The RET proto-oncogene encodes a receptor tyrosine kinase for members of the glial cell line-derived neurotrophic factor (GDNF) family of extracellular signalling molecules. Chromosomal rearrangements that generate a fusion gene, resulting in the juxtaposition of the C-terminal region of the RET protein with an N-terminal portion of another protein, can also lead to constitutive activation of the RET kinase. These types of mutations are associated withpapillary thyroid carcinoma (PTC), and the fusion oncoproteins generated are termed RET/PTC proteins.

ALECENSA is a tyrosine kinase inhibitor that targets ALK and RET. The approvals rely on the ALK targeting; it is nto clear at this time how the effect on RET can be clinically used. It remains to be studied. There is a study: A Study of Alectinib in RET-rearranged Non-small Cell Lung Cancer or RET-mutated Thyroid Cancer, NCT03131206

Kodama T et al, Alectinib shows potent antitumor activity against RET-rearranged non-small cell lung cancer. Mol Cancer Ther. 2014 Dec;13(12):2910-8.

Alecensa Prescribing Information 2017

NCCN. Esophageal Cancer 2017