Lenvatinib is especially proficient in treating medullary thyroid cancer, and is used as an alternative to RAI. In a phase III clinical trial, patients were only eligible if an imaging scan showed traces of at least one lesion that did not take up iodine from RAI. Lenvatinib is also an oral tyrosine kinase inhibitor, which can directly inhibit the function of PET, RAF, and certain VEGF receptors. Inhibition of these specific kinase-dependent pathways can disrupt the cancerous pathway by decreasing proliferation of cancerous cells. Therefore, patients were divided into a placebo group versus a treatment group. The orally administered Lenvatinib resulted in an a median progression free survival rate of 18.3 months compared to only 3.6 months in the placebo group. In addition, there was a significant difference in the response rates between the two subgroups. The patients who received treatment had a response rate of 64.8% with four patients having a complete remission compared to only a 1.5% response rate in the placebo group. There were no classifications or distinctions made based on the mutation present in the study, and there was no significant difference on response rates whether the patient had the BRAF V600E mutation versus the RET/PTC rearrangement. Based on these results, Lenvatinib is considered an effective drug that targets all …show more content…
This drug is an orally administered tyrosine kinase inhibitor that inhibits the RET kinase and VEGF receptor. In a phase III clinical trial, patients were screened and eligible only if they had metastatic tumors from either sporadic or germ-line MTC. The researchers screened for a positive M918T mutation found in the RET kinase, which is responsible for over 75% of mutations found in sporadic MTC. Polymerase Chain Reaction amplification of RET allowed them to determine if any of the patients had this specific mutation, and were able to track its involvement and development during this targeted therapeutic trial. The progression free survival was higher in the Vandetanib group at 30.5 months compared 19.3 months in the placebo group. There was no significant data found in the progression free survival in the treatment group compared to the placebo group, but there was an evident trend that showcased the effects of Vandetanib is positive compared to no treatment at all. Finally, results showed that patients who have sporadic MTC and tested positive for the M918T mutation in the RET kinase seemed to have a higher response rate than those who were M918T mutation negative in the study. This concludes that Vandetanib may target that specific oncogenic driven kinase receptor, which explains why it is a useful drug in targeted therapy for patients who have MTC (Figure