(IVANHOE NEWSWIRE) - The results are in. After a phase 2 trial, 49 percent of patients with advanced differentiated thyroid cancers responded to treatment using a drug designed to stop tumor blood vessel growth. The name of drug that has shown the highest response of any treatment to date for advanced thyroid cancer: pazopanib. The estimated time two-thirds of these patients are likely to have a response to the drug: 1 year or longer. With the incidence of thyroid cancer doubling in the past decade, this is a monumental advance in medicine for doctors and for patients with differentiated thyroid cancers.
Pazopanib is a drug that targets receptors of proteins involved in angiogenesis (a physiological process involved in the growth of new blood vessels from pre-existing ones). The study, conducted by lead author Keith Bible from the Mayo Clinic, Rochester, USA, assessed the efficacy and safety of Pazopanib. Bible reported that after analyzing the results of 37 patients with advanced, rapidly progressing thyroid cancer, 18 (49 percent) had their tumors shrank. Furthermore, a higher number of patients with follicular thyroid cancer (73 percent) had partial responses to the treatment than patients with the more common papillary thyroid cancer (33 percent).
With every positive comes a negative. For every pro there is a con. And with every medication comes side effects. The most common were diarrhea, hypertension, and raised aminotransferase concentrations. Treatment dose was lowered in 15 (41 percent) patients due to these adverse effects.
"The partial response rate for pazopanib in our study seems very favourable in the light of results from previous trials and, to our knowledge, represents the highest response rate yet reported in patients with differentiated thyroid cancers," the authors of the study were quoted as saying. "Moreover, pazopanib seemed to modify the disease course in responders."
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