Six RCTs (n=560) were included in the review. Two hundred and seventy-eight patients were randomised to the GEM-DDP combination and 282 to GEM alone.
All of the included studies scored 3 points on the Jadad quality scale and were considered by the authors to be of high quality. No significant heterogeneity was detected in any of the meta-analyses, except adverse events.
A marginally significant improvement of 6% in objective remission rate was observed for the GEM-DDP combination group (5 studies; RD 0.06, 95% confidence interval, CI: 0.000, 0.12). There was no significant improvement in clinical benefit response for the GEM-DDP combination group (3 studies).
There was no significant improvement in 6-month survival rate for the GEM-DDP combination group (5 studies; RD 0.05, 95% CI: -0.03, 0.13).
There was a marginal significant improvement of 9% in 6-month time to progression/time to treatment failure for the GEM-DDP combination group (5 studies; RD 0.09, 95% CI: 0.01, 0.17).
Grade 3-4 toxicity was higher in the GEM-DDP combination group for neutropenia (RD 0.06, 95% CI: -0.01, 0.12), thrombocytopenia (RD 0.08, 95% CI: -0.03, 0.18) and vomiting or nausea (RD 0.11, 95% CI: -0.01, 0.22), but none of these findings were statistically significant. However, significant heterogeneity was detected and the number of studies included was not reported.