Dr. Gogineni on Implications of the APT Trial in HER2+ Breast Cancer

Keerthi Gogineni, MD, MSHP, an assistant professor, Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, discusses the clinical implications of the phase II APT trial in HER2-positive breast cancer.

The APT trial, launched in 2015, and led by Sara M. Tolaney, MD, MPH, of Dana-Farber Cancer Institute, evaluated de-escalation strategies in women with small, node-negative HER2-positive breast cancer. Investigators evaluated a chemotherapy backbone of adjuvant paclitaxel in combination with trastuzumab (Herceptin). Notably, the 7-year disease-free survival rate (DFS) was 93%. This trial demonstrated that women with small, node-negative tumors could receive the regimen with manageable toxicity, while ensuring they are at low risk of relapse, says Gogineni.

Since then, several studies, including meta analyses, have evaluated a shorter duration of trastuzumab. For example, the phase III HERA trial evaluated a 24- and 12-month duration of trastuzumab versus observation, while the phase III PERSEPHONE trial examined a 6- and 12-month duration of the agent. Eleven years of follow-up from the HERA trial showed that 12 months of adjuvant trastuzumab significantly improved long-term DFS compared with observation, and 24 months of trastuzumab did not provide any additional benefit. PERSEPHONE showed noninferiority between the 6- and 12-month durations of trastuzumab.

However, these regimens are no longer commonplace in practice, and it may not be safe to de-escalate both the chemotherapy and the duration of trastuzumab, concludes Gogineni.