Dr. Todd McMullen, an associate professor in the Department of Surgery at the University of Alberta, is hoping he can contribute to improved outcomes for patients with advanced thyroid cancer.
His research into cancer treatment has instigated an investigator initiated trial (IIT) — a study led by researchers rather than pharmaceutical companies — that is now taking place out of Edmonton’s Cross Cancer Institute. The trial is in its early days, but, if successful, it could change medical practice around the world.
Patients are diagnosed with thyroid cancer when abnormal cells grow on the small, butterfly-shaped gland located in the front of the neck. Typically, individuals with thyroid cancer are given radioactive iodine, which McMullen explains can sometimes control the spreading of the cancer from the thyroid to the lymph nodes, lungs and bones. However, if a tumour is aggressive and patients are insensitive to radioactive iodine, there are no other active treatments available.
McMullen’s research could offer those patients hope. “I found that a drug called imatinib targets the part of the cancer cell that tells it to be aggressive and turns it off,” says McMullen. “The thyroid cells then become more likely to take up the radioactive iodine. The hope is that imatinib makes a thyroid cell act like a thyroid cell again.”
This research is now in phase I of an IIT, which was launched in June 2018. McMullen has paired with Dr. Jennifer Spratlin, a medical oncologist at the Cross Cancer Institute. Spratlin and the phase I team are the only dedicated staff in Edmonton who do early phase I trials for cancer patients, and they are now working with 18 individuals with aggressive thyroid carcinoma who aren’t responding to any thyroid cancer treatments that are currently available.
“The scientific reason for this trial is to try to find the lowest, safest dosage of imatinib possible that re-sensitizes patients to radioactive iodine,” says Spratlin. “The bonus would be if, during the clinical trial, we can also help these patients shrink their tumours, which may or may not result in them living longer.”
The goal is to advance this IIT through to the second and third phases of testing if it proves to be effective, and then to change how medical practitioners around the world go about treating thyroid cancer patients.
“If this proves to be successful, it would be a whole new aspect of therapy. Previously, nobody knew what molecule specifically was making thyroid cancers aggressive, and nobody had targeted cancerous thyroid cells [with imatinib] so they would act like a thyroid cell again and take up radioactive iodine,” says McMullen.
“If this works, it could be applied to every thyroid cancer patient around the world.”