From the Guidelines
The recommended duration of bevacizumab adjuvant therapy for BRCA1-related ovarian cancer is typically 15 months (22 cycles when given every 3 weeks at 15 mg/kg). This recommendation is based on the most recent and highest quality study available, which is the 2023 ESMO clinical practice guideline for diagnosis, treatment, and follow-up of newly diagnosed and relapsed epithelial ovarian cancer 1. The study suggests that bevacizumab, in combination with paclitaxel and carboplatin, followed by bevacizumab maintenance, results in a statistically significant increase in progression-free survival (PFS) versus chemotherapy alone, particularly in the clinical ‘high-risk’ population. Some key points to consider when administering bevacizumab include:
- The licensed dose of bevacizumab is 15 mg/kg given for 15 months in combination with first-line paclitaxel and carboplatin chemotherapy to patients with stage IIIB-IV ovarian cancer, regardless of histology.
- Treatment should be monitored for side effects including hypertension, proteinuria, wound healing complications, and thromboembolism.
- Regular blood pressure checks and urinalysis are needed during treatment.
- The rationale for bevacizumab in BRCA1 ovarian cancer is that it targets angiogenesis by inhibiting VEGF, complementing the DNA repair defects exploited by chemotherapy and PARP inhibitors in these patients. It's worth noting that some oncologists may extend bevacizumab treatment up to 22 months in high-risk cases with suboptimal debulking or advanced disease, but this is not universally recommended 1. Additionally, for patients with BRCA1 mutations, this regimen is often followed by or combined with PARP inhibitor maintenance therapy, which has shown particular benefit in BRCA-mutated tumors.
From the Research
Bevacizumab Adjuvant Therapy Duration for BRCA1-Related Ovarian Cancer
- The optimal duration of bevacizumab adjuvant therapy for BRCA1-related ovarian cancer is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, study 3 suggests that a bevacizumab treatment duration of 15 months remains the standard of care, as longer treatment duration up to 30 months did not improve progression-free survival (PFS) or overall survival (OS) in patients with primary epithelial ovarian, fallopian tube, or peritoneal cancer.
- Study 4 assessed the safety and efficacy of extending bevacizumab therapy beyond 15 months in nonprogressive ovarian cancer and found that median progression-free survival was 25.5 months, which is the longest reported for frontline bevacizumab-containing therapy.
- Study 6 explored the association of location of BRCA1 and BRCA2 mutations with benefit from olaparib and bevacizumab maintenance in high-grade ovarian cancer, but did not provide information on the optimal duration of bevacizumab adjuvant therapy.
Bevacizumab Treatment Duration in Ovarian Cancer Studies
- Study 3: 15 months (standard duration) vs 30 months (extended duration)
- Study 4: up to 24 months (extended duration)
- Study 5: median duration of 12.2 months (range 0-28 months)
BRCA1-Related Ovarian Cancer and Bevacizumab Therapy
- Study 6 found that advanced-stage BRCA-mutated high-grade ovarian cancer patients reported PFS benefit from maintenance olaparib and bevacizumab regardless of mutation location.
- The benefit was particularly high for patients with mutations located in the DNA-binding domain (DBD) of BRCA1.