Abstract 319P
Background
A 4-weekly schedule of Pegylated Liposomal Doxorubicin (PLD) has been approved for the treatment of Metastatic Breast Cancer (MBC). Phase II trials have suggested interest for a 2-weekly regimen. The aim of this study was to compare efficacy and safety of these two modalities.
Methods
Data from MBC patients treated with PLD at two hospitals in Strasbourg between 2011 and 2021 were retrospectively collected. The objective was to demonstrate the non-inferiority of the 2-weekly versus the 4-weekly schedule in terms of 6-month progression free survival (PFS) rates. The non-inferiority margin was defined based on a pooled analysis of previous anthracycline trials in MBC. A propensity score to receive the 4-weekly versus the 2-weekly schedule was estimated using a multivariate logistic regression. Survival analyses using Cox regression models weighted by the propensity score were performed to compare 2-weekly versus 4-weekly regimens.
Results
A total of 192 patients treated with PLD for MBC were included. Among them, 96 (50%) underwent the 2-weekly PLD schedule. In the modified intent-to-treat (mITT) population (n=191), the median age was 63 years. The median number of previous systemic therapies was 4. Anthracyclines were previously used in in 63.9% of cases for Early Breast Cancer (EBC) and in 7.8% for MBC. There was a comparable distribution of adverse events in both groups in the ITT population. Treatment was discontinued because of adverse events in 15.7% of overall patients, well balanced between the two groups. The most common all-grade toxicity was cutaneous, concerning 30.4% of patients. There was no death presumably related to PLD administration. The median follow-up was 10.1 months. The progression-free survival analyses weighted by propensity score will be presented.
Conclusions
This study was the first to compare 2-weekly versus 4-weekly administration of PLD with the aim to demonstrate non-inferiority between the two modalities.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Philippe Trensz.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.