Abstract 767P
Background
Bevacizumab (BVZ) is a humanized monoclonal antibody that has demonstrated benefit in the front-line, recurrent platinum-sensitive and recurrent platinum-resistant ovarian cancer settings. Phase III trials of BVZ in ovarian cancer show a benefit in the dose-intensity range of 2.5 mg/kg/week to 5 mg/kg/week, but the optimal dose of this drug is still unknown. Some evidence suggests that high-dose BVZ is associated with a higher incidence of adverse events. In addition, in many countries, health services have restricted access to BVZ due its high cost.
Methods
We carried out a retrospective study comparing low-dose (< 2.5 mg/kg/week) and high-dose (> 2.5 mg/kg/week) BVZ in combination with chemotherapy, in patients with recurrent platinum-resistant ovarian cancer that received treatment in the Instituto Nacional de Cancerología between 2012 and 2017. Demographic and clinicopathological characteristics were retrieved from medical records. We compared PFS and OS by use of a log-rank test. We also examined BVZ adverse events of special interest.
Results
Of 79 patients that received BVZ, 41 received low dose and 38 received high dose. Mean dose was 2.3 mg/kg/week in the low-dose group and 4.22 mg/kg/week in the high-dose group. No differences in mean age, history of hypertension and number of BVZ cycles were found between groups. The low-dose group had a higher proportion of low-grade serous histology (9.8% vs 0%), and a lower proportion of clear-cell histology (4.9% vs 10.5%). Median PFS was 7.5 months (CI 95%, 0.56 - 1.7) with low dose and 7.7 months (CI 95%, 0.58 - 1.7) with high dose (p = 0.81). OS was 28.1 months (CI 95%, 0.68 - 2.4) and 21.6 months (CI 95%, 0.40 - 1.4) (p = 0.09). There were no differences in the incidence of adverse events of special interest.
Conclusions
Results from this retrospective study suggest that low-dose BVZ may have a similar efficacy compared to high-dose. The administered dose did not affect the incidence of BVZ-related adverse events. However, clinical data from prospective studies need to be assessed in order to validate these results. If low-dose BVZ treatment demonstrates to be non-inferior, a larger number of patients will be able to receive this treatment with a better cost-effectiveness ratio.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.