ABSTRACT Introduction Tyrosine kinase inhibitors (TKIs) have transformed the treatment of chronic myeloid leukemia (CML); yet, diverse molecular responses and resistance persist. BCR::ABL1 kinase‐domain (TKD) mutations constitute just a fraction of this resistance, and the impact of additional somatic mutations on disease progression and early molecular response remains incompletely defined. Methods This single‐centre cohort study analyzed 109 NGS‐tested patients with CML, comprising 44 with TKI‐resistant disease and 65 newly diagnosed patients. Targeted next‐generation sequencing using a 135‐gene myeloid panel was performed on 109 patients. An additional pilot subgroup of 30 TKI‐resistant patients underwent BCR::ABL1 kinase‐domain analysis by PCR/Sanger sequencing and was analyzed separately. Molecular response was assessed using BCR::ABL1 transcript levels on the International Scale and interpreted according to ELN 2020 recommendations. Results Somatic mutations were identified in 52.3% of TKI‐resistant and 29.2% of newly diagnosed patients. All Cohort 1 blast‐crisis patients were mutation‐positive, and several concurrent abnormalities were more common in Cohort 1 than in Cohort 2, indicating clonal complexity. In Cohort 2, MMR was achieved in 28/39 (71.8%) mutation‐negative and 6/13 (46.2%) mutation‐positive patients. Mutation‐positivity at baseline was associated with reduced MMR chances but not statistically significant (odds ratio 0.34; 95% confidence interval 0.09–1.23; p = 0.099). ASXL1 emerged as the most common non‐ABL1 mutation but was not statistically significant. Conclusions In this Indian CML cohort, somatic mutations were prevalent in TKI‐resistant disease, linked to advanced phase and clonal complexity, and demonstrated a non‐significant trend toward lower early MMR at diagnosis, highlighting the importance of genomic testing in this context.
Mishra et al. (Sun,) studied this question.