Robert Coleman, MD, FACOG, FACS, Chief Scientific Officer US Oncology Research discusses ASCO 2020 A phase III randomized controlled trial of secondary surgical cytoreduction (SSC) followed by platinum-based combination chemotherapy (PBC), with or without bevacizumab (B) in platinum-sensitive, recurrent ovarian cancer (PSOC): A NRG Oncology/Gynecologic Oncology Group (GOG) study.
Context: GOG-0213 is an international, open-label, randomized phase 3 trial of PSOC women with two objectives: 1) to research the addition of B to paclitaxel/carboplatin simultaneously and as maintenance; and 2) to determine the effect of SSC. Overall survival (OS) is the principal endpoint. The results of Objective 1 [HR 0.829; 95 % CI: 0.683-1.005; p = 0.056) Coleman RL, et al Lancet Oncol 2017] have been previously published, and the results of Objective 2 are now published.
Methods: 485 women with investigator-determined resectable PSOC were randomized to SSC 1:1 from Dec-2007 until Jun-2017, followed by PBC (n = 240) or PBC alone (n = 245). The platinum-free interval (PFI) was included in the stratification variables. Surgical candidacy was based on the probability of full resection (R0) being achieved. For Objective 2, the use of B was the preference of the investigator. The primary endpoint for a pre-specified interim review reached maturity in Nov-2017. 2-sided alpha = 0.05 is the basis for the performance.
Results: The treatment was performed by 215/240 (90 percent) evaluable patients who were randomized to SSC. At 63 per cent, R0 was achieved. Adjuvant B (84 percent) was popular. The median period of follow up is 34.6 mos. The HR for death (SSC vs. none) is 1.28, leading to a median OS of 53.6 mos vs. 65.7 mos, respectively (95 % CI: 0.92-1.79). In those receiving PBC+B vs. those who did not (p = 0.022), there is a substantially different influence of SCC on OS. The HR for death (SCC vs. none) is 2.18 (95 percent CI: 0.86-5.51) among 77 patients receiving PBC, while the HR for death is 1.03 (95 percent CI: 0.57-1.88) among 408 patients receiving PBC+B. In the SSC cohort, the median progression-free survival was 18.2 mos vs.16.5 mos without SCC, HR: 0.88 (95 % CI: 0.70-1.11). Due to complications from SSC, one patient died. There were no new safety signals found.
Conclusions: SSC can be done safely in PSOC patients, but the OS in this population has not improved. Additional studies are ongoing and will be provided (e.g. effect of PFI, SSC result, disease burden, and chemotherapy regimen on OS by SSC allocation). Data on clinical trials: NCT00565851.