Patients with melanoma have been given hope with the news that ipilimumab (Yervoy; Bristol-Myers Squibb), a monoclonal antibody specific for cytotoxic T lymphocyte antigen 4 (CTLA4), has been approved by the US Food and Drug Administration (FDA) (FDA website, 25 Mar 2011).

Ipilimumab blocks the activity of CTLA4, thus allowing tumour-specific T cell activation. In contrast to other therapies that “slam on the immune system's gas pedal”, ipilimumab “releases the brakes” explained Patrick Hwu, from the MD Anderson Cancer Center in Houston, Texas (Nature News, 28 Mar 2011). Ipilimumab was tested in a study of 676 metastatic melanoma patients, either alone or in combination with a tumour vaccine, and led to increased survival in both cases (FDA website, 25 Mar 2011).

The approval of ipilimumab is a milestone in cancer therapy for two reasons. First, it “further strengthens the case for cancer immunotherapy”, according to Thomas Gajewski, president of the Society for Immunotherapy of Cancer (Washington Post, 25 Mar 2011). Second, as Richard Pazdur, director of the Office of Oncology Drug Products in the FDA Center for Drug Evaluation and Research, stated: “Yervoy is the first therapy approved by the FDA to clearly demonstrate that patients with metastatic melanoma live longer by taking this treatment” (Financial Times, 25 Mar 2011).

However, not all patients will be able to afford this therapy, as Bristol-Myers Squibb have set a price of US$120,000 for a full course of treatment with Yervoy (New York Times, 30 Mar 2011). Moreover, the response rate is only approximately 20% (CNN, 25 Mar 2011). So, cancer immunotherapy still has a long way to go in order to provide treatments that are effective and financially accessible to most patients.