However, some patients do not respond (primary resistance) or lose response (secondary resistance) to the TKI they receive. Regular monitoring of BCR-ABL1 transcript levels in response to TKIs is crucial to detect the emergence of resistance.[1–5]
A common mechanism of resistance is the presence of mutations in the BCR-ABL1 kinase domain. These mutations can impair or prevent the binding of certain TKIs, reducing their efficacy and ultimately leading to resistance.
Therefore, timely detection of mutations in the BCR-ABL1 kinase domain that confer TKI resistance can help facilitate appropriate treatment decisions.