Vandetanib for Symptomatic and Progressive Medullary Thyroid Cancer
Posted: Tuesday, September 8, 2020
According to Martin Schlumberger, MD, of the Université Paris Saclay, Villejuif, France, and colleagues, patients with symptomatic and progressive medullary thyroid cancer seem to derive a clinical benefit from treatment with vandetanib. This tyrosine kinase inhibitor has been approved in the United States, European Union, and Japan. Results of the post hoc analysis from the phase III ZETA trial were published in the Journal of Clinical Oncology.
“Targeting patients with RET-positive status and medullary thyroid cancer has a therapeutic potential. Vascular endothelial growth factor receptor and epidermal growth factor receptor also contribute to growth and invasiveness of medullary thyroid cancer,” the investigators commented. “Vandetanib…acts by targeting several cell receptors in combination, including those involved in RET, VEGFR2, and EGFR signaling.”
A total of 331 patients with unresectable locally advanced or metastatic medullary thyroid cancer were enrolled in the original ZETA trial. In a 2:1 ratio, patients were randomly assigned to receive either vandetanib at a starting dose of 300 mg (n = 231) or a placebo (n = 100) once daily. For the post hoc analysis, the investigators divided eligible patients into four disease severity subgroups: disease progression and symptoms; symptoms alone; disease progression alone; and no disease progression and no symptoms at baseline.
Of the overall trial population, 184 patients presented with progressive and symptomatic disease. After receiving the experimental treatment, this subgroup experienced a similar progression-free (hazard ratio = 0.43; P < .0001) and overall survival (hazard ratio = 1.08; P = .71) as the overall trial population; they also seemed to experience a similar length of time without pain (hazard ratio = 0.67; P = .07). The objective response rates in the experimental and placebo arms of this subgroup were 37% versus 2%, respectively. The safety profile appeared to be congruent with previous reports.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.