Francis P. Worden, MD

The moderator of the session, Francis P. Worden, MD, a medical oncologist at the University of Michigan Health System Comprehensive Cancer Center, in Ann Arbor, highlighted the number of poorly differentiated carcinomas, which is higher than reported in other previous, large studies.

“In previous cancer studies, poorly differentiated carcinomas tend to be closer to 10% of this population, and these patients often have worse progression-free survival and don’t respond as well,” Dr. Brose replied. “If anything, this says that this drug is an even more active agent.”

‘Meaningful Data’

“Cabozantinib appears to be a very active agent in the treatment of radioactive iodine–refractory differentiated thyroid carcinomas, with 34 of 35 patients experiencing tumor shrinkage, including a fair number with undifferentiated thyroid carcinoma,” said Dr. Worden.

“When a larger, phase III study is conducted, there will likely be fewer patients with poorly differentiated carcinomas, suggesting that we may see even more meaningful responses.”

“The data presented by Dr. Brose are very encouraging,” Dr. Worden added. “Although we have two U.S. Food and Drug Administration–approved therapies for patients with [radioactive iodine–refractory differentiated thyroid cancer], more agents are needed to expand our treatment options. Many people afflicted with this disease often live much longer when compared to other solid tumor patients with metastatic disease.” ■

DISCLOSURE: Dr. Worden has received grant funding from Bayer, Eisai, AstraZeneca, Merck, IRX Therapeutics, Galera Therapeutics, and Bristol-Myers Squibb. He has also received honoraria or consulting fees from Merck.