The cost of inequity: Estimating the impact of delayed access to neoadjuvant pertuzumab in Canada.

Abstract

e23060 Background: Pertuzumab, when used as a neoadjuvant treatment together with chemotherapy and trastuzumab for early-stage HER2-positive breast cancer, has been shown to significantly improve pathological complete response (pCR) rates, which predict for superior disease free survival outcomes at the patient level and avoidance of the need for postoperative chemotherapy (trastuzumab-emtansine), and allow for the use of anthracycline sparing chemotherapy backbones. Progression-free survival and disease-free survival were also improved. Despite these proven benefits and its adoption as a global standard of care, CADTH issued negative funding recommendations in 2015 and 2022. A recent positive recommendation ended a nearly decade-long inequity for Canadians. Methods: An analysis was conducted to estimate the impact of delayed treatment access on Canadian patients. An epidemiologic model was developed using Canadian breast cancer incidence and population growth data. Clinical outcomes were based on the NEOSPHERE trial, with scenario analyses conducted using alternate trials. The model examined a 10-year period (2015-2025), estimating the total number of eligible patients and those anticipated to achieve a pCR with pertuzumab-based regimens. Results: Our analysis estimates 10,154 Canadian breast cancer patients were eligible for neoadjuvant pertuzumab over the past decade. Consequently, an estimated 423-1,941 additional patients could have achieved a pCR and benefitted from access to pertuzumab during this unfunded period. Furthermore, potential long-term health system benefits from minimizing residual disease were not realized. Conclusions: This study highlights the implications of delayed funding on patients and the healthcare system, stressing the importance of ensuring equitable and timely access to innovative cancer treatments.