Combination of everolimus with trastuzumab plus paclitaxel as first-line treatment for patients with HER2-positive advanced breast cancer (BOLERO-1): a phase 3, randomised, double-blind, multicentre trial.

BACKGROUND: mTOR inhibition reverses trastuzumab resistance via the hyperactivated PIK/AKT/mTOR pathway due to PTEN loss, by sensitising PTEN-deficient tumours to trastuzumab. The BOLERO-1 study assessed the efficacy and safety of adding everolimus to trastuzumab and paclitaxel as first-line treatment for patients with HER2-positive advanced breast cancer. METHODS: In this phase 3, randomised, double-blind trial, patients were enrolled across 141 sites in 28 countries. Eligible patients were aged 18 years or older, with locally assessed HER2-positive advanced breast cancer, with Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, who had not received previous trastuzumab or chemotherapy for advanced breast cancer within 12 months of randomisation, had measurable disease as per Response Evaluation Criteria in Solid Tumors (RECIST) or bone lesions in the absence of measurable disease, without previous systemic treatment for advanced disease except endocrine therapy. Patients were randomly assigned (2:1) with an interactive voice and web response system to receive either 10 mg everolimus once a day orally or placebo plus weekly trastuzumab intravenously at 4 mg/kg loading dose on day 1 with subsequent weekly doses of 2 mg/kg of each 4 week cycle plus paclitaxel intravenously at a dose of 80 mg/m(2) on days 1, 8, and 15 of each 4 week cycle. Randomisation was stratified according to previous use of trastuzumab and visceral metastasis. Patients and investigators were masked to the assigned treatments. Identity of experimental treatments was concealed by use of everolimus and placebo that were identical in packaging, labelling, appearance, and administration schedule. The two primary objectives were investigator-assessed progression-free survival in the full study population and in the subset of patients with hormone receptor-negative breast cancer at baseline; the latter was added during the course of the study, before unmasking based on new clinical and biological findings from other studies. All efficacy analyses were based on the intention-to-treat population. Enrolment for this trial is closed and results of the final progression-free survival analyses are presented here. This trial is registered with ClinicalTrials.gov, number NCT00876395. FINDINGS: Between Sept 10, 2009, and Dec 16, 2012, 719 patients were randomly assigned to receive everolimus (n=480) or placebo (n=239). Median follow-up was 41·3 months (IQR 35·4-46·6). In the full population, median progression-free survival was 14·95 months (95% CI 14·55-17·91) with everolimus versus 14·49 months (12·29-17·08) with placebo (hazard ratio 0·89, 95% CI 0·73-1·08; p=0·1166). In the HR-negative subpopulation (n=311), median progression-free survival with everolimus was 20·27 months (95% CI 14·95-24·08) versus 13·08 months (10·05-16·56) with placebo (hazard ratio 0·66, 95% CI 0·48-0·91; p=0·0049); however, the protocol-specified significance threshold (p=0·0044) was not crossed. The most common adverse events with everolimus were stomatitis (314 [67%] of 472 patients in the everolimus group vs 77 [32%] of 238 patients in the placebo group), diarrhoea (267 [57%] vs 111 [47%] patients), and alopecia (221 [47%] vs 125 [53%]). The most frequently reported grade 3 or 4 adverse events in the everolimus group versus the placebo group were neutropenia (117 [25%] vs 35 [15%]), stomatitis (59 [13%] vs three [1%]), anaemia (46 [10%] vs six [3%]) and diarrhoea (43 [9%] vs 10 [4%]) On-treatment adverse event-related deaths were reported in 17 (4%) patients in the everolimus group and none in the placebo group. INTERPRETATION: Although progression-free survival was not significantly different between groups in the full analysis population, the 7·2 months prolongation we noted with the addition of everolimus in the HR-negative, HER2-positive population warrants further investigation, even if it did not meet prespecified criteria for significance. The safety profile was generally consistent with what was previously reported in BOLERO-3. Proactive monitoring and early management of adverse events in patients given everolimus and chemotherapy is crucial. FUNDING: Novartis Pharmaceuticals.

Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): a randomised, open-label, multicentre, phase 3 trial.

BACKGROUND: The anti-HER2 monoclonal antibody trastuzumab and the tyrosine kinase inhibitor lapatinib have complementary mechanisms of action and synergistic antitumour activity in models of HER2-overexpressing breast cancer. We argue that the two anti-HER2 agents given together would be better than single-agent therapy. METHODS: In this parallel groups, randomised, open-label, phase 3 study undertaken between Jan 5, 2008, and May 27, 2010, women from 23 countries with HER2-positive primary breast cancer with tumours greater than 2 cm in diameter were randomly assigned to oral lapatinib (1500 mg), intravenous trastuzumab (loading dose 4 mg/kg [DOSAGE ERROR CORRECTED], subsequent doses 2 mg/kg), or lapatinib (1000 mg) plus trastuzumab. Treatment allocation was by stratified, permuted blocks randomisation, with four stratification factors. Anti-HER2 therapy alone was given for the first 6 weeks; weekly paclitaxel (80 mg/m(2)) was then added to the regimen for a further 12 weeks, before definitive surgery was undertaken. After surgery, patients received adjuvant chemotherapy followed by the same targeted therapy as in the neoadjuvant phase to 52 weeks. The primary endpoint was the rate of pathological complete response (pCR), analysed by intention to treat. This trial is registered with ClinicalTrials.gov, NCT00553358. FINDINGS: 154 patients received lapatinib, 149 trastuzumab, and 152 the combination. pCR rate was significantly higher in the group given lapatinib and trastuzumab (78 of 152 patients [51·3%; 95% CI 43·1-59·5]) than in the group given trastuzumab alone (44 of 149 patients [29·5%; 22·4-37·5]; difference 21·1%, 9·1-34·2, p=0·0001). We recorded no significant difference in pCR between the lapatinib (38 of 154 patients [24·7%, 18·1-32·3]) and the trastuzumab (difference -4·8%, -17·6 to 8·2, p=0·34) groups. No major cardiac dysfunctions occurred. Frequency of grade 3 diarrhoea was higher with lapatinib (36 patients [23·4%]) and lapatinib plus trastuzumab (32 [21·1%]) than with trastuzumab (three [2·0%]). Similarly, grade 3 liver-enzyme alterations were more frequent with lapatinib (27 [17·5%]) and lapatinib plus trastuzumab (15 [9·9%]) than with trastuzumab (11 [7·4%]). INTERPRETATION: Dual inhibition of HER2 might be a valid approach to treatment of HER2-positive breast cancer in the neoadjuvant setting. FUNDING: GlaxoSmithKline.

Phase II study of docetaxel, capecitabine, and cisplatin as neoadjuvant chemotherapy for locally advanced breast cancer.

PURPOSE: Docetaxel, capecitabine, and cisplatin are effective chemotherapeutic agents for breast cancer with significant synergistic cytotoxicity demonstrated by in vitro studies. The purpose of this study was to assess the efficacy of a combination of docetaxel, capecitabine, and cisplatin (TXP) in patients diagnosed with locally advanced breast cancer (LABC). METHODS: Patients (n = 42) with chemotherapy-naïve LABC (stage IIIa or IIIb) were enrolled. The chemotherapeutic regimen consisted of 4-6 cycles of intravenous docetaxel (60 mg/m(2)) and cisplatin (50 mg/m(2)) on day 1, plus oral capecitabine (1,800 mg/m(2)/day) on day 1-14, repeated every 3 weeks. Upon completion of therapy, the primary tumor was resected when not contraindicated. RESULTS: Median patient age was 48.5 years (range 31-66 years). Median tumor size was 6.8 cm (range 2.7-15 cm), 29 patients were node-positive, and 12 patients were hormone receptor positive. A total of 216 cycles (median 5; range 3-6 cycles) were administered without prophylactic G-CSF. The predominant toxicities were grade 3/4 neutropenia (30%/28%) and no grade 3/4 thrombocytopenia, febrile neutropenia, or grade 4 non-hematological toxicities were observed. Grade 3 non-hematological toxicities included hand-foot syndrome (5.6%) and vomiting (0.5%). The overall clinical response rate was 97.6% (41/42). Six of the 42 patients (14.3%) achieved a complete pathological response. Of 22 patients who completed 6 cycles of combination treatment, the complete pathological response was 27.3% (6/22). CONCLUSIONS: A combination of TXP can be administered safely without prophylactic G-CSF, and appears to be an effective neoadjuvant regimen in patients with LABC.

ErbB2-mediated Src and signal transducer and activator of transcription 3 activation leads to transcriptional up-regulation of p21Cip1 and chemoresistance in breast cancer cells.

Overexpression of the ErbB2 receptor tyrosine kinase is prevalent in approximately 30% of human breast cancers and confers Taxol resistance. Our previous work has shown that ErbB2 inhibits Taxol-induced apoptosis in breast cancer cells by transcriptionally up-regulating p21(Cip1). However, the mechanism of ErbB2-mediated p21(Cip1) up-regulation is unclear. Here, we show that ErbB2 up-regulates p21(Cip1) transcription through increased Src activity in ErbB2-overexpressing cells. Src activation further activated signal transducer and activator of transcription 3 (STAT3) that recognizes a SIE binding site on the p21(Cip1) promoter required for ErbB2-mediated p21(Cip1) transcriptional up-regulation. Both Src and STAT3 inhibitors restored Taxol sensitivity in resistant ErbB2-overexpressing breast cancer cells. Our data suggest that ErbB2 overexpression can activate STAT3 through Src leading to transcriptional up-regulation of p21(Cip1) that confers Taxol resistance of breast cancer cells. Our study suggests a potential clinical application of Src and STAT3 inhibitors in Taxol sensitization of ErbB2-overexpressing breast cancers.