A phase III trial has shown adding the PD-1 inhibitor nivolumab to anthracycline- and taxane-based chemotherapy that patients receive ahead of surgery may improve breast cancer cure rates.
CheckMate-7FL involved 510 patients with estrogen receptor (ER)-positive, HER2-negative early breast cancer, which accounts for around 70% of cases of the disease. Results of the trial were published in Nature Medicine by Sherene Loi, MD, PhD, and colleagues.
Sherene Loi, MD, PhD
Dr. Loi said the addition of nivolumab to neoadjuvant chemotherapy led to approximately twice as many patients achieving a pathologic complete response (pCR) compared with neoadjuvant chemotherapy plus placebo.
“These patients are considered to be likely cured, because their tumor was removed and samples of breast and lymph node tissue collected at the same time also show no detectable cancer cells,” she explained. “The number of patients who achieved this pCR improved significantly as a result of nivolumab, an exciting result that points to a new treatment paradigm in this most common type of breast cancer.”
Overall, pCR rates were 24.5% in the trial participants treated with nivolumab vs 13.8% in the placebo group (P = .0021).
In a subgroup of patients with tumors that had the PD-L1 biomarker—indicating heightened responsiveness to nivolumab—the pCR rate was 44.3% in the nivolumab group compared to 20.2% in patients who received the placebo.
There were no new safety signals identified in the trial; however, there were five deaths in the nivolumab treatment arm, with two related to nivolumab toxicity. There were no deaths reported in the placebo arm.
Dr. Loi added that while patients with ER-positive, HER2-negative disease generally have better outcomes than patients with other subtypes of breast cancer, survival can vary; she also noted that there is a more aggressive type of ER-positive, HER2-negative breast cancer in young women that is more likely to recur.
“It seems that these [patients] may be the most responsive to immunotherapy and chemotherapy,” stated.
The study’s researchers concluded their report with, “Adding nivolumab to neoadjuvant chemotherapy significantly increased pCR rates in high-risk, early-stage ER-positive, HER2-negative breast cancer, particularly among patients with higher stromal tumor–infiltrating lymphocyte levels or PD-L1 expression, suggesting a new treatment paradigm that emphasizes the role of immunotherapy and T-cell immunosurveillance in luminal disease.”
Disclosure: For full disclosures of the study authors, visit nature.com.
