Health-related quality of life of patients with resistant/intolerant chronic phase chronic myeloid leukemia treated with asciminib or bosutinib in the phase 3 ASCEMBL trial

Treatment-free remission after discontinuation of tyrosine kinase inhibitors in patients with chronic myeloid leukemia in the chronic phase: a systematic review and meta-analysis

BACKGROUND

Treatment-free remission (TFR) is a new long-term goal for treating selected patients with chronic myeloid leukemia in the chronic phase (CML-CP). Still, the appropriate group in which TFR can be attempted and the factors influencing it have not yet been identified. This meta-analysis aimed to explore TFR in CML-CP patients who achieved a deep molecular response (DMR) before Tyrosine kinase inhibitors (TKIs) discontinuation and to explore possible factors influencing TFR and the safety of discontinuation.

METHODS

We performed a systematic review and single-arm meta-analysis with a systematic search of published literature up to September 2023 in PubMed, Embase, Web of Science, Cochrane Library, and CNKI databases. The assessment was performed using the MINORS scale. Random-effects models were used to calculate outcome metrics, including overall mean TFR rates at 12 and 24 months and subgroup differences. Data synthesis and analysis were done by Stata17.0 software.

RESULTS

A total of 19 single-arm trials involving 2336 patients were included in this meta-analysis, with an overall mean TFR rate of 59% [95CI:0.56-0.63] at 12 months and 55% [95CI:0.52-0.59] at 24 months, and no CML-related deteriorations or deaths reported during the TFR period. Our subgroup analysis showed that better TFR was associated with prior interferon therapy (P = 0.003), and molecular response depth MR5.0 (P = 0.020).

CONCLUSION

Our study demonstrated that prior interferon therapy and attainment of a molecular response depth of MR5.0 or greater were associated with higher TFR rates, with patients who attained MR5.0 or greater achieving a TFR rate of up to 62% in the second year after TKI discontinuation. Considering the high heterogeneity of the included trials, the above influences still require further validation and more detailed subgroup analysis in future discontinuation trials.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/ (Registration No. CRD42023471334).

Asciminib in Patients With CML-CP Previously Treated With ≥ 2 Tyrosine Kinase Inhibitors: 96-Week Results From the Japanese Subgroup Analysis of the ASCEMBL Study

Asciminib is a first-in-class BCR::ABL1 inhibitor that Specifically Targets the ABL1 Myristoyl Pocket (STAMP). It is approved worldwide and in Japan for chronic myeloid leukemia in chronic phase (CML-CP) with resistance or intolerance to previous tyrosine kinase inhibitor (TKI) therapy. In the Phase 3 ASCEMBL study, patients with CML-CP who received ≥ 2 prior ATP-competitive TKIs were randomized (2:1) to asciminib 40 mg twice-daily or bosutinib 500 mg once-daily. Here, we report the 96-week results of the subgroup analysis of Japanese patients (asciminib, n = 13; bosutinib, n = 3) in the ASCEMBL study. The MMR rate at Week 96 was 46.2% in asciminib-treated patients, increasing from Weeks 24 and 48. Patients who achieved MMR at Week 24 remained in MMR up to the Week 96 cutoff. While a high proportion of patients treated with asciminib remained on treatment at cutoff, none randomized to bosutinib were on treatment at Week 96. Despite the longer duration of exposure to asciminib, its safety and tolerability continued to be favorable with no new or worsening safety findings. Overall, the efficacy and safety outcomes in the Japanese subgroup were comparable with the ASCEMBL global study population, which supports the use of asciminib in Japanese patients with previously treated CML-CP.

Bilateral Retinal Vascular Tortuosity and Hemorrhages

A 28-year-old man presented with decreased visual acuity in his right eye for the past 2 weeks. Examination revealed dilated and tortuous veins, Roth spots, and white intraretinal agglomerates. What would you do next?

Genetic Landscape of Chronic Myeloid Leukemia and a Novel Targeted Drug for Overcoming Resistance

Tyrosine kinase inhibitors (TKIs) exemplify the success of molecular targeted therapy for chronic myeloid leukemia (CML). However, some patients do not respond to TKI therapy. Mutations in the kinase domain of BCR::ABL1 are the most extensively studied mechanism of TKI resistance in CML, but BCR::ABL1-independent mechanisms are involved in some cases. There are two known types of mechanisms that contribute to resistance: mutations in known cancer-related genes; and Philadelphia-associated rearrangements, a novel mechanism of genomic heterogeneity that occurs at the time of the Philadelphia chromosome formation. Most chronic-phase and accelerated-phase CML patients who were treated with the third-generation TKI for drug resistance harbored one or more cancer gene mutations. Cancer gene mutations and additional chromosomal abnormalities were found to be independently associated with progression-free survival. The novel agent asciminib specifically inhibits the ABL myristoyl pocket (STAMP) and shows better efficacy and less toxicity than other TKIs due to its high target specificity. In the future, pooled analyses of various studies should address whether additional genetic analyses could guide risk-adapted therapy and lead to a final cure for CML.