In a meta-analysis reported in JAMA Oncology, Villacampa et al found that the addition of neoadjuvant immune checkpoint inhibitor treatment to chemotherapy was associated with improved outcomes among subgroups of patients with early breast cancer.
Study Details
A literature search through December 2023 identified randomized controlled trials assessing the addition of adjuvant or neoadjuvant immune checkpoint inhibitor treatment to chemotherapy in early breast cancer. Nine randomized controlled trials involving 5,114 patients met the inclusion criteria; the population included 2,097 patients with triple-negative breast cancer, 1,924 with hormone receptor (HR)-positive/HER2-negative disease, and 1,115 with HER2-positive disease.
Among patients with triple-negative breast cancer, the addition of an immune checkpoint inhibitor to chemotherapy was associated with an absolute improvement in pathologic complete response > 10%, irrespective of PD-L1 status. Among patients with HR-positive/HER2-negative tumors, the addition of an immune checkpoint inhibitor was associated with an absolute improvement in pathologic complete response of 12.2% in the PD-L1–positive subgroup. Among patients with HER2-positive disease, no benefit in pathologic complete response was observed with the addition of an immune checkpoint inhibitor.
Among patients with triple-negative breast cancer who achieved a pathologic complete response, the addition of an immune checkpoint inhibitor was associated with improved event-free survival (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.42–1.00), with 5 year rates of 92.0% vs 88.0%. Among patients with residual disease, those who received a neoadjuvant immune checkpoint inhibitor had improved event-free survival (HR = 0.77, 95% CI = 0.61–0.98), with 5-year rates of 63.3% vs 56.1%. Adjuvant immune checkpoint inhibitor treatment was not associated with improvement in event-free survival among patients with a pathologic complete response or residual disease (all HRs >1).
Summary
The investigators concluded: “These findings suggest that neoadjuvant [immune checkpoint inhibitor] therapy improves efficacy outcomes in early-stage [triple-negative breast cancer] and [PD-L1–positive, HR-positive/HER2-negative] tumors with an acceptable safety profile; however, no benefit was observed with adjuvant [immune checkpoint inhibitor]. Given the financial and toxicity costs associated with [immune checkpoint inhibitors], future research should prioritize identifying patients most likely to benefit from the addition of [immune checkpoint inhibitors] to neoadjuvant chemotherapy.”
Tomas Pascual, MD, of the Medical Oncology Department, Hospital Clinic of Barcelona, Barcelona, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was supported by the Instituto de Salud Carlos III and Swedish Society for Medical Research. For full disclosures for all study authors, visit jamanetwork.com.
