Abstract P6-05-36: Cost-effectiveness of CDK4/6 inhibitors as a First line Therapy for Metastatic Breast Cancer. A Mexican Cohort
Authors: Ramos-Ramírez Maritza , Guzman-vazquez Silvia , Dominguez-Esquivel Vanessa , Espinosa-Fernandez Jose Rodrigo , Ruiz-Cruz Sandy , Cabrera-Galeana Paula , Garcilazo Alexandra , Cabrera-Miranda Luis Antonio , Salinas Claudia Haydee Arce 
Published: March 2023

Abstract
BACKGROUND. Breast cancer is the most frequent neoplasm worldwide, as reported by GLOBOCAN 2020, there were 2.2 million new cases per year and 680,000 deaths. In Mexico, it represents the leading cause of death from cancer in women, and therefore represents a public health problem in our country. The standard treatment for patients with hormone receptor-positive, her2-negative breast cancer is endocrine tehrapy with an aromatase inhibitor plus a CDK4/6 inhibitor (CDK4/6i+AI), however access to these therapies is difficult and limited resources in developing countries, lead to treatment strategies such as aromatase inhibitors alone (AI) or chemotherapy (ChT) still being used. However, management with ChT involves an increase in the use of reosurces due to cost per infusión, use of premedication and granulocyte colony-stimulating agents.
OBJECTIVE The aim of this study was to provide an economic evaluation of CDK4/6i+AI compared with AI alone or ChT as a first line in MBC to better understand its value from the healthcare point of view in a developing country.
METHODS. We designed a retrospective cost-effectiveness analysis of three different therapies CDK4/6i+AI, AI alone and ChT administered as first-line therapy for patients with MBC.
RESULTS. A cost-effectiveness analysis was performed on a retrospective cohort of 150 MBC patients (march 2011 to April 2020) with a follow-up of al least 2 years. The median age at diagnosis was 55 years old. The utilization of health care resources was retrieved from clinical charts. Only direct costs associated with pre-progression, progression, and management of adverse events were considered and expressed on current USD. Seventy-six percent were diagnosed with de novo stage IV disease, 66% were postmenopausal and 76% had ductal histology. The most common sites of metastasis were visceral 55% and 29% had only bone metastases. We identified 3 treatment groups: (1) CDK4/6i+AI, 18.66% (28/150), (2) AI, 48.66% (73/150) and (3) ChT, 32.66% (49/150). The median PFS of iCDK4/6 + TH was 32.10 months compared with 18.87 (95%CI: 16.4, 28.7) months for the AI group and 6.57 months for chemotherapy. The HR of iCDK4/6+TH vs HT was 0.357 (95%CI: 0.18-0.72) and that of iCDK4/6+TH vs chemotherapy was 0.09 (95%CI: 0.04-0.22). Median OS survival was not reached in any arm. The most frequent adverse events grade 3 were fatigue 10.71%, neutropenia 32.14%, diarrhea 7.14%, myalgias 3.57% and arthralgias 3.57% in the CDK4/6i +AI group, fatigue 2.74% and arthralgias 4.11% in AI group and fatigue 20.41%, neutropenia 18.37%, nausea 10.2%, diarrhea 6.12%, myalgias 2.4% and headache 2.4% with chemotherapy. PFS was used as the outcome for the cost-effectiveness analysis, with 5 years of follow-up, CDK4/6i+AI offer an incremental efficacy of 1.4 years in PFS compared with AI and 2.43 years with ChT, they are related to an incremental cost of $28,151.61 and $26,720.47 concerning AI and ChT, respectively. The ICER for CDK4/6i+AI compared to AI is $20,108.29 and $10,996.07 compared to chemotherapy.
CONCLUSION. CDK4/6i+AI increase years of life gained when compared to AI and chemotherapy. Is a cost-effective tratment in our institution because it is less than two GDP per capita. CDK4/6i+AI is the standar treatment around the world even in develop countries like Mexico.
PFS 3 arms PFS 3 arms
Citation Format: Maritza Ramos-Ramírez, Silvia Guzman-vazquez, Vanessa Dominguez-Esquivel, Jose Rodrigo Espinosa-Fernandez, Sandy Ruiz-Cruz, Paula Cabrera-Galeana, Alexandra Garcilazo, Luis Antonio Cabrera-Miranda, Claudia Haydee Arce Salinas. Cost-effectiveness of CDK4/6 inhibitors as a First line Therapy for Metastatic Breast Cancer. A Mexican Cohort. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-05-36.