Thirteen studies were included in the review (n=1,439, range 18 to 329). Seven studies reported adequate randomisation and allocation concealment; none were blinded.
There was no statistically significant difference in all-cause mortality between any of the regimens (12 RCTs). There was a statistically significant reduction in aGVHD associated with MTX-containing versus non-MTX-containing regimens (RR 0.49, 95% CI 0.38 to 0.65, NNT=4, 95% CI 3 to 7; six RCTs, I2=5%), but no statistically significant difference between the groups in rates of severe aGVHD.
Tacrolimus-based regimens were associated with a statistically significant reduction in aGVHD (RR 0.62, 95% CI 0.52 to 0.75; NNT=5, 95% CI: 4 to 9; three RCTs, I2=55%) and in severe aGVHD (RR 0.67, 95% CI 0.47 to 0.95; three RCTs, I2=0%) compared to cyclosporine-based regimens. However, tacrolimus-based regimens were associated with a significantly higher rate of renal failure (RR 1.20, 95% CI 1.03 to 1.39; two RCTs, I2=28%).
No significant differences in rates of chronic GVHD, treatment-related mortality or relapse rate were found between any regimens in the review. Regimens with and without corticosteroids were compared and there was no statistically significant difference between the groups for any outcome.