Background: Currently, the choice of treatment for individuals with metastatic soft tissue sarcomas (MSTS) presents a significant challenge to clinicians. The aim of this retrospective study was to assess the efficacy and safety of nivolumab plus ipilimumab (NPI) versus nivolumab alone (NIV) in individuals with treatment-naive programmed death-ligand 1 (PD-L1) positive MSTS.
Methods: Prospectively maintained databases were reviewed from 2013 to 2018 to assess individuals with treatment-naive PD-L1 MSTS who received NPI (nivolumab 3 mg/kg and ipilimumab 1 mg/kg every 3 weeks for 4 doses followed by nivolumab 3 mg/kg every 2 weeks) or NIV (3 mg/kg every 2 weeks) until disease progression, withdrawal, unendurable [AEs], or death. The co-primary endpoints were overall survival (OS) and progression-free survival (PFS).
Results: The median follow-up was 16.0 months (IQR 14.4-18.5) after targeted intervention. The median OS was 12.2 months (95% confidence interval [CI], 6.1-13.7) and 9.2 months (95% CI, 4.2-11.5) for the NPI and NIV groups, respectively (hazard ratio [HR] 0.49, 95% CI, 0.33-0.73; p=0.0002); the median PFS was 4.1 months (95% CI, 3.2-4.5) and 2.2 months (95% CI, 1.1-3.4) for the NPI and NIV groups, respectively (HR 0.51, 95% CI, 0.36-0.71; p< 0.0001). Key grade 3-5 AEs occurred more frequently in the NPI group than in the NIV group (94 [72.9%] for NPI vs. 35 [27.1%], p< 0.001).
Conclusions: For treatment-naive PD-L1 positive MSTS, NPI seems to be less tolerated but has a greater survival advantage than NIV as the primary therapy.
Keywords: Adverse events; Metastatic; Overall survival; Sarcoma; Treatment.