Exploring the efficacy of low-dose dacomitinib/dacomitinib (15 mg/day) in patients

Dacomitinib/Dacomitinib (Dacomitinib) has shown superior therapeutic effects for patients with epidermal growth factor receptor (EGFR) sensitive mutations, especially those carrying exon 21 L858R mutations. However, the incidence of grade 3-4 treatment-related adverse events was higher in patients initially treated with dacomitinib 45 mg. Based on this, a new study explored the application of low-dose dacomitinib as a first-line treatment in patients with non-small cell lung cancer with EGFR exon 21 mutations.

In this clinical study, researchers used the Scorpion Amplified Refractory Mutation System (ARMS) or next-generation sequencing (NGS) to identify EGFR mutations. A total of nine NSCLC patients with exon 21 mutations were included in the study. The patients were treated with 15 mg of dacomitinib once daily until disease progression or unacceptable toxicity. Treatment efficacy was evaluated according to the Response Evaluation Criteria in Solid Tumors version 1.1.

The primary outcome measure of the study is objective response rate (ORR), and secondary outcomes include disease control rate (DCR), median progression-free survival (PFS), and treatment-related toxicities. The study results showed that among the nine patients participating, 8 carried the L858R mutation and 1 carried the L861Q mutation. The total effective rate of treatment was as high as 77.8%, and the DCR reached 100%. As of the last follow-up, none of these patients had experienced disease progression.

During treatment, most adverse events experienced by patients were minor. Among them, the most common toxic reaction was rash (incidence rate44.4%). Other adverse events, such as itching, diarrhea, abnormal liver function, anemia, and elevated creatinine, occurred only once during the treatment period. Of note, no patients experienced grade 3 or higher toxicities.

This study preliminarily shows that a low-dose dacomitinib of 15 mg per day may have a good therapeutic effect in patients with non-small cell lung cancer carrying EGFR exon 21 mutations, and its toxic effects are significantly reduced compared with the standard dose. However, further prospective or real-world studies are needed to further explore the specific impact of low-dose dacomitinib in these patients.