Patients with chronic myeloid leukemia (CML) are conventionally put on life long therapy with tyrosine kinase inhibitor drugs (Imatinib mesylate in India). Patients who achieve a deep molecular response which has been sustained for at least three years, can be taken off the drug therapy. Thereafter a close monitoring is required to monitor their disease relapse. In case there is evidence of disease recurrence on highly sensitive molecular assays, their drug therapy is restarted. The study aims to identify proportion of patients who can be kept off drug therapy in a state of sustained molecular remission.

While a large number of studies which have stopped TKI therapy in similar patients exist in Europe and USA, no such study has been done on Indian or other south Asian population. Almost all studies done previously have noted that in relapsed patients, who show disease recurrence on stopping their TKI therapy, their remission state is regained once the TKI therapy is restarted.

Inclusion Criteria:

1. Patients of CML on TKI (Imatinib) therapy for more than 5 years
2. Patients who have been in complete molecular response (MR 4.5 +) for at least three years

Exclusion Criteria:

1. Patients who ever had blast crisis
2. Patients achieving molecular response with second generation TKI due to failure of Imatinib