A recent phase 3 clinical trial has revealed that adding a targeted immunotherapy drug to chemotherapy significantly increased the cure rate for patients with the most common type of breast cancer, almost doubling it. This discovery suggests a new approach to treating the disease.
A few years back, New Atlas reported on the success of combining an immunotherapy drug with chemotherapy in treating Hodgkin lymphoma, resulting in improved remission rates compared to chemotherapy alone.
Now, the results of an international phase 3 clinical trial led by Australia’s Peter MacCallum Cancer Center (Peter Mac) have shown that the same treatment combination is effective against the most prevalent form of breast cancer.
Worldwide, more than 2.3 million new cases of breast cancer were diagnosed in 2020, with 70% being estrogen receptor-positive (ER+) and human epidermal growth factor receptor 2-negative (HER2–) subtypes. ER+ cancer cells have receptors that respond to estrogen hormones, promoting cancer cell growth. HER2– cancer cells lack an excess of HER2 receptors, making them less aggressive and slower-growing.
The response of ER+/HER2– breast cancer to treatment varies, impacting clinical outcomes and posing challenges in managing the condition. Current treatments for high-risk early-stage ER+/HER2– breast cancer include chemotherapy followed by surgery or prolonged hormone therapy, with or without targeted immunotherapy drugs.
The CheckMate 7FL study aimed to study the benefits of adding the immunotherapy drug nivolumab to neoadjuvant therapy in patients with early-stage high-risk ER+/HER2– breast cancer. Nivolumab blocks the programmed cell death protein 1 (PD-1) receptor, enabling T cells to attack cancer cells effectively.
In the phase 3 trial, 510 patients received chemotherapy with either nivolumab or a placebo. Patients treated with nivolumab and chemotherapy had significantly higher pathological complete response (pCR) rates, almost double those who received the placebo and chemotherapy: 24.5% versus 13.8%.
Professor Sherene Loi, the trial lead, stated that patients achieving pCR are likely cured, as their tumors and tissue samples showed no detectable cancer cells. Subgroup analysis showed even higher pCR rates in patients with PD-L1 biomarker-positive tumors.
Although there were common adverse events like alopecia, nausea, anemia, and fatigue, the researchers were pleased with the treatment’s effectiveness. The study results represent a significant advancement in neoadjuvant treatment for ER+/HER2– breast cancer.
The study was published in Nature Medicine. Source: Peter Mac
