198P - Biomarker (BM) results from GOG-0218, a phase 3 trial of front-line bevacizumab (BV) + chemotherapy (CT) for ovarian cancer (OC)
|Date||30 September 2012|
|Event||ESMO Congress 2012|
|Session||Poster presentation II|
|Topics|| Ovarian Cancer
M.J. Birrer1, H. Lankes2, R.A. Burger3, R. Mannel4, H. Homesley5, V. Henschel6, M. Sovak7, S.J. Scherer8, S. de Haas9, C. Pallaud10
GOG-0218 showed significantly improved progression-free survival (PFS) in patients (pts) receiving BV 15 mg/kg q3w concurrently with CT and continued alone until progression or for up to 15 mo. GOG-0218 includes extensive BM evaluation to identify pts benefitting most from BV. Analysis of plasma VEGF-A and VEGFR-2 was prioritised based on encouraging findings in BV trials in several tumour types.
|Median, mo||HR||Median, mo||HR|
Q = quartileMethods
Pts with newly diagnosed stage IV or macroscopic optimal stage III OC were randomised to 6 cycles (c) of CT with: placebo (PL) c2−22 (arm A); BV c2−6 → PL c7−22 (arm B); or BV c2−22 (arm C). Post-surgery pre-CT plasma samples were analysed using a multiplex ELISA. Baseline (BL) BM levels were used to dichotomise pts. Potential interactions between BM levels and PFS (1° endpoint) and overall survival (OS; 2° endpoint) were tested using log-rank testing and Cox regression approaches.Results
Post-surgery samples were available from 582 of 1248 pts in arms A and C. Median BL VEGF-A and VEGFR-2 levels were 144.3 pg/mL and 14.7 ng/mL, respectively. No significant interaction was seen at α = 0.05. Exploratory analyses with other cut-offs are hypothesis generating for potential predictive (VEGF-A and VEGFR-2) or prognostic (VEGF-A: OS) value. Exploratory analyses revealed no correlation between plasma VEGF-A and time since surgery.Conclusions
The potential prognostic (VEGF-A) and predictive (VEGF-A, VEGFR-2) value seen in breast, pancreatic and gastric cancers was not apparent in post-surgery samples from GOG-0218 using a median cut-off. Results with other cut-offs provide a rationale for further investigation of potential prognostic and predictive value. Findings may reflect differing biology and interplay between VEGF-A isoforms across tumour types. The possible impact of pre- vs post-surgery samples is also being investigated.Disclosure
R.A. Burger: RB has served on Advisory Boards for Roche/Genentech.
R. Mannel: RM has served on Advisory Boards for Genentech.
V. Henschel: VH is employed by and holds shares in Roche.
M. Sovak: MS is an employee of Genentech.
S.J. Scherer: SS is an employee of Genentech Inc.
S. De Haas: SdH is an empoloyee of F Hoffmann-La Roche Ltd.
C. Pallaud: CP is an employee of F Hoffmann-La Roche Ltd.
All other authors have declared no conflicts of interest.