Imatinib Optimized Therapy Improves Major Molecular Response Rates in Patients with Chronic Myeloid Leukemia

Abstract

The registered dose for imatinib is 400 mg/d, despite high inter-patient variability in imatinib plasmatic exposure. Therapeutic drug monitoring (TDM) is routinely used to maximize a drug’s efficacy or tolerance. We decided to conduct a prospective randomized trial (OPTIM-imatinib trial) to assess the value of TDM in patients with chronic phase chronic myelogenous treated with imatinib as first-line therapy (NCT02896842). Eligible patients started imatinib at 400 mg daily, followed by imatinib [C]min assessment. Patients considered underdosed ([C]min IS ≤ 0.1%) at 12 months. Out of 133 evaluable patients on imatinib 400 mg daily, 86 patients had a [C]min p = 0.017). This early advantage persisted over the 3-year study period, in which we considered imatinib cessation as a censoring event. Imatinib TDM was feasible and significantly improved the 12-month MMR rate. This early advantage may be beneficial for patients without easy access to second-line TKIs.

Keywords

• imatinib
• therapeutic drug monitoring
• chronic myelogenous leukemia