Thyroid Cancer

Thyroid cancer is the most common form of endocrine malignancy and its incidence is increasing. Thyroid cancers usually present as painless nodules found upon palpation, and nodules >1 cm should be evaluated as they have a higher potential for being clinically significant cancers.

RET is a tyrosine kinase receptor that, when fused with a partner molecule, activates oncogenic activity. RET abnormalities are found in both papillary and medullary thyroid cancers and are promising targets for treatment.

Medullary thyroid cancer (MTC) accounts for 5% of all thyroid cancers. The only curative treatment option for MTC is surgery, but understanding of the RET pathway and the development of therapies targeting this pathway may improve outcomes for these patients.

Papillary thyroid cancer is the most prevalent thyroid cancer, accounting for 80% of thyroid cancer diagnoses. Prognosis is good for patients with early and aggressive treatment, and the new and emerging therapies targeting the RET pathway may improve outcomes for patients with advanced disease.

Among patients with radioiodine-refractory advanced or metastatic thyroid cancer, tyrosine kinase inhibitors are guideline recommended. New RET-specific kinase inhibitors have recently demonstrated positive outcomes for these patients.

This section provides a brief overview of new cancer drugs or new indications approved by the FDA between May 26 and June 15, 2020.

On January 29, 2020, Eli Lilly announced that the FDA granted priority review to their New Drug Application for selpercatinib (LOXO-292) for the treatment of patients with advanced RET fusion-positive non–small-cell lung cancer, RET-mutant medullary thyroid cancer, and RET fusion-positive thyroid cancer. The FDA is aiming to provide its decision on the approval of selpercatinib in the third quarter of 2020.