Phase II study of bevacizumab, cisplatin, and docetaxel plus maintenance bevacizumab as first-line treatment for patients with advanced non-squamous non-small-cell lung cancer combined with exploratory analysis of circulating endothelial cells: Thoracic Oncology Research Group (TORG)1016.

Background: Preclinical studies have demonstrated that docetaxel and bevacizumab may act synergistically by decreasing endothelial cell proliferation and preventing circulating endothelial progenitor mobilization. The objective of this study was to assess the efficacy and safety of a combination therapy of bevacizumab, cisplatin, and docetaxel in chemotherapy-naive Japanese patients with advanced non-squamous non-small-cell lung cancer (NSCLC).

Methods: Eligible patients were chemotherapy-naive and had advanced/recurrent non-squamous NSCLC. The patients received 4 cycles of docetaxel (60 mg/m), cisplatin (80 mg/m), and bevacizumab (15 mg/kg) once every 3 weeks, followed by bevacizumab as maintenance therapy, every 3 weeks until disease progression or attainment of unacceptable toxicity level. The primary endpoint was objective response rate (ORR). The numbers of circulating endothelial cells (CEC) were also estimated on days 1 and 8 of the first cycle for the exploratory analysis of efficacy prediction.

Results: A total of 47 patients were enrolled from October 2010 to April 2012. Bevacizumab as maintenance therapy was administered to 41 patients (87.2%), and the median number of total treatment cycles was 9 (range: 1-36). ORR, median progression-free survival (PFS), and median overall survival of the patients were 74.5%, 9.0 months, and 27.5 months, respectively. The most common grade 3/4 adverse event was neutropenia (95.7%), followed by leukopenia (59.6%) and hypertension (46.8%). PFS was longer in patients with ≥10 count increase in CECs than that in patients with < 10 count increase in CECs (respective median PFS of 11.0 months versus 6.90 months) although the difference was not statistically significant (p = 0.074).

Conclusions: A combination therapy of bevacizumab, cisplatin, and docetaxel, followed by bevacizumab as maintenance was highly effective in patients with non-squamous NSCLC despite the high incidence of grade 3/4 neutropenia. The increase in CEC count between days 1 and 8 may predict the efficacy of our bevacizumab-contained treatment regimen.

Trial Registration: UMIN Clinical Trial Registry; UMIN000004368 . Registered date; October 11, 2010 (Retrospectively registered).