CML: Study Evaluates Long-term Outcomes After Imatinib Discontinuation
Imatinib discontinuation in patients with chronic myeloid leukemia in chronic phase who achieved undetected minimal residual disease.
Imatinib discontinuation in patients with chronic myeloid leukemia in chronic phase (CML-CP) who achieved undetected minimal residual disease (UMRD) after frontline imatinib therapy led to favorable long-term outcomes with respect to safety and feasibility, a study published in the journal Acta Haematologica has shown.1
Because limited data exist on the long-term outcomes following imatinib discontinuation in patients treated with first-line imatinib therapy, researchers in South Korea sought to assess the long-term outcomes of patients with CML-CP and UMRD who discontinue imatinib.
For the study, researchers enrolled 19 patients with CML-CP who discontinued imatinib after achieving UMRD for 12 or more months between June 2009 and January 2013.
Results showed that after imatinib was discontinued, 74% of patients lost UMRD after a median of 4.0 months. Of those, 14 patients relapsed within the first 9 months after imatinib discontinuation and the other 2 patients relapsed at 20.5 and 22.8 months, respectively.
With a median follow-up of 58.1 months, researchers estimated the 5-year persistence rate to be 23.7%. All patients who had a molecular relapse were retreated with imatinib, and 12 of those 14 patients re-achieved UMRD at a median of 5.3 months.
The study also demonstrated that a high-risk Sokal score, delayed UMRD achievement, and short-term treatment with imatinib were significantly associated with molecular relapse.
RELATED: Hematopoietic Transplant Remains Valid Option for CML in Era of TKIs
Imatinib is a tyrosine kinase inhibitor indicated for the treatment of newly diagnosed adult and pediatric patients with Philadelphia chromosome (Ph)-positive CML-CP, as well those in accelerated phase, chronic phase, or blast crisis after failure of interferon-alpha therapy.
- Yhim H-Y, Lee N-R, Song E-K, et al. Long-term outcomes after imatinib mesylate discontinuation in chronic myeloid leukemia patients with undetectable minimal residual disease. Acta Haematol. 2016;135:133-139.