ESMO Congress 2023 | OncologyPRO

Abstract 2227P

Background

Surgical resection is the cornerstone of treatment for thyroid cancer. However, some patients present with locally advanced disease at first diagnosis, and they are not eligible for radical resection. Meanwhile, neoadjuvant therapy is a treatment option for some patients. Lenvatinib is a multi-target kinase inhibitor exhibiting antiangiogenic activity in cancer therapy, and it has been approved for differentiated thyroid cancer (DTC). This trial evaluated the safety and efficacy of lenvatinib as neoadjuvant therapy in locally advanced DTC (LADTC) (ChiECRCT20210247).

Methods

In this single-arm, phase II trial, patients with LADTC and at least one measurable target lesion received lenvatinib 24 mg once daily for at least 8 weeks. The primary endpoint was the objective response rate (ORR) per RECIST v1.1. Additional endpoints included the disease control rate (DCR), R0/1 resection rate, and safety.

Results

Twelve patients with LADTC received lenvatinib for a median of 8 weeks (range, 4–32 weeks). The ORR and DCR of lenvatinib were 33.3% (95% confidence interval [CI] = 11.3%–64.6%) and 91.7%, respectively. Three patients did not undergo surgery because of tumor progression and their refusal, and R0/1 resection was performed in eight of the nine remaining patients (88.9%). The most common drug-related adverse events (AEs) were hypertension (41.7%), diarrhea (41.7%) and fatigue (33.3%). No major treatment-related perforation events or grade 5 treatment-related AEs occurred.

Conclusions

Despite a relatively high R0/1 resection rate and acceptable safety, the response of lenvatinib is not yet acceptable in the neoadjuvant treatment. Further studies are warranted to investigate the effect of combination therapies and identify the appropriate patient populations.