Routine-Dose and High-Dose Icotinib in Patients with Advanced Non-Small Cell Lung Cancer Harboring EGFR Exon 21-L858R Mutation: the Randomized, Phase II, INCREASE Trial

PURPOSE

Our primary purpose is to explore safety and efficacy of high-dose icotinib in comparison with routine-dose icotinib in patients with non-small cell lung cancer (NSCLC) harboring 21-L858R mutation.

PATIENTS AND METHODS

Patients with treatment-naïve, EGFR-mutant (21-L858R or exon 19 deletion at 2:1) NSCLC were enrolled. Patients with 21-L858R mutation were randomized to receive routine-dose icotinib (125 mg, thrice daily; L858R-RD) or high-dose icotinib (250 mg, thrice daily; L858R-HD), whereas patients with exon 19 deletion received only routine-dose icotinib (19-Del-RD) until progression, death, or unacceptable toxicity. The primary endpoint was median progression-free survival (mPFS), assessed by an independent review committee.

RESULTS

From May 2015 to November 2017, 253 patients (86 in L858R-RD; 90 in L858R-HD; and 77 in 19-Del-RD) were enrolled. The mPFS in L858R-HD group was similar to that in 19-Del-RD group (12.9 months and 12.5 months, respectively) and was significantly longer than that in L858R-RD group [12.9 months vs. 9.2 months, hazard ratio (HR): 0.75; 95% confidence interval (CI), 0.53-1.05]. A longer but statistically nonsignificant mPFS was observed between 19-Del-RD and L858R-RD groups (12.5 months vs. 9.2 months, HR: 0.80; 95% CI, 0.57-1.13). A higher objective response rate (ORR) was observed in L858R-HD group compared with L858R-RD group (73% vs. 48%), also between 19-Del-RD and L858R-RD groups (75% vs. 48%). Similar incidences of grade 3/4 toxicities were observed among the three treatment groups.

CONCLUSIONS

High-dose icotinib improved mPFS and ORR in patients with NSCLC harboring 21-L858R mutation with acceptable tolerability, which could be a new therapeutic option for this patient population.

A Phase I Study of the Safety and Pharmacokinetics of Higher-Dose Icotinib in Patients With Advanced Non-Small Cell Lung Cancer

LESSONS LEARNED

This phase I study evaluated the maximum tolerated dose, dose-limiting toxicities, safety, pharmacokinetics, and efficacy of icotinib with a starting dose of 250 mg in pretreated, advanced non-small cell lung cancer patients. We observed a maximum tolerated dose of 500 mg with a favorable pharmacokinetics profile and antitumor activity.These findings provide clinicians with evidence for application of higher-dose icotinib.

BACKGROUND

Icotinib, an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has shown favorable tolerability and antitumor activity at 100-200 mg in previous studies without reaching the maximum tolerated dose (MTD). In July 2011, icotinib was approved by the China Food and Drug Administration at a dose of 125 mg three times daily for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after failure of at least one platinum-based chemotherapy regimen. This study investigated the MTD, tolerability, and pharmacokinetics of higher-dose icotinib in patients with advanced NSCLC.

METHODS

Twenty-six patients with advanced NSCLC were treated at doses of 250-625 mg three times daily The EGFR mutation test was not mandatory in this study.

RESULTS

Twenty-four (92.3%) of 26 patients experienced at least one adverse event (AE); rash (61.5%), diarrhea (23.1%), and oral ulceration (11.5%) were most frequent AEs. Dose-limiting toxicities were seen in 2 of 6 patients in the 625-mg group, and the MTD was established at 500 mg. Icotinib was rapidly absorbed and eliminated. The amount of time that the drug was present at the maximum concentration in serum (T_max) ranged from 1 to 3 hours (1.5-4 hours) after multiple doses. The t_1/2 was similar after single- and multiple-dose administration (7.11 and 6.39 hours, respectively). A nonlinear relationship was observed between dose and drug exposure. Responses were seen in 6 (23.1%) patients, and 8 (30.8%) patients had stable disease.

CONCLUSION

This study demonstrated that higher-dose icotinib was well-tolerated, with a MTD of 500 mg. Favorable antitumor activity and pharmacokinetic profile were observed in patients with heavily pretreated, advanced NSCLC.