Two New Weapons Against Thyroid Cancer

Thyroid cancers respond to medications sorafenib and vemurafenib

(RxWiki News) There hasn’t been much progress in the treatment of advanced thyroid cancer over the last 40 years. And there are really no treatment options for thyroid cancer involving the mutated gene called BRAF. Two new weapons offer good news on both fronts.

Results from a recently completed phase lll trial show that Nexavar (sorafenib) can more than double progression-free survival (the period during which the disease doesn’t get worse) for advanced differentiated thyroid cancer.

And Zelboraf (vemurafenib) was shown in a phase ll trial to extend progression-free survival (PFS) in patients with advanced papillary thyroid cancer.

"Ask your oncologist about clinical trial study results."

Marcia Brose, MD, PhD, an assistant professor in the department of Otorhinolaryngology: Head and Neck Surgery and the division of Hematology/Oncology in the Abramson Cancer Center at the University of Pennsylvania was the lead author on both studies.

The DECISION trial measured survival benefits of Nexavar in 417 patients with metastatic (where disease has spread) differentiated thyroid cancer that has not responded to radioactive iodine – a common treatment for thyroid cancer.

Nexavar is already approved to treat kidney and liver cancer. It’s a member of a group of drugs called kinase inhibitors.

The research team looked at the impact of Nexavar on thyroid cancers that have two genetic mutations – altered BRAF and RAS genes.

Participants were randomly assigned to take either Nexavar or a placebo (sugar pill).

Over half (256) of the patient’s tumors were analyzed for genetic mutations and most did have the BRAF and RAS mutations.

Researchers found that patients treated with Nexavar had a PFS of 10.8 months compared to 5.8 months for patients in the placebo group.

Survival benefit was seen regardless of the genetic mutations.

Nexavar is currently being reviewed by the US Food and Drug Administration as a first-line treatment for advanced differentiated thyroid cancer, which would become the first effective drug for advanced thyroid patients in more than 40 years.

The second study looked at patients with advanced papillary thyroid cancer (PTC), the most common form of metastatic thyroid cancer.

The trial’s goal was to see if Zelboraf (vemurafenib) would benefit patients with papillary thyroid cancer which had mutations in the BRAF gene.

All 51 patients had been previously treated with surgery and radioactive iodine therapy. Some participants had also received either Zelboraf or another kinase inhibitor.

Progression-free survival of patients who had not previously been treated with a kinase inhibitor was 15.6 months, and 35 percent of these patients responded to Zelboraf.

For the previously treated group, progression-free survival was 6.3 months with a response rate of 26 percent.

"By understanding similarities across different types of cancers, we have been able to show that therapies previously shown to be effective in other cancers, such as liver, kidney and bone, can be effectively used to treat a rare cancer, providing significant hope to these patients," Dr. Brose said in a prepared statement.

Results of these studies were presented at the 2013 European Cancer Congress (ECC2013).

Hoffmann-La Roche, the maker of Zelboraf, funded the papillary thyroid cancer trial, and two of the authors are employees of Genentech, which is owned by Hoffman-La Roche.

Several of the authors of the DECISION trial are employees of Bayer HealthCare Pharmaceuticals, the maker of Nexavar.

Before publication in a peer-reviewed journal, all research is considered preliminary. 

Review Date: 
October 4, 2013