Dr. Kalinksy on pCR as a Surrogate Marker for EFS in TNBC

Kevin Kalinsky, MD, MS, assistant professor of medicine, Division of Hematology and Oncology, NewYork-Presbyterian Hospital/Columbia University Medical Center, discusses the use of pathologic complete response (pCR) rate as a surrogate marker for event-free survival (EFS) in triple-negative breast cancer (TNBC).

Pooled data suggest that patients with TNBC, HER2-positive disease, and potentially proliferative tumors, such as those that are hormone receptor—positive and HER2-negative, who experience an improvement in pCR may also experience an improvement in EFS. This has been shown in several studies, particularly in the HER2-positive space with targeted therapies, says Kalinsky.

However, it is not clear whether improved pCR in patients who receive checkpoint inhibition or immunotherapy will translate into an improvement in EFS. Notably, the NeoTRIP trial, which did not show an improvement in pCR with neoadjuvant atezolizumab (Tecentriq) and chemotherapy in patients with TNBC, was powered to look at an improvement in EFS. Longer-term follow-up may shed light on whether a patient can still experience an improvement in EFS in the absence of a pCR improvement, concludes Kalinsky.