Imatinib and pegylated IFN-alpha 2b discontinuation in first-line chronic myeloid leukemia patients following a major molecular response

• Objectives Previous studies indicate that 40-50% of patients with chronic myeloid leukemia in prolonged complete molecular remission may discontinue imatinib therapy without imminent relapse. The combination of pegylated interferon-alpha (Peg-IFN-alpha 2b) and imatinib may increase the rate of successful discontinuation. Methods In this pilot study, we prospectively stopped imatinib from patients (n=12) who had achieved major molecular response (MMR) after >= 12months of treatment with either imatinib or imatinib+Peg-IFN-alpha 2b. Molecular monitoring was carried out monthly for BCR-ABL1. In addition, analyses of lymphocyte immunophenotype, function, and plasma cytokines were performed. Results In the monotherapy group, 5/6 patients lost MMR within 4months. One patient remains to date in MR4.0 61months after discontinuation. In the combination therapy group, 2/6 patients relapsed within 4months while still receiving Peg-IFN-alpha 2b. Four of six patients were able to discontinue both treatments, but three of these patients relapsed after 3months. One patient is still in sustained MR4.0 at 58months off all treatment. All relapsed patients re-responded to imatinib. The two successfully discontinued patients had either an increased number of NK-cells or functionally active T-cells. Conclusions A higher frequency of relapsed patients in our study in comparison with other studies may be due to the shorter duration of imatinib treatment prior to discontinuation. However, in selected patients with an active immune system, even a short duration of TKI therapy (<2yr) may allow for therapy discontinuation but this needs to be confirmed in larger prospective studies.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Hematologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Hematology (hsv//eng)

Keyword

chronic myeloid leukemia

interferon

immune system

tyrosine kinase inhibitor

therapy discontinuation

Publication and Content Type

ref (subject category)

art (subject category)