(HealthDay News) — The tyrosine kinase inhibitor vandetanib is associated with longer progression-free survival (PFS) compared with placebo for patients with locally advanced or metastatic differentiated thyroid carcinoma, according to a study published online Aug. 14 in The Lancet Oncology.
Sophie Leboulleux, M.D., from the Université Paris-Sud in Villejuif, France, and colleagues examined the efficacy and safety of vandetanib in a double-blind, phase 2 trial involving adults (18 years or older) with locally advanced or metastatic differentiated thyroid cancer at 16 European medical centers. Patients were randomly allocated to receive vandetanib (72 patients) or matched placebo (73 patients).
The researchers found that, by data cut-off, 72 percent of patients in the vandetanib group and 84 percent in the placebo group had progressed, and 26 and 29 percent, respectively, had died. The median PFS was 11.1 months for patients in the vandetanib group and 5.9 months in the placebo group, with a significantly longer PFS for the vandetanib group (hazard ratio, 0.63). The most common grade 3 or worse adverse events that occurred more frequently in the vandetanib group versus the placebo group were QTc prolongation (14 percent versus none), diarrhea (10 percent versus none), asthenia (7 versus 4 percent), and fatigue (5 percent versus none). Death from treatment-related serious adverse events occurred for two patients in the vandetanib group and one in the placebo group.
“To the best of our knowledge, vandetanib is the first targeted agent to demonstrate improved PFS in patients with locally advanced or metastatic differentiated thyroid cancer in a randomized phase 2 study,” the authors write. “Substantial prolongation of the time to disease progression would benefit these patients, but meaningful assessment of PFS needs a randomized phase 3 study.”
Several authors disclosed financial ties to pharmaceutical companies, including AstraZeneca, which funded the study and manufactures vandetanib.