Exelixis has commenced the Phase lll COSMIC-311 trial to evaluate cabozantinib for the treatment of patients with radioiodine-refractory differentiated thyroid cancer (DTC) who have progressed after up to two prior vascular endothelial growth factor receptor (VEGFR)-targeted therapies.
The multicentre, randomised, double-blind, placebo-controlled pivotal trial intends to enrol around 300 patients at nearly 150 sites across the globe.
During the trial, the patients will be randomised in a 2:1 ratio to receive a once-daily dose of either cabozantinib at 60mg or placebo.
The trial’s co-primary endpoints are progression-free survival and objective response rate.
COSMIC-311 trial principal investigator Marcia Brose said: “With the incidence of thyroid cancer increasing more rapidly than any other type of cancer in the US, and limited options available to patients whose disease has progressed following anti-VEGFR therapy, there is an urgent need for new treatments.
“Given the positive results from earlier stage trials, we are eager to learn more from this Phase lll study about cabozantinib’s potential benefit in this patient population.”
Thyroid cancer is usually diagnosed at a younger age than most other adult cancers. It is estimated to be the most rapidly increasing cancer in the US, with incidence tripling in the last three decades.
Nearly 54,000 new cases of thyroid cancer are expected to be diagnosed in the US this year, with around three out of four cases anticipated to be found in women.
Cancerous thyroid tumours are observed in differentiated, medullary and anaplastic forms.
Cabometyx (cabozantinib) tablets are currently approved in the US for use in the treatment of patients with advanced renal cell carcinoma (RCC), a type of kidney cancer.
However, Cabometyx is not approved for radioiodine-refractory DTC.