Dr. Gibney on the Potential for Fixed-Duration Immunotherapy in Melanoma

Geoffrey T. Gibney, MD, co-leader of the Melanoma Disease Group, and a member of the Developmental Therapeutics (Phase I) program at the Lombardi Comprehensive Cancer Center and MedStar Cancer Network, MedStar Georgetown University Hospital, discusses the potential utility of fixed-duration immunotherapy in melanoma.

Historically, the pivotal trials for PD-1/PD-L1 inhibitors, such as nivolumab (Opdivo) and pembrolizumab (Keytruda), in melanoma did not evaluate the agents as a time-limited treatment, says Gibney. Instead, the studies indicated that treatment could be continuous, even in patients who were tolerating and responding to the therapy, Gibney explains.

As such, the debate as to whether patients responding to immunotherapy can stop therapy at a prespecified timepoint remains open, Gibney says. However, efforts are ongoing to answer this question. For example, the phase 3 KEYNOTE-006 study evaluated 2 years of pembrolizumab in patients with advanced melanoma. 

It is likely that patients can stop immunotherapy after 2 years; however, since the optimal duration of immunotherapy is still not well defined, many patients receive a longer course of therapy, Gibney says. Additionally, many patients may be able to stop therapy after 1 year, Gibney adds. Time-limited therapy can lower the financial burden of therapy, minimize late-onset toxicities, and eliminate unnecessary visits to the clinic that can put strain on the health care system overall, concludes Gibney.