Pembrolizumab was projected to be a cost-effective treatment option versus chemotherapy alone for patients with high-risk, early-stage, triple-negative breast cancer, with estimated incremental cost-effectiveness ratios (ICERs) lower than all commonly cited willingness-to-pay thresholds in Switzerland.

Results for the ICER were most sensitive to changes in the event-free survival (EFS) extrapolation from the KEYNOTE-522 trial, performed due to the lack of long-term data. Despite the robustness of the base-case ICER being supported by the sensitivity analysis, further research to obtain long-term EFS data could reduce the uncertainty around the extrapolation.