Data show lenvatinib improves progression-free survival for people with progressive radioiodine-refractory differentiated thyroid cancer (RR-DTC) regardless of metastatic site, with the exception of the brain.

These lenvatinib Phase III SELECT trial sub-analyses were presented at the 15th International Thyroid Congress (ITC).

The sub-analysis observed response rates of more than 50% and a progression-free survival benefit among people treated with lenvatinib with common sites of metastasis (bone, liver, lung, lymph node).

The study examined 392 patients being treated with lenvatinib vs placebo, and identified metastatic subgroups as an important determinant of progression-free survival for people treated with lenvatinib.

Lenvatinib is currently indicated in Europe for the treatment of adult patients with progressive locally advanced or metastatic, differentiated (papillary, follicular, Hürthle cell) thyroid carcinoma (DTC) refractory to radioactive iodine (RAI).

“These encouraging survival data confirm lenvatinib’s efficacy profile across different patient sub-populations and metastatic sites. These data also suggest that people with advanced thyroid cancer should be treated with lenvatinib after the development of metastases in order to experience the significant progression-free survival benefit,” comments Professor Martin Schlumberger, M.D. Institut Gustave Roussy, University Paris Sud, Paris, France.

A second analysis of the Phase III SELECT study at ITC 2015 demonstrates that lenvatinib maintains progression-free survival irrespective of body mass index, as seen in a sub-analysis of three patient groups: under-and-normal weight (<25kg/m2), overweight (25–29.99 kg/m2), and obese (≥30 kg/m2).

Obese patients who receive lenvatinib exhibited the greatest progression-free survival versus placebo (median PFS 16.7 months; HR 0.13; 95% CI 0.07-0.24; p<0.0001), but significant improvement in progression-free survival was observed across all subgroups.

Similarly lenvatinib showed comparable toxicities across all groups.

Data from a third sub-analysis show that lenvatinib improves overall survival in older patients with RR-DTC, irrespective of dose intensity.

The analysis shows a significant correlation between progression-free and overall survival in patients older than 65.

This analysis is of particular importance, as progressive radioiodine-refractory differentiated thyroid cancer is more common in older patients.

Results from an indirect analysis of the numbers needed to treat (NNT) for lenvatinib and sorafenib in the SELECT and DECISION trials respectively will also be presented at ITC 2015. 

Against placebo, the NNT at 24 months for 1 patient to achieve PFS was 2.5 for lenvatinib and 10.9 for sorafenib; OS was 11.5 for lenvatinib and 41.7 for sorafenib.

"These data from the indirect comparison between studies suggest there is an advantage in treatment with lenvatinib over sorafenib in achieving both progression-free and overall survival in patients with this hard-to-treat cancer.  Our continuing work in the evaluation of survival in RAI-R DTC and the ongoing accrual of knowledge about lenvatinib in this disease reflects our strong commitment to the oncology community," comments Dr Alton Kremer, Deputy President, Oncology PCU and Chief Medical Officer, Global Oncology Business Unit, Eisai Inc.

Further SELECT sub-analyses presented at ITC 2015 examine the relationship between treatment-related adverse events such as hypertension and diarrhoea for lenvatinib.

One analysis demonstrates that common adverse events for people who are treated with lenvatinib typically occur early during treatment and can primarily be managed with dose modification.

A second analysis found that female gender, baseline hepatic impairment, and a lower number of metastatic sites may be associated with a higher likelihood of developing treatment-emergent hypertension (TE-HTN) in patients treated with lenvatinib.

Differentiated thyroid cancer is the most common form of thyroid cancer and accounts for approximately 90% of all thyroid cancers.

Lenvatinib is an oral multiple receptor tyrosine kinase (RTK) inhibitor with a novel binding mode that selectively inhibits the kinase activities of vascular endothelial growth factor (VEGF) receptors, in addition to other proangiogenic and oncogenic pathway-related RTKs involved in tumour proliferation.

Lenvatinib has been approved for the treatment of refractory thyroid cancer in the United States, South Korea, Europe and Japan, and has been submitted for regulatory approval in Switzerland, Canada, Singapore, Russia, Australia and Brazil.

Lenvatinib was granted Orphan Drug Designation in Japan for thyroid cancer, in the United States for treatment of follicular, medullary, anaplastic, and metastatic or locally advanced papillary thyroid cancer and in Europe for follicular and papillary thyroid cancer.

Source: Eisai