Oral Presentation 2025 Joint Meeting of the COSA ASM and IPOS Congress

First-line bevacizumab in the real-world (126511)

Tanya Ross 1 2 , Susan Jordan 1 2 , Nina (Renhua) Na 1 2 , Michael Friedlander 3 4 , Philip Beale 5 6 , Peter Grant 7 , Dinuka Ariyaratne 8 , Sian Fereday 8 , Anna DeFazio AM 5 9 10 , Penelope Webb 1 2
  1. Population Health, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
  2. School of Public Health, University of Queensland, Herston, QLD, Australia
  3. Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
  4. Department of Medical Oncology, Prince of Wales Hospital, Sydney, NSW, Australia
  5. Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
  6. Concord Cancer Centre, Concord Repatriation General Hospital, Sydney, NSW, Australia
  7. Department of Obstetrics, Gynaecology and Newborn Health, The University of Melbourne, Melbourne, VIC, Australia
  8. Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
  9. Department of Gynaecological Oncology, Westmead Hospital, Westmead, Sydney, NSW, Australia
  10. Centre for Cancer Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Sydney, NSW, Australia

Background: Trials have shown bevacizumab improves epithelial ovarian cancer (EOC) survival in patients at high-risk of progression. An Australian government-subsidy for first-line bevacizumab was introduced in 2014. We assessed (i) use of bevacizumab; and (ii) the association with progression-free (PFS) and overall survival (OS) in the real-world (overall and by subsidy-eligibility).

Methods: We used data from two EOC cohort studies (Ovarian Cancer, Prognosis and Lifestyle study diagnosed 2012-2015; and Australian Ovarian Cancer Study II diagnosed 2015-2021). Those with advanced disease managed with platinum-based chemotherapy were eligible. Criteria for subsidised bevacizumab were performance-status ≤2 and FIGO stage IV or stage IIIB/IIIC with >1cm residual/inoperable disease. We estimated restricted mean survival time (RMST) using generalised linear models (pseudovalue regression method; adjusted for age, stage, germline-BRCA1/2 status, primary or interval cytoreduction, chemotherapy, residual disease, months from diagnosis to chemotherapy completion and study) to assess survival time differences between bevacizumab recipients and non-recipients, measuring survival from primary chemotherapy completion. Those who progressed during chemotherapy were ineligible (n=15). We modeled RMST differences up to 24-months for PFS and 60-months for OS respectively.

Results: Overall, 16% of 1022 participants received first-line bevacizumab, varying from 28% of subsidy-eligible (n=419), to 10% of possibly-eligible (neoadjuvant-chemotherapy+≤1cm residual; n=255) and 7% of subsidy-ineligible (n=348). After subsidisation, uptake increased to 27% overall, and 45%, 15% and 13% by subsidy-eligibility. Overall, PFS was significantly longer in bevacizumab recipients (RMST difference=1.7 months; 95% confidence interval [95%CI]=0.5-3.0); driven by those subsidy-eligible (RMST difference=2.0 months; 95%CI=0.3-3.6). Similar results were seen for OS with an overall difference of 2.7 months (95%CI=-0.3-5.8); and 4.9 months (95%CI=0.6-9.2) longer survival among those subsidy-eligible.

Conclusion: Survival benefits of first-line bevacizumab among patients at high-risk of progression were similar to those seen in trials, with limited benefits beyond this group. Bevacizumab appeared to be under-utilised in those most likely to benefit.