NEW OPTIONS FOR TRIPLE NEGATIVE BREAST CANCER PATIENTS

Researchers are seeking additional treatments for early-stage triple negative breast cancer (TNBC) when standard chemotherapy proves ineffective.

Conducted by Breast Cancer Trials researchers in Australia, the CHARIOT clinical trial evaluated the effectiveness of two immunotherapy drugs, nivolumab and ipilimumab, combined with standard chemotherapy in treating TNBC. The study enrolled 34 patients with newly diagnosed stage-3 TNBC who had a suboptimal response to initial anthracycline-based chemotherapy. These patients then received nivolumab and ipilimumab with paclitaxel chemotherapy prior to surgery. The results, presented at the American Society of Clinical Oncology (ASCO) international conference, show promise in this uphill battle.

TNBC is a breast cancer subtype with the poorest prognosis, as it is more likely to spread within the body and can be less sensitive to chemotherapy than other subtypes. For patients who still have evidence of cancer after receiving chemotherapy and before surgery, the risk of relapse and death within three years is concerningly high.

The CHARIOT clinical trial aimed to determine if adding immunotherapy drugs to standard chemotherapy could safely and effectively stimulate the body’s immune system to kill cancer cells and eradicate residual cancer cells. The results were encouraging: 24% of participants experienced a complete disappearance of cancer within the breast and lymph nodes by the time of surgery. These results were regardless of the patients’ varying levels of PD-L1, a specific protein that can affect how well they respond to immunotherapy.

Although the treatment came with expected side effects, these were manageable. The most common immune-related event was low-grade pneumonitis (lung inflammation), which occurred in 27% of patients and typically resolved promptly with appropriate treatment.

Professor Sherene Loi, the study chair of the CHARIOT clinical trial, celebrated the results but acknowledged more research is needed. “While we have seen some promising results in the pathological response rate of this treatment, the survival benefits of adding ipilimumab to treatment is currently unclear,” she says, adding that the study will now follow up with patients to determine event-free survival (EFS) and overall survival (OS).

Publication:

Loi, S., Francis, P. A., Zdenkowski, N., Gebski, V., Fox, S. B., White, M., Kiely, B. E., Woodward, N. E., Hui, R., Redfern, A. D., Calvert, R., Rennie, L., Boyle, F. M., & Breast Cancer Trials-Australia and New Zealand (2022). Neoadjuvant ipilimumab and nivolumab in combination with paclitaxel following anthracycline-based chemotherapy in patients with treatment-resistant early-stage triple-negative breast cancer (TNBC): A single-arm phase 2 trial. Journal of Clinical Oncology, 40(16_suppl), 602-602. Published online June 2, 2022.