Several cancer treatments available for patients with HR+/HER2- advanced or metastatic breast cancer (ABC/MBC) may be associated with prolonged corrected QT interval (QTc), which may increase the risk of life-threatening ventricular arrhythmias, such as Torsades de Pointes (TdP). Therefore, identifying risk factors for QTc prolongation is imperative to ensuring safe and effective therapy tailored to individual patients. This interim analysis characterizes QTc/TdP risk among women with HR+/HER2- MBC living in Italy and Germany included in the MARIA registry.
MARIA is an ongoing non-interventional, prospective, multicenter study that includes women in Italy and Germany initiating their first or second therapy in the HR+/HER2- ABC/mBC setting. Comorbidities collected at baseline were examined to identify patients with specific cardiovascular conditions associated with QTc/TdP risk (i.e., myocardial infarction, hypertension, and heart failure). QTc/TdP risk burden was summarized as the proportion of patients with any risk factor (comorbidity or medication), as well as comorbidity and medication risk factors only.
A total of 318 patients (mean age 61 [SD 12.3], 94.3% stage IV at enrolment) were included. Of these, 180 (56.6%) patients had at least one risk factor for QTc/TdP. There were 115 (36.2%) patients with at least one risk factor related to comorbidity and 123 (38.7%) patients with at least one medication-related risk factor for QTc/TdP.
The results of this study suggest that more than half of women with HR+/HER2- mBC enrolled thus far in the MARIA registry had at least one comorbidity or medication associated with increased risk of developing QTc prolongation or TdP. This analysis underscores the need for clinical decision-making that incorporates individual characteristics that may change the benefit-risk profile of cancer related treatments.
Pfizer Inc.
Pfizer Inc.
N. Harbeck: Honoraria: Lilly, Novartis, Pfizer; Consulting/lectures: Lilly, Novartis, Pfizer. E.H. Law, D. Mitra: Employee, stock ownership: Pfizer. M. Ajmera, K. Davis: Employee: RTI Health Solutions, who were paid consultants to Pfizer in connection with the development of this abstract. M. De Laurentiis: Honoraria: Pfizer, Novartis, Roche, Celgene, AstraZeneca, Eisai, Eli Lilly. All other authors have declared no conflicts of interest.