Efficacy of First-Line Nivolumab Plus Ipilimumab in Unresectable Pleural Mesothelioma: A Multicenter Real-World Study (ImmunoMeso LATAM)

The CheckMate-743 trial demonstrated OS benefit with nivolumab plus ipilimumab over chemotherapy as firstline treatment of unresectable pleural mesothelioma. We analyzed this regimen in a real-world setting in LATAM including 96 patients. Median PFS and OS were 8 months, and 22 months, respectively. Treatment efficacy was consistent among different subgroups, including histology. No OS impact was observed in patients that had dose delay or treatment discontinuation. This study constitutes the only real-world evidence in this frontline setting in LATAM. Background: The phase 3 CheckMate-743 trial demonstrated a prolonged overall survival (OS) benefit with nivolumab plus ipilimumab over chemotherapy as first-line treatment in patients with unresectable pleural mesothelioma (PM). However, given that Latin American (LATAM) patients were notably underrepresented in this trial, we retrospectively assessed the effectiveness and safety of this regimen in this population. Methods: This retrospective study included patients from 15 centers in LATAM with unresectable or metastatic PM treated with first-line nivolumab plus ipilimumab in a real-world data (RWD) scenario. Demographic, clinicopathological characteristics, and safety data were collected from medical charts. Progression-free survival (PFS), and OS were calculated using the Kaplan-Meier method. Results: From June 2017, and January 202496 patients were included: epithelioid 78% (n = 75), 81% were ECOG 0-1 (n = 78). With a median follow-up of 24.1 months, median PFS and OS were 8 months (95% CI, 6.6-9.4), and 22 months (95% CI, 18.9-25), respectively. No statistical difference in OS was observed between epithelioid versus nonepithelioid histology (median 23 months vs. 19 months, respectively; P = .29). Treatment efficacy was also consistent among different clinical subgroups. Any and grade 3-4 adverse events were found in 43.1% (n = 28), and 18.5% (n = 12) of patients, respectively. Remarkably, no OS impact was observed in patients who had dose delay or treatment discontinuation due to immune- related adverse events, and those who experienced any adverse event. Conclusions: This multicenter RWD study demonstrated the clinically meaningful benefit of first-line ipilimumab and nivolumab in LATAM patients with unresectable or metastatic PM, and data is consistent with previous trial findings.