8-Week Relative Dose Intensity: Predictive of Outcomes With Lenvatinib in Thyroid Cancer?
Posted: Tuesday, April 20, 2021
The administration of a target dose of lenvatinib at a maximum during the first 8 weeks of therapy may optimize survival outcomes in some patients with thyroid cancer, according to research presented in the Endocrine Journal. Though lenvatinib is a standard treatment of patients with radioiodine-refractory differentiated thyroid cancer, it is often associated with a high incidence rate of adverse events, particularly among Japanese patients.
“Administration of a sufficient dose of lenvatinib for the first 8 weeks is essential to achieve significant tumor shrinkage and prolong [progression-free survival], and targeting for ≥ 60% of [8 weeks’ relative dose intensity] is adequate,” concluded Shunji Takahashi, MD, of The Japanese Foundation for Cancer Research in Tokyo, and colleagues.
The retrospective analysis included 42 patients, 16 (38.1%) of whom were men, who had received more than 8 weeks of lenvatinib treatment between January 2012 and July 2020. A total of 38 patients (90.5%) had been diagnosed with papillary thyroid cancer, and 4 patients (9.5%) had been diagnosed with follicular thyroid cancer. Receiver operating characteristic curve analysis identified an optimal cutoff value of 60% for 8 weeks of relative dose intensity.
At a median follow-up of 16.4 months, the overall response rate was 73.8%. The disease control rate was 97.6%, the median progression-free survival was 20.2 months, and the median overall survival was 35.2 months. Compared with patients who received less than 60% relative dose intensity treatment, patients who received at least 60% relative dose intensity treatment experienced higher median progression-free survival (not reached vs. 11.0 months) and overall survival (not reached vs. 27.6 months). An 8-week course of relative dose intensity of lenvatinib of at least 60% was an independent prognostic factor for progression-free survival.
Disclosure: The study authors reported no conflicts of interest.