Important genetic and ethnic factors could affect the toxicity and efficacy of
tyrosine kinase inhibitors. Though
nilotinib has been available in India since 2010, there is no report on its safety and toxicity from Indian patients with
chronic myeloid leukemia. This is an analysis of efficacy and toxicity of
nilotinib when used as a second line drug after failure or intolerance to
imatinib. Thirty-seven patients started
nilotinib [median age 46 years, median duration from diagnosis 5 years, 73% in chronic phase at time of switch] between 2010 to 2016. Reason for switch: failure of
imatinib in 33 (89%) and intolerance in 4 (11%). Starting dose 600 mg/day. Dose modifications: 15 (40%) patients required initial dose modifications, but subsequently 25 (67%) patients could tolerate 600 mg/day. Nine (24%) patients were able to tolerate 800 mg/day. The commonest grade 3/4 toxicities were
thrombocytopenia (n = 9, 24%),
hyperbilirubinemia (n = 7, 18%) and
leukopenia (n = 3, 8%). Six patients (16%) discontinued
nilotinib due to toxicity while 8 (21%) stopped due to lack of efficacy. After a median duration of 14 months among those continuing
nilotinib, 54% of patients responded which included 14 patients who achieved CHR and seven who achieved major molecular response. In the first report on use of
nilotinib in Indian patients, we observed a higher incidence of liver toxicity compared to previous reports. This should be seen the context that all these patients received
nilotinib as second line
therapy.