RhTSH in aiding dynamic assessment in patients with differentiated thyroid Cancer.

Purpose: To evaluate the efficacy of a novel recombinant human thyroid-stimulating hormone (ZGrhTSH) as an alternative to thyroid hormone withdrawal (THW) in dynamic assessment of DTC patients.

Methods: This phase 3, open-label, multicenter trial, conducted across 27 sites in China, employed a self-controlled design to enroll patients. Eligible patients had previously undergone total or near-total thyroidectomy, with or without RAI therapy. During both the ZGrhTSH-stimulated phase and the THW phase, Dx-WBS and serum Tg measurements were performed on all participants. The study focused on the concordance of Dx-WBS results, stimulated Tg levels, and their combination in patients across the two phases. Additionally, the safety and immunogenicity profiles of ZGrhTSH were assessed as well.

Results: In the assessment of radioiodine uptake and stimulated Tg levels, ZGrhTSH demonstrated efficacy comparable to that of THW. The concordance rate for scans between the two phases was 88.2% (95% CI: 83.7-92.7%). When setting stimulated Tg levels with a cutoff of 1 ng/mL, the concordance rate was 90.4% (95% CI: 86.1-94.6%), and the concordance of scans combined with stimulated Tg was 93.6% (95% CI: 90.1-97.1%). Adverse events associated with ZGrhTSH were reported in 22 patients (10.9%), all of which were mild and transient, graded as 1 or 2.

Conclusion: ZGrhTSH showed non-inferior performance in detecting radioiodine uptake and serum Tg, and could be an effective and safe alternative for the dynamic evaluation of DTC patients.

Trial Registration: ClinicalTrials.gov, NCT04971473. Registered July 7, 2021.