Lenvatinib as first-line treatment for advanced thyroid cancer: long progression-free survival

Lenvatinib (LEN) has been approved for the treatment of patients with progressive radioiodine-refractory differentiated thyroid cancer (RAI-R DTC). Real-life studies reported a lower progression-free survival (PFS) than the registration study, likely due to the more advanced stage of tumors, the more frequent pretreatment with other TKIs, the limited follow-up, and the worse clinical condition of the patients included.

We evaluated the clinical data of our cohort of 13 consecutive patients, all receiving LEN as a first-line TKI treatment, and followed-up in a single tertiary Center.

All patients had an ECOG of 0-1 and regional or distant metastases were documented in 61.5% and 77% of patients, respectively. Median PFS was 22 months (95% CI 14-35) with partial response in 69% and stable disease in 31% of patients. All patients experienced at least one adverse event (AE), the most frequent being fatigue, anorexia, diarrhea, and hypertension. The daily dose was reduced in 70% of patients and only one patient (7.7%) discontinued the drug for AEs.

In this series of RAI-R DTC patients, with the unique features to have an ECOG 0 or 1 and to be naive for TKI treatments, PFS was the longest among all real-life published so far, with the highest rate of patients with partial response and one of the lowest drug discontinuation rate for AEs. The correct timing of treatment start, the tailoring of the dose, and a proper management of the AEs may have a significant impact on the treatment response to LEN.