Dr. Suzanne L. Topalian on PD-L1 and Emerging Biomarkers for Immunotherapy

Suzanne L. Topalian, MD, professor of Surgery, Johns Hopkins Medicine, discusses the role of the PD-L1 biomarker and other biomarkers on the horizon for the use in immunotherapy.

PD-L1 is a difficult biomarker to use in every circumstance, says Topalian. It may be determined that it is useful in only some kinds of cancers, but not all, she adds. This is still a story that is evoloving.

There are additional biomarkers being investigated. This includes genetic biomarkers, says Topalian. Microsatellite instability (MSI) testing is one potenetial biomarker that has shown some success in colon cancer and other cancers. Patients that are MSI high have tumors that harbor many mutations and they are more likely to respond to PD-1 inhibitors, she says.

Another emerging is area is virus-associated cancers. About 20% of cancers are associated with a virus and these viruses are strongly seen by the immune system, says Topalian. Viruses in tumors could provide a biomarker of which patients are more likely to respond to anti-PD-1 therapy.