The efficacy and safety of camrelizumab combined with apatinib for neoadjuvant therapy in locally advanced differentiated thyroid cancer

Radical resection for locally advanced differentiated thyroid cancer (DTC) is challenging and associated with significant morbidity. This study aimed to evaluate the efficacy and safety of neoadjuvant apatinib (a multikinase inhibitor) and camrelizumab (a PD-1 inhibitor) in this setting. This was a single-center, single-arm, phase 2 trial. Eligible patients with locally advanced, unresectable or borderline-resectable DTC received neoadjuvant apatinib (250 mg daily) and camrelizumab (200 mg every two weeks) until surgery, disease progression or unacceptable toxicity. The primary endpoint was the objective response rate (ORR). Secondary endpoints included R0/R1 resection rate, disease control rate (DCR), and safety. Six patients were enrolled before the trial was terminated early due to the COVID-19 pandemic. Among five evaluable patients, the ORR was 60% (95% CI: 23.1%-88.2%), and the DCR was 100% (95% CI: 56.6%-100.0%). All five patients underwent subsequent surgery with an R0/R1 resection rate of 100%, which facilitated preservation of involved critical structures in most cases. Treatment-related adverse events were primarily grade 1–2. No grade 4/5 events occurred. At a median follow-up of 36.4 months, no disease progression or death was observed. Pathological analysis revealed heterogeneous treatment-induced morphological changes and PD-L1 Tumor Proportion Score (TPS) dynamics based on treatment response. Neoadjuvant apatinib plus camrelizumab demonstrated promising antitumor activity and an acceptable safety profile in patients with locally advanced DTC, enabling successful surgical resection with organ preservation in this preliminary cohort. These results warrant further investigation in larger prospective studies. ClinicalTrials.gov: NCT04612894 (Registration Date: 2020-10-30).