Evaluation of platinum-free interval and chemotherapeutic effect of subsequent platinum-containing chemotherapy in patients with recurrent ovarian cancer initially treated with bevacizumab: SGSG018/Intergroup study

Objective: The effect of bevacizumab on platinum sensitivity in recurrent ovarian cancer remains poorly understood. This study examined the association between platinum-free interval (PFI) and sensitivity to subsequent platinum-containing chemotherapy in patients with first relapsed ovarian cancer after bevacizumab chemotherapy.
Methods: We retrospectively analyzed patients who received platinum-based chemotherapy for platinum-sensitive recurrence between November 2013, and December 2019, and who were initially treated by platinum-based chemotherapy with concurrent and maintenance bevacizumab. The primary endpoint was response rate to subsequent chemotherapy after various periods of PFI. The relevance between response rate and PFI was assessed for each PFI of 6–12, 12–24 and ≧24 months using Cochran-Armitage test. The secondary endpoint was progression-free survival (PFS) defined as time from chemotherapy for first recurrence to subsequent progression and response rate to subsequent chemotherapy for each treatment-free interval since last administration of bevacizumab (Bev-TFI).
Results: A total of 77 patients were eligible. The median PFI until first recurrence was 12 months (range: 6–43). The response rates of subsequent chemotherapy for patients with PFI of 6–12, ≥12-24, and 24 months were 42 %, 65 %, and 80 %, showing a linear trend (p < 0.05). Median PFS among the three groups was 8 (95 %CI: 6.7–9.2), 11 (95 %CI: 8.4–13.5) and 13 months (95 % CI: 5.4–20.5) (p = 0.107, log-rank test), respectively. By contrast, no linear trend was observed between Bev-TFI and response rate (p = 0.225)
Conclusion: In patients with first relapse of primary ovarian cancer and bevacizumab beyond progression, the prolonged PFS effect of bevacizumab does not seem to affect sensitivity to subsequent platinum-based chemotherapy.