Immune checkpoint inhibitors have significantly changed the treatment landscape of many forms of cancer, and use of these agents for the treatment of hematologic malignancies has risen in recent years. As a result, there have been several randomized trials evaluating the efficacy and safety of these therapies in multiple types of cancer, including non-small cell lung cancer, melanoma, renal cell carcinoma, and various hematologic malignancies.1,2
When it was approved by the US Food and Drug Administration (FDA) for use in patients with advanced melanoma, ipilimumab became the first immune checkpoint inhibitor to be approved in the United States. In a recent review article in JCO Precision Oncology, Elvire Pons-Tostivint, MD, of the Institut Universitaire du Cancer Toulouse-Oncopole in France, and colleagues compared various treatment responses of patients treated with checkpoint inhibitors for different types of cancer with other drug therapies.
“Patients with cancer with recurrent and/or metastatic disease usually have been considered as being incurable,” the researchers wrote. “Achievement of a durable response is a major goal for [cancer] patients, although cure is the ultimate aim of cancer research.”
They continued, “Durable response has been advocated to be one of the specificities of immune checkpoint inhibitors among others.”
Efficacy of Checkpoint Inhibitors in Hematologic Cancers
Several clinical trials have demonstrated that checkpoint inhibitors improve survival outcomes in patients with nonhematologic malignancies, including prostate, lung, urothelial, and renal cancers.3 In addition, these agents have shown the ability to reestablish immune function in patients with certain hematologic malignancies, particularly lymphomas, leukemias, and myelodysplastic syndrome.4 Recent studies have also started to evaluate the use of checkpoint inhibitors in combination with allogeneic hematopoietic stem cell transplantation (HSCT), where therapy may be given before, during, or after transplantation.
The most common hematologic malignancy these agents are used to treat is Hodgkin lymphoma. A recent literature search indicated that Hodgkin lymphoma was the most frequent indication for individuals receiving checkpoint inhibitor therapy before or after allogeneic HSCT. Other hematologic conditions for which patients received both checkpoint inhibitor therapy and transplantation included non-Hodgkin lymphoma, multiple myeloma, chronic lymphocytic leukemia, myelodysplastic syndrome, and others. The specific agents used in these studies were nivolumab, ipilimumab, and pembrolizumab.