One of the prominent areas of mesothelioma research today is around the development of an effective, tolerable, second-line treatment for recurrent cases. Studies have shown mesothelioma recurrence is highly prevalent, even among patients who are able to undergo aggressive primary therapy, like surgery. Some studies have noted recurrence rates ranging from 10 – 72% of patients.
Currently, patients are often treated with a second-line treatment of standard chemotherapy, though researchers have noted this option does little to improve survival or achieve stable disease. Two clinical trials published in January 2019, however, both highlight how the immunotherapy drug Opdivo® could be an effective second-line therapy for achieving stable disease and improving prognosis.
Opdivo and Yervoy for Recurrent Pleural Mesothelioma
One recent study, dubbed INITIATE, focused on testing the efficacy and safety of immunotherapy drugs nivolumab (brand name Opdivo) and ipilimumab (brand name Yervoy®) in pleural mesothelioma patients who had previously been treated with a platinum-based chemotherapy drug, like cisplatin.
Opdivo is a type of immunotherapy called a checkpoint inhibitor, meaning it works by targeting a specific protein in the body (PD-1) that cancer cells often mimic to avoid triggering an immune system response. Yervoy is another type of immunotherapy, a monoclonal antibody. Monoclonal antibodies are synthetic proteins injected into the body to help the immune system recognize dangerous cancer cells and attack. In the study, 36 patients received Opdivo every two weeks, followed by Yervoy every six weeks. Depending on an individual’s case and response to the therapy, treatment could be continued for up to two years.
Researchers found that 29% of the participants achieved a partial response, with 38% achieving stable disease. Overall, 68% of the patients were considered to have disease control, meaning the cancer didn’t spread or worsen during treatment. Though 94% of patients experienced side effects from the treatment, researchers noted that most of these were minimal and tolerable. The most common side effects reported included fatigue, skin disorders, and other effects at the injection site.
Because of the efficacy and general tolerability of this immunotherapy combination, researchers stated that the research warranted a larger phase-3 clinical trial to further test the treatment and hopefully will eventually lead to approval by the Food and Drug Administration (FDA) for wide availability.
Clinical Trial Tests Opdivo Alone Vs. Opdivo and Yervoy
Another clinical trial also focused on the efficacy of Opdivo as a second-line mesothelioma treatment. This time, researchers tested the drug alone, as well as compared the response in patients treated with the combination of Opdivo and Yervoy. Patients in this study also had either first-line or second-line treatments of standard chemotherapy with at least one platinum-based drug.
Patients were given Opdivo intravenously every two weeks. For those in the combination group, Yervoy was also given intravenously every six weeks. Researchers hoped to see at least 40% of patients achieve stable disease at the 12-week mark for the trial to be considered worthy of further study. For the 108 eligible patients, researchers found that 44% in the Opdivo group achieved stable disease, while 50% of patients in the combination group saw stable disease.
Unlike the other study, researchers noted a wider range of side effects among the two groups, with some more serious conditions reported. Most common among both groups was asthenia, or lack of energy and strength, which can lead to more complicated muscular issues. In a few cases, patients experienced severe toxicities that contributed to their death. In the three patients, all of whom were treated with the combination therapy, fulminant hepatitis, encephalitis, and acute kidney failure arose. No patients treated with Opdivo alone faced such severe toxicities.
Hope for an Effective Second-Line Treatment
While both of these studies have given researchers and doctors hope for this second-line treatment, further study is required to fully understand potential side effects and the efficacy of the treatment. Immunotherapy is a promising area of study for mesothelioma and other cancers, and researchers continue to test its efficacy as both a first-line and second-line of treatment.
So far, no immunotherapy drugs have achieved FDA approval for the treatment of mesothelioma, but drugs like Keytruda® have been approved for other cancers like non-small cell lung cancer. With more research, doctors hope one or more immunotherapy drugs can be approved and become widely available to patients beyond those eligible for clinical trials.