Factors Modifying the Associations of Single or Combination Programmed Cell Death 1 and Programmed Cell Death Ligand 1 Inhibitor Therapies With Survival Outcomes in Patients With Metastatic Clear Cell Renal Cell Carcinoma: A Systematic Review and Meta-analysis.

Abstract

Importance\nProgrammed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are immune checkpoint inhibitors widely used in the treatment of metastatic clear cell renal cell carcinoma (ccRCC) and other cancers. There is a lack of understanding regarding which factors are associated with therapeutic response.\n\n\nObjectives\nTo conduct a systematic literature review of trials reporting on factors associated with differential response to PD-1/PD-L1 inhibitors among patients diagnosed with metastatic ccRCC and quantitatively synthesize the magnitude to which each factor modified the response to PD-1/PD-L1 inhibitors.\n\n\nData Sources\nThe MEDLINE and Cochrane Register of Trials databases were searched for studies published in English from 2006 onward. Searches were last run on September 3, 2019.\n\n\nStudy Selection\nThis systematic review and meta-analysis assessed 662 phase 2/3 randomized clinical trials that provided subgroup analyses of any baseline characteristics regarding the treatment response to PD-1/PD-L1 inhibitors, alone or as part of a combination therapy, with respect to overall survival (OS) or progression-free survival (PFS) among patients with metastatic ccRCC.\n\n\nData Extraction and Synthesis\nA novel quantitative approach was used to synthesize subgroup findings across trials. The ratio of the subgroup-specific hazard ratios (HRs) from each study were pooled using a random-effects meta-analysis whereby ratios of 1.00 would indicate that the subgroup-specific HRs were equal in magnitude.\n\n\nMain Outcomes and Measures\nMain outcomes were OS and PFS.\n\n\nResults\nFrom an initial 662 reports, 7 trials were considered eligible for inclusion. Meta-analyses suggested the treatment response to PD-1/PD-L1 inhibitors in patients with metastatic ccRCC was significantly associated with age (OS: ratio of HR for age ≥75 years to HR for age <65 years, 1.51; 95% CI, 1.01-2.26), PD-L1 expression (PFS: ratio of HR for PD-L1\u2009<\u20091% to HR for PD-L1\u2009≥\u200910%, 2.21; 95% CI, 1.14-4.27; ratio of HR for PD-L1\u2009<\u20091% to HR for PD-L1\u2009≥\u20091%, 1.36; 95% CI, 1.10-1.68), Memorial Sloan Kettering Cancer Center risk score (PFS: ratio of HR for immediate risk score to HR for poor risk score, 1.62; 95% CI, 1.14-2.29; ratio of HR for favorable risk score to HR for poor risk score, 1.53; 95% CI, 1.00-2.34; ratio of HR for favorable risk score to HR for intermediate risk score, 0.96; 95% CI, 0.70-1.30), and sarcomatoid tumor presence (PFS: ratio of HR for no sarcomatoid differentiation to HR for sarcomatoid differentiation, 1.54; 95% CI, 1.07-2.21).\n\n\nConclusions and Relevance\nThis analysis suggests that older age, low levels of PD-L1 expression, and the absence of sarcomatoid tumor differentiation are associated with a diminished response to anti-PD-1/PD-L1 immunotherapies with respect to survival outcomes among patients with metastatic ccRCC.