AACR II: Adding Interferon-Gamma to Neoadjuvant Chemotherapy for HER2-Positive Breast Cancer
Posted: Tuesday, July 7, 2020
In an early-phase study, more than half of patients with hormone receptor–positive, HER2-positive breast cancer achieved a pathologic complete response from treatment with interferon-gamma (IFN- γ) plus paclitaxel, trastuzumab, and pertuzumab, according to Hyo S. Han, MD, of the Moffitt Cancer Center, Tampa, and colleagues. The results, which were presented during the 2020 American Association for Cancer Research (AACR) Virtual Annual Meeting II (Abstract CT185), suggested this regimen was also well tolerated with manageable toxicities.
“IFN- γ, a cytokine that plays diverse roles in innate and adaptive immunity, has been shown to be essential in [the] antitumor immune response,” the investigators explained. “This regimen met the criteria to proceed to the second stage of the phase II trial and appears promising, especially in hormone receptor–positive HER2-positive breast cancer.”
A total of 23 patients with early-stage HER2-positive breast cancer were enrolled. Specifically, patients with stage II or III (86%) disease and those who were node-positive (43%) were included. The majority of patients (82%) presented with hormone receptor–positive disease. The patients received intravenous paclitaxel weekly and intravenous trastuzumab and pertuzumab every 3 weeks. IFN-γ was administered subcutaneously three times weekly.
The overall patient population showed a pathologic complete response of 52%. The pathologic complete response rate was higher in the hormone receptor–positive HER2-positive subgroup (57%) than in the hormone receptor–negative HER2-positive subgroup (25%). In addition, 12 patients had no residual cancer burden (based on the residual cancer burden score). Two serious adverse events were reported; serious adverse events included pneumonitis/heart failure and hematochezia. The most common grade 1 and 2 adverse events were fatigue (69%), diarrhea (59%), rash (41%), and nausea (41%). Grade 3 diarrhea was observed in at least 4% of patients. No grade 4 adverse events were reported.
Disclosure: For full disclosures of the study authors, visit abstractsonline.com.
