Efficacy and Safety of Pertuzumab and Trastuzumab Administered in a Single Infusion Bag, Followed by Vinorelbine: VELVET Cohort 2 Final Results.

BACKGROUND: VELVET Cohort 1 demonstrated the applicability of pertuzumab, trastuzumab, and vinorelbine as an alternative first-line treatment regimen for patients with HER2-positive locally advanced or metastatic breast cancer (MBC) who cannot receive docetaxel. Co-infusion of pertuzumab and trastuzumab may reduce clinic time and medical resource utilization. We report results from Cohort 2, in which pertuzumab and trastuzumab were co-infused, followed by vinorelbine. PATIENTS AND METHODS: During cycle 1, patients with HER2-positive locally advanced or MBC received loading doses of pertuzumab (840 mg) and trastuzumab (8 mg/kg) on consecutive days, followed by vinorelbine (25 mg/m2) on days two and nine. From cycle 2 onwards, patients received a co-infusion of pertuzumab (420 mg) and trastuzumab (6 mg/kg) on day one, followed by vinorelbine (30-35 mg/m2) on days one and eight (or days two and nine). The primary endpoint was objective response rate (ORR) in patients with measurable disease. Secondary endpoints included progression-free survival (PFS) and safety. RESULTS: Cohort 2 enrolled 107 patients. The ORR was 63.7% (95% confidence interval [CI] 53.0-73.6) in patients with measurable disease (91/107; 85.0%). Median PFS was 11.5 months (95% CI 10.3-15.8). The most common adverse events [AEs] were diarrhea (57.9%), neutropenia (57.0%), and nausea (41.1%). Grade ≥3 AEs occurred in 85 patients (79.4%) and serious AEs in 44 patients (41.1%). Eighteen patients (16.8%) had AEs suggestive of congestive heart failure. CONCLUSION: These results support the feasibility of pertuzumab and trastuzumab co-infusion from a safety perspective and support Cohort 1 conclusions that vinorelbine offers an alternative chemotherapy companion for pertuzumab and trastuzumab. The Oncologist 2017;22:1160-1168 IMPLICATIONS FOR PRACTICE: Combined treatment with pertuzumab, trastuzumab, and docetaxel is the standard of care for first-line HER2-positive metastatic breast cancer. However, some patients cannot, or choose not to, receive docetaxel. VELVET Cohort 2 results support the results from Cohort 1 that suggest that pertuzumab plus trastuzumab and vinorelbine is a suitable alternative for these patients. In addition to this, results from Cohort 2 support the feasibility of administering pertuzumab and trastuzumab together in a single infusion bag, which has the potential to offer greater patient convenience and reduce active health care professional time and medical resource utilization compared with administering them separately.

PAM50 proliferation score as a predictor of weekly paclitaxel benefit in breast cancer.

To identify a group of patients who might benefit from the addition of weekly paclitaxel to conventional anthracycline-containing chemotherapy as adjuvant therapy of node-positive operable breast cancer. The predictive value of PAM50 subtypes and the 11-gene proliferation score contained within the PAM50 assay were evaluated in 820 patients from the GEICAM/9906 randomized phase III trial comparing adjuvant FEC to FEC followed by weekly paclitaxel (FEC-P). Multivariable Cox regression analyses of the secondary endpoint of overall survival (OS) were performed to determine the significance of the interaction between treatment and the (1) PAM50 subtypes, (2) PAM50 proliferation score, and (3) clinical and pathological variables. Similar OS analyses were performed in 222 patients treated with weekly paclitaxel versus paclitaxel every 3 weeks in the CALGB/9342 and 9840 metastatic clinical trials. In GEICAM/9906, with a median follow up of 8.7 years, OS of the FEC-P arm was significantly superior compared to the FEC arm (unadjusted HR = 0.693, p = 0.013). A benefit from paclitaxel was only observed in the group of patients with a low PAM50 proliferation score (unadjusted HR = 0.23, p < 0.001; and interaction test, p = 0.006). No significant interactions between treatment and the PAM50 subtypes or the various clinical-pathological variables, including Ki-67 and histologic grade, were identified. Finally, similar OS results were obtained in the CALGB data set, although the interaction test did not reach statistical significance (p = 0.109). The PAM50 proliferation score identifies a subset of patients with a low proliferation status that may derive a larger benefit from weekly paclitaxel.

Adjuvant docetaxel for high-risk, node-negative breast cancer.

BACKGROUND: A regimen of docetaxel, doxorubicin, and cyclophosphamide (TAC) is superior to a regimen of fluorouracil, doxorubicin, and cyclophosphamide (FAC) when used as adjuvant therapy in women with node-positive breast cancer. The value of taxanes in the treatment of node-negative disease has not been determined. METHODS: We randomly assigned 1060 women with axillary-node-negative breast cancer and at least one high-risk factor for recurrence (according to the 1998 St. Gallen criteria) to treatment with TAC or FAC every 3 weeks for six cycles after surgery. The primary end point was disease-free survival after at least 5 years of follow-up. Secondary end points included overall survival and toxicity. RESULTS: At a median follow-up of 77 months, the proportion of patients alive and disease-free was higher among the 539 women in the TAC group (87.8%) than among the 521 women in the FAC group (81.8%), representing a 32% reduction in the risk of recurrence with TAC (hazard ratio, 0.68; 95% confidence interval [CI], 0.49 to 0.93; P=0.01 by the log-rank test). This benefit was consistent, regardless of hormone-receptor status, menopausal status, or number of high-risk factors. The difference in survival rates (TAC, 95.2%; FAC, 93.5%) was not significant (hazard ratio, 0.76; 95% CI, 0.45 to 1.26); however, the number of events was small (TAC, 26; FAC, 34). Rates of grade 3 or 4 adverse events were 28.2% with TAC and 17.0% with FAC (P<0.001). Toxicity associated with TAC was diminished when primary prophylaxis with granulocyte colony-stimulating factor was provided. CONCLUSIONS: As compared with adjuvant FAC, adjuvant TAC improved the rate of disease-free survival among women with high-risk, node-negative breast cancer. (Funded by GEICAM and Sanofi-Aventis; ClinicalTrials.gov number, NCT00121992.).

Blockade of epidermal growth factor receptors chemosensitizes breast cancer cells through up-regulation of Bnip3L.

Epidermal growth factor receptor-1 (EGFR) and EGFR-2 (HER2) have become major targets for cancer treatment. Blocking antibodies and small-molecule inhibitors are being used to silence the activity of these receptors in different tumors with varying efficacy. Thus, a better knowledge on the signaling pathways activated by EGFR and HER2 may help unravel novel therapeutic targets and molecular markers of response. Here, we show that treatment of breast cancer cell lines with blocking antibodies against EGFR (cetuximab) or HER2 (trastuzumab) promotes the specific induction of proapoptotic Bnip3L and chemosensitization. Moreover, we found that the Bnip3L gene is transcriptionally activated by FoxO3a. Trastuzumab-mediated induction of Bnip3L and nuclear translocation of FoxO3a was also shown in pleural effusion cells from a breast cancer patient. Transfection of breast cancer cells with constitutively active FoxO3a or with Bnip3L promotes sensitization to chemotherapy-induced apoptosis. On the contrary, blockade of Bnip3L expression by a small interfering RNA strategy significantly diminished the chemosensitizing effect of cetuximab. We found also an inverse correlation between EGFR and Bnip3L expression in surgical specimens from patients with breast cancer. Therefore, blockading EGFR or HER2 specifically up-regulates Bnip3L, which is required for chemosensitization of breast cancer cells. This novel pathway provides also the rationale for therapeutic strategies aimed to induce the expression of Bnip3L.

Vinorelbine as a 96-hour continuous infusion in heavily pretreated patients with metastatic breast cancer: a cooperative study by the GEICAM group.

The efficacy of vinorelbine given as a continuous infusion was evaluated in 47 patients with breast cancer who had received previous treatment with first-line, second-line, and third-line chemotherapy including taxanes and/or anthracyclines. For inclusion into the study, patients were required to have histology-proven bi-dimensionally measurable disease. The treatment schedule was a bolus injection of vinorelbine 8 mg/m(2) administered over 5-10 minutes on day 1 followed by vinorelbine 8 mg/m(2) continuous infusion on days 1-4, every 21 days for 6 cycles. On an intent-to-treat basis, a 2% complete response rate and a 17% partial response rate were observed. The median time to progression was 2.4 months (95% CI, 1.83-2.97). Median survival was 7.73 months (95% CI, 4.48-10.98; range, 0.33-55.0 months). Major toxicities included febrile neutropenia in 40 cycles (24%) affecting 24 patients (51%) and 1 toxic death. Other nonhematologic toxicities included stomatitis (13%) and asthenia (13%). We conclude that this treatment shows considerable therapeutic activity, albeit at considerable toxicity costs, even in patients who have had multiple lines of prior chemotherapy. However, the results do not indicate clear advantages compared to the conventional weekly scheme of administration.

Resistance to chemotherapy via Stat3-dependent overexpression of Bcl-2 in metastatic breast cancer cells.

Disruption of apoptosis may allow metastatic cell survival and confer resistance to chemotherapeutic drugs. We have analysed the molecular pathways that activate these survival genes in specific sites of metastasis. Estrogen receptor-negative breast cancer cell line MDA-MB435 and two metastatic sublines derived from lung (435L) and brain (435B) were analysed for the expression of members of the Bcl-2 family of apoptosis regulators. The levels of Bcl-2 were higher in the metastatic sublines than in parental cells, which correlated with the activation of Stat3, but not with the expression and/or activation of known bcl-2 transcription factors (CREB and WT1). In the brain subline, both expression of Bcl-2 and Stat3 activation were induced by epidermal growth factor and abrogated after treatment with kinase inhibitors specific for epidermal growth factor receptor or Jak2. Furthermore, transfection of 435B with a dominant-negative Stat3 markedly reduced the expression of Bcl-2 protein, whereas transient expression of a constitutively active Stat3 increased Bcl-2 in parental 435 cells. In addition, blockade of Stat3 activation by treatment with epidermal growth factor receptor and Jak2 kinase inhibitors or transfection with a dominant negative Stat3, sensitizes 435B cells to chemotherapy-induced apoptosis. Our data suggest that an increased activation of the Stat3-Bcl-2 pathway in estrogen receptor-negative metastatic breast cancer cell lines confer a survival advantage to these cells and contribute to their chemoresistance.