AstraZeneca announced that the US Food and Drug Administration (FDA) approved the orphan drug vandetanib for the treatment of medullary thyroid cancer that cannot be removed by surgery or that has spread to other parts of the body.

Vandetanib is a kinase inhibitor indicated for the treatment of symptomatic or progressive medullary thyroid cancer in patients with unresectable (non-operable) locally advanced or metastatic disease. The use of vandetanib in patients with indolent, asymptomatic or slowly progressing disease should be carefully considered because of the treatment-related risks.

“Vandetanib is the only medicine to receive FDA approval specifically for use in patients with advanced medullary thyroid cancer and is the first treatment that AstraZeneca has developed and brought to market under orphan drug designation in the US,” said Howard Hutchinson, chief medical officer, AstraZeneca.

The approval of vandetanib is based on the results of the ZETA study, a phase III, double-blind trial that randomized 331 patients with unresectable locally advanced or metastatic medullary thyroid cancer to vandetanib 300 mg (n=231) or placebo (n=100). In the study, patients randomized to vandetanib showed a statistically significant improvement in progression-free survival (PFS) when compared to those randomized to placebo (Hazard Ratio [HR]=0.35; 95% Confidence Interval [CI]=0.24-0.53; p<0.0001). This difference reflects a 65% reduction in risk for disease progression. Median progression-free survival was 16.4 months in the placebo arm and at least 22.6 months in the vandetanib arm. At the primary PFS analysis, no significant overall survival difference was noted. QT prolongation, Torsades de pointes, and sudden death are included in the boxed warning for vandetanib. The most common adverse drug reactions (>20%) seen in the ZETA trial with vandetanib were diarrhoea (57%), rash (53%), acne (35%), nausea (33%), hypertension (33%), headache (26%), fatigue (24%), decreased appetite (21%), and abdominal pain (21%).

A Risk Evaluation and Mitigation Strategy (REMS) is required for vandetanib due to the risks of QT prolongation, Torsades de pointes, and sudden death. Only prescribers and pharmacies who are certified through the vandetanib REMS programme, a restricted distribution programme, will be able to prescribe and dispense vandetanib.

Vandetanib received orphan drug designation in medullary thyroid cancer in 2005. Vandetanib is also under regulatory review in the European Union and Canada.

AstraZeneca is a global, innovation-driven biopharmaceutical business with a primary focus on the discovery, development and commercialisation of prescription medicines for gastrointestinal, cardiovascular, neuroscience, respiratory and inflammation, oncology and infectious disease.