Patients with recurrent mesothelioma cancer often have few options. A new study by the Hyogo College of Medicine in Japan may have a potential answer.
This study tested the safety and efficacy of two drugs following mesothelioma surgery after cancer recurrence. The combination of immunotherapy drugs nivolumab and ipilimumab, known by the brand names Opdivo and Yervoy, was recently approved for mesothelioma.
The new treatment led to a 6-month survival of 87% in pleural mesothelioma patients. The 12-month survival rate was 74.2%.
“Nivolumab with ipilimumab has promising efficacy in treating recurrent MPM [malignant pleural mesothelioma] in the postoperative setting,” the authors wrote.
The authors also noted a higher rate of adverse events than in prior studies.
Asbestos exposure can cause mesothelioma, an aggressive form of rare cancer. Mesothelioma can develop in the chest or abdomen. In rare cases, it can also form in tissues that line the heart and testes. With treatment, about 40% of patients live one year or more after diagnosis.
“This combination is expected to improve the treatment results in patients with MPM,” the authors wrote. “To our knowledge, no prior clinical studies have investigated nivolumab with ipilimumab in patients with recurrent MPM after primary curative-intent surgery.”
The study reviewed Hyogo College of Medicine patients between January 2004 and October 2022. Patients all had pleural mesothelioma and had multimodal therapy. Their treatment included chemotherapy before or after surgery. Most patients underwent a pleurectomy and decortication surgical procedure. In some cases, patients also had radiation therapy.
Between June 2021 and July 2022, researchers treated 41 patients with nivolumab and ipilimumab. The dosage was 360 mg of nivolumab administered by IV every three weeks. Patients received 1 mg/kg of ipilimumab every six weeks by IV.
The study participants underwent evaluation every six to 12 weeks via radiological imaging. The treatment led to a partial response in 18 patients. This means their tumors had a measurable decrease in size. Researchers reported stable disease, or no change in tumor size, in 13 patients.
Only 10 patients had an increase in tumor size or number during the study period. The objective response rate was 43.9%, and the disease control rate was 75.6%. Median progression-free survival was 7.3 months. This means patients survived for over seven months without an increase in their cancer.
At the end date of the study, 20 of the 41 patients still had an ongoing response. In other words, their treatment was effective even after the mesothelioma clinical trial. Common side effects were an inflamed pituitary gland and adrenal insufficiency. Other adverse effects included colitis and hyperthyroidism.
“While our patients experienced a high frequency of AEs [adverse events], most of the AEs were manageable with treatment protocol-specific guidelines,” the study authors said. “This protocol provides a novel treatment option for recurrent MPM when few options are available.”
In October 2020, the U.S. Food and Drug Administration approved Opdivo and Yervoy for mesothelioma. The guidelines allow the drugs as a first-line therapy for pleural mesothelioma patients who are not eligible for surgery.
The combination was the first new mesothelioma drug regimen in over 15 years. It is still only the second FDA-approved systemic therapy. Clinical trials are necessary to expand the benefits of these medications to more patients.
“Combination therapy with nivolumab and ipilimumab is an important treatment option for recurrent MPM after P/D [pleurectomy and decortication],” the researchers wrote.
They cited a prior study, called MERIT, that evaluated nivolumab as a second-line therapy for mesothelioma. The study consisted of 34 patients with a median survival of 17.3 months.
CheckMate 743 was the clinical trial that led to the FDA approval of Opdivo and Yervoy. In that study, the overall response rate was 39.6%. Patients also had a significant increase in overall survival compared to chemotherapy.
The Hyogo researchers stressed the importance of treatment for cancer recurrence in a previous trial. In that study, the median survival for patients treated for recurrent cancer was 24.1 months. Patients who received supportive care had a median survival of 4.2 months.
The researchers are optimistic that this treatment could have further benefits.
“Nivolumab with ipilimumab [had] promising efficacy but was also complicated by serious AEs,” they wrote. “Further multi-institutional studies to evaluate long-term survival, prognostic factors and development of AEs with this protocol deserve consideration.”