Osimertinib early dose reduction as a risk to brain metastasis control in EGFR-mutant non-small cell lung cancer

Clinical Impact of Osimertinib Dose Reduction in the First-Line Setting on EGFR Mutation-Positive Non-Small Cell Lung Cancer: A Retrospective Monocentric Study

Purpose

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. In the FLAURA trial, osimertinib demonstrated longer progression-free survival (PFS) and overall survival (OS) compared to gefitinib or erlotinib. In the trial, dose reductions occurred in 5% of patients, primarily due to QT prolongation. However, various adverse events can also lead to dose reductions in clinical practice, and the efficacy of osimertinib after dose reduction remains unclear. The present study was conducted to evaluate the clinical impact of osimertinib dose reduction.

Patients and Methods

This monocentric retrospective study was conducted at Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital. Ninety patients with EGFR mutation-positive non-squamous non-small-cell lung cancer receiving osimertinib as their first-line therapy between August 2018 and December 2021 were included.

Results

Of the cohort, 23 patients had an osimertinib dose reduction during their clinical course. The dose reduction group tended to have a lower median body weight and a higher proportion of elderly patients aged 80 years or older. The median PFS was 21.2 months (95% confidence interval [CI]: 8.22-34.18) in the dose reduction group and 18.6 (95% CI: 13.04-24.23) months in the regular-dose group. The median OS was 29.6 months (95% CI: 17.44-41.70) in the osimertinib dose-reduction group and 37.7 (95% CI: 27.10-48.23) months in the regular-dose group. Dose reduction did not significantly impact the time-dependent hazard ratio (HR) for PFS (HR 1.22 [95% CI: 0.55-1.89]) or OS (HR: 1.24 [95% CI: 0.64-2.42]). The adverse events leading to dose reduction were mainly rash, anorexia, and paronychia, and no fatal adverse events were observed after dose reduction.

Conclusion

The present study suggests that dose reduction may not compromise the efficacy of osimertinib. However, the clinical impact of dose reduction is not fully understood. Physicians should carefully weigh its benefits and risks before implementation.

Dose Reduction of EGFR-TKIs for EGFR-positive Non-small Cell Lung Cancer: A Retrospective Study

Background/Aim

The epidermal growth factor receptor (EGFR) gene was the first driver gene discovered in non-small cell lung cancer (NSCLC), and the introduction of tyrosine kinase inhibitors (TKIs) has improved patient prognosis, but often at reduced doses. Conventional dose determination methods for cytotoxic antitumor drugs were not applicable to EGFR-TKIs and were determined differently. The purpose of this study was to determine the characteristics of patients undergoing EGFR-TKI dose reduction, and the impact of such dose reduction on survival.

Patients and Methods

Patient characteristics, treatment, overall survival, and progression-free survival of patients with EGFR mutation-positive NSCLC treated with EGFR-TKIs between August 2008 and April 2024 at two hospitals were retrospectively evaluated.

Results

Of 165 patients, 67.3% received TKI dose reduction; patients who received TKI dose reduction had a smaller body surface area (p=0.029), which was more common in patients with better performance status (p=0.026). Side effects, especially diarrhea and rash, were the main reasons for this. Overall survival was significantly longer in the dose reduction group than in the recommended dose group (p=0.011). Multivariate analysis showed that TKI dose reduction was a favorable factor with a hazard ratio of 0.68 (p=0.046).

Conclusion

Reducing TKI dose is an option for patients with EGFR-mutated NSCLC, especially in elderly or underweight patients who develop adverse effects, and there is no reason to hesitate to reduce the TKI dose in these patients.

Outcome of osimertinib-treated patients with epidermal growth factor receptor mutation-positive nonsmall cell lung cancer requiring dose reduction: a secondary analysis of the Reiwa study

BACKGROUND

Osimertinib is effective in patients with epidermal growth factor receptor (EGFR) mutation-positive nonsmall cell lung cancer (NSCLC). However, some patients require osimertinib dose reduction because of adverse events. This study assessed the characteristics of osimertinib dose reduction and compared the efficacies of reduced-dose and regular-dose osimertinib.

METHODS

This multicenter, prospective, observational study enrolled patients with EGFR mutation-positive NSCLC who started first-line osimertinib treatment between September 2018 and August 2020. We categorized the patients into two groups: those who required dose reduction during osimertinib treatment (reduction group) and those who continued osimertinib treatment at a dose of 80 mg/day without dose reduction (nonreduction group). The primary endpoints were progression-free survival (PFS) and pattern of progression, whereas the secondary endpoints included overall survival (OS) and reasons for osimertinib dose reduction.

RESULTS

Of the included 575 patients, 175 (30.4%) and 400 (69.6%) were classified into the reduction and nonreduction groups, respectively. PFS was significantly better in the reduction group than in the nonreduction group [hazard ratio (HR) = 0.67, 95% confidence interval (CI) = 0.54-0.84; P <0.001]. Meanwhile, the pattern of progression and OS (HR = 0.82, 95% CI = 0.62-1.08; P = 0.15 ) did not differ significantly between the two groups. Osimertinib was reduced due to physician's decision or adverse events and the main reasons were rash and gastrointestinal symptoms such as nausea and diarrhea.

CONCLUSIONS

Many patients require osimertinib dose reduction due to adverse events, but this process does not adversely affect the drug efficacy.

Efficacy and safety of 40 mg osimertinib administered every other day for non-small cell lung cancer harboring an epidermal growth factor receptor mutation: A single-center retrospective cohort study

Osimertinib is a first-line or adjuvant therapy for non-small cell lung cancer (NSCLC) harboring an epidermal growth factor receptor (EGFR) mutation. However, owing to the adverse events associated with treatment, certain patients cannot maintain a daily regimen of 80 or 40 mg. In this study, we examined the efficacy of 40 mg of osimertinib administered every other day. In this single-center, retrospective study, we evaluated patients with NSCLC harboring an EGFR mutation in whom treatment was initiated with 40 mg osimertinib every other day at our institution between May 2016 and June 2023. The major outcome was the duration of administering 40 mg osimertinib every other day. Six patients with NSCLC were evaluated. The median duration of 40 mg osimertinib intake every other day was 12.6 months. Four of the six patients weighed below 50 kg, and four experienced weight loss. Additionally, four of the six patients had severe renal impairment upon receiving 40 mg osimertinib every other day. Thus, our findings suggest the efficacy of administering 40 mg osimertinib every other day in patients with low bodyweight, weight loss, or severe renal impairment.