Bevacizumab Plus Chemotherapy Improves PFS in Early Ovarian Cancer

A recent study evaluated the impact of adding bevacizumab to chemotherapy treatment for patients who were newly diagnosed with ovarian cancer. The results, published in Gynecologic Oncology, found that while the addition of bevacizumab greatly improved progression-free survival (PFS), it did not improve overall survival (OS).

The open-label randomized phase 3 ICON7 trial enrolled women with newly diagnosed ovarian cancer that was either high-risk early stage or advanced. Patients were randomized after primary surgery (unless disease was inoperable) to receive 6 cycles of chemotherapy either alone or in combination with bevacizumab at 7.5 mg/kg every 3 weeks for up to 12 months until disease progression or unacceptable toxicity. The primary end point of the trial was PFS and the secondary end point was OS.

In total, the trial enrolled 119 patients with stage I disease, 163 patients with stage II disease, 1034 patients with stage III disease, and 201 patients with stage IV disease. The median duration of follow up was 28 months for PFS and 49 months for OS.

For PFS, the researchers found that all stages indicate better outcomes with the addition of bevacizumab. However, researchers noted that the data found for OS was less clear. This could be due to “the extremely low event rates in the stage I and stage II subgroups compared with the stage III and stage IV.”

Additionally, PFS and OS were also analyzed within the stage IIIB to IV subgroup. The study authors found that, irrespective of residual disease status, all patients in this subgroup derived a PFS benefit from the addition of bevacizumab to chemotherapy. Conversely, no OS difference was seen in either the stage IIIB to IV subgroup or the other subgroups classified by the presence or absence of residual disease.

Overall, the addition of bevacizumab to carboplatin and paclitaxel chemotherapy improved PFS in most of the evaluated subgroups. The study found that the main patient populations who appeared not to derive a PFS improvement from the addition of bevacizumab were those with stage I or II disease, though the authors note that this could be due to smaller sample sizes.

Reference

Martin A, Oza A, Embleton A, et al. Exploratory outcome analyses according to stage and/or residual disease in the ICON7 trial of carboplatin and paclitaxel with or without bevacizumab for newly diagnosed ovarian cancer [published online November 15, 2018]. Gyn Oncol. doi: 10.1016/j.ygyno.2018.08.036.