Rheumatic immune-and nonimmune-related adverse events in phase 3 clinical trials assessing PD-(L)1 checkpoint inhibitors for lung cancer: A systematic review and meta-analysis.

Objectives: We aimed to analyze rheumatic immune-related (ir) and nonimmune-related adverse events (AEs) due to immune-checkpoint inhibitors (ICIs) targeting programmed cell death-1 or its ligand PD-(L)1 in lung cancer patients from the available literature.

Methods: We performed a systematic review and meta-analysis of phase III randomized clinical trials (RCTs) assessing PD-(L)1-ICIs in lung cancer patients, from inception until January 12th, 2021. We extracted data of each trial to estimate odds ratio (OR) for rheumatic ir or non-irAE as classified in RCTs safety data. Sensitivity analyses (by ICI, treatment group and histology) were performed.

Results: Eighteen RCTs met the inclusion criteria (n=12172 subjects). The OR [95%IC] for rheumatic irAE in ICIs versus controls (either placebo or chemotherapy) was 2.20 [0.85,5.72]. Among rheumatic non-irAEs, both overall and severe (grade≥3) back pain were significantly more frequent in ICIs versus controls, 2.01 [1.09;3.73] and 2.90 [1.18;7.08], respectively. The overall frequency of arthralgia was similar between ICIs and controls; by sensitivity analysis RCTs assessing ICIs in combination with chemotherapy showed a significant association with arthralgia (1.55 [1.15;2.10]). Similarly, the frequency of myalgia was significantly lower in RCTs assessing ICIs alone versus chemotherapy (OR 0.32 [0.24;0.42]). Muscular pain was not significantly increased with ICI.

Conclusion: Rheumatic irAEs are not increased in RCTs assessing PD-(L)1 inhibitors, not reflecting the real-life incidence, therefore likely underreported or misclassified. Back pain is significantly associated with them regardless its severity, while arthralgia only when ICIs are added on conventional chemotherapy.