2228P - Long-term clinical outcomes of Lenvatinib in patients with differentiated thyroid cancer: Results from the real-world practice of a single institution

Background

Lenvatinib is the preferred drug for locally recurrent or metastatic progressive radioiodine-refractory differentiated thyroid cancer (RR-DTC) based on the results of the SELECT trial (NCT01321554); however, there are few reports on long-term outcomes. The current study aimed to evaluate the long-term clinical outcomes of lenvatinib in RR-DTC.

Methods

We retrospectively reviewed the medical records of 91 patients with RR-DTC who received lenvatinib from September 2011 to November 2022 at National Cancer Center Hospital East. The cut-off date was December 31, 2022. All patients started lenvatinib at a dose of 24mg/day. Planned drug holidays were allowed to avoid severe or intolerable toxicities. Further, dose escalations were allowed after disease progression.

Results

All patients had a performance status of 0 or 1, and the median age was 70 years (range: 42-84) at the initiation of lenvatinib. Histological subtype included papillary carcinoma (64.8%), then follicular carcinoma (24.2%), and poorly differentiated carcinoma (11.0%). The objective response rate and the clinical benefit (complete response, partial response, and durable stable disease defined as the status of stable disease persisting for at least 23 weeks) rate were 58.2% (95% confidence interval [CI]: 47.4-68.5%) and 83.5% (95% CI: 74.3-90.5%), respectively. With a median follow-up time of 2.3 years (range, 0.02-11.2 years) as of the cut-off date, 34 patients (37.4%) were under lenvatinib treatment. The median progression-free survival (PFS) was 3.1 years (95% CI: 1.70-4.00) with a 2-year PFS of 55.0% (95% CI, 43.0-65.5), and the median overall survival (OS) was 5.1 years (95% CI: 3.21-6.66) with a 2-year OS of 79.9 % (95% CI, 69.1-87.2). Ten (11.0%) patients experienced permanent treatment discontinuations due to AE; most common included mucosal perforation (n=3, 3.2%), while no treatment death was seen.

Conclusions

Long-term follow-up in the real world, for the first time, revealed that lenvatinib provides a reliable clinical outcome, represented by long-lasting disease stabilization with a favorable safety profile in RR-DTC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

S. Okano: Financial Interests, Personal, Invited Speaker: MSD, BMS, Merck Biopharma. M. Tahara: Financial Interests, Personal, Invited Speaker: Ono Pharmaceutical, Bayer, MSD, BMS, Merck Biopharma, Pfizer, Rakuten Medical, Lilly, Boehringer Ingelheim, Eisai, Chugai Pharmaceutical, Daiichi Sankyo, Janssen Pharmaceutical, Genmab, AstraZeneca, AbbVie and Astellas. All other authors have declared no conflicts of interest.