Is it effective to take 15 mg of dacomitinib/dacomitinib a day?

Compared with gefitinib, dacomitinib/dacomitinib (Dacomitinib) has better efficacy in patients with epidermal growth factor receptor (EGFR)-sensitizing mutations, especially those carrying exon 21 L858R mutations. However, grade 3-4 treatment-related adverse events were more common in patients who initially received dacomitinib 45 mg. Thereforeresearchers conducted a study exploring low-dose dacomitinib as first-line treatmentfor patients with non-small cell lung cancer with EGFR exon 21 mutations.

In clinical studies, Scorpion Amplified Refractory Mutation System (ARMS) or next-generation sequencing (NGS) are used to identify EGFR mutations. A total of nine NSCLC patients with exon 21 mutations were included. All these patients received dacomitinib (15 mg once daily) until disease progression or unacceptable toxicity. Response was assessed according to Response Assessment Criteria in Solid Tumors version 1.1. The primary endpoint is objective response rate (ORR). Secondary endpoints were disease control rate (DCR), median progression-free survival (PFS), and treatment-related toxicity. The results showed that in this study among the 9 non-small cell lung cancer patients with exon exon 21 mutations, 8 carried L858R mutation and 1 carried L861Q mutation. The overall effectiveness rate was 77.8% and the DCR was 100%. Median PFS data are immature. None of these patients had disease progression until the last follow-up date. Treatment-related adverse events were generally mild. The most common toxicity was rash (44.4%), with remaining adverse events including rash, pruritus, diarrhea, liver function abnormalities, anemia, and increased creatinine, all of which occurred only once during treatment. No patients experienced grade 3 or higher toxicities.

Studies have shown that dacomitinib (15 mg once daily) may also be effective in patients with non-small cell lung cancer carrying EGFR exon 21 mutations, with significantly reduced toxicity compared with standard doses. Prospective or real-world studies are needed to further elucidate the impact of low-dose dacomitinib in patients with EGFR exon 21 mutations.