A type of immunotherapy appears to be effective in treating a deadly subset of thyroid cancer, according to the results of a clinical trial published in JAMA Oncology.

While they are rare, aggressive thyroid carcinomas can be deadly and have limited treatment options, said Jochen Lorch, MD, professor of Medicine in the Division of Hematology and Oncology, and senior author of the study.

In the current clinical trial, investigators set out to test a combination immunotherapy of the drugs nivolumab and ipilimumab, which prevent cancer from suppressing the immune system.

In the study, 49 patients with different types of aggressive thyroid cancers were given the drugs every two weeks for a maximum of two years. Only 9 percent of patients with differentiated thyroid carcinoma responded to the treatment and those with medullary thyroid carcinoma showed no signs of responding to the treatment, according to the study.

However, patients with anaplastic thyroid carcinoma had a response rate of 30 percent, a significant number considering there are currently no effective treatments for the cancer, Lorch said.

“Among the anaplastic thyroid cancers, we saw three profound responses out of 10 patients, a relatively small exploratory cohort,” said Lorch, who is also a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. “Aplastic thyroid cancer is one of the most aggressive cancers that you can get, with a median survival of roughly four months and no cure rate. To have such a high rate of responses was shocking.”

While the immunotherapy was not effective for all types of thyroid cancers, the response among anaplastic thyroid carcinoma patients merits further study, Lorch said.

Building off this finding, Lorch has launched additional clinical trials for the treatment. He hopes to share his findings soon, he said.

“This has already sparked a number of developments already,” Lorch said. “It has the potential to become a standard of care for this otherwise terrible, rapidly fatal disease.”

The study was supported by the Dana-Farber Cancer Institute, with additional funding from Bristol-Myers Squibb.