Pediatric Hematology Oncology Journal (Mar 2023)
Treatment free remission in pediatric chronic myeloid leukemia
Abstract
Background: The aim was to evaluate the impact of discontinuation of imatinib in children in chronic phase of chronic myeloid leukemia (CML) and assess treatment free remission (TFR). Patients and methods: We performed a retrospective study in children diagnosed with CML chronic phase up to 18 years of age, who were on imatinib for 5 years and had consistent BCR:ABL1 negative/undetectable transcripts through RT-PCR. Complete blood counts were monitored monthly and BCR:ABL1 transcripts by RT-PCR monitored 3 months. Results: Among the 14 patients who continued to remain PCR negative, we attempted discontinuing imatinib in eleven children as per the above-mentioned criteria. Eight (72%) continued to be in remission and did not require imatinib to be restarted. Among the remaining three patients, one child was noted to have increasing basophilia in the differential counts and was hence restarted on imatinib. Two other patients demonstrated recurrence of BCR:ABL1 transcript copy numbers six months after stopping TKI, following which imatinib was restarted. All three patients had documented major molecular response within three months of therapy. The median duration of TFR was 18 months in our cohort (range: 3 months–5 years). Among patients who continued to be off imatinib, TKI withdrawal symptoms were documented in 4 (36%) patients. Conclusions: Treatment free remission was achieved in 8/11 (72%) children after discontinuation of imatinib, and re-introduction of imatinib resulted in major molecular response in those with recurrence. Monitoring of BCR:ABL1 transcripts through RT PCR is essential.
