Approvals mark ‘tip of the iceberg’ for PD-L1 testing

What the FDA giveth, the FDA may taketh away.

On Oct. 2, the agency approved the use of Merck’s immunotherapy drug Keytruda (pembrolizumab) to treat patients with metastatic non-small cell lung cancer whose disease has progressed after chemotherapy and whose tumors express the PD-L1 protein. Dako’s IHC 22C3 pharmDx test kit was approved as a companion diagnostic for use with the drug.

Aside from offering patients another, less toxic treatment option, the FDA action seemed to portend a big boost to the surgical pathologist’s role in lung cancer care, says Philip T. Cagle, MD. He is medical director of pulmonary pathology at Houston Methodist Hospital and editor in chief of Archives of Pathology & Laboratory Medicine.

“Almost all of the lung cancer patients, one would expect, would be potential candidates for immunotherapy. They may get some other therapy first, but eventually they would be candidates for this,” he says. “The test is immunohistochemistry, and the good news about that is pathologists are already mostly set up to do IHC.…And they can bill and get reimbursed for immunohistochemistry, in contrast to a lot of the issues we have with molecular tests. There are many positives for pathologists, surgical pathologists, and cytopathologists to do this test themselves rather than simply collect tissue for the molecular lab. That’s the good news.”

My lead item in November’s “Put It on the Board” section of CAP TODAY. Read the whole shebang to find out some of the not-so-good news from the FDA.