Pazopanib Promising for Differentiated Thyroid Cancers
Partial response observed in nearly half of patients treated in phase 2 trial
MONDAY, Sept. 20 (HealthDay News) -- Pazopanib results in a partial response in nearly half of patients with metastatic, rapidly progressive, and radioiodine-refractory differentiated thyroid cancers, according to research published online Sept. 20 in The Lancet Oncology.
Keith C. Bible, M.D., of the Mayo Clinic in Rochester, Minn., and colleagues conducted a phase 2 trial of pazopanib in 37 patients with metastatic, rapidly progressive, radioiodine-refractory differentiated thyroid cancers. The patients were treated with 800 mg continuous pazopanib daily in four-week cycles until disease progressed or drug intolerance occurred.
Patients received a median of 12 pazopanib treatment cycles. The researchers observed partial responses in 49 percent of patients, 66 percent of whom were predicted to have a response duration of longer than one year. Maximum concentration of pazopanib in plasma during cycle one was significantly correlated with radiographic response.
"Given the promising activity of pazopanib noted in this trial, we are currently undertaking further investigations, including an expanded cohort of patients with differentiated thyroid cancers, as well as separate cohorts of patients with medullary or anaplastic thyroid cancers," the authors write.