Phase II Clinical Study of Sinibolimab Combined with Lenvatinib As Neoadjuvant Therapy for Locally Advanced Unresectable Differentiated Thyroid Carcinoma

This study is a single-arm, prospective Phase II clinical trial designed to evaluate the efficacy and safety of Sinibolimab in combination with Lenvatinib as a neoadjuvant therapy for patients with locally advanced, unresectable differentiated thyroid carcinoma (DTC). A total of 20 patients with locally advanced unresectable papillary thyroid carcinoma (PTC) meeting eligibility criteria will be enrolled. Participants will receive four cycles of the combination therapy consisting of Sinibolimab, a PD-1 inhibitor, and Lenvatinib, a tyrosine kinase inhibitor known for its anti-angiogenic and anti-proliferative properties.

After completing the four treatment cycles, tumor response will be evaluated using imaging and pathological assessments to determine if surgical resection of the tumor becomes feasible. The primary endpoints are the major pathological response (MPR) after neoadjuvant therapy and the R0/R1 resection rate, which measures the proportion of patients achieving complete or near-complete tumor removal.

Secondary endpoints include objective response rate (ORR), defined as the proportion of patients exhibiting a measurable reduction in tumor size after four cycles, as well as 1-year and 2-year disease-free survival (DFS) rates. Additionally, the trial will comprehensively monitor treatment-related safety, focusing on the incidence of serious adverse events (SAEs) and immune-related adverse events (irAEs). Patients who complete the trial will enter a post-treatment follow-up phase to evaluate long-term outcomes, including survival and late-onset adverse effects.

This investigation will provide insight into the potential of Sinibolimab combined with Lenvatinib to convert unresectable tumors into resectable states, thereby improving therapeutic options for patients with advanced thyroid carcinoma.