Two immunotherapy drugs currently approved by the U.S. Food and Drug Administration (FDA) for the treatment of melanoma also show promise for treating a rare but aggressive form of papillary thyroid cancer.
Up to 44 percent of papillary thyroid cancer patients have a B-raf mutation that can be specifically targeted by existing cancer drugs.
The B-raf gene belongs to a class of genes known as “oncogenes,” which send signals to normal cells that cause them become cancerous. B-raf gene mutations have known roles in the development of many human cancers including melanoma, lung and thyroid cancer.
In a randomized, phase 2 multi-center clinical study let by doctors at The Ohio State James Cancer Institute tested the effectiveness of the targeted therapy drug, Tafinlar given alone compared with the same drug given in combination with MeKinist to treat a subset of advanced papillary thyroid cancer patients with B-raf mutations.
Initial data shows that both Tafinlar alone and combined Tafinlar / MeKinist therapy are well tolerated by patients, resulting in a 50 to 54 percent response rate among the patients advanced BRAF-mutated papillary thyroid cancer participating in the trial.
“This is an entirely new approach to treating a disease that has limited treatment options. There is no clear ‘winner’ between single- and dual-agent targeted therapy yet but the good news is that both therapy approaches resulted in positive outcomes for patients, and that gives us more treatment options to help patients with this disease,” says Shah, a medical oncologist and researcher with the OSUCCC – James Translational Therapeutics Research Program. “Targeted therapy has the potential to change the standard of care for patients affected by this rare but aggressive form of thyroid cancer.”
Researchers will continue to follow patients on this trial to determine if Tafinlar alone or Tafinlar given in combination with MeKinist is more effective long term.
Study Design and Methods
For this study oncologists recruited 53 patients with progressive B-raf-mutated progressive papillary thyroid cancer. Patient median age was 63 and all received treatment at Ohio State, Massachusetts General Hospital, MD Anderson, University of California – San Diego or University of Chicago. Patients were randomized to receive twice daily Tafinlar alone or Tafinlar given in combination with once-a-day MeKinist. All drugs are administered orally. Patients who experienced disease progression on Tafinlar alone were able to cross over into the combination treatment arm.