A new groundbreaking study
revealed that recombinant human thyrotropin (SNA001) is as efficient as thyroid
hormone withdrawal (THW) plus 3.7 GBq radioactive iodine (RAI) in individuals
with intermediate-risk differentiated thyroid cancer. The study results were
published in the journal JAMA Network Open.

Differentiated thyroid cancers
constitute a major portion of thyroid cancers. Surgery, postoperative
radioactive iodine (131I or RAI) therapy, and personalized thyroid
hormone therapy are some of the treatment modalities for thyroid cancers. Previous
guidelines recommended routine RAI therapy for patients with intermediate- or
high-risk DTC and recombinant human thyrotropin instead of undergoing thyroid
hormone withdrawal (THW) for low- or intermediate-risk- DTC. RAI dose is
another important issue in the management of DTC as greater therapeutic
efficacy but also a higher incidence of adverse effects. As there is ambiguity on
the appropriate dose of RAI for patients with intermediate-risk DTC,
researchers from China conducted a trial to compare the efficacy and safety of
recombinant human thyrotropin (SNA001) with thyroid hormone withdrawal (THW)
plus 3.7 GBq RAI in patients with intermediate-risk DTC.Also Read: Subclinical Hyperthyroidism Enhances Metformin’s Impact on Gonadotropins in Postmenopausal Women: Study Finds

An open-label, non-inferior, phase
3 randomized clinical trial was conducted at 19 sites in China from April 16,
2020, to September 9, 2021, with a follow-up period of 8 months. Patients aged
18 to 70 years with DTC who had undergone a total or near-total thyroidectomy
and had no distant metastasis were enrolled in the trial. Individuals were
randomly assigned 1:1 to receive SNA001, 0.9 mg, intramuscular injection daily
for 2 days or to undergo thyroid hormone withdrawal for 3 to 6 weeks. The primary
end point of measurement was the success rate after 6 to 8 months of RAI
therapy. Success was defined as a negative diagnostic whole-body scan result
and a stimulated thyroglobulin level of less than 1.0 ng/mL. Statistical
analysis followed the full analysis and per-protocol analysis sets and was
performed between November 18, 2021, and April 18, 2022.

Findings:

A total of 307 patients were randomized 154 to
the SNA001 group and 153 to the THW group. About 192 females [62.5%] with a median [range] age of 40 [19-69] years participated in the trial.Baseline characteristics were evenly matched
between the 2 groups. RAI therapy was successfully found to be non-inferior
between groups, with success rates of 43.8% in the SNA001 group and 47.1% in
the THW group Forty-six patients (29.9%) in the SNA001 group
reported adverse events compared with 90 (58.8%) in the THW group during RAI
therapy (P < .001). No treatment-related adverse events leading to
discontinuation and drug modification occurred in the SNA001 group.Also Read: Autoimmune disorders in women linked with premature ovarian insufficiency, reveals research

Thus, the study found that SNA001
was found to be non-inferior to THW plus 3.7 GBq RAI in patients with
predominantly intermediate-risk DTC. The researchers also found that it
demonstrated a favorable safety profile compared with THW and had a lower
incidence of adverse events. Overall, this trial was a viable and safe alternative
to thyroid hormone withdrawal for RAI therapy preparation in patients with
intermediate-risk differentiated thyroid cancer.

Further reading: Tan H, Gu Y, Xiu
Y, et al. Recombinant Human Thyrotropin Plus Radioactive Iodine Among Patients
With Thyroid Cancer: A Noninferiority Randomized Clinical Trial . JAMA
Netw Open. 2024;7(11):e2443407. doi:10.1001/jamanetworkopen.2024.43407.