Meeting NewsPerspective

Long-term treatment-free remission achievable for chronic myeloid leukemia

CHICAGO — Patients with chronic myeloid leukemia who have attained sustained deep molecular response with second-line nilotinib therapy can achieve treatment-free remission persisting nearly 3 years, according to updated results of the ENESTop study presented at the ASCO Annual Meeting.

“Treatment-free remission is a new treatment goal in patients with CML who achieve a sustained deep molecular response,” François-Xavier Mahon, MD, PhD, professor and senior house physician at University of Bordeaux in France, said during his presentation. “Together with previous results showing higher MR rates with a switch to second-line nilotinib [Tasigna, Novartis] vs. remaining on imatinib, these findings suggest that switching to nilotinib may enable more patients to reach eligibility for attempting and achieving treatment-free remission.”

The researchers originally enrolled 163 patients with Philadelphia chromosome-positive CML in the chronic phase who received tyrosine kinase inhibitor therapy for at least 3 years — including more than 4 weeks with imatinib, followed by 2 or more years of nilotinib — and achieved a deep molecular response of MR while receiving nilotinib. Researchers defined MR as BCR-ABL1 0.0032% on the International Scale.

Participants then entered a 1-year consolidation period, during which they received nilotinib. After this period, patients with no confirmed loss of MR could attempt treatment-free remission. The researchers restarted nilotinib in patients with loss of major molecular response or confirmed loss of MR.

Earlier results from the study showed, of patients who sustained a deep molecular response with second-line nilotinib, 57.9% remained in treatment-free remission at 48 weeks — meeting the study’s primary endpoint — and 53.2% remained in remission 96 weeks after stopping treatment.

Data cutoff for the current analysis occurred when all patients had completed at least 144 weeks of treatment-free remission, restarted nilotinib or discontinued the study.

Of 126 patients in treatment-free remission, 61 remained in remission at data cutoff, 58 restarted nilotinib — due to loss of major molecular response (n = 34) or loss of MR4 (n = 24) — and seven discontinued the study.

At 144 weeks, 48.4% (95% CI, 39.4-57.5) remained in treatment-free remission, and the treatment-free survival was 52% (95% CI, 42.9-60.4).

Only three patients experienced loss of response between the 96- and 144-week follow-up; 93% of patients who reinitiated nilotinib regained MR.

The overall rate for adverse events decreased as time increased during treatment-free remission. Researchers observed no reports of disease progression or deaths associated with CML. – by Jennifer Southall

Reference:

Mahon FX, et al. Abstract 7003. Presented at: ASCO Annual Meeting; June 1-5, 2018; Chicago.

Disclosures: Mahon reports honoraria from Bristol-Myers Squibb, Novartis Pharma and Pfizer; advisory board roles with Ariad/Incyte, Bristol-Myers Squibb and Novartis Pharma; and research support from Novartis Pharma. Please see the abstract for all other authors’ relevant financial disclosures.

 

CHICAGO — Patients with chronic myeloid leukemia who have attained sustained deep molecular response with second-line nilotinib therapy can achieve treatment-free remission persisting nearly 3 years, according to updated results of the ENESTop study presented at the ASCO Annual Meeting.

“Treatment-free remission is a new treatment goal in patients with CML who achieve a sustained deep molecular response,” François-Xavier Mahon, MD, PhD, professor and senior house physician at University of Bordeaux in France, said during his presentation. “Together with previous results showing higher MR rates with a switch to second-line nilotinib [Tasigna, Novartis] vs. remaining on imatinib, these findings suggest that switching to nilotinib may enable more patients to reach eligibility for attempting and achieving treatment-free remission.”

The researchers originally enrolled 163 patients with Philadelphia chromosome-positive CML in the chronic phase who received tyrosine kinase inhibitor therapy for at least 3 years — including more than 4 weeks with imatinib, followed by 2 or more years of nilotinib — and achieved a deep molecular response of MR while receiving nilotinib. Researchers defined MR as BCR-ABL1 0.0032% on the International Scale.

Participants then entered a 1-year consolidation period, during which they received nilotinib. After this period, patients with no confirmed loss of MR could attempt treatment-free remission. The researchers restarted nilotinib in patients with loss of major molecular response or confirmed loss of MR.

Earlier results from the study showed, of patients who sustained a deep molecular response with second-line nilotinib, 57.9% remained in treatment-free remission at 48 weeks — meeting the study’s primary endpoint — and 53.2% remained in remission 96 weeks after stopping treatment.

Data cutoff for the current analysis occurred when all patients had completed at least 144 weeks of treatment-free remission, restarted nilotinib or discontinued the study.

Of 126 patients in treatment-free remission, 61 remained in remission at data cutoff, 58 restarted nilotinib — due to loss of major molecular response (n = 34) or loss of MR4 (n = 24) — and seven discontinued the study.

At 144 weeks, 48.4% (95% CI, 39.4-57.5) remained in treatment-free remission, and the treatment-free survival was 52% (95% CI, 42.9-60.4).

Only three patients experienced loss of response between the 96- and 144-week follow-up; 93% of patients who reinitiated nilotinib regained MR.

The overall rate for adverse events decreased as time increased during treatment-free remission. Researchers observed no reports of disease progression or deaths associated with CML. – by Jennifer Southall

Reference:

Mahon FX, et al. Abstract 7003. Presented at: ASCO Annual Meeting; June 1-5, 2018; Chicago.

Disclosures: Mahon reports honoraria from Bristol-Myers Squibb, Novartis Pharma and Pfizer; advisory board roles with Ariad/Incyte, Bristol-Myers Squibb and Novartis Pharma; and research support from Novartis Pharma. Please see the abstract for all other authors’ relevant financial disclosures.

 

    Perspective
    Javier Pinilla-Ibarz

    Javier Pinilla-Ibarz

    This trial — initiated a while ago — is one of the longest follow-up treatment discontinuation trials to date. The data presented here are now being reproduced in multiple trials. The results demonstrate the same findings we have seen in the past — around 52% of the patients are still in molecular response at a median follow-up of around 3 years. This success rate is being reproduced in multiple trials — no matter the drug used as the second drug of choice.

    This once again confirms that the discontinuation of a TKI is safe. More than 95% of patients in this study reached the same molecular levels they had before after reinitiating treatment. Even among the few patients who did not reach these molecular levels, progress may still be in motion.

    • Javier Pinilla-Ibarz, MD
    • Moffitt Cancer Center

    Disclosures: Pinilla-Ibarz reports no relevant financial disclosures.

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