New treatment for rare form of thyroid cancer

The USA Food and Drug Administration (FDA) approved on 6 April 2011 vandetanib to treat adult patients with late-stage (metastatic) medullary thyroid cancer who are ineligible for surgery and who have disease that is growing or causing symptoms.

Medullary thyroid cancer involves specific types of cells 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.

Common symptoms of medullary thyroid cancer may include coughing, difficulty swallowing, enlargement of the thyroid gland, swelling of the neck, a lump on the thyroid, and changes in a person's voice or hoarseness.

Vandetanib targets medullary thyroid cancer's ability to grow and expand. There are currently no approved treatments for this type of cancer. Vandetanib is administered orally on a daily basis.

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 progression-free survival. Patients who received vandetanib had a longer period of time without disease progression when compared to patients receiving placebo. Median progression-free survival was 16.4 months in the placebo arm and at least 22.6 months in the vandetanib arm. It is too early to determine the median progression-free survival in patients treated with vandetanib or overall survival compared to patients treated with placebo.

Common side effects occurring from vandetanib use include diarrhea, rash, nausea, high blood pressure, headache, fatigue, decreased appetite, and 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 sepsis.

Vandetanib is being approved with a Risk Evaluation and Mitigation Strategy (REMS) to inform health care professionals about serious heart-related risks. Only health care professionals and pharmacies certified through the vandetanib REMS program, a restricted distribution program, will be able to prescribe and dispense the drug. Patients will also receive an FDA-approved Medication Guide informing them of the potential risks.

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

Source: European Society for Medical Oncology