A new targeted therapy directed against the RET tyrosine kinase receptor led to tumor shrinkage in a third of people with advanced thyroid and lung cancer carrying certain mutations.

Known as BLU-667, the drug showed broad antitumor activity against cancers with a variety of RET alterations.

Although BLU-667 works against only a small proportion of cancers, it supports an emerging paradigm of targeting cancers with specific genetic characteristics regardless of where they occur in the body—pointing to the need for more genetic testing to match individuals to appropriate therapies.

“I encourage all cancer patients to undergo genomic testing, as tumors with rare genomic aberrations may have effective drugs that are in clinical trials that could be beneficial to them,” says lead investigator Vivek Subbiah, MD, of MD Anderson Cancer Center.