The U.S. Food and Drug Administration (FDA) approved an immunotherapy for adults and children with classical Hodgkin lymphoma who were not benefiting from existing treatments. The Leukemia & Lymphoma Society (LLS) applauds this approval as an important step forward in ultimately finding a cure for these patients.
While Hodgkin lymphoma is now considered one of the most curable forms of cancer – with a more than 88 percent five-year-survival rate overall – this therapy is for patients who have relapsed after being treated with current therapies, and otherwise have limited treatment options.
The approved therapy, pembrolizumab (Keytruda ®), is among a class of drugs known as immune checkpoint inhibitors, which work by removing the brakes that stop the immune system from attacking cancer.
The body’s immune system has T-cells that patrol the body constantly looking for signs of infection or foreign cells (such as cancer cells). Certain proteins on cells indicate if it is healthy or cancerous – and if it is cancerous, the T-cell will attack it. Sometimes the T-cells are unable to recognize the cancer cells because they carry “checkpoint” proteins that act like masks, helping the cancer cells blend in with normal cells.
In this case, the “mask” is a protein called PD-L1, which interacts with another protein, PD-1, allowing cancer cells to evade attack from immune T-cells. The newly approved drug, pembrolizumab, targets PD-1, unleashing the patient’s immune system to fight the cancer. This marks the second FDA approval of a PD-1 checkpoint inhibitor for Hodgkin lymphoma patients, with nivolumab (Opdivo ®) approved in May 2016.
FDA based the approval of pembrolizumab on data from a clinical trial of 210 patients who were not benefiting from previous treatment. Within the trial, 69 percent of patients responded positively and 22 percent showed no detectable sign of cancer.
The approval reinforces the hope that immunotherapy will prove useful for a wide variety of cancers, as the drug was previously approved for head and neck cancer, non-small cell lung cancer and melanoma.
Furthermore, LLS is currently funding research studying the benefits of pembrolizumab or nivolumab for patients with non-Hodgkin lymphoma. Stephen Ansell, M.D., Ph.D., Mayo Clinic, Margret Shipp, M.D., Dana-Farber Cancer Institute, and Sattva Neelapu, M.D., MD Anderson Cancer Center, are leading these research efforts.