According to results from a study published in the Journal of Clinical Oncology, a percentage of patients with chronic myeloid leukemia (CML) receiving imatinib can safely discontinue treatment when they have had undetectable minimal residual disease (UMRD) for at least two years.
The STIM1 (Evaluation of the Persistence of the Complete Molecular Remission After Stopping Imatinib Chronic Myeloid Leukemia) study, conducted by Gabriel Etienne, MD, PhD, from the Institut Bergonié in Bordeaux, France, and authors, included 100 patients with CML.
After a median follow-up of 77 months (range = 9-95 months), molecular recurrence-free survival was 43 percent (95% CI 33-52) at six months and 38 percent (95% CI 29-47) at 60 months.
Sixty-one patients lost UMRD status after a median of 2.5 months (range = 1-22 months), and 57 of those patients restarted imatinib treatment. Most patients (n=55) again achieved UMRD status after a median of four months (range =1-16 months). One patient died with UMRD at 10 months, and no patients experienced CML progression.
At the time of last follow-up, 57 patients were alive, and 43 (70%) were receiving a tyrosine kinase inhibitor (TKI). Nine of the 14 patients not on TKI therapy had achieved a sustained second UMRD status and discontinued the treatment once again.
Source: Etienne G, Guilhot J, Rea D, et al. Long-term follow-up of the French Stop Imatinib (STIM1) study in patients with chronic myeloid leukemia. J Clin Oncol. 2016 October 3. [Epub ahead of print]