Low Dose of Lenvatinib Treatment for Patients of Radioiodine-Refractory Differentiated Thyroid Carcinoma - A Real-World Experience

Background

Lenvatinib treatment of 24 mg/day for radioiodine-refractory differentiated thyroid carcinoma (RRDTC) patients was almost intolerable, with high rates of dose reduction, interruption and discontinuation. Balancing treatment safety with disease risks remains challenging, and the appropriate dosage remains unclear in Asia.

Patients and Methods

A total of 65 RRDTC patients treated with lenvatinib were retrospectively collected from Oct. 2015 to Jun. 2020 from two medical centers of South Taiwan. The drug tolerability, treatment efficacy and clinical outcomes were analyzed.

Results

Different doses of lenvatinib were initiated but ultimately maintained with a median dose of 10 mg/day within the first 3 months. The disease control rate reached 89.2%, including 24.6% partial response and 64.6% stable disease. Disease progression occurred in 10.8% of patients and increased to 40.0% at the end. Eventually, the treatment dose achieved a median progression-free survival (PFS) of 26.1 months (95% CI: 17.1-NA) with overall survival (OS) not reached yet (24.1~NA). Overall, the 48-month PFS rate was 35.6% (95% CI: 18.5–68.4) and 48-month OS was 54.3% (95% CI: 41.2–71.7). The dose was tolerable with a dose reduction rate of 44.6%, dose interruption rate of 40.0% and fewer high-graded adverse events. The drug discontinuation rate was only 3.1%. However, RRDTC patients with bone metastasis or maximal dose exposure to RAI (≥600 mCi) may have less efficacy to the low maintenance dose treatment.

Conclusion

Assessing treatment intensity, safety and efficacy, low-dose lenvatinib treatment was well tolerated by RRDTC patients and displayed acceptable drug efficacy and outcomes.

Lenvatinib for Radioactive Iodine-Refractory Differentiated Thyroid Carcinoma and Candidate Biomarkers Associated with Survival: A Multicenter Study in Korea

Background: Lenvatinib, an oral multikinase inhibitor, is the latest addition to the treatment options for radioactive iodine (RAI)-refractory progressive differentiated thyroid carcinoma (DTC). This study investigated the efficacy of lenvatinib in real-world practice and prognostic biomarkers of survival. Methods: This multicenter study included 43 patients receiving lenvatinib as first-line or second-line treatment after sorafenib for RAI-refractory DTC. Progression-free survival (PFS) was evaluated according to various clinical factors including thyroglobulin doubling time (TgDT), tumor volume DT (TVDT), and tumor growth slope (TGS; slope of tumor change rate). Results: Patients were treated with lenvatinib for a median of 14 months; 32 were previously treated with sorafenib. The median follow-up from lenvatinib initiation to the last censoring or death was 16 months. The median starting dose of 20 mg was reduced to a median sustainable dose of 10 mg in accordance with patient adverse events (AEs). The median PFS was 21.8 months; the median overall survival was not reached. The disease control rate was 97.7%, with the first objective response at 3.8 months. PFS was not significantly associated with previous sorafenib treatment, metastatic sites, or sustainable dose. TGS measured before (TGS_pre, p = 0.003) and after (TGS_post, p = 0.036) the initiation of lenvatinib was associated with PFS. The sum of the largest diameters of target lesions (p = 0.043) and TgDT (p = 0.024) were associated with PFS, but TVDT calculated before (TVDT_pre, p = 0.923) or after (TVDT_post, p = 0.966) lenvatinib treatment did not impact PFS. Lenvatinib was withdrawn in 24 patients (55.8%): in 6 patients because of treatment-induced AEs and in 18 patients because of disease progression or poor performance status. AEs of any grade were reported in all patients, and grade 3-4 AEs in 23.2% of the patients. The most frequent AE was fatigue or asthenia. Conclusions: Our results indicate that reduced doses of lenvatinib triggered by emergent AEs did not abrogate its apparent efficacy in patients with RAI-refractory DTCs. Rather, the sustained use of reduced doses of lenvatinib with a low rate of severe AEs may have contributed to the favorable outcomes. TgDT and TGS can assist in predicting the outcomes in these patients.

Extended Real-World Observation of Patients Treated with Sorafenib for Radioactive Iodine-Refractory Differentiated Thyroid Carcinoma and Impact of Lenvatinib Salvage Treatment: A Korean Multicenter Study

Background: Treatment for patients with radioactive iodine (RAI)-refractory differentiated thyroid carcinoma (DTC) is challenging. Recently, two tyrosine kinase inhibitors (sorafenib and lenvatinib) have been approved and showed benefits for progression-free survival with tolerable adverse events. Methods: This is an extension study of a previous multicenter, retrospective cohort study of real-world experience in treating 98 patients with progressive RAI-refractory DTC with sorafenib. The primary endpoint was overall survival (OS). The efficacy of lenvatinib as salvage therapy after disease progression on first-line sorafenib was evaluated by comparing outcomes in 32 patients who were treated with lenvatinib with 41 patients who were not and therefore served as a no salvage treatment group. Results: The median OS of all 98 patients treated with sorafenib was 41.5 months, and the median progression-free survival was 13.5 months. Patients without disease-related symptoms before sorafenib treatment had better OS than those with symptoms (hazard ratio [HR] = 0.56 [95% confidence interval, CI 0.31-0.99], p = 0.048). Larger tumor size was associated with a minimally increased risk of death (HR = 1.02 [CI 1.00-1.03], p = 0.049). Best tumor response was not associated with OS (p = 0.490). Lenvatinib salvage treatment significantly improved OS in patients receiving it compared with those who did not (HR = 0.28 [CI 0.15-0.53], p < 0.001). The median OS from the time of disease progression after first-line sorafenib treatment was 4.9 months in no salvage treatment group, whereas it was not reached in the lenvatinib salvage group. Conclusions: The absence of disease-related symptoms and smaller tumor burden was associated with survival benefits of first-line sorafenib treatment in patients with progressive RAI-refractory DTC. Lenvatinib salvage therapy was effective in improving OS in patients with disease progression after first-line sorafenib.

Treatment-related adverse effects with TKIs in patients with advanced or radioiodine refractory differentiated thyroid carcinoma: a systematic review and meta-analysis

Background

Tyrosine kinase inhibitors (TKIs) have been administered to advanced or radio-iodine refractory differentiated thyroid carcinoma (RR-DTC) patients for years. We performed a pooled analysis to explore the frequency of severe adverse effects in advanced or RR-DTC patients treated with sorafenib and lenvatinib.

Methods

We performed a comprehensive search of computerized databases, including PubMed, Web of Science, Ovid, EMASE, and the Cochrane Library, from the drugs' inception to July 2018 to identify clinical trials. All grade and severe adverse events (AEs; grade ≥3) were analyzed. This meta-analysis was conducted in accordance with PRISMA guidelines.

Results

In total, seve studies published from 2012-2018 with 657 patients were eligible for this study. We included two studies (238 patients) that received 200 mg sorafenib twice and five studies (419 patients) that received 24 mg lenvatinib daily. The frequency of AEs was different among the two drugs. Patients in the sorafenib group had a significantly higher frequency of all grade hand-foot syndrome, hypocalcemia, rash, elevated alanine aminotransferase (ALT), and elevated aspartate aminotransferase (AST). Conversely, the lenvatinib group experienced more frequent all grade voice change, hypertension, nausea, and vomiting compared with those with sorafenib. For grade ≥3 adverse effects, hand-foot syndrome, hypocalcemia, and elevated ALT were more frequent in sorafenib-treated patients. Moreover, lenvatinib-treated patients had a significantly higher incidence of severe weight loss, hypertension, and nausea.

Conclusion

Significant differences in common adverse effects, such as all-grade and severe AEs, were detected between sorafenib and lenvatinib in the current study. Early intervention and management of treatment-related AEs (TRAEs) can minimize the impact on patients' quality-of-life, and avoid unnecessary dose reductions and treatment-related discontinuations.

Prolonged duration of response in lenvatinib responders with thyroid cancer

We present an updated analysis of lenvatinib in radioiodine-refractory differentiated thyroid cancer (RR-DTC) with new duration of response (DOR) data unavailable for the primary analysis. In this randomized, double-blind, multicenter, placebo-controlled phase 3 study, patients ≥18 years old with measurable, pathologically confirmed RR-DTC with independent radiologic confirmation of disease progression within the previous 13 months were randomized 2:1 to oral lenvatinib 24 mg/day or placebo. The main outcome measures for this analysis are DOR and progression-free survival (PFS). The median DOR for all lenvatinib responders (patients with complete or partial responses; objective response rate: 60.2%; 95% confidence interval (CI) 54.2-66.1) was 30.0 months (95% CI 18.4-36.7) and was generally similar across subgroups. DOR was shorter in patients with greater disease burden and with brain and liver metastases. Updated median PFS was longer in the overall lenvatinib group vs placebo (19.4 vs 3.7 months; hazard ratio (HR) 0.24; 99% CI 0.17-0.35; nominal P < 0.0001). In lenvatinib responders, median PFS was 33.1 months (95% CI 27.8-44.6) vs 7.9 months (95% CI 5.8-10.7) in non-responders. The median DOR of 30.0 months seen with patients who achieved complete or partial responses with lenvatinib (60.2%) demonstrates that lenvatinib responders can have prolonged, durable and clinically meaningful responses. Prolonged PFS (33.1 months) was also observed in these lenvatinib responders.