Sunitinib is a drug that inhibits multiple proteins in cancer cells, thus limiting their growth and division. It has been already used in treating advanced renal cell cancer and two other forms of malignancy. In the new phase-2 trial conducted by the Med Start Washington Hospital Center (Washington, D.C.), the treatment proved to be efficient against advanced thyroid cancer as well. Principal Investigator Kenneth Burman, MD, Chief of Endocrine at MedStar Washington Hospital Center, declared that the drug has great potential as adjunctive treatment in patients with advanced differentiated thyroid cancer, which is the most common of thyroid malignancies. Although it does not cure cancer, the treatment increases the period of progression-free survival (PFS) – the interval when the tumor, although not eradicated, stops its growth.
The main treatments in the case of this disease are surgery and treatment with radioactive iodine, which destroy the cancer cells, but in patients with advanced differentiated thyroid cancer the tumors sometimes resume their progress. Sunitinib helps slow down this progress. The drug was tested by Burman’s team on 23 subjects with advanced-stage differentiated thyroid cancer, who had already been treated with radioactive iodine at least once. Except for measuring progression-free survival, they also tested the patients employing the Response Evaluation Criteria in Solid Tumors (RECITS). The dose of Sunitinib that was administered to each patient was 37.5 milligrams per day. The median PFS period was 241 days (roughly eight months).
It being a Phase 2 clinical trial, there was no control group, but the researchers compared their findings with those of a recently published study whose control group had received a placebo. The PFS interval was significantly larger in the patients included in Dr. Burman’s study than it was in this placebo group. Sunitinib’s effects were comparable to those of Sorafenib’s (another tumor-inhibiting drug).
The study abstract reported that 83% of the persons (19 out of 23 subjects) suffering from advanced differentiated thyroid cancer who were treated with Sunitinib showed a positive response to the treatment – six patients had their tumors reduced in size (partial response) and 13 patients showed a slower progression of the malignancy (stable disease). Side effects were said by patients to be relatively mild. Dr. Burman is convinced that Sunitinib should go through another phase of testing, with more subjects undergoing treatment and with a control group as well.
image credit: Dr Sircus