FDA OKs new drug to treat thyroid cancer

The U.S. Food and Drug Administration (FDA) has approved vandetanib to treat adult patients with late-stage medullary thyroid cancer who are ineligible for surgery and whose disease is growing or causing symptoms.

Medullary thyroid cancer involves specific types of cells that are found in the thyroid gland and can occur spontaneously or be part of a genetic syndrome. Medullary thyroid cancer is estimated to represent 3% to 5% of all thyroid cancer; its estimated incidence in the U.S. for 2010 is about 1,300 to 2,200 patients, making it one of the rarer forms of thyroid cancer.

Vandetanib targets medullary thyroid cancer's ability to grow and expand. It is administered orally on a daily basis. It is the first drug approved by the FDA to treat medullary thyroid cancer.

Vandetanib's safety and effectiveness were established in a single, randomized international study of 331 patients with late-stage medullary thyroid cancer. Patients in the study were selected to receive vandetanib or placebo. The study was designed to measure the length of time a patient lived without their cancer progressing. Patients who received vandetanib had a longer period of time without disease progression when compared with patients receiving placebo, according to the FDA. Median progression-free survival was 16.4 months in the placebo arm and at least 22.6 months in the vandetanib arm.

Common side effects occurring from vandetanib use include diarrhea, rash, nausea, high blood pressure, headache, fatigue, decreased appetite, and stomach (abdominal) pain. Serious side effects reported during the study resulted in five deaths in patients treated with vandetanib. Causes of death included breathing complications, heart failure, and a bacterial infection in the blood (sepsis).

As a result, vandetanib is being approved with a risk evaluation and mitigation strategy (REMS) to inform healthcare professionals about these serious heart-related risks. Only healthcare professionals and pharmacies certified through the vandetanib REMS program, a restricted distribution program, will be able to prescribe and dispense the drug.

Vandetanib is marketed by AstraZeneca Pharmaceuticals. There is no trade name established for this drug at this time.