Cancer treatments have traditionally been tested and prescribed for tumors in specific parts of the body—but that’s starting to change.

The Food and Drug Administration decided in late November to approve Vitrakvi (larotrectinib), the first medication developed to treat cancers with a specific genetic mutation regardless of where in the body they occur.

Vitrakvi is a tropomyosin receptor kinase inhibitor that works against cancers with mutations known as TRK fusions. When a TRK-producing gene in a cancer cell fuses with another gene, it acts as an ignition switch to accelerate cancer growth. Although TRK fusion mutations occur in only around 1 percent of cancers overall, they’re common in some rare cancers.

Vitrakvi made its debut at the 2017 American Society of Clinical Oncology meeting, where researchers reported that among 55 adults and children with 17 types of cancers, about three quarters experienced complete or partial tumor shrinkage.

At the recent European Society for Medical Oncology 2018 Congress, Ulrik Lassen, MD, of Rigshospitalet in Copenhagen, presented follow-up data showing an overall response rate of 80 percent, including 18 percent with complete responses. After a year on treatment, 75 percent were still responding.

Lassen suggested that everyone diagnosed with solid tumors or brain cancers should be tested for gene fusions to see whether Vitrakvi might work for them.