SFJ formed a partnership with Eisai to develop the oral multikinase inhibitor, lenvatinib for the treatment of thyroid cancer. The target group was patients with differentiated thyroid cancer (the most common type of thyroid cancer, responsible for 90% of cases) who were refractory to treatment with radioactive iodine. The prognosis for these patients was poor with a 10 year survival rate of 10%.
At the time of the investment, Eisai had shown encouraging Phase II data in the target patient population. A global Phase III trial had started but no data was available. In March 2011, the Fukushima power plant in Japan suffered a nuclear disaster following a tsunami. Exposure to radiation is a known risk factor for thyroid cancer and the Japanese FDA equivalent was keenly aware of this. We felt that positive clinical data in a radioactive-iodine-resistant thyroid cancer would be likely to receive a favourable review.
The pivotal trial ran to plan, producing highly impressive results. Progression free survival in the lenvatinib-treated patients was 18.4 months, compared with 3.6 months in the placebo-treated patients, a fivefold increase. Based on the unmet need for this indication, the FDA granted the marketing application Priority Review and approved it in February 2015, triggering a significant payment to EFV-Thyroid. Subsequently, the drug was approved in both Japan and Europe.