OBJECTIVES : To estimate the economic impact of relapse prevention associated with the addition of pertuzumab on the neoadjuvant treatment of HER2-positive breast cancer patients on the Brazilian public healthcare system (SUS).

METHODS : Pertuzumab associated with trastuzumab and chemotherapy (PTC) was compared with trastuzumab and chemotherapy (TC) on the neoadjuvant treatment setting. Local and distant recurrence rates were extracted from the NeoSphere trial and extrapolated for a 5-year time horizon with a Weibull distribution. HER2-positive breast cancer population was estimated from an epidemiological approach. It was assumed, based on real-world literature data, that 65% of patients were stage II or III, 19% were HER2-positive and 36% would receive neoadjuvant treatment. A progressive market share scenario of pertuzumab uptake was adopted and considered a maximum use of 40% in the fifth year. Direct medical costs were included: drug acquisition, administration, support procedures and adverse events related to relapse treatment. Costs were estimated on 2018 BRL and USD. Two lines of treatment were considered for metastatic setting.

RESULTS : The cost of one local and distant relapse was 392,445 BRL (100,627 USD) and 928,957 BRL (238,255 USD), respectively. For distant relapse, average yearly costs were 175,375 BRL (44,968 USD) for first line and 7,437 BRL (1,907 USD) for second. The use of PTC as neoadjuvant setting, compared with TC, avoided 166 local relapses and 553 distant relapses in five years. Per patient, cost savings related to recurrence avoidance were estimated from 1,896 BRL (486 USD) in the second year to 11,119 BRL (2,851 USD) in the fifth year of treatment. Cost offsets for the total population was 69,347,316 BRL (17,781,363 USD) for the Brazilian public healthcare system in five years.

CONCLUSIONS : The use of PTC in neoadjuvant treatment represents cost savings in further line treatments in patients with HER2-positive breast cancer, under SUS perspective.