melanoma recurrence, with an average recurrence-free survival of 26.1 months versus 17.1 months for patients receiving placebo.
In addition, 46.5% of ipilimumab-treated patients survived 3 years without experiencing recurrence, compared with 34.8% of placebo-treated patients.
Patients who had microscopic metastatic disease in their regional lymph nodes and a tumour that had a breakdown of the overlaying skin responded best to ipilimumab treatment.
Despite these promising results, ipilimumab treatment was associated with significantly higher toxicity than placebo treatment, including higher rates of gastrointestinal disorders, alterations in kidney function, and inflammation of the pituitary gland. These adverse events resulted in 52% of patients on ipilimumab discontinuing treatment before its completion, including 39% of patients during the first 4 doses of ipilimumab. Furthermore, 5 patients on ipilimumab died during treatment due to adverse events.
The dose used in this study was significantly higher than the dose commonly used in patients with melanoma. Additional studies are required to ensure that the benefit of this dose of ipilimumab does not outweigh the added toxicity risks, the authors reported.