Comparing Second-Line Therapies for Recurrent Mesothelioma

University of Pennsylvania researchers have some hopeful news for people with recurrent mesothelioma after chemotherapy: Second-line immunotherapy might increase their odds of survival.

Previous studies show that recurrent mesothelioma patients who had immunotherapy lived longer than those on placebo. But doctors were not sure how second-line immunotherapy compared to second-line chemotherapy in these patients.

The new study showed a clear survival advantage for those who had immunotherapy. 

Coping with Recurrent Mesothelioma

Malignant pleural mesothelioma is a rare cancer with a grim prognosis. Most people who receive a mesothelioma diagnosis start treatment with chemotherapy. A combination of Alimta (pemetrexed) and a platinum drug is the most common first-line treatment. 

But even the standard-of-care rarely keeps this virulent cancer at bay for very long. Recurrent mesothelioma is common. This is true even for the 40 percent of people who respond well to chemotherapy. Eventually, most mesothelioma patients relapse. 

There is no standard treatment for recurrent mesothelioma. Researchers around the world are still trying to find the best approach. Some studies suggest that more chemotherapy can help. Others suggest that immunotherapy is better. 

The University of Pennsylvania study compares the survival of real-world patients with recurrent mesothelioma. 

Second-Line Chemotherapy Versus Second-Line Immunotherapy

The new study included 176 advanced mesothelioma patients. They came from several different medical centers. Most were white men between 69 and 79 with epithelioid mesothelioma. All patients started treatment with chemotherapy. All relapsed. 

Thirty-five percent of the recurrent mesothelioma patients received second-line chemotherapy. Sixty-five percent had immunotherapy. Eighty of those patients received the immunotherapy drug Keytruda (pembrolizumab). Thirty-one had Opdivo (ipilimumab). Four patients had the newly-approved combination of Opdivo and Yervoy (nivolumab). 

“Treatment with ICI [immune checkpoint inhibitors] was associated with significantly longer median overall survival compared to chemotherapy,” writes lead author Roger Kim in the journal Lung Cancer. 

Recurrent mesothelioma patients on immunotherapy lived a median of 3.7 months longer than those who had second-line chemotherapy. The odds of living for at least 12 months with recurrent mesothelioma was 36.7 percent for the immunotherapy group. Only 15.6 percent of the second-line chemotherapy patients lived that long. 

“Our findings suggest that ICI may benefit patients with advanced malignant pleural mesothelioma and progression after initial platinum-based chemotherapy,” concludes the report. 

A Japanese study earlier this year suggests that the patients who responded well to first-line chemotherapy were most likely to have good results with second-line chemotherapy. In that study, the addition of an immunotherapy drug helped chemotherapy work better in some patients. 

Sources: 

Kim, R, et al, “Comparative effectiveness of second-line immune checkpoint inhibitor therapy versus chemotherapy for malignant pleural mesothelioma”, July 17, 2021, Lung Cancer, Online ahead of print, https://linkinghub.elsevier.com/retrieve/pii/S0169500221004736

Kitadai, R, et al, “Efficacy of second-line treatment and prognostic factors in patients with advanced malignant peritoneal mesothelioma: a retrospective study”, March 21, BMC Cancer, https://bmccancer.biomedcentral.com/articles/10.1186/s12885-021-08025-x