Second-line bevacizumab-containing therapy in patients with triple-negative breast cancer: subgroup analysis of the RIBBON-2 trial.

Patients with metastatic triple-negative breast cancer (TNBC) typically have a poor prognosis and limited treatment options. To determine the impact of combining bevacizumab with second-line chemotherapy in patients with metastatic TNBC, we performed an exploratory subgroup analysis of the randomized phase 3 RIBBON-2 trial. RIBBON-2 enrolled patients with metastatic breast cancer that had progressed on first-line non-bevacizumab-containing chemotherapy. After selection of chemotherapy (taxane, gemcitabine, capecitabine, or vinorelbine), patients were randomized 2:1 to receive chemotherapy with either bevacizumab (10 mg/kg every 2 weeks or 15 mg/kg every 3 weeks) or placebo. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), and safety. Of 684 patients treated in RIBBON-2, 159 (23%) had TNBC. Baseline characteristics were reasonably balanced in the two treatment groups. The majority received taxane chemotherapy. The hazard ratio (HR) for PFS was 0.494 [95% confidence interval (CI) 0.33-0.74; P = 0.0006]. Median PFS was 6.0 months with bevacizumab-chemotherapy versus 2.7 months with chemotherapy alone. Median OS was 17.9 versus 12.6 months, respectively (HR 0.624, 95% CI 0.39-1.007; P = 0.0534). ORR was 41 versus 18%, respectively (P = 0.0078). The safety profile was consistent with the overall study population and previous phase 3 trials of bevacizumab. Patients with metastatic TNBC derived significant PFS and response benefits from the combination of bevacizumab with second-line chemotherapy. Despite the small sample size and immature data, there was a trend toward improved OS.

First-line bevacizumab-containing therapy for triple-negative breast cancer: analysis of 585 patients treated in the ATHENA study.

BACKGROUND: The prognosis for patients with triple-negative breast cancer (TNBC) is poor and treatment options are limited. Bevacizumab improves the efficacy of standard first-line therapy in locally recurrent/metastatic breast cancer (LR/mBC). The benefit of bevacizumab seen in patients with TNBC appears similar to that observed in the overall population. We conducted an exploratory analysis of patients with TNBC treated in the single-arm routine oncology practice ATHENA study. METHODS: Patients with previously untreated LR/mBC received standard first-line chemotherapy combined with bevacizumab (10 mg/kg every 2 weeks or 15 mg/kg every 3 weeks, until progression, unacceptable toxicity, or patient/physician decision). RESULTS: Of 2,264 patients treated in ATHENA, 585 (26%) had TNBC. Most patients received single-agent taxane with bevacizumab. In the TNBC subgroup, the overall response rate was 49%, including complete responses in 10%; only 16% had primary resistant disease. Median time to progression was 7.2 months (95% CI 6.6-7.8) and median overall survival was 18.3 months (95% CI 16.4-19.7). The 1-year overall survival rate was 60%. The safety profile in TNBC was consistent with results in the overall population. CONCLUSION: This exploratory subgroup analysis suggests that first-line chemotherapy in combination with bevacizumab is an active regimen in patients with metastatic TNBC.

Final overall survival results and effect of prolonged (≥ 1 year) first-line bevacizumab-containing therapy for metastatic breast cancer in the ATHENA trial.

The ATHENA study expanded on the safety and efficacy data derived from first-line trials of bevacizumab combined with standard chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC). In ATHENA, 2,264 patients received first-line bevacizumab-containing therapy in routine oncology practice. Overall survival (OS) data are now mature; additional analyses from this large data set can provide insights into treatment duration and the effect of prolonged bevacizumab exposure, where data are currently limited. Patients with HER2-negative LR/mBC received first-line bevacizumab with standard chemotherapy until disease progression, unacceptable toxicity, or physician/patient decision. We performed subgroup analyses on data from patients treated for ≥12 months and those who continued single-agent bevacizumab after stopping chemotherapy. After median follow-up of 20.1 months, median OS was 25.2 months (95% confidence interval [CI] 24.0-26.3 months) in the entire population. Median OS was 30.0 months (95% CI 28.5-32.7 months) in 1,205 patients who continued bevacizumab after discontinuation of chemotherapy and 18.4 months (95% CI 17.2-19.7 months) in 1,058 patients who discontinued bevacizumab before or at the same time as stopping chemotherapy. Bevacizumab treatment was continued for ≥12 months in 473 patients (21%). In most, bevacizumab was administered as monotherapy for extended periods after stopping chemotherapy. In the subgroup of patients treated for ≥12 months, the median time to onset of grade 3-5 adverse events was 5.0 months. There was no evidence that first onset of adverse events of special interest, except for proteinuria, was more common in later than earlier cycles. No relationship was detected between development of hypertension and OS. Findings from these analyses suggest that patients with LR/mBC can receive bevacizumab for prolonged periods without major toxicity or progression of disease. In the absence of progression, continuation of single-agent bevacizumab appears to be a reasonable approach, with minimal toxicity and the possibility of long-term disease control.

Efficacy and safety of bevacizumab in combination with docetaxel for the first-line treatment of elderly patients with locally recurrent or metastatic breast cancer: results from AVADO.

BACKGROUND: Oncologic treatment in elderly patients is challenging, due to comorbidities, often impaired organ function, limited clinical trial evidence, inadequate guidelines and no consistent 'elderly' definition. We report exploratory sub-analyses of safety and efficacy in elderly patients, defined as ⩾ 65years old, in AVastin And DOcetaxel (AVADO) receiving first-line bevacizumab plus docetaxel for metastatic breast cancer (mBC). PATIENTS AND METHODS: Patients with HER2-negative, locally recurrent or mBC were randomised to 3-weekly docetaxel (100mg/m(2)) with placebo, bevacizumab 7.5mg/kg or bevacizumab 15 mg/kg, for 9 cycles or until disease progression or unacceptable toxicity. Patients had no prior chemotherapy for mBC. RESULTS: Progression-free survival (PFS) was increased with bevacizumab in the elderly subpopulation (n=127), the effect being greater with higher dose (hazard ratio=0.63 [95% confidence interval (CI) 0.383-1.032] versus 0.76 [95% CI: 0.46-1.262], respectively). PFS was numerically similar in the elderly and overall populations, but the former failed to achieve statistical significance. Overall response rates for docetaxel plus placebo, bevacizumab 7.5mg/kg and 15 mg/kg were 44.7%, 36.6% and 50.0%, respectively. Effects on survival were not statistically significant. Bevacizumab was well tolerated in elderly patients, the most common adverse effects were neutropenia and febrile neutropenia; there was no excess of grade⩾3 cardiovascular events. There was no clear correlation between baseline hypertension and its development during study treatment. CONCLUSIONS: In this exploratory sub-analysis in AVADO, bevacizumab plus docetaxel showed efficacy in elderly patients similar to the overall study population. There were no unexpected safety signals in patients aged 65 years or older.