Japanese pharmaceutical firm Eisai has reported that once-daily oral lenvatinib (E7080) met the primary endpoint of improving progression-free survival (PFS) vs placebo in the phase 3 SELECT (study 303) trial to treat radioiodine-refractory differentiated thyroid cancer (RR-DTC).

According to the preliminary safety analyses, the five most common adverse reactions to lenvatinib were hypertension, diarrhea, decreased appetite, decreased weight and nausea.

Based on the results of the SELECT (study of E7080 LEnvatinib in differentiated cancer of the thyroid) study, the company intends to file marketing authorisation applications for lenvatinib to health authorities in the US, Japan and Europe.

The multi-centre, randomised, double-blind, placebo-controlled trial was designed to compare the PFS of patients with RR-DTC and radiographic evidence of disease progression within the prior 12 months, treated with once-daily, oral lenvatinib (24mg) vs placebo.

Secondary endpoints of the trial included overall response rate (ORR), overall survival (OS) and safety.

"RR-DTC remains an unmet need with a limited number of treatment options."

A total of 392 patients were enrolled in the trial, which was carried out at over 100 sites in Europe, North and South America, and Asia by Eisai in collaboration with the SFJ Pharmaceuticals Group.

Eisai product creation systems president of oncology product creation unit Kenichi Nomoto said: "RR-DTC remains an unmet need with a limited number of treatment options."

Eisai-developed lenvatinib secured Orphan Drug Designation (ODD) in Japan for thyroid cancer in August 2012; in the US for follicular, medullary, anaplastic and metastatic or locally advanced papillary thyroid cancer in December 2012; and in Europe for follicular and papillary thyroid cancer in April 2013.

Lenvatinib is an oral inhibitor of select receptor tyrosine kinases (RTKs), including VEGFR 1-3, FGFR 1-4, PDGFR-ß, KIT and RET involved in angiogenesis and tumour proliferation.

The company’s ongoing global clinical trial programme includes phase 3 and phase 2 studies in several other tumour types.

Currently the drug is under investigation as a potential treatment for thyroid, hepatocellular, endometrial and other solid tumour types.

Image: Micrograph of a lymph node with papillary thyroid carcinoma. Photo: courtesy of Nephron.