{'fraction_non_alphanumeric': 0.060144346431435444, 'fraction_numerical': 0.03889334402566159, 'mean_word_length': 5.206467661691542, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Lenvatinib compared with sorafenib as a first-line treatment for radioactive iodine‒refractory, progressive, differentiated thyroid carcinoma: Real-world outcomes in a multicenter retrospective cohort study.

BACKGROUND
Sorafenib and lenvatinib have been widely adopted to treat radioactive iodine (RAI)-refractory differentiated thyroid carcinoma (DTC). However, limited data exists regarding a direct comparison of these tyrosine kinase inhibitors (TKIs). We aimed to evaluate the clinical efficacy and safety of two TKIs as first-line therapy in patients with distant metastatic or locally advanced, progressive, radioactive iodine (RAI)-refractory DTC in real-world practice.


METHODS
In this multicenter, retrospective cohort study, we evaluated 136 patients with progressive, distant metastatic or locally advanced, progressive, RAI-refractory DTC who received first-line sorafenib or lenvatinib treatment. The primary outcome was progression-free survival (PFS). We also evaluated the objective response rate, disease-control rate, clinical benefit rate, and safety.


RESULTS
The median age of the patients was 68 years, and 35% (47/136) were male. Eighty and fifty-six patients were included in the sorafenib and lenvatinib groups, respectively. The median PFS was 13.3 months (95% confidence interval [CI], 9.9-18.1 months) in the sorafenib group and 35.3 months (95% CI, 18.2 months-upper limit not reported as the median was not reached) in the lenvatinib group (p=0.001). A significantly prolonged PFS was observed in the lenvatinib group (compared with the sorafenib group) after adjusting for age, sex, pathology, disease-related symptom, lung-only metastasis, cumulative RAI dose, time from diagnosis, treatment duration and longest diameter of the target lesion (HR=0.34, 95% CI, 0.19-0.60, p<0.001). The partial response rate was 24% and 59% in the sorafenib and lenvatinib groups, respectively (p<0.001). More common grade 3-4 adverse events were hypertension (16%, 9/56 vs 1%, 1/80, p=0.002), proteinuria (32%, 18/56 vs 0%, p<0.001) in lenvatinib group, and hand-foot skin reaction (24%, 19/80 vs 4%, 2/56, p=0.001) in the sorafenib group.


CONCLUSION
In our study of Asian patients, first-line lenvatanib treatment of metastatic or locally advanced, progressive, RAI-refractory DTC was associated with a longer PFS compared to sorafenib. However, severe hypertension and proteinuria were observed more frequently after lenvatinib treatment than after sorafenib treatment.