Lenvatinib Effective For Radioiodine-Refractory Differentiated Thyroid Cancer Patients Of All Ages

Lenvatinib efficacy is not linked to patient age in the treatment of radioiodine-refractory differentiated thyroid cancer, although side effects may be more prominent in older individuals

medwireNews: The progression-free survival (PFS) gain with lenvatinib therapy in radioiodine-refractory differentiated thyroid cancer (RR) is independent of age, findings from the SELECT trial suggest, although older patients appear to be more susceptible to toxicity. Furthermore, "[d]espite the allowance of crossover after disease progression, the OS [overall survival] benefit was observed in older patients, suggesting that lenvatinib should be considered for treatment of patients of any age with RR-DTC", say Marcia Brose, from the University of Pennsylvania in Philadelphia, USA, and co-workers. The prespecified analysis of the phase III trial follows initial SELECT findings demonstrating improved PFS in the 261 RR-DTC patients randomly assigned to receive lenvatinib 24 mg/day compared with the 131 patients given placebo, the researchers explain in the Journal of Clinical Oncology.

Patients were stratified by age of 65 years or less versus over 65 years and the median ages in the younger and older groups were 56 years and 71 years, respectively.

PFS was longer with lenvatinib than with placebo in both the younger (median 20.2 vs 3.2 months) and older (16.7 vs 3.7 months) patient groups, with significant hazard ratios (HRs) of 0.19 and 0.27, respectively.

And further analysis indicated that PFS was not significantly linked to patient in age in the younger or older groups, the researchers emphasize.

Older lenvatinib-treated patients had a significant gain in OS compared with their placebo-treated counterparts (HR=0.53) but survival data were not mature for the younger trial participants.

The authors note that age is a significant Prognostic factor for thyroid cancer mortality and, as expected. OS in the placebo arm was significantly longer in patients aged 65 years or younger than those aged over 65 years.

And they highlight that the “association between age and poorer OS in the placebo arm was abrogated in lenvatinib-treated patients; no significant difference in OS was observed between older and younger patients in the lenvatinib arm.”

Patients given lenvatinib were significantly  more likely to achieve and objective response than those using placebo regardless of age, with odds ratios of 45.7 in younger patients and 16.8 for older patients. Time to response was a median of 2.0 months in both younger and older lenvatinib-treated patients and median duration of response was not reached and 17.0 months, respectively.

In addition, grade 3 or more severe treatment-related adverse events occurred in 67.1% of younger patients given lenvatinib versus 88.7% of older individuals, a significant difference. Hypertension was the most common grade 3 or worse event with lenvatinib, affecting 36.8% of younger and 49.1% of older patients, with grade 3 and more severe proteinuria reported in 13.2% of older patients.

"In view of our findings of improved PFS and OS (in older patients) and manageable toxicities, we contend that lenvatinib treatment should be considered as a treatment option for all patients with RR-DTC who fulfill eligibility criteria as used in SELECT, including older patients", the team concludes.

Reference

Brose MS, Worden FP, Newbold KL, Guo M, Arti Hurria A. Effect of age on the efficacy and safety of lenvatinib in radioiodine-refractory differentiated thyroid cancer in the phase III SELECT trial. J Clin Oncol; Advance online publication 14 June 2017. https://doi.org/10.1200/JCO.2016.71.6472

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