Immune checkpoint inhibitor—chemo combo potent against small cell lung cancer

In the treatment of small cell lung cancer (SCLC), the combination of an immune checkpoint inhibitor plus chemotherapy boosts response and patient survival compared with chemotherapy alone, according to the results of a meta-analysis.

The meta-analysis included five articles evaluating the efficacy and tolerability of using an immune checkpoint inhibitor (eg, programmed cell death protein 1/ligand 1 [PD-1/PD-L1] inhibitor or cytotoxic T-lymphocyte antigen [CTLA]-4 inhibitor) in combination with chemotherapy in the first-line treatment of SCLC.

Study endpoints included overall survival, progression-free survival, objective response rate, and adverse events. The random-effects model facilitated pooling of data, with significant heterogeneity represented by a p-value of <0.05 or an I² value of ≥50 percent. Otherwise, the fixed-effects model was used.

Joint immune checkpoint inhibitor plus chemotherapy treatment yielded significant gains in both overall survival (hazard ratio [HR], 0.83, 95 percent confidence interval [CI], 0.75–0.91; p<0.001) and progression-free survival (HR, 0.80, 95 percent CI, 0.73–0.86; p<0.001). Moreover, the immune checkpoint inhibitor  combination regimens had tolerable grade ≥3 adverse event rates similar to that of conventional chemotherapy (relative risk, 1.05, 95 percent CI, 0.98–1.12; p=0.17).

In a subgroup analysis, patient survival and objective response rate greatly increased with a combination of anti–PD-1/PD-L1, but not anti–CTLA-4, plus chemotherapy.