Japanese drug regulators have awarded orphan drug status to Eisai's anticancer drug lenvatinib for the treatment of thyroid cancer.

Lenvatinib is an investigational anti-angiogenic agent that, according to the firm, has a unique inhibitory profile against the receptor tyrosine kinase family of kinases. 

The drug works as a potent inhibitor of the VEGF (Vascular Endothelial Growth Factor) receptor, VEGFR2, plus various other types of kinases involved in angiogenesis and tumor proliferation, and it is therefore hoped that it will prove to be an effective weapon against the disease.

Thyroid cancer is an area with significant unmet medical needs because of the limited treatment options currently available for patients with advanced stages of the disease, and thus the drug meets the criteria for an orphan medicine.

Lenvatinib is currently being tested in Phase III studies in patients with radioiodine-refractory differentiated thyroid cancer (DTC) as part of a global development program, and Eisai said it is hoping to submit marketing applications for the drug before the end of fiscal 2013. 

The firm is also conducting Phase II studies assessing its potential in endometrial cancer, melanoma, glioma and non-small cell lung cancer, and a PhaseI/II study in hepatocellular carcinoma, which is taking place in Japan and Asia.