Study Supports Opdivo as Second-Line Mesothelioma Treatment
Research & Clinical Trials
Written by Tim Povtak | Edited By Walter Pacheco
When the effectiveness of first-line chemotherapy fails and malignant mesothelioma returns, more patients could soon turn with confidence to a proven, second-line treatment.
The first phase III, placebo-controlled, double-blind clinical trial studying the safety and efficacy of Opdivo, the immunotherapy drug known generically as nivolumab, has raised the level of confidence in this option for patients with relapsed disease.
“The evidence is robust, the survival significant,” Dr. Dean Fennell, chair of Thoracic Medical Oncology, University of Leicester and University Hospitals in the United Kingdom, told The Mesothelioma Center at Asbestos.com. “This was the first trial to show evidence of real improvement in a relapsed setting.”
Fennell, former president of the International Mesothelioma Interest Group, was the principal investigator and lead author of the study. The Lancet Oncology published the results online in October.
Opdivo/Yervoy Combination in Use
The U.S. Food and Drug Administration and the European Commission have already approved the combination of Opdivo and Yervoy, another immunotherapy drug, for first-line treatment of unresectable pleural mesothelioma, although its use is still far from universal. The most effective treatment combination for pleural mesothelioma continues to be the multidisciplinary regimen of surgery, chemotherapy and radiation.
Debate over the best second-line treatment continues, but this latest clinical trial, which has built on earlier phase II studies, could change the direction in favor of Opdivo.
The trial involved 332 patients spread across 24 hospitals throughout the United Kingdom. There were no restrictions on the number of previous therapies given, although all had received at least one platinum-based chemotherapy treatment.
Patients were given either Opdivo or a placebo every two weeks until disease progression, withdrawal from treatment, or for a maximum of 12 months. The median follow-up was 11.6 months, with 33% of the patients receiving the placebo.
Survival Numbers Could Increase
In the study, median progression-free survival after treatment with nivolumab was three months compared to 1.8 months for those receiving the placebo. The median overall survival was 10.2 months compared to 6.9 months in the placebo group.
Fennell expects the difference in median overall survival to grow in the coming months.
“This was preliminary data. The study was underpowered for final results,” he said. “Some of the patients are still out there, so those survival numbers will increase.”
Progression-free survival at one year for those getting Opdivo was 14.2% and overall survival was 43.4%.
Fennell also thinks the results will continue to build on the growing belief that Opdivo will be included in more effective immunotherapy combinations beyond Yervoy, known generically as ipilimumab.
“I think a number of combinations will be explored, and there is no reason why, with mesothelioma, that we can’t provide better second-line options,” he said. “There is more to come.”
Some Side Effects Prove Limiting
Opdivo has been approved by the FDA for a variety of cancers, including melanoma. It also is used today for lung cancer, Hodgkin lymphoma, head and neck cancers and high-risk urothelial carcinoma, with the latest approval in August.
Opdivo works with mesothelioma by blocking the protein PD-1, which stops a patient’s own immune system from attacking the tumor cells. The drug has shown an ability to help the immune system work more effectively, but that duration is limited.
Side effects also can be an issue, according to the study. Adverse events led to treatment discontinuation in 14% of patients receiving Opdivo compared to 3% of those receiving the placebo.
The most common problems leading to discontinuation were infusion-related reactions and diarrhea. Serious adverse events occurred in 41% of those in the Opdivo group and 44% of those in the placebo group.
