The Pattern Of Imatinib Dose Change And Its Implications In Chronic Myeloid Leukemia In A Cohort Of Patients Attending The Glivec Internationalpatient Assistance Program (Gipap) In Nairobi, Kenya

Abstract

Background: Imatinib has been used clinically to treat chronic myeloid leukaemia since 2002. The standard starting dose for all patients was determined in early studies and set at four hundred milligrams orally once a day. Our experience at the Nairobi GIPAP has been that this dose of four hundred milligrams is sometimes decreased or increased in some of our patients for different reasons. This phenomenon has not been studied in Nairobi and elsewhere before. Objectives: We undertook to quantify the magnitude of this phenomenon. Secondly, we want to study how it affects patient outcomes on follow-up. Study methods: Seven hundred and nine (709) patient files were studied from our GIPAP clinic in Nairobi. All were adults aged eighteen and above. They were all diagnosed with CML and they were on imatinib for varying lengths of time. Data on their gender, age, phase of disease, changes made to dose and follow-up phase were extracted. Results: Three hundred and fifty eight (51%) of the patients studied experienced the change in their dose. Fifty five percent (55%) of them were male and the remainder were female. Forty six (14.6%) of females under study had their dose increased, fifty three (16,8%) of females under study had their dose decreased and sixty two (19,6%) of all females in our study had an imatinib dose change that was equivocal. Sixty four males (16.3%) had an increase in the dose of their imatinib, fifty seven (14.5%) had their dose decreased and sixty four male (19.3%) had a change that was equivocal. These changes between genders were not statistically significant (p=0,638). Among females the change of the dose of imatinib, whether it was increased or decreased, did not influence the outcome of these patients in a statistically significant way (p=0.549). However, males who experienced increased dosage of imatinib were lost to follow-up (p=0.003) The attrition rate was high, reaching 40%, even amongst patients who had experienced no change in the dose of imatinib. 8 Conclusions: The change in imatinib dose reaches 50% in the GIPAP clinic in Nairobi. Males who had an increase in their imatinib dose did not do well. This observation begs to be explored further. Our clinic however has a high attrition rate.