Dasatinib discontinuation after sustained deep molecular response for more than 1 year is feasible in patients with chronic myeloid leukemia (CML), a new study published online ahead of print in the journal The Lancet Haematology has shown.1

Because first-line imatinib can be successfully discontinued in patients with CML after deep molecular response has been sustained for at least 2 years, researchers in Japan sought to evaluate the safety and efficacy of discontinuing second-line or subsequent dasatinib after at least 1 year of deep molecular response.

For the prospective, multicenter, Dasatinib Discontinuation trial, researchers enrolled 88 patients receiving dasatinib consolidation therapy with confirmed deep molecular response for at least 1 year.

Of those, 63 discontinued therapy and were followed up with every month in year 1, every 3 months in year 2, and every 6 months in year 3 to assess deep molecular response and immunological profiles.

Results showed that after a median follow-up of 20 months, 30 of the 63 patients maintained deep molecular response while 33 patients experienced molecular relapses within 7 months after discontinuation. The other 25 patients who were excluded from discontinuation continued to receive treatment and none experienced disease progression.

The study demonstrated an overall treatment-free remission of 49% (95% CI, 36 – 61) at 6 months.

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In regard to safety, no severe treatment-related toxicities were observed.

The 33 patients who relapsed restarted treatment and rapid molecular response was achieved in all 33, of whom 88% regained deep molecular response within 3 months. The other 4 achieved deep molecular response by 6 months.

Reference

  1. Imagawa J, Tanaka H, Okada M, et al. Discontinuation of dasatinib in patients with chronic myeloid leukaemia who have maintained deep molecular response for longer than 1 year (DADI trial): a multicentre phase 2 trial [published online ahead of print November 9, 2015]. Lancet Haematol. doi: 10.1016/S2352-3026(15)00196-9.