Imatinib withdrawal syndrome and longer duration of imatinib have a close association with a lower molecular relapse after treatment discontinuation: the KID study

Abstract

The aim of the Korean Imatinib Discontinuation Study was to identify predictors for safe and successful imatinib discontinuation. A total of 90 patients with a follow-up of ≥12 months were analyzed. After a median follow-up of 26.6 months after imatinib discontinuation, 37 patients lost the major molecular response. The probability of sustained major molecular response at 12 months and 24 months was 62.2% and 58.5%, respectively. All 37 patients who lost major molecular response were retreated with imatinib therapy for a median of 16.9 months, and all achieved major molecular response again at a median of 3.9 months after resuming imatinib therapy. We observed newly developed or worsened musculoskeletal pain and pruritus in 27 (30%) patients after imatinib discontinuation. Imatinib withdrawal syndrome was associated with a higher probability of sustained major molecular response (P=0.003) and showed a trend for a longer time to major molecular response loss (P=0.098). Positivity (defined as ≥ 17 positive chambers) of digital polymerase chain reaction at screening and longer imatinib duration before imatinib discontinuation were associated with a higher probability of sustained major molecular response. Our data demonstrated that the occurrence of imatinib withdrawal syndrome after imatinib discontinuation and longer duration of imatinib were associated with a lower rate of molecular relapse. In addition, minimal residual leukemia measured by digital polymerase chain reaction had a trend for a higher molecular relapse. (Trial registered at ClinicalTrials.gov: NCT01564836).

Copyright© Ferrata Storti Foundation.

Figures

Figure 1.

Probability of sustained MMR (A) and time to MMR loss (B) in patients with follow-up ≥ 12 months (N=90).

Figure 2.

Probability of sustained MMR (A) and time to MMR loss (B) according to positivity of dPCR (defined as > 17 positive chambers) at baseline.

Figure 3.

Probability of sustained MMR (A) and time to MMR loss (B) according to the presence of IM withdrawal syndrome.

Figure 4.

Probability of sustained MMR according to the number of predictive factors (negative dPCR, presence of IMWS, and longer than 62 months of IM therapy duration).