Evaluating the addition of bevacizumab to endocrine therapy as first-line treatment for hormone receptor-positive metastatic breast cancer: a pooled analysis from the LEA (GEICAM/2006-11_GBG51) and CALGB 40503 (Alliance) trials

BACKGROUND

Randomised trials comparing the efficacy of standard endocrine therapy (ET) versus experimental ET + bevacizumab (Bev) in 1st line hormone receptor-positive patients with metastatic breast cancer have thus far shown conflicting results.

PATIENTS AND METHODS

We pooled data from two similar phase III randomised trials of ET ± Bev (LEA and Cancer and Leukemia Group B 40503) to increase precision in estimating treatment effect. Primary end-point was progression-free survival (PFS). Secondary end-points were overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety. Exploratory analyses were performed within subgroups defined by patients with recurrent disease, de novo disease, prior endocrine sensitivity or resistance and reported grades III-IV hypertension and proteinuria.

RESULTS

The pooled sample consisted of 749 patients randomised to ET or ET + Bev. Median PFS was 14.3 months for ET versus 19 months for ET + Bev (unadjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.66-0.91; p < 0.01). ORR and CBR with ET and ET + Bev were 40 versus 61% (p < 0.01) and 64 versus 77% (p < 0.01), respectively. There was no difference in OS (HR 0.96; 95% CI 0.77-1.18; p = 0.68). PFS was superior for ET + Bev for endocrine-sensitive patients (HR 0.68; 95% CI 0.53-0.89; p = 0.004). Grade III-IV hypertension (2.2 versus 20.1%), proteinuria (0 versus 9.3%), cardiovascular (0.5 versus 4.2%) and liver events (0 versus 2.9%) were significantly higher for ET + Bev (all p < 0.01). Hypertension and proteinuria were not predictors of efficacy (interaction test p = 0.33).

CONCLUSION

The addition of Bev to ET increased PFS overall and in endocrine-sensitive patients but not OS at the expense of significant additional toxicity.

TRIALS REGISTRATION

ClinicalTrial.Gov NCT00545077 and NCT00601900.

Abstract P3-14-15: Nabrax: Neoadjuvant therapy of breast cancer with weekly nab-paclitaxel: Final safety of GEICAM 2011-02

Aims: nab-paclitaxel is an innovative chemotherapy that consists of nano-particles of human serum albumin bound paclitaxel. It exploits the role of albumin as the natural carrier of hydrophobic molecules in human to increase paclitaxel delivery to tumor cells. Weekly nab-paclitaxel showed a superior efficacy compared to every 3-weeks docetaxel in a randomized phase II study in metastatic breast cancer (Gradishar JCO 2009, Clin. Breast Cancer 2012). This single arm phase II trial has been designed to evaluate the activity and safety of weekly nab-paclitaxel as neoadjuvant treatment of early stage breast cancer patients with positive estrogen receptors and negative HER2.

Methods: Stage II-III patients were included and treated with nab-paclitaxel weekly at a dose of 150 mg/m2 on days 1, 8 and 15 every 4 weeks for 4 cycles. Following chemotherapy, patients undergo surgery and adjuvant therapy (with radiation, chemo and endocrine therapy) under the investigator criteria. The primary objective is to determine the residual cancer burden class III as measured by the Symmans criteria (JCO 25:4422,2007). Secondary objectives include pathological complete response, overall response, invasive disease free survival, safety and potential correlative biomarkers.

Results: Eighty-three patients have been recruited in the study in 13 Spanish institutions. Here we report safety data from 77 patients. Median age was 48 years, 62% were postmenopausal and 94% had ECOG PS 0; most patients were stage II (23% IIa and 36% IIb). A total of 259 cycles have been administered to date; 47 patients completed 4 cycles as planned, 5 patients discontinued treatment early (due to grade 2-3 sensory neuropathy in 4 patients), the remaining patients are still under treatment. The treatment was delayed in 8.1% of patients; nab-paclitaxel doses were omitted and reduced in 3.9% and 9.7% of cycles respectively, for a relative dose intensity of nab-paclitaxel of 97.3%. The most frequent reasons for dose modifications were neutropenia (5.4%) and neuropathy (2.7%). The main grade 2/3 adverse events are described in table 1.

Table 1Related adverse events.Per patient (N = 74)Per Cycle (N = 259)NCI-CTCAE vs 4.0. (&gt;5% grade 2-4)Grade 2, N (%)Grade 3, N (%)Grade 2, N (%)Grade 3, N (%)Leukopenia6 (8.1)1 (1.4)11 (4.2)1 (0.4)Neutropenia17(23)7 (9.5)30 (11.6)9 (3.5)Alopecia47(63.5)—121 (46.7)—Fatigue11 (14.9)2 (2.7)17 (6.6)2 (0.8)Neuropathy: Sensory17 (23)2 (2.7)25(9.6)5 (1.9)Musculoskeletal Pain11 (14.9)0 (0)13 (5.0)0 (0)

Conclusions: Neoadjuvant therapy with weekly nab-paclitaxel at dose of 150 mg/m2 on days 1, 8 and 15 every 4 weeks was well tolerated. Final safety data for the entire treated patients will be mature and presented at the meeting.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-15.

The effect of obesity on prognosis in operable breast cancer patients treated with adjuvant anthracyclines and taxanes according to pathologic subtypes

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Background: According to observational studies, obesity is an unfavourable prognostic factor in breast cancer (BC), regardless of menopausal status and treatment received. Information collected in clinical trials should confirm this effect and serves to test its homogeneity by pathologic subtype. Methods: We retrospectively analysed 5,683 operable BC patients enrolled in four randomized clinical trials (GEICAM/9906, 9805, 2003–02, and BCIRG 001) evaluating adjuvant anthracyclines and taxanes. Our primary aim was to assess the prognostic effect of body mass index (BMI) on disease recurrence, breast cancer mortality (BCM), and overall mortality (OM). A secondary aim was to detect differences by BC subtypes (ER/PR-positive/HER2-negative, HER2-positive, triple-negative). Cox models were fitted for each end-point, adjusted by potential confounders. Results: Analyses adjusting for age, tumor size, nodal status, menopausal status, surgery, grade, hormone receptor and HER2 status, chemotherapy regimen, and undertreatment showed that obese patients (BMI 30.0–34.9) had similar prognoses to that of patients with a BMI<25 (reference group) in terms of recurrence (HR 1.08 [95% CI 0.9–1.3]; p=0.41), BCM (HR 1.02 [0.81–1.29]; p=0.85), and OM (HR 0.97 [0.78–1.19]; p=0.747). Patients with severe obesity (BMI≥35) had a significantly increased risk of recurrence (HR 1.26 [1.00–1.59]; p=0.05), BCM (HR 1.32 [1.00–1.74]; p=0.05), and OM (HR 1.35 [1.06–1.71]; p=0.02) compared to our reference group (Table). The prognostic effect of severe obesity did not vary by subtype. Conclusions: Severely obese patients treated with anthracyclines and taxanes present a worse prognosis regarding recurrence, BCM, and OM than patients with a BMI<25. The magnitude of the harmful effect of BMI was similar across subtypes. [Table: see text]

Pegylated liposomal doxorubicin in combination with cyclophosphamide and trastuzumab in HER2-positive metastatic breast cancer patients: efficacy and cardiac safety from the GEICAM/2004-05 study

BACKGROUND

In order to determine the feasibility of substituting pegylated liposomal doxorubicin (PLD) for doxorubicin in combination with cyclophosphamide and trastuzumab as adjuvant therapy, we conducted a phase II study of the combination as first-line therapy in human epidermal growth factor receptor 2 (HER2) overexpressing metastatic breast cancer (MBC).

METHODS

PLD 50 mg/m(2) and cyclophosphamide 600 mg/m(2) were administered every 4 weeks for six cycles; trastuzumab (4 mg/kg loading dose, then 2 mg/kg) was administered weekly for 24 weeks. The primary end point was objective response rate (ORR), and the secondary end points included time to progression (TTP), overall survival (OS), and safety.

RESULTS

Among the 48 evaluable patients, ORR was 68.8% [95% confidence interval (CI) 55.69% to 81.91%], with 6 patients (12.5%) achieving a complete response and 27 (56.2%) a partial response. The median TTP was 12 months (95% CI 9-15.1 months), and the median OS was 34.2 months (95% CI 27.2-41.2 months). Febrile neutropenia was seen in three patients, grade 3 hand-foot syndrome in 29.2% of patients, and grade 3-4 mucositis in 22.9% of patients. Symptomatic congestive heart failure was not observed, and 16.7% of patients experienced grade 2 asymptomatic left ventricular systolic dysfunction.

CONCLUSION

The combination of PLD-cyclophosphamide-concurrent trastuzumab is a feasible, safe, and effective first-line regimen for HER2-overexpressing MBC.