Probability of t790m mutation after dacomitinib/dacomitinib resistance

Dacomitinib (Dacomitinib) is an oral, once-daily, irreversible, pan-human epidermal growth factor receptor tyrosine kinase inhibitor (TKI) indicated for the treatment of metastatic non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 19 deletion or exon 21 L858R substitution mutation detected by a U.S. Food and Drug Administration (FDA)-approved test.

However, like otherEGFR-TKIs, resistance to dacomitinib may also occur during treatment. Among them, T790M mutation is one of the more common EGFR resistance mechanisms. The T790M mutation means that thymine (T) at position 790 on the EGFR gene is replaced by methionine (M). This mutation will lead to structural changes in the EGFR protein, thereby affecting its ability to bind to TKI drugs, making TKI drugs that originally inhibit EGFR ineffective. Therefore, the T790M mutation is one of the important causes of dacomitinib resistance.

About the probability of T790M mutation after dacomitinib resistanceThis is actually a complex issue because it is affected by multiple factors. First of all, the patient's genetic background, tumor type, stage, and EGFR mutation status before treatment will all affect the probability of T790M mutation after drug resistance. Secondly, the dosage, duration of medication and combination with other drugs during treatment may also have an impact on the resistance mechanism.

Generally speaking, the probability of T790M mutation after dacomitinib resistance is not fixed, but gradually increases with the extension of treatment time. Some studies have shown that among patients treated with dacomitinib, the probability of T790M mutation after drug resistance can reach a certain proportion, but the specific value will vary depending on the research population, research methods and other factors.