Results of a Phase II clinical trial indicate that Zactima™ (vandetanib) has significant activity for the treatment of patients with advanced, hereditary medullary thyroid cancer. These results were published in the Journal of Clinical Oncology.
Thyroid cancer is treated by surgery and 131Iodine. Patients who fail these therapies respond poorly to radiotherapy and chemotherapy. Thus, new treatments are needed for patients who fail conventional therapy. Recent studies have shown that the targeted therapies Nexavar® (sorafenib) and axitinib have activity in patients with advanced thyroid cancer.
Zactima is a targeted therapy with several mechanisms of action. Among other things, it inhibits a protein known as RET that plays an important role in hereditary medullary thyroid cancer.
To explore the efficacy of Zactima for the treatment of advanced, hereditary medullary thyroid cancer, researchers conducted a Phase II clinical trial among 30 patients with locally advanced or metastatic cancer that could not be surgically removed.
Patients were treated with Zactima 300 mg/day.
- 20% of patients experienced a partial reduction in detectable cancer.
- An additional 53% of patients experienced stable disease that lasted for at least 24 weeks.
- The most common side effects of treatment were diarrhea (70%), rash (67%), fatigue (63%), and nausea (63%).
These results, along with previous results for Nexavar and axitinib, suggest that targeted drugs may play an important role in the treatment of thyroid cancers.
Reference: Wells SA, Gosnell JE, Gagel RF et al. Vandetanib for the treatment of patients with locally advanced or metastatic hereditary medullary thyroid cancer. Journal of Clinical Oncology [early online publication]. January 11, 2010.