4CPS-103 Second-generation tyrosin kinase inhibitors in front-line therapy. comparing responses

BackgroundSecond-generation tyrosine kinase inhibitors(2G-TKI) have increased considerably over the past few years. Despite good and maintained results with imatinib, 2G-TKI have shown a growing trend in their use due to their quick and deep response. However, there is no clear positioning between nilotinib and dasatinib.PurposeTo analyse differences in the response according to the 2G-TKI used in front-line therapy in chronic myeloid leukaemia (CML) patients.Material and methodsDescriptive retrospective observational study conducted in a tertiary hospital. Patients with front-line therapy with nilotinib or dasatinib from June 2011 until April 2016 were included.Study variables were: sociodemographic (sex, age), clinical (time from diagnosis, p210 rearrangement, hydroxiurea cytoreduction, 2G-TKI, dosage regimen, time with TKI).Response was assessed in terms of molecular response and classified according to European Leukaemia Net (ELN) 2013 criteria.Degree of response at 3, 6 and 12 months according to 2G-TKI employed was analysed using the Mann–Witney U test.Timing to major molecular response (MMR) and major cytogenetic response (MCR), according to 2G-TKI were also tested using the Chi square test. Data were analysed with SPSS 19 software.ResultsTwenty-two patients received front-line 2G-TKI. Seventy seven per cent (n=17) were males, and mean age was 56.5 (±14.3). Median time since diagnosis was 33 months (2–57). p210 rearrangement was present in 18 of our patients (four had no available data). All of them received hydroxiurea.2G-TKI among our population were: 59% (n=13) nilotinib and 41% (n=9) dasatinib. Three patients required dose adjustment (one nilotinib, two dasatinib). Median time receiving TKI was 28.5 months (3–57).No significant differences were found in terms of degree and time to MMR or MCR between nilotinib and dasatinib in any point of the study (p>0.05).ConclusionOur results suggest that both 2G-ITK are reasonable options in front-line therapy, with fast and deep responses obtained. No significant differences were found between them among our population.Consequently, treatment choice should be done according to toxicity, comorbidities, clinician experience and dosage-regimen.No conflict of interest