Nivolumab boosts survival in relapsed malignant mesothelioma

Reuters Health - 02/02/2021 - Treatment with the programmed death-1 (PD-1) inhibitor nivolumab significantly improved overall and progression-free survival in patients with relapsed malignant mesothelioma in the CONFIRM study.

It marks the first time a phase-3 study has demonstrated improved survival in the setting of relapsed malignant mesothelioma, said Dr. Dean Fennell of University of Leicester, in the U.K., in a presentation of the results at the International Association for the Study of Lung Cancer (IASLC) virtual World Conference on Lung Cancer (WCLC).

"Nivolumab is a safe and effective treatment and should be considered the standard treatment for patients with relapsed mesothelioma," he told a gathering of reporters.

The CONFIRM trial enrolled 332 adults with previously treated, unresectable malignant mesothelioma and Eastern Cooperative Oncology Group performance status of zero to one. Patients were stratified by epithelioid and non-epithelioid history and randomly allocated to nivolumab (240 mg on a 14-day cycle, 221 patients) or placebo (111 patients), administered until progression, unacceptable toxicity, withdrawal or 12 months.

While the overall survival data are immature (total number of events 232 vs. a target of 291), patients lived significantly longer on nivolumab than placebo (median 9.2 vs. 6.6 months; hazard ratio, 0.72; 95% confidence interval, 0.55 to 0.94; P=0.018), Dr. Fennell reported.

Progression-free survival was also significantly longer with nivolumab (median, 3.0 vs. 1.8 months; HR, 0.61; 95% CI, 0.48 to 0.77; P<0.001).

There was no statistically significant association between PD-L1 tumor proportion score (TPS) greater than 1% (in 34% of included patients) and survival. "There was no evidence to support PD-L1 TPS as being predictive," Dr. Fennell said.

However, the benefit of nivolumab appeared to differ by subtype. Nivolumab provided significant clinical benefit in epithelioid disease (HR for overall survival: 0.71; 95% CI, 0.53 to 0.95; P=0.021), but not in non-epithelioid disease (HR, 0.79; 95% CI, 0.35 to 1.79; P=0.572).

However, briefing commentator Dr. Rina Hui of The University of Sydney, Australia, noted that the sample size of the non-epithelioid subgroup in the study "may have been too small to detect a difference in outcomes" and said she "would not deny patients with non-epithelioid histology from considering nivolumab in the salvage setting."

Dr. Fennell noted that the safety profile of nivolumab was consistent with its known profile with no new safety signals.

Grade-3/4 treatment-related adverse events were reported in 19% of patients on nivolumab and 6.3% on placebo; 13.1% and 2.7% of patients, respectively, stopped treatment due to toxicity. There were five (3.6%) deaths due to serious adverse events in the nivolumab group and four (5.3%) in the placebo group.

The CONFIRM trial was an investigator-initiated study supported by Stand Up to Cancer/Cancer Research UK.

SOURCE: https://wclc2020.iaslc.org/ IASLC World Conference on Lung Cancer, held January 28-31, 2021.

By Megan Brooks



Posted on 2 February 202116 February 2021