Real-World Data for Lenvatinib in Radioiodine-Refractory Differentiated Thyroid Cancer (RELEVANT)‎: A Retrospective Multicentric Analysis of Clinical Practice in Austria

Abstract EN

Background.

Lenvatinib has proven efficacy in progressive, radioiodine- (RAI-) refractory thyroid cancer (TC).

Dose reductions are commonly performed due to decreased tolerability and adverse effects.

This retrospective multicenter study analyzed overall survival (OS) and progression-free survival (PFS) and tolerability in the Austrian patient population treated with lenvatinib.

Methods.

Clinical data of 43 patients (25 males and 18 females) with a median age of 70 years (range: 39–91 years) and RAI-refractory TC with metastases to the lymph nodes (74%), lungs (86%), bone (35%), liver (16%), and brain (12%) were analyzed.

The mean duration of treatment with lenvatinib was 26.6 ± 15.4 months with dosage reductions required in 39 patients (91%).

Results.

PFS after 24 months was 71% (95% CI: 56–87), and overall survival (OS) was 74% (95% CI: 60–88), respectively.

OS was significantly shorter (p=0.048) in patients with a daily maintenance dosage ≤ 10 mg (63%) (95% CI: 39–86) as compared to patients on ≥ 14 mg lenvatinib (82%) (95% CI: 66–98) daily.

Dose reduction was noted in 39 patients (91%).

Grade ≥3 toxicities (hypertension, diarrhea, weight loss, and palmar-plantar erythrodysesthesia syndrome) were most common leading to discontinuation of lenvatinib in 7 patients (16%).

Conclusion.

Lenvatinib showed sustained clinical efficacy in patients with metastatic RAI-refractory TC even with reduced maintenance dosages over years.

The effects were comparable to the registration trial, although patients had a higher median age and, more commonly, dose reductions.