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Background: CLEOPATRA was a phase 3 study comparing the efficacy and safety of pertuzumab, trastuzumab, and docetaxel with placebo, trastuzumab, and docetaxel in patients with HER2-positive metastatic breast cancer. In the primary analysis and subsequent reports, progression-free and overall survival were significantly improved in the pertuzumab group compared with the placebo group. Here, we report the end-of-study analysis of CLEOPATRA., Methods: This was a double-blind, randomised, placebo-controlled, phase 3 trial that was done at 204 centres in 25 countries. Eligible patients were 18 years or older, had HER2-positive, metastatic breast cancer, had not received previous chemotherapy or biological treatment for their metastatic disease, and had an Eastern Cooperative Oncology Group performance status of 0 or 1. All study drugs were given intravenously, every 3 weeks. Patients were assigned to receive either pertuzumab or placebo at a loading dose of 840 mg, and 420 mg thereafter; plus trastuzumab at 8 mg/kg loading dose and 6 mg/kg thereafter; and docetaxel at 75 mg/m 2 , escalating to 100 mg/m 2 if tolerated. Pertuzumab or placebo and trastuzumab were given until disease progression; docetaxel was given for six cycles, or longer at the investigators' discretion. Randomisation (1:1) was done by use of an interactive voice-response system and was stratified by geographical region (Asia, Europe, North America, or South America) and previous treatment (previous adjuvant or neoadjuvant chemotherapy vs none). The primary endpoint was independent review facility-assessed progression-free survival, which has been reported previously. Since the confirmatory overall survival analysis had also occurred before this prespecified end-of-study analysis, analyses presented here are descriptive. Overall survival analyses were based on the intention-to-treat population with crossover patients analysed in the placebo group; analyses were not adjusted for crossover to the pertuzumab group and are likely to be conservative. Safety analyses were based on treatment received; crossover patients were counted in the placebo group up to the day before first pertuzumab dose. This trial is registered with ClinicalTrials.gov, number NCT00567190., Findings: Between Feb 12, 2008, and July 7, 2010, 1196 patients were assessed for eligibility, of whom 808 were enrolled and randomly assigned. 402 patients were assigned to receive docetaxel plus trastuzumab plus pertuzumab, and 406 patients were assigned to receive docetaxel plus trastuzumab plus placebo. Clinical cutoff for this analysis was Nov 23, 2018. Between July 2012 and clinical cutoff, 50 patients crossed from the placebo to the pertuzumab group. Median follow-up was 99·9 months in the pertuzumab group (IQR 92·9-106·4) and 98·7 months (90·9-105·7) in the placebo group. Median overall survival was 57·1 months (95% CI 50-72) in the pertuzumab group and 40·8 months (36-48) in the placebo group (hazard ratio 0·69, 95% CI 0·58-0·82); 8-year landmark overall survival rates were 37% (95% CI 31-42) in the pertuzumab group and 23% (19-28) in the placebo group. The most common grade 3-4 adverse event was neutropenia (200 [49%] of 408 patients in the pertuzumab group, 183 [46%] of 396 patients in the placebo group). Five (1%) of 408 patients in the pertuzumab group and six (2%) of 396 patients in the placebo group had treatment-related deaths. One new serious adverse event suggestive of congestive heart failure (pertuzumab group) and one new symptomatic left ventricular systolic dysfunction (post-crossover) occurred since the previous analysis., Interpretation: Our analysis shows that the previously observed improvements in overall survival with pertuzumab, trastuzumab, and docetaxel versus placebo, trastuzumab, and docetaxel were maintained after a median of more than 8 years of follow-up. The long-term safety and cardiac safety profiles of pertuzumab, trastuzumab, and docetaxel were maintained in the overall safety population and within crossover patients. HER2-targeted therapy has changed the natural history of HER2-positive metastatic breast cancer, with the dual blockade of pertuzumab and trastuzumab, with docetaxel, demonstrating an 8-year landmark overall survival rate of 37%., Funding: F Hoffmann-La Roche and Genentech., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Endocrine treatment is recommended by clinical guidelines as the preferred treatment option for premenopausal as well as postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer. In real-world clinical practice, however, a substantial number of patients are treated with chemotherapy. We aimed to compare the clinical antitumour activity and safety of palbociclib plus endocrine therapy with that of capecitabine chemotherapy in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer., Methods: This multicentre, open-label, randomised, phase 2 study was done in 14 academic institutions in South Korea. Premenopausal women aged 19 years or older with hormone receptor-positive, HER2-negative breast cancer that had relapsed or progressed during previous tamoxifen therapy and with an Eastern Cooperative Oncology Group performance status of 0-2 were included. One line of previous chemotherapy for metastatic breast cancer was allowed. Patients were randomly assigned, using a random permuted block design (with a block size of two), to receive palbociclib plus combination endocrine therapy (oral exemestane 25 mg per day for 28 days and oral palbociclib 125 mg per day for 21 days every 4 weeks plus leuprolide 3·75 mg subcutaneously every 4 weeks) or chemotherapy (oral capecitabine 1250 mg/m 2 twice daily for 2 weeks every 3 weeks). Randomisation was stratified by previous chemotherapy for metastatic breast cancer and visceral metastasis. The primary endpoint was progression-free survival. All analyses were done in a modified intention-to-treat population that excluded patients who did not receive study medication. This study is registered with ClinicalTrials.gov, NCT02592746, and is ongoing for follow-up of overall survival., Findings: Between June 15, 2016, and Dec 10, 2018, 189 patients were enrolled, of whom 184 were randomly assigned to the palbociclib plus endocrine therapy group (n=92) or the capecitabine group (n=92). Six patients in the capecitabine group withdrew from the study before drug administration; therefore, 92 patients in the palbociclib plus endocrine therapy group and 86 patients in the capecitabine group were included in the modified intention-to-treat analyses. 46 (50%) of 92 patients in the palbociclib plus endocrine therapy group and 45 (51%) of 92 in the capecitabine group were treatment naive for metastatic breast cancer. During a median follow-up of 17 months (IQR 9-22), median progression-free survival was 20·1 months (95% CI 14·2-21·8) in the palbociclib plus endocrine therapy group versus 14·4 months (12·1-17·0) in the capecitabine group (hazard ratio 0·659 [95% CI 0·437-0·994], one-sided log-rank p=0·0235). Treatment-related grade 3 or worse neutropenia was more common in the palbociclib plus endocrine therapy group than in the capecitabine group (69 [75%] of 92 vs 14 [16%] of 86 patients). 2 (2%) patients in the palbociclib plus endocrine therapy group and 15 (17%) patients in the capecitabine group had treatment-related serious adverse events. No treatment-related deaths occurred., Interpretation: Exemestane plus palbociclib with ovarian function suppression showed clinical benefit compared with capecitabine in terms of improved progression-free survival in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer. Palbociclib plus exemestane with ovarian suppression is an active treatment option in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer who have been pretreated with tamoxifen., Funding: Pfizer, Shinpoong, and Daewoong Korea and Takeda., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: In MONALEESA-2, ribociclib plus letrozole showed improved progression-free survival compared with letrozole alone as first-line treatment for postmenopausal patients with hormone receptor (HR)-positive, HER2-negative, advanced breast cancer. MONALEESA-7 aimed to assess the efficacy and safety of ribociclib plus endocrine therapy in premenopausal women with advanced, HR-positive breast cancer., Methods: This phase 3, randomised, double-blind, placebo-controlled trial was done at 188 centres in 30 countries. Eligible patients were premenopausal women aged 18-59 years who had histologically or cytologically confirmed HR-positive, HER2-negative, advanced breast cancer; an Eastern Cooperative Oncology Group performance status of 0 or 1; measurable disease as per Response Evaluation Criteria in Solid Tumors version 1.1 criteria, or at least one predominantly lytic bone lesion; and had not received previous treatment with cyclin-dependent kinases 4 and 6 inhibitors. Endocrine therapy and chemotherapy in the adjuvant or neoadjuvant setting was permitted, as was up to one line of chemotherapy for advanced disease. Patients were randomly assigned (1:1) via interactive response technology to receive oral ribociclib (600 mg/day on a 3-weeks-on, 1-week-off schedule) or matching placebo with either oral tamoxifen (20 mg daily) or a non-steroidal aromatase inhibitor (letrozole 2·5 mg or anastrozole 1 mg, both oral, daily), all with goserelin (3·6 mg administered subcutaneously on day 1 of every 28-day cycle). Patients and investigators were masked to treatment assignment. Efficacy analyses were by intention to treat, and safety was assessed in all patients who received at least one dose of any study treatment. The primary endpoint was investigator-assessed progression-free survival. MONALEESA-7 is registered with ClinicalTrials.gov, NCT02278120 and is ongoing, but no longer enrolling patients., Findings: Between Dec 17, 2014, and Aug 1, 2016, 672 patients were randomly assigned: 335 to the ribociclib group and 337 to the placebo group. Per investigator's assessment, median progression-free survival was 23·8 months (95% CI 19·2-not reached) in the ribociclib group compared with 13·0 months (11·0-16·4) in the placebo group (hazard ratio 0·55, 95% CI 0·44-0·69; p<0·0001). Grade 3 or 4 adverse events reported in more than 10% of patients in either group were neutropenia (203 [61%] of 335 patients in the ribociclib group and 12 [4%] of 337 in the placebo group) and leucopenia (48 [14%] and four [1%]). Serious adverse events occurred in 60 (18%) of 335 patients in the ribociclib group and 39 (12%) of 337 in the placebo group, of which 15 (4%) and six (2%), respectively, were attributed to the study regimen. 12 (4%) of 335 patients in the ribociclib group and ten (3%) of 337 in the placebo group discontinued treatment because of adverse events. No treatment-related deaths occurred. 11 deaths occurred (five [1%] in the ribociclib group and six [2%] in the placebo group) during or within 30 days after treatment, most of which were due to progression of the underlying breast cancer (three [1%] and six [2%]). The remaining two deaths in the ribociclib group were due to an intracranial haemorrhage in an anticoagulated patient, and a pre-existing wound haemorrhage in another patient., Interpretation: Ribociclib plus endocrine therapy improved progression-free survival compared with placebo plus endocrine therapy, and had a manageable safety profile in patients with premenopausal, HR-positive, HER2-negative, advanced breast cancer. The combination could represent a new first-line treatment option for these patients., Funding: Novartis., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: In the primary analysis of the NeoSphere trial, patients given neoadjuvant pertuzumab, trastuzumab, and docetaxel showed a significantly improved pathological complete response compared with those given trastuzumab and docetaxel after surgery. Here, we report 5-year progression-free survival, disease-free survival, and safety., Methods: In this multicentre, open-label, phase 2 randomised trial in hospitals and medical clinics, treatment-naive adults with locally advanced, inflammatory, or early-stage HER2-positive breast cancer were randomly assigned (1:1:1:1) to receive four neoadjuvant cycles of trastuzumab (8 mg/kg loading dose, followed by 6 mg/kg every 3 weeks) plus docetaxel (75 mg/m(2) every 3 weeks, increasing to 100 mg/m(2) from cycle 2 if tolerated; group A), pertuzumab (840 mg loading dose, followed by 420 mg every 3 weeks) and trastuzumab plus docetaxel (group B), pertuzumab and trastuzumab (group C), or pertuzumab and docetaxel (group D). After surgery, patients received three cycles of FEC (fluorouracil 600 mg/m(2), epirubicin 90 mg/m(2), and cyclophosphamide 600 mg/m(2)) every 3 weeks (patients in group C received four cycles of docetaxel prior to FEC), and trastuzumab 6 mg/kg every 3 weeks to complete 1 year's treatment (17 cycles in total). Randomisation was done by a central centre using dynamic allocation, stratified by operable, locally advanced, and inflammatory breast cancer, and by oestrogen and/or progesterone receptor positivity. Safety analyses were done according to treatment received. The primary endpoint (pathological complete response) was previously reported; secondary endpoints reported here are 5-year progression-free survival (analysed in the intention-to-treat population) and disease-free survival (analysed in patients who had surgery). Secondary and exploratory analyses were not powered for formal statistical hypothesis testing, and therefore results are for descriptive purposes only. The study ended on Sept 22, 2014 (last patient, last visit). This study is registered with ClinicalTrials.gov, number NCT00545688., Findings: Between Dec 17, 2007, and Dec 22, 2009, 417 eligible patients were randomly assigned to group A (107 patients), group B (107 patients), group C (107 patients), or group D (96 patients). One patient in group A withdrew before treatment. One patient assigned to group D received group A treatment, one patient assigned to group D received group B treatment, and one patient assigned to group B received group C treatment. At clinical cutoff, 87 patients had progressed or died. 5-year progression-free survival rates were 81% (95% CI 71-87) for group A, 86% (77-91) for group B, 73% (64-81) for group C, and 73% (63-81) for group D (hazard ratios 0·69 [95% CI 0·34-1·40] group B vs group A, 1·25 [0·68-2·30] group C vs group A, and 2·05 [1·07-3·93] group D vs group B). Disease-free survival results were consistent with progression-free survival results and were 81% (95% CI 72-88) for group A, 84% (72-91) for group B, 80% (70-86) for group C, and 75% (64-83) for group D. Patients who achieved total pathological complete response (all groups combined) had longer progression-free survival compared with patients who did not (85% [76-91] in patients who achieved total pathological response vs 76% [71-81] in patients who did not achieve total pathological response; hazard ratio 0·54 [95% CI 0·29-1·00]). There were no new or long-term safety concerns and tolerability was similar across groups (neoadjuvant and adjuvant treatment periods combined). The most common grade 3 or worse adverse events were neutropenia (group A: 71 [66%] of 107 patients; group B: 59 [55%] of 107; group C: 40 [37%] of 108; group D: 60 [64%] of 94), febrile neutropenia (group A: 10 [9%]; group B: 12 [11%]; group C: 5 [5%]; group D: 15 [16%]), and leucopenia (group A: 13 [12%]; group B: 6 [6%]; group C: 4 [4%]; group D: 8 [9%]). The number of patients with one or more serious adverse event was similar across groups (19-22 serious adverse events per group in 18-22% of patients)., Interpretation: Progression-free survival and disease-free survival at 5-year follow-up show large and overlapping CIs, but support the primary endpoint (pathological complete response) and suggest that neoadjuvant pertuzumab is beneficial when combined with trastuzumab and docetaxel. Additionally, they suggest that total pathological complete response could be an early indicator of long-term outcome in early-stage HER2-positive breast cancer., Funding: F Hoffmann-La Roche., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Trastuzumab resistance is a key therapeutic challenge in metastatic breast cancer. We postulated that broader inhibition of ErbB receptors with afatinib would improve clinical outcomes compared with HER2 inhibition alone in patients who had progressed on previous trastuzumab treatment. LUX-Breast 1 compared afatinib plus vinorelbine with trastuzumab plus vinorelbine for such patients with HER2-positive metastatic breast cancer., Methods: We did this open-label trial at 350 hospitals in 41 countries worldwide. We enrolled female patients with HER2-overexpressing metastatic breast cancer who had progressed on or following adjuvant trastuzumab or first-line treatment of metastatic disease with trastuzumab. Participants were randomly assigned (2:1) to receive oral afatinib (40 mg/day) plus intravenous vinorelbine (25 mg/m(2) per week) or intravenous trastuzumab (2 mg/kg per week after 4 mg/kg loading dose) plus vinorelbine. Randomisation was done centrally and stratified by previous trastuzumab treatment (adjuvant vs first-line treatment), hormone receptor status (oestrogen receptor and progesterone receptor positive vs others), and region. The primary endpoint was progression-free survival, assessed in the intention-to-treat population. This trial is closed to enrolment and is registered with ClinicalTrials.gov, NCT01125566., Findings: Between Aug 26, 2010, and April 26, 2013, we enrolled 508 patients: 339 assigned to the afatinib group and 169 assigned to the trastuzumab group. Recruitment was stopped on April 26, 2013, after a benefit-risk assessment by the independent data monitoring committee was unfavourable for the afatinib group. Patients on afatinib plus vinorelbine had to switch to trastuzumab plus vinorelbine, afatinib monotherapy, vinorelbine monotherapy, or receive treatment outside of the trial. Median follow-up was 9·3 months (IQR 3·7-16·0). Median progression-free survival was 5·5 months (95% CI 5·4-5·6) in the afatinib group and 5·6 months (5·3-7·3) in the trastuzumab group (hazard ratio 1·10 95% CI 0·86-1·41; p=0·43). The most common drug-related adverse events of grade 3 or higher were neutropenia (190 [56%] of 337 patients in the afatinib group vs 102 [60%] of 169 patients in the trastuzumab group), leucopenia (64 [19%] vs 34 [20%]), and diarrhoea (60 [18%] vs none)., Interpretation: Trastuzumab-based therapy remains the treatment of choice for patients with HER2-positive metastatic breast cancer who had progressed on trastuzumab., Funding: Boehringer Ingelheim., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: The optimum endocrine treatment for postmenopausal women with advanced hormone-receptor-positive breast cancer that has progressed on non-steroidal aromatase inhibitors (NSAIs) is unclear. The aim of the SoFEA trial was to assess a maximum double endocrine targeting approach with the steroidal anti-oestrogen fulvestrant in combination with continued oestrogen deprivation., Methods: In a composite, multicentre, phase 3 randomised controlled trial done in the UK and South Korea, postmenopausal women with hormone-receptor-positive breast cancer (oestrogen receptor [ER] positive, progesterone receptor [PR] positive, or both) were eligible if they had relapsed or progressed with locally advanced or metastatic disease on an NSAI (given as adjuvant for at least 12 months or as first-line treatment for at least 6 months). Additionally, patients had to have adequate organ function and a WHO performance status of 0-2. Participants were randomly assigned (1:1:1) to receive fulvestrant (500 mg intramuscular injection on day 1, followed by 250 mg doses on days 15 and 29, and then every 28 days) plus daily oral anastrozole (1 mg); fulvestrant plus anastrozole-matched placebo; or daily oral exemestane (25 mg). Randomisation was done with computer-generated permuted blocks, and stratification was by centre and previous use of an NSAI as adjuvant treatment or for locally advanced or metastatic disease. Participants and investigators were aware of assignment to fulvestrant or exemestane, but not of assignment to anastrozole or placebo. The primary endpoint was progression-free survival (PFS). Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, numbers NCT00253422 (UK) and NCT00944918 (South Korea)., Findings: Between March 26, 2004, and Aug 6, 2010, 723 patients underwent randomisation: 243 were assigned to receive fulvestrant plus anastrozole, 231 to fulvestrant plus placebo, and 249 to exemestane. Median PFS was 4·4 months (95% CI 3·4-5·4) in patients assigned to fulvestrant plus anastrozole, 4·8 months (3·6-5·5) in those assigned to fulvestrant plus placebo, and 3·4 months (3·0-4·6) in those assigned to exemestane. No difference was recorded between the patients assigned to fulvestrant plus anastrozole and fulvestrant plus placebo (hazard ratio 1·00, 95% CI 0·83-1·21; log-rank p=0·98), or between those assigned to fulvestrant plus placebo and exemestane (0·95, 0·79-1·14; log-rank p=0·56). 87 serious adverse events were reported: 36 in patients assigned to fulvestrant plus anastrozole, 22 in those assigned to fulvestrant plus placebo, and 29 in those assigned to exemestane. Grade 3-4 adverse events were rare; the most frequent were arthralgia (three in the group assigned to fulvestrant plus anastrozole; seven in that assigned to fulvestrant plus placebo; eight in that assigned to exemestane), lethargy (three; 11; 11), and nausea or vomiting (five; two; eight)., Interpretation: After loss of response to NSAIs in postmenopausal women with hormone-receptor-positive advanced breast cancer, maximum double endocrine treatment with 250 mg fulvestrant combined with oestrogen deprivation is no better than either fulvestrant alone or exemestane., (Copyright © 2013 Johnston et al. Open Access article distributed under the terms of CC BY-NC-SA. Published by Elsevier Ltd. All rights reserved.)

Background: The addition of bevacizumab to chemotherapy improves progression-free survival in metastatic breast cancer and pathological complete response rates in the neoadjuvant setting. Micrometastases are dependent on angiogenesis, suggesting that patients might benefit from anti-angiogenic strategies in the adjuvant setting. We therefore assessed the addition of bevacizumab to chemotherapy in the adjuvant setting for women with triple-negative breast cancer., Methods: For this open-label, randomised phase 3 trial we recruited patients with centrally confirmed triple-negative operable primary invasive breast cancer from 360 sites in 37 countries. We randomly allocated patients aged 18 years or older (1:1 with block randomisation; stratified by nodal status, chemotherapy [with an anthracycline, taxane, or both], hormone receptor status [negative vs low], and type of surgery) to receive a minimum of four cycles of chemotherapy either alone or with bevacizumab (equivalent of 5 mg/kg every week for 1 year). The primary endpoint was invasive disease-free survival (IDFS). Efficacy analyses were based on the intention-to-treat population, safety analyses were done on all patients who received at least one dose of study drug, and plasma biomarker analyses were done on all treated patients consenting to biomarker analyses and providing a measurable baseline plasma sample. This trial is registered with ClinicalTrials.gov, number NCT00528567., Findings: Between Dec 3, 2007, and March 8, 2010, we randomly assigned 1290 patients to receive chemotherapy alone and 1301 to receive bevacizumab plus chemotherapy. Most patients received anthracycline-containing therapy; 1638 (63%) of the 2591 patients had node-negative disease. At the time of analysis of IDFS, median follow-up was 31·5 months (IQR 25·6-36·8) in the chemotherapy-alone group and 32·0 months (27·5-36·9) in the bevacizumab group. At the time of the primary analysis, IDFS events had been reported in 205 patients (16%) in the chemotherapy-alone group and in 188 patients (14%) in the bevacizumab group (hazard ratio [HR] in stratified log-rank analysis 0·87, 95% CI 0·72-1·07; p=0·18). 3-year IDFS was 82·7% (95% CI 80·5-85·0) with chemotherapy alone and 83·7% (81·4-86·0) with bevacizumab and chemotherapy. After 200 deaths, no difference in overall survival was noted between the groups (HR 0·84, 95% CI 0·64-1·12; p=0·23). Exploratory biomarker assessment suggests that patients with high pre-treatment plasma VEGFR-2 might benefit from the addition of bevacizumab (Cox interaction test p=0·029). Use of bevacizumab versus chemotherapy alone was associated with increased incidences of grade 3 or worse hypertension (154 patients [12%] vs eight patients [1%]), severe cardiac events occurring at any point during the 18-month safety reporting period (19 [1%] vs two [<0·5%]), and treatment discontinuation (bevacizumab, chemotherapy, or both; 256 [20%] vs 30 [2%]); we recorded no increase in fatal adverse events with bevacizumab (four [<0·5%] vs three [<0·5%])., Interpretation: Bevacizumab cannot be recommended as adjuvant treatment in unselected patients with triple-negative breast cancer. Further follow-up is needed to assess the potential effect of bevacizumab on overall survival., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Studies with pertuzumab, a novel anti-HER2 antibody, show improved efficacy when combined with the established HER2-directed antibody trastuzumab in breast cancer therapy. We investigated the combination of pertuzumab or trastuzumab, or both, with docetaxel and the combination of pertuzumab and trastuzumab without chemotherapy in the neoadjuvant setting., Methods: In this multicentre, open-label, phase 2 study, treatment-naive women with HER2-positive breast cancer were randomly assigned (1:1:1:1) centrally and stratified by operable, locally advanced, and inflammatory breast cancer, and by hormone receptor expression to receive four neoadjuvant cycles of: trastuzumab (8 mg/kg loading dose, followed by 6 mg/kg every 3 weeks) plus docetaxel (75 mg/m(2), escalating, if tolerated, to 100 mg/m(2) every 3 weeks; group A) or pertuzumab (loading dose 840 mg, followed by 420 mg every 3 weeks) and trastuzumab plus docetaxel (group B) or pertuzumab and trastuzumab (group C) or pertuzumab plus docetaxel (group D). The primary endpoint, examined in the intention-to-treat population, was pathological complete response in the breast. Neither patients nor investigators were masked to treatment. This study is registered with ClinicalTrials.gov, number NCT00545688., Findings: Of 417 eligible patients, 107 were randomly assigned to group A, 107 to group B, 107 to group C, and 96 to group D. Patients given pertuzumab and trastuzumab plus docetaxel (group B) had a significantly improved pathological complete response rate (49 of 107 patients; 45·8% [95% CI 36·1-55·7]) compared with those given trastuzumab plus docetaxel (group A; 31 of 107; 29·0% [20·6-38·5]; p=0·0141). 23 of 96 (24·0% [15·8-33·7]) women given pertuzumab plus docetaxel (group D) had a pathological complete response, as did 18 of 107 (16·8% [10·3-25·3]) given pertuzumab and trastuzumab (group C). The most common adverse events of grade 3 or higher were neutropenia (61 of 107 women in group A, 48 of 107 in group B, one of 108 in group C, and 52 of 94 in group D), febrile neutropenia (eight, nine, none, and seven, respectively), and leucopenia (13, five, none, and seven, respectively). The number of serious adverse events was similar in groups A, B, and D (15-20 serious adverse events per group in 10-17% of patients) but lower in group C (four serious adverse events in 4% of patients)., Interpretation: Patients given pertuzumab and trastuzumab plus docetaxel (group B) had a significantly improved pathological complete response rate compared with those given trastuzumab plus docetaxel, without substantial differences in tolerability. Pertuzumab and trastuzumab without chemotherapy eradicated tumours in a proportion of women and showed a favourable safety profile. These findings justify further exploration in adjuvant trials and support the neoadjuvant approach for accelerating drug assessment in early breast cancer., Funding: F Hoffmann-La Roche., (Copyright © 2012 Elsevier Ltd. All rights reserved.)