Imatinib therapy prior to myeloablative allogeneic stem cell transplantation.

It is unknown whether imatinib prior to myeloablative haematopoietic stem cell transplantation (HSCT) increases transplant-related toxicity. Among the side effects induced by imatinib, myelosuppression and liver injury might worsen HSCT outcomes. We retrospectively analysed engraftment, liver toxicity, acute graft-versus-host disease (aGVHD) incidence and 100-day mortality in 30 patients with BCR/ABL-positive leukaemias who received imatinib before HSCT and compared results of 48 age-matched controls who did not receive preceding imatinib. Both neutrophil and platelet engraftment occurred more rapidly among imatinib patients but the differences adjusted for Gratwohl scale were not statistically significant (P = 0.18 and 0.22, respectively). The adjusted hazards of having liver function tests (LFTs) >1.5 normal increased and the adjusted durations of elevated LFTs were not significantly different. The estimated adjusted difference in mean peak bilirubin values was also not significantly different (P = 0.48). However, the adjusted hazard of increased creatinine >1.5 normal was significantly higher in the imatinib group (HR = 4.09, P = 0.02). The adjusted odds of grades II-IV aGVHD were similar in both groups (OR = 0.86, P = 0.78), and while the adjusted odds of 100-day mortality were lower among imatinib patients, the difference was not significant (OR = 0.65, P = 0.60). These data do not provide any evidence that imatinib preceding HSCT increases acute transplant-related toxicities.