Novel recombinant human thyroid-stimulating hormone in aiding postoperative assessment of patients with differentiated thyroid cancer-phase I/II study.

ABSTRACT

PURPOSE: Thyroid hormone withdrawal (THW) inevitably induced hypothyroidism in patients with differentiated thyroid cancer (DTC), and we aimed to evaluate the safety and efficacy of a novel recombinant human thyroid-stimulating hormone (rhTSH, ZGrhTSH) as an alternative of THW in China. METHODS: Totally, 64 DTC patients were enrolled with 24 in the dose-escalation cohort equally grouped into 0.9 mg × 1 day, 0.9 mg × 2 day, 1.8 mg × 1 day, and 1.8 mg × 2 day dosage, and 40 further enrolled into 0.9 mg × 2 day dose-expansion cohort. All patients underwent both ZGrhTSH phase and levothyroxine (L-T4) withdrawal phase for self-comparison in terms of TSH levels, the radioactive iodine (RAI) uptake, stimulated thyroglobulin level, and the quality of life (QoL). RESULTS: In ZGrhTSH phase, no major serious adverse events were observed, and mild symptoms of headache were observed in 6.3%, lethargy in 4.7%, and asthenia in 3.1% of the patients, and mostly resolved spontaneously within 2 days. Concordant RAI uptake was noticed in 89.1% (57/64) of the patients between ZGrhTSH and L-T4 withdrawal phases. The concordant thyroglobulin level with a cut-off of 1 µg/L was noticed in 84.7% (50/59) of the patients without the interference of anti-thyroglobulin antibody. The QoL was far better during ZGrhTSH phase than L-T4 withdrawal phase, with lower Billewicz (- 51.30 ± 4.70 vs. - 39.10 ± 16.61, P < 0.001) and POMS (91.70 ± 16.70 vs. 100.40 ± 22.11, P = 0.011) scores which indicate the lower the better. Serum TSH level rose from basal 0.11 ± 0.12 mU/L to a peak of 122.11 ± 42.44 mU/L 24 h after the last dose of ZGrhTSH. In L-T4 withdrawal phase, a median of 23 days after L-T4 withdrawal was needed, with the mean TSH level of 82.20 ± 31.37 mU/L. The half-life for ZGrhTSH clearance was about 20 h. CONCLUSION: The ZGrhTSH held the promise to be a safe and effective modality in facilitating RAI uptake and serum thyroglobulin stimulation, with better QoL of patients with DTC compared with L-T4 withdrawal.