SILVER SPRING, Md.—AstraZeneca Pharmaceuticals LP announcedtoday that they have secured U.S. Food and Drug Administration (FDA) approvalfor the drug vandetanib for the treatment of adult patients suffering fromlate-stage (metastatic) medullary thyroid cancer whose disease is growing andwho are ineligible for surgery. This is the first such drug with FDA approvalfor treating medullary thyroid cancer.
Thyroid cancer consists of cancerous growths of the thyroidgland, the small organ at the base of the throat that produces the hormonesresponsible for regulating such things as heart rate, body temperature, bloodpressure and weight. There are four main types of thyroid cancer: papillary, follicular,medullary and anaplastic. Medullary thyroid cancer involves the parafollicularcalcitonin-secreting cells located in the thyroid gland, and it can eitheroccur spontaneously or be a component of a genetic syndrome.
According to the National Cancer Institute, there wereapproximately 44,670 new cases of thyroid cancer diagnosed in the United Statesin 2010, and approximately 1,690 people died from thyroid cancer. Of thosecancer diagnoses, 2 percent to 3 percent are medullary thyroid cancer. The averagesurvival rate for medullary thyroid cancer is lower than that of the morecommon kinds of thyroid cancer, as there is generally an 83 percent five-yearsurvival for medullary thyroid cancer compared to a 90 percent to 94 percentfive-year survival for papillary or follicular thyroid cancer.
The most common symptoms of medullary thyroid cancer includeenlargement of the thyroid gland, coughing, difficulty swallowing, hoarsenessor changes in a person's voice, swelling of the neck and a lump on the thyroid.
"Vandetanib's approval underscores FDA's commitment toapproving treatments for patients with rare and difficult to treat diseases,"says Richard Pazdur, M.D., director of the Office of Oncology Drug Products inthe FDA's Center for Drug Evaluation and Research.
Vandetanib was studied in a randomized trial of 331 patientswith late-stage medullary thyroid cancer in order to study the safety andefficacy of the drug and to determine the length of time that patients livedwithout their cancer progressing (progression-free survival). Patients in thestudy received either vandetanib or a placebo, and those who receivedvandetanib experienced longer periods of time without disease progressioncompared to the patients who received the placebo sugar pill. The medianprogression-free survival for those who received the placebo was 16.4 monthsand at least 22.6 months for those who received the vandetanib.
Vandetanib is taken daily and is administered orally, andworks by targeting medullary thyroid cancer's ability to grow. Common sideeffects of the drug include rash, nausea, headache, diarrhea, fatigue, stomach(abdominal pain), decreased appetite and high blood pressure. Serious sideeffects were reported during the study and resulted in five deaths of patientstaking vandetanib. Heart failure, breathing complications and a bacterial bloodinfection (sepsis) were the reported causes of death. Vandetanib was shown tohave an effect on the electrical activity of the heart, which can causeirregular heartbeats and possibly lead to death. As such, it is being approvedwith a Risk Evaluation and Mitigation Strategy (REMS).
AstraZenecais marketing vandetanib, though no trade name has been established for the drugas of yet.
