Patterns of Relapse and Toxicity in Patients of CML (Chronic Phase) on Imatinib Therapy.

44 patients of CML (in chronic phase) were evaluated for their hematological, cytogenetic and molecular response (by doing quantitative PCR- for bcr-abl/abl), over a period of last 4 years. The toxicity profile of these patients was also evaluated. The mean age of study group was 54.5 years, with a male: female ratio of 1.8:1 (28 males and 16 females). 13/44 (29.3%) patients were treated with interferon prior to imatinib therapy, while the rest (31) were started on imatinib (400mg/day) upfront. 43/44 (97.7%) patients achieved a complete hematological response. 1 patient who did not respond to imatinib therapy had long duration of disease (111 months). 24/44 (54.6%) had complete cytogenetic response, 4 (9.1%) had major and 5 (11.3%) had minor cytogenetic response. 7/44 (15.9%) had hematological relapse while on Imatinib therapy. 3/44 (6.8%) had cytogenetics / molecular relapse only. Out of the 13 patients who had received prior interferon, 4 developed hematological relapse and of these 4 patients, 1 developed blast crisis and other 3 are in accelerated phase. 3/31 (9.7%) patients who received imatinib therapy upfront developed hematological relapse, while 6/31 (19.2%) developed cytogenetic/molecular relapse including the 3 patients who developed hematological relapse. A median of 17 months of imatinib therapy was given in patients who did not receive prior interferon. 36/44 (81%) developed hypopigmentation 19/44 (43%) had fluid retention, 9/44 (20%) had muscle cramps and 3/44 (6.8%) developed myelosupression. The relapse rate in patients of CML in chronic phase is more in those who have received interferon prior to imatinib therapy (37.7%). At a median follow up of 17 months the relapse rate in patients who received imatinib de novo was 19.2%.