Eisai Inc., an US  subsidiary of Eisai Co., Ltd, has received approval of its in-house developed novel anticancer agent Lenvima (lenvatinib mesylate) as a treatment for locally recurrent or metastatic, progressive, radioactive iodine-refractory differentiated thyroid cancer (RAI-R DTC) from the US Food and Drug Administration (FDA). Lenvima was granted priority review status by the FDA, and was ultimately approved six months from the submission of the New Drug Application in August 2014, two months ahead of the FDA priority review action date. This marks the first country in the world where the agent has received marketing authorisation.

Lenvima is an orally administered molecular targeted agent that selectively inhibits the activities of several different molecules including VEGFR, FGFR, RET, KIT and PDGFR. In particular, the agent simultaneously inhibits VEGFR, FGFR and also RET which are especially involved in tumor angiogenesis and proliferation of thyroid cancer. Furthermore, Lenvima has been confirmed through X-ray crystal structural analysis to be the first compound to demonstrate a new binding mode (Type V) to VEGFR2, and exhibits rapid and potent inhibition of kinase activity, according to kinetic analysis.

The approval was based on the results of a multicenter, randomized, double-blind, placebo-controlled phase III study (the SELECT study) of 392 patients with progressive RAI-R DTC. In the study's primary endpoint of progression-free survival (PFS), Lenvima demonstrated a statistically significant extension in PFS compared to placebo (p<0.001; median PFS in the Lenvima group: 18.3 months, median PFS in the placebo group: 3.6 months; Hazard Ratio (HR) 0.21 [99 per cent CI: 0.14-0.31]). In addition, Lenvima demonstrated a statistically significant improvement in response rate (sum of complete and partial responses) compared to placebo (p<0.001; Lenvima: 64.8 per cent vs placebo: 1.5 per cent). In particular, complete response was observed in 1.5 per cent (4 patients) of the Lenvima group and zero in the placebo group. The most common Lenvima treatment-related adverse events of any grade, which occurred in more than 40 per cent of patients in the Lenvima group, were hypertension (67.8 per cent), diarrhea (59.4 per cent), fatigue or asthenia (59.0 per cent), decreased appetite (50.2 per cent), weight loss (46.4 per cent) and nausea (41.0 per cent).

Currently, the agent is undergoing regulatory review in Japan and the EU, as well as Switzerland, South Korea, Canada, Singapore, Russia, Australia and Brazil, and Lenvima was also granted accelerated assessment in the EU. Eisai will continue to file applications seeking regulatory approval for the agent in countries around the world, and the company will market the agent in those countries where approval has been received. Furthermore, Eisai is conducting a global phase III trial of Lenvima in hepatocellular carcinoma as well as phase II studies of Lenvima in several other tumor types such as renal cell carcinoma and non-small cell lung cancer.

The number of patients newly diagnosed with thyroid cancer in 2012 in the United States was estimated to be approximately 52,000. Although treatment is possible for most types of thyroid cancer, there are few treatment options available once thyroid cancer has progressed, therefore it remains a disease with significant unmet medical needs. In addition to providing Lenvima as a new treatment option for thyroid cancer, Eisai is committed to exploring the potential clinical benefits of Lenvima in order to further contribute to patients with cancer, and their families.