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The problem of resistance to therapy in cancer is multifaceted. Here we take a reductionist approach to define and separate the key determinants of drug resistance, which include tumour burden and growth kinetics; tumour heterogeneity; physical barriers; the immune system and the microenvironment; undruggable cancer drivers; and the many consequences of applying therapeutic pressures. We propose four general solutions to drug resistance that are based on earlier detection of tumours permitting cancer interception; adaptive monitoring during therapy; the addition of novel drugs and improved pharmacological principles that result in deeper responses; and the identification of cancer cell dependencies by high-throughput synthetic lethality screens, integration of clinico-genomic data and computational modelling. These different approaches could eventually be synthesized for each tumour at any decision point and used to inform the choice of therapy.

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are effective in cancers with defective homologous recombination DNA repair (HRR), including BRCA1/2-related cancers. A test to identify additional HRR-deficient tumors will help to extend their use in new indications. We evaluated the activity of the PARPi olaparib in patient-derived tumor xenografts (PDXs) from breast cancer (BC) patients and investigated mechanisms of sensitivity through exome sequencing, BRCA1 promoter methylation analysis, and immunostaining of HRR proteins, including RAD51 nuclear foci. In an independent BC PDX panel, the predictive capacity of the RAD51 score and the homologous recombination deficiency (HRD) score were compared. To examine the clinical feasibility of the RAD51 assay, we scored archival breast tumor samples, including PALB2-related hereditary cancers. The RAD51 score was highly discriminative of PARPi sensitivity versus PARPi resistance in BC PDXs and outperformed the genomic test. In clinical samples, all PALB2-related tumors were classified as HRR-deficient by the RAD51 score. The functional biomarker RAD51 enables the identification of PARPi-sensitive BC and broadens the population who may benefit from this therapy beyond BRCA1/2-related cancers., (© 2018 The Authors. Published under the terms of the CC BY 4.0 license.)

Purpose: This multicenter phase II trial evaluated lurbinectedin (PM01183), a selective inhibitor of active transcription of protein-coding genes, in patients with metastatic breast cancer. A unicenter translational substudy assessed potential mechanisms of lurbinectedin resistance., Patients and Methods: Two arms were evaluated according to germline BRCA1/2 status: BRCA1/2 mutated (arm A; n = 54) and unselected ( BRCA1/2 wild-type or unknown status; arm B; n = 35). Lurbinectedin starting dose was a 7-mg flat dose and later, 3.5 mg/m 2 in arm A. The primary end point was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST). The translational substudy of resistance mechanisms included exome sequencing (n = 13) and in vivo experiments with patient-derived xenografts (n = 11) from BRCA1/2-mutated tumors., Results: ORR was 41% (95% CI, 28% to 55%) in arm A and 9% (95% CI, 2% to 24%) in arm B. In arm A, median progression-free survival was 4.6 months (95% CI, 3.0 to 6.0 months), and median overall survival was 20.0 months (95% CI, 11.8 to 26.6 months). Patients with BRCA2 mutations showed an ORR of 61%, median progression-free survival of 5.9 months, and median overall survival of 26.6 months. The safety profile improved with lurbinectedin dose adjustment to body surface area. The most common nonhematologic adverse events seen at 3.5 mg/m 2 were nausea (74%; grade 3, 5%) and fatigue (74%; grade 3, 21%). Neutropenia was the most common severe hematologic adverse event (grade 3, 47%; grade 4, 10%). Exome sequencing showed mutations in genes related to the nucleotide excision repair pathway in four of seven tumors at primary or acquired resistance and in one patient with short-term stable disease. In vivo, sensitivity to cisplatin and lurbinectedin was evidenced in lurbinectedin-resistant (one of two) and cisplatin-resistant (two of three) patient-derived xenografts., Conclusion: Lurbinectedin showed noteworthy activity in patients with BRCA1/2 mutations. Response and survival was notable in those with BRCA2 mutations. Additional clinical development in this subset of patients with metastatic breast cancer is warranted.

Mutations in ERBB2 , the gene encoding epidermal growth factor receptor (EGFR) family member HER2, are common in and drive the growth of "HER2-negative" (not ERBB2 amplified) tumors but are rare in "HER2-positive" ( ERBB2 amplified) breast cancer. We analyzed DNA-sequencing data from HER2-positive patients and used cell lines and a patient-derived xenograft model to test the consequence of HER2 mutations on the efficacy of anti-HER2 agents such as trastuzumab, lapatinib, and neratinib, an irreversible pan-EGFR inhibitor. HER2 mutations were present in ~7% of HER2-positive tumors, all of which were metastatic but not all were previously treated. Compared to HER2 amplification alone, in both patients and cultured cell lines, the co-occurrence of HER2 mutation and amplification was associated with poor response to trastuzumab and lapatinib, the standard-of-care anti-HER2 agents. In mice, xenografts established from a patient whose HER2-positive tumor acquired a D769Y mutation in HER2 after progression on trastuzumab-based therapy were resistant to trastuzumab or lapatinib but were sensitive to neratinib. Clinical data revealed that six heavily pretreated patients with tumors bearing coincident HER2 amplification and mutation subsequently exhibited a statistically significant response to neratinib monotherapy. Thus, these findings indicate that coincident HER2 mutation reduces the efficacy of therapies commonly used to treat HER2-positive breast cancer, particularly in metastatic and previously HER2 inhibitor-treated patients, as well as potentially in patients scheduled for first-line treatment. Therefore, we propose that clinical studies testing the efficacy of neratinib are warranted selectively in breast cancer patients whose tumors carry both amplification and mutation of ERBB2 /HER2., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

BRAF V600E colorectal cancers are insensitive to RAF inhibitor monotherapy due to feedback reactivation of receptor tyrosine kinase signaling. Combined RAF and EGFR inhibition exerts a therapeutic effect, but resistance invariably develops through undefined mechanisms. In this study, we determined that colorectal cancer progression specimens invariably harbored lesions in elements of the RAS-RAF-MEK-ERK pathway. Genetic amplification of wild-type RAS was a recurrent mechanism of resistance in colorectal cancer patients that was not seen in similarly resistant melanomas. We show that wild-type RAS amplification increases receptor tyrosine kinase-dependent activation of RAS more potently in colorectal cancer than in melanoma and causes resistance only in the former. Currently approved RAF inhibitors inhibit RAF monomers but not dimers. All the drug-resistant lesions we identified activate BRAF V600E dimerization directly or by elevating RAS-GTP. Overall, our results show that mechanisms of resistance converge on formation of RAF dimers and that inhibiting EGFR and RAF dimers can effectively suppress ERK-driven growth of resistant colorectal cancer. Cancer Res; 77(23); 6513-23. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Purpose AKT1 E17K mutations are oncogenic and occur in many cancers at a low prevalence. We performed a multihistology basket study of AZD5363, an ATP-competitive pan-AKT kinase inhibitor, to determine the preliminary activity of AKT inhibition in AKT-mutant cancers. Patients and Methods Fifty-eight patients with advanced solid tumors were treated. The primary end point was safety; secondary end points were progression-free survival (PFS) and response according to Response Evaluation Criteria in Solid Tumors (RECIST). Tumor biopsies and plasma cell-free DNA (cfDNA) were collected in the majority of patients to identify predictive biomarkers of response. Results In patients with AKT1 E17K-mutant tumors (n = 52) and a median of five lines of prior therapy, the median PFS was 5.5 months (95% CI, 2.9 to 6.9 months), 6.6 months (95% CI, 1.5 to 8.3 months), and 4.2 months (95% CI, 2.1 to 12.8 months) in patients with estrogen receptor-positive breast, gynecologic, and other solid tumors, respectively. In an exploratory biomarker analysis, imbalance of the AKT1 E17K-mutant allele, most frequently caused by copy-neutral loss-of-heterozygosity targeting the wild-type allele, was associated with longer PFS (hazard ratio [HR], 0.41; P = .04), as was the presence of coincident PI3K pathway hotspot mutations (HR, 0.21; P = .045). Persistent declines in AKT1 E17K in cfDNA were associated with improved PFS (HR, 0.18; P = .004) and response ( P = .025). Responses were not restricted to patients with detectable AKT1 E17K in pretreatment cfDNA. The most common grade ≥ 3 adverse events were hyperglycemia (24%), diarrhea (17%), and rash (15.5%). Conclusion This study provides the first clinical data that AKT1 E17K is a therapeutic target in human cancer. The genomic context of the AKT1 E17K mutation further conditioned response to AZD5363.

Background: The antibody-drug conjugate trastuzumab emtansine is indicated for the treatment of patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and a taxane. Approval of this drug was based on progression-free survival and interim overall survival data from the phase 3 EMILIA study. In this report, we present a descriptive analysis of the final overall survival data from that trial., Methods: EMILIA was a randomised, international, open-label, phase 3 study of men and women aged 18 years or older with HER2-positive unresectable, locally advanced or metastatic breast cancer previously treated with trastuzumab and a taxane. Enrolled patients were randomly assigned (1:1) via a hierarchical, dynamic randomisation scheme and an interactive voice response system to trastuzumab emtansine (3·6 mg/kg intravenously every 3 weeks) or control (capecitabine 1000 mg/m 2 self-administered orally twice daily on days 1-14 on each 21-day cycle, plus lapatinib 1250 mg orally once daily on days 1-21). Randomisation was stratified by world region (USA vs western Europe vs or other), number of previous chemotherapy regimens for unresectable, locally advanced, or metastatic disease (0 or 1 vs >1), and disease involvement (visceral vs non-visceral). The coprimary efficacy endpoints were progression-free survival (per independent review committee assessment) and overall survival. Efficacy was analysed in the intention-to-treat population; safety was analysed in all patients who received at least one dose of study treatment, with patients analysed according to the treatment actually received. On May 30, 2012, the study protocol was amended to allow crossover from control to trastuzumab emtansine after the second interim overall survival analysis crossed the prespecified overall survival efficacy boundary. This study is registered with ClinicalTrials.gov, number NCT00829166., Findings: Between Feb 23, 2009, and Oct 13, 2011, 991 eligible patients were enrolled and randomly assigned to either trastuzumab emtansine (n=495) or capecitabine and lapatinib (control; n=496). In this final descriptive analysis, median overall survival was longer with trastuzumab emtansine than with control (29·9 months [95% CI 26·3-34·1] vs 25·9 months [95% CI 22·7-28·3]; hazard ratio 0·75 [95% CI 0·64-0·88]). 136 (27%) of 496 patients crossed over from control to trastuzumab emtansine after the second interim overall survival analysis (median follow-up duration 24·1 months [IQR 19·5-26·1]). Of those patients originally randomly assigned to trastuzumab emtansine, 254 (51%) of 495 received capecitabine and 241 [49%] of 495 received lapatinib (separately or in combination) after study drug discontinuation. In the safety population (488 patients treated with capecitabine plus lapatinib, 490 patients treated with trastuzumab emtansine), fewer grade 3 or worse adverse events occurred with trastuzumab emtansine (233 [48%] of 490) than with capecitabine plus lapatinib control treatment (291 [60%] of 488). In the control group, the most frequently reported grade 3 or worse adverse events were diarrhoea (103 [21%] of 488 patients) followed by palmar-plantar erythrodysaesthesia syndrome (87 [18%]), and vomiting (24 [5%]). The safety profile of trastuzumab emtansine was similar to that reported previously; the most frequently reported grade 3 or worse adverse events in the trastuzumab emtansine group were thrombocytopenia (70 [14%] of 490), increased aspartate aminotransferase levels (22 [5%]), and anaemia (19 [4%]). Nine patients died from adverse events; five of these deaths were judged to be related to treatment (two in the control group [coronary artery disease and multiorgan failure] and three in the trastuzumab emtansine group [metabolic encephalopathy, neutropenic sepsis, and acute myeloid leukaemia])., Interpretation: This descriptive analysis of final overall survival in the EMILIA trial shows that trastuzumab emtansine improved overall survival in patients with previously treated HER2-positive metastatic breast cancer even in the presence of crossover treatment. The safety profile was similar to that reported in previous analyses, reaffirming trastuzumab emtansine as an efficacious and tolerable treatment in this patient population., Funding: F Hoffmann-La Roche/Genentech., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Pertuzumab disrupts heterodimerization between human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), HER3, and HER4. Thus, pertuzumab could result in adverse events similar to those observed with EGFR antagonists, such as diarrhea. We report the incidence and severity of diarrhea observed with pertuzumab in the CLEOPATRA, NeoSphere, and TRYPHAENA studies., Patients and Methods: Patients (n = 1443) had metastatic [CLEOPATRA (n = 804)] or early-stage breast cancer [NeoSphere (n = 416) and TRYPHAENA (n = 223)]. The incidence and severity of diarrhea were analyzed by treatment received. The incidence of febrile neutropenia concurrent with diarrhea and the effect of pre-existing gastrointestinal comorbidities were also evaluated. Subgroup analyses were carried out using CLEOPATRA data., Results: The incidence of all-grade diarrhea across studies was generally greater for pertuzumab-based treatment, ranging from 28% to 72% (grade 1, 21%-54%; grade 2, 8%-37%; grade 3, 0%-12%; grade 4, 0%). Incidence was highest during the first pertuzumab-containing cycle, decreasing with subsequent cycles. Dose delays or discontinuations due to diarrhea were infrequent, ranging from 0% to 8%. Among pertuzumab-treated patients with diarrhea, 47%-67% received pharmacological intervention, most commonly with loperamide. Overlap between diarrhea and febrile neutropenia was uncommon, ranging from 0% to 11%. No relationship was observed between pre-existing gastrointestinal comorbidities and diarrhea. In CLEOPATRA, patients ≥65 years treated with pertuzumab had a higher incidence of grade 3 diarrhea than patients <65 years (19% versus 8%). All-grade diarrhea occurred at greater frequency among pertuzumab-treated Asian versus white patients with metastatic breast cancer (74% versus 63%); the corresponding rates in the control arm were 53% and 45%, respectively., Conclusions: In both the metastatic and early-stage breast cancer settings, diarrhea was common but manageable for all pertuzumab-containing regimens. Diarrheal episodes were mainly low grade and occurred most often during the first treatment cycle. Diarrheal-related drug delays or discontinuations were uncommon., Clinicaltrials.gov Identifiers: NCT00567190 (CLEOPATRA), NCT00545688 (NeoSphere), NCT00976989 (TRYPHAENA)., (© The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Mucositis and dysphagia are common adverse effects of radiotherapy (RT) treatment of locally advanced squamous cell cancer of the head and neck (LA-SCCHN). Chemotherapy added to RT increases survival rates but causes worse mucositis and dysphagia. The aim of this analysis was to assess the impact of p16 status on mucositis, dysphagia, and feeding tube use in LA-SCCHN among patients treated with RT±cetuximab in the phase 3 IMCL-9815 trial., Methods: Patients received RT plus weekly cetuximab or RT alone. Subgroup analyses were conducted on patients with p16-positive (n=75) or p16-negative (n=106) oropharyngeal cancer (OPC), as determined by immunohistochemical analysis. The onset and duration of mucositis and dysphagia by treatment arm and p16 status were displayed using Kaplan-Meier curves and the log-rank test. P values for the incidence of mucositis and dysphagia were calculated using the Fisher exact test. Feeding tube use was assessed as the percent of patients reporting use., Results: The baseline characteristics of patients treated with RT±cetuximab were similar in both the p16-positive and p16-negative OPC subgroups. Patients within the p16-positive OPC subgroup had higher Karnofsky scores and were more likely to have stage T1-T3 cancer and be from the United States. Regardless of p16 status, there was no difference in the onset or duration of grade 3/4 mucositis or dysphagia in patients receiving RT plus cetuximab compared with those receiving RT alone. In the overall population, and the p16-positive and p16-negative OPC subpopulations, feeding tube use was not different for patients receiving RT plus cetuximab compared with RT alone., Conclusion: Regardless of p16 status, the addition of cetuximab to RT did not alter the incidence, time to onset, severity, or duration of mucositis and dysphagia and did not impact the frequency of feeding tube use., Competing Interests: J.A.B. receives honorarium from Merck Serono, Eli Lilly, and Bristol-Myers Squibb. J.B. is a consultant for Merck and in the advisory boards for Eli Lilly. J.L. is an employee of Merck Serono, Beijing, China. J.S. is an employee of Merck KGaA, Darmstadt, Germany. D.I.R. receives research funding (grant) from Merck Serono and is in the advisory boards for Merck Serono and Bristol-Myers Squibb. All other authors have no conflicts to report., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The PI3K pathway is often aberrantly activated in estrogen receptor positive (ER(+)) breast cancer and therapies combining PI3K inhibitors and antiestrogens are under clinical development. Given that many PI3K inhibitors have substantial toxicities with continuous dosing and that alternate dosing schedules are equally active, further clinical exploration is warranted. Clin Cancer Res; 22(9); 2099-101. ©2016 AACRSee related article by Yang et al., p. 2250., (©2016 American Association for Cancer Research.)

Purpose: ActivatingPIK3CAgenomic alterations are frequent in head and neck squamous cell carcinoma (HNSCC), and there is an association between phosphoinositide 3-kinase (PI3K) signaling and radioresistance. Hence, we investigated the therapeutic efficacy of inhibiting PI3K with GDC-0032, a PI3K inhibitor with potent activity against p110α, in combination with radiation in HNSCC., Experimental Design: The efficacy of GDC-0032 was assessedin vitroin 26 HNSCC cell lines with crystal violet proliferation assays, and changes in PI3K signaling were measured by Western blot analysis. Cytotoxicity and radiosensitization were assessed with Annexin V staining via flow cytometry and clonogenic survival assays, respectively. DNA damage repair was assessed with immunofluorescence for γH2AX foci, and cell cycle analysis was performed with flow cytometry.In vivoefficacy of GDC-0032 and radiation was assessed in xenografts implanted into nude mice., Results: GDC-0032 inhibited potently PI3K signaling and displayed greater antiproliferative activity in HNSCC cell lines withPIK3CAmutations or amplification, whereas cell lines withPTENalterations were relatively resistant to its effects. Pretreatment with GDC-0032 radiosensitizedPIK3CA-mutant HNSCC cells, enhanced radiation-induced apoptosis, impaired DNA damage repair, and prolonged G2-M arrest following irradiation. Furthermore, combined GDC-0032 and radiation was more effective than either treatment alonein vivoin subcutaneous xenograft models., Conclusions: GDC-0032 has increased potency in HNSCC cell lines harboringPIK3CA-activating aberrations. Further, combined GDC-0032 and radiotherapy was more efficacious than either treatment alone inPIK3CA-altered HNSCCin vitroandin vivo This strategy warrants further clinical investigation., (©2015 American Association for Cancer Research.)

Background: Lapatinib (L) plus trastuzumab (T) improves outcomes for metastatic human epidermal growth factor 2-positive breast cancer and increases the pathologic complete response in the neoadjuvant setting, but their role as adjuvant therapy remains uncertain., Methods: In the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization trial, patients with centrally confirmed human epidermal growth factor 2-positive early breast cancer were randomly assigned to 1 year of adjuvant therapy with T, L, their sequence (T→L), or their combination (L+T). The primary end point was disease-free survival (DFS), with 850 events required for 80% power to detect a hazard ratio (HR) of 0.8 for L+T versus T., Results: Between June 2007 and July 2011, 8,381 patients were enrolled. In 2011, due to futility to demonstrate noninferiority of L versus T, the L arm was closed, and patients free of disease were offered adjuvant T. A protocol modification required P ≤ .025 for the two remaining pairwise comparisons. At a protocol-specified analysis with a median follow-up of 4.5 years, a 16% reduction in the DFS hazard rate was observed with L+T compared with T (555 DFS events; HR, 0.84; 97.5% CI, 0.70 to 1.02; P = .048), and a 4% reduction was observed with T→L compared with T (HR, 0.96; 97.5% CI, 0.80 to 1.15; P = .61). L-treated patients experienced more diarrhea, cutaneous rash, and hepatic toxicity compared with T-treated patients. The incidence of cardiac toxicity was low in all treatment arms., Conclusion: Adjuvant treatment that includes L did not significantly improve DFS compared with T alone and added toxicity. One year of adjuvant T remains standard of care., (© 2015 by American Society of Clinical Oncology.)

This retrospective analysis conducted using data from patients enrolled onto the Herceptin Adjuvant has two objectives: The first is to evaluate the impact of the time interval between the end of adjuvant trastuzumab and distant recurrence (TDRI) upon overall survival (OS). The second is to describe the duration of trastuzumab-based regimens in the metastatic setting for patients previously treated with adjuvant trastuzumab. The first objective included 187 patients treated with adjuvant trastuzumab and diagnosed with distant recurrence at 4-year median follow-up. The second objective included data from questionnaires sent to investigators retreating patients with trastuzumab upon distant recurrence: 144 of 156 questionnaires were returned (93 %), and 90 patients were selected based on available clinical information and consent for subsequent studies. There was no statistically significant relationship between TDRI following 1 year of adjuvant trastuzumab and OS from distant recurrence: hazard ratio 0.991, p = 0.46. The median OS from distant recurrence was numerically longer among patients with a TDRI of ≥12 months (n = 103) than <12 months (n = 84) but not statistically significant (23.7 vs. 17.8 months, p = 0.47). The median duration of first-line trastuzumab-based regimens for patients previously treated with adjuvant trastuzumab and diagnosed with distant disease recurrence was 8.8 months (n = 88). This retrospective, exploratory study suggests that TDRI did not impact on OS measured from distant recurrence. We argue that prospective collection of treatment information beyond disease progression should be included in future clinical studies.

Purpose: PI3K pathway activation occurs in concomitance with RAS/BRAF mutations in colorectal cancer, limiting the sensitivity to targeted therapies. Several clinical studies are being conducted to test the tolerability and clinical activity of dual MEK and PI3K pathway blockade in solid tumors., Experimental Design: In the present study, we explored the efficacy of dual pathway blockade in colorectal cancer preclinical models harboring concomitant activation of the ERK and PI3K pathways. Moreover, we investigated if TP53 mutation affects the response to this therapy., Results: Dual MEK and mTORC1/2 blockade resulted in synergistic antiproliferative effects in cell lines bearing alterations in KRAS/BRAF and PIK3CA/PTEN. Although the on-treatment cell-cycle effects were not affected by the TP53 status, a marked proapoptotic response to therapy was observed exclusively in wild-type TP53 colorectal cancer models. We further interrogated two independent panels of KRAS/BRAF- and PIK3CA/PTEN-altered cell line- and patient-derived tumor xenografts for the antitumor response toward this combination of agents. A combination response that resulted in substantial antitumor activity was exclusively observed among the wild-type TP53 models (two out of five, 40%), but there was no such response across the eight mutant TP53 models (0%). Interestingly, within a cohort of 14 patients with colorectal cancer treated with these agents for their metastatic disease, two patients with long-lasting responses (32 weeks) had TP53 wild-type tumors., Conclusions: Our data support that, in wild-type TP53 colorectal cancer cells with ERK and PI3K pathway alterations, MEK blockade results in potent p21 induction, preventing apoptosis to occur. In turn, mTORC1/2 inhibition blocks MEK inhibitor-mediated p21 induction, unleashing apoptosis. Clin Cancer Res; 21(24); 5499-510. ©2015 AACR., (©2015 American Association for Cancer Research.)

Background: BRAF V600 mutations occur in various nonmelanoma cancers. We undertook a histology-independent phase 2 "basket" study of vemurafenib in BRAF V600 mutation-positive nonmelanoma cancers., Methods: We enrolled patients in six prespecified cancer cohorts; patients with all other tumor types were enrolled in a seventh cohort. A total of 122 patients with BRAF V600 mutation-positive cancer were treated, including 27 patients with colorectal cancer who received vemurafenib and cetuximab. The primary end point was the response rate; secondary end points included progression-free and overall survival., Results: In the cohort with non-small-cell lung cancer, the response rate was 42% (95% confidence interval [CI], 20 to 67) and median progression-free survival was 7.3 months (95% CI, 3.5 to 10.8). In the cohort with Erdheim-Chester disease or Langerhans'-cell histiocytosis, the response rate was 43% (95% CI, 18 to 71); the median treatment duration was 5.9 months (range, 0.6 to 18.6), and no patients had disease progression during therapy. There were anecdotal responses among patients with pleomorphic xanthoastrocytoma, anaplastic thyroid cancer, cholangiocarcinoma, salivary-duct cancer, ovarian cancer, and clear-cell sarcoma and among patients with colorectal cancer who received vemurafenib and cetuximab. Safety was similar to that in prior studies of vemurafenib for melanoma., Conclusions: BRAF V600 appears to be a targetable oncogene in some, but not all, nonmelanoma cancers. Preliminary vemurafenib activity was observed in non-small-cell lung cancer and in Erdheim-Chester disease and Langerhans'-cell histiocytosis. The histologic context is an important determinant of response in BRAF V600-mutated cancers. (Funded by F. Hoffmann-La Roche/Genentech; ClinicalTrials.gov number, NCT01524978.).

Importance: The presence of tumor-infiltrating lymphocytes (TILs) is associated with improved outcomes in human epidermal growth factor receptor 2 (HER2)-positive early breast cancer treated with adjuvant trastuzumab and chemotherapy. The prognostic associations in the neoadjuvant setting of other anti-HER2 agents and combinations are unknown., Objective: To determine associations between presence of TILs, pathological complete response (pCR), and event-free survival (EFS) end points in patients with early breast cancer treated with trastuzumab, lapatinib, or the combination., Design, Setting, and Participants: The NeoALTTO trial (Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimization) randomly assigned 455 women with HER2-positive early-stage breast cancer between January 5, 2008, and May 27, 2010, to 1 of 3 neoadjuvant treatment arms: trastuzumab, lapatinib, or the combination for 6 weeks followed by the addition of weekly paclitaxel for 12 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide after surgery. The primary end point used in this study was pCR in the breast and lymph nodes, with a secondary end point of EFS. We evaluated levels of percentage of TILs using hematoxylin-eosin-stained core biopsy sections taken at diagnosis (prior to treatment) in a prospectively defined retrospective analysis., Main Outcomes and Measures: Levels of TILs were examined for their associations with efficacy end points adjusted for prognostic clinicopathological factors including PIK3CA genotype., Results: Of the 455 patients, 387 (85.1%) tumor samples were used for the present analysis. The median (interquartile range [IQR]) level of TILs was 12.5% (5.0%-30.0%), with levels lower in hormone receptor-positive (10.0% [5.0%-22.5%]) vs hormone receptor-negative (12.5% [3.0%-35.0%]) samples (P = .02). For the pCR end point, levels of TILs greater than 5% were associated with higher pCR rates independent of treatment group (adjusted odds ratio, 2.60 [95% CI, 1.26-5.39]; P = .01). With a median (IQR) follow-up time of 3.77 (3.50-4.22) years, every 1% increase in TILs was associated with a 3% decrease in the rate of an event (adjusted hazard ratio, 0.97 [95% CI, 0.95-0.99]; P = .002) across all treatment groups., Conclusions and Relevance: The presence of TILs at diagnosis is an independent, positive, prognostic marker in HER2-positive early breast cancer treated with neoadjuvant anti-HER2 agents and chemotherapy for both pCR and EFS end points., Trial Registration: clinicaltrials.gov Identifier: NCT00553358.

Current anticancer chemotherapy relies on a limited set of in vitro or indirect prognostic markers of tumor response to available drugs. A more accurate analysis of drug sensitivity would involve studying tumor response in vivo. To this end, we have developed an implantable device that can perform drug sensitivity testing of several anticancer agents simultaneously inside the living tumor. The device contained reservoirs that released microdoses of single agents or drug combinations into spatially distinct regions of the tumor. The local drug concentrations were chosen to be representative of concentrations achieved during systemic treatment. Local efficacy and drug concentration profiles were evaluated for each drug or drug combination on the device, and the local efficacy was confirmed to be a predictor of systemic efficacy in vivo for multiple drugs and tumor models. Currently, up to 16 individual drugs or combinations can be assessed independently, without systemic drug exposure, through minimally invasive biopsy of a small region of a single tumor. This assay takes into consideration physiologic effects that contribute to drug response by allowing drugs to interact with the living tumor in its native microenvironment. Because these effects are crucial to predicting drug response, we envision that these devices will help identify optimal drug therapy before systemic treatment is initiated and could improve drug response prediction beyond the biomarkers and in vitro and ex vivo studies used today. These devices may also be used in clinical drug development to safely gather efficacy data on new compounds before pharmacological optimization., (Copyright © 2015, American Association for the Advancement of Science.)

Some mutations in cancer cells can be exploited for therapeutic intervention. However, for many cancer subtypes, including triple-negative breast cancer (TNBC), no frequently recurring aberrations could be identified to make such an approach clinically feasible. Characterized by a highly heterogeneous mutational landscape with few common features, many TNBCs cluster together based on their 'basal-like' transcriptional profiles. We therefore hypothesized that targeting TNBC cells on a systems level by exploiting the transcriptional cell state might be a viable strategy to find novel therapies for this highly aggressive disease. We performed a large-scale chemical genetic screen and identified a group of compounds related to the drug PKC412 (midostaurin). PKC412 induced apoptosis in a subset of TNBC cells enriched for the basal-like subtype and inhibited tumor growth in vivo. We employed a multi-omics approach and computational modeling to address the mechanism of action and identified spleen tyrosine kinase (SYK) as a novel and unexpected target in TNBC. Quantitative phosphoproteomics revealed that SYK inhibition abrogates signaling to STAT3, explaining the selectivity for basal-like breast cancer cells. This non-oncogene addiction suggests that chemical SYK inhibition may be beneficial for a specific subset of TNBC patients and demonstrates that targeting cell states could be a viable strategy to discover novel treatment strategies., (© 2015 The Authors. Published under the terms of the CC BY 4.0 license.)

Purpose: TGFβ signaling plays a key role in tumor progression, including malignant glioma. Small-molecule inhibitors such as LY2157299 monohydrate (LY2157299) block TGFβ signaling and reduce tumor progression in preclinical models. To use LY2157299 in the treatment of malignancies, we investigated its properties in a first-in-human dose (FHD) study in patients with cancer., Experimental Design: Sixty-five patients (58 with glioma) with measurable and progressive malignancies were enrolled. Oral LY2157299 was given as a split dose morning and evening on an intermittent schedule of 14 days on and 14 days off (28-day cycle). LY2157299 monotherapy was studied in dose escalation (part A) first and then evaluated in combination with standard doses of lomustine (part B). Safety was assessed using Common Terminology Criteria for Adverse Events version 3.0, echocardiography/Doppler imaging, serum troponin I, and brain natriuretic peptide (BNP) levels. Antitumor activity was assessed by RECIST and Macdonald criteria., Results: In part A, 16.6% (5/30) and in part B, 7.7% (2/26) of evaluable patients with glioma had either a complete (CR) or a partial response (PR). In both parts, 15 patients with glioma had stable disease (SD), 5 of whom had SD ≥ 6 cycles of treatment. Therefore, clinical benefit (CR+PR+SD ≥ 6 cycles) was observed in 12 of 56 patients with glioma (21.4%). LY2157299 was safe, with no cardiac adverse events., Conclusions: On the basis of the safety, pharmacokinetics, and antitumor activity in patients with glioma, the intermittent administration of LY2157299 at 300 mg/day is safe for future clinical investigation., (©2014 American Association for Cancer Research.)

Purpose: To explore the prognostic and/or predictive value of human epidermal growth factor receptor 2 (HER2) pathway-related biomarkers in the phase III CLEOPATRA study of pertuzumab plus trastuzumab plus docetaxel versus placebo plus trastuzumab plus docetaxel as first-line treatment for patients with HER2-positive metastatic breast cancer., Patients and Methods: Mandatory tumor and serum samples were collected (N = 808; 58% to 99.8% were assessable), and amphiregulin, betacellulin, epidermal growth factor (EGF), transforming growth factor alpha, EGF receptor, HER2, HER3, insulin-like growth factor 1 receptor, PTEN, phosphorylated AKT, PIK3CA, CMYC, serum HER2 extracellular domain (sHER2), and FCγR were assessed using appropriate assays. Two types of correlations were investigated using univariable Cox regression: predictive effects (qualitative association of biomarkers with pertuzumab progression-free survival [PFS] benefit) and prognostic effects independent of treatment arm (relationship of each biomarker to clinical outcome in both arms pooled)., Results: Pertuzumab consistently showed a PFS benefit, independent of biomarker subgroups (hazard ratio < 1.0), including estrogen receptor-negative and -positive subgroups. High HER2 protein, high HER2 and HER3 mRNA levels, wild-type PIK3CA, and low sHER2 showed a significantly better prognosis (P < .05). PIK3CA showed the greatest prognostic effect, with longer median PFS for patients whose tumors expressed wild-type versus mutated PIK3CA in both the control (13.8 v 8.6 months) and pertuzumab groups (21.8 v 12.5 months)., Conclusion: Through comprehensive prospective analyses, CLEOPATRA biomarker data demonstrate that HER2 is the only marker suited for patient selection for the trastuzumab plus pertuzumab-based regimen in HER2-positive metastatic breast cancer. HER2, HER3, and PIK3CA were relevant prognostic factors., (© 2014 by American Society of Clinical Oncology.)

Human epidermal growth factor receptor 2 (HER2)-positive breast cancers are currently treated with trastuzumab, an anti-HER2 antibody. About 30% of these tumors express a group of HER2 fragments collectively known as p95HER2. Our previous work indicated that p95HER2-positive tumors are resistant to trastuzumab monotherapy. However, recent results showed that tumors expressing the most active of these fragments, p95HER2/611CTF, respond to trastuzumab plus chemotherapy. To clarify this discrepancy, we analyzed the response to chemotherapy of cell lines transfected with p95HER2/611CTF and patient-derived xenografts (n = 7 mice per group) with different levels of the fragment. All statistical tests were two-sided. p95HER2/611CTF-negative and positive tumors showed different responses to various chemotherapeutic agents, which are particularly effective on p95HER2/611CTF-positive cells. Furthermore, chemotherapy sensitizes p95HER2/611CTF-positive patient-derived xenograft tumors to trastuzumab (mean tumor volume, trastuzumab alone: 906 mm(3), 95% confidence interval = 1274 to 538 mm(3); trastuzumab+doxorubicin: 259 mm(3), 95% confidence interval = 387 to 131 mm(3); P < .001). This sensitization may be related to HER2 stabilization induced by chemotherapy in p95HER2/611CTF-positive cells., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Purpose: To document the rate and outcome of trastuzumab-associated cardiac dysfunction in patients following 1 or 2 years of adjuvant therapy., Patients and Methods: The Herceptin Adjuvant (HERA) trial is a three-arm, randomized trial comparing 2 years or 1 year of trastuzumab with observation in 5,102 patients with human epidermal growth factor receptor 2 (HER2) -positive early-stage breast cancer. Cardiac function was closely monitored. Eligible patients had left ventricular ejection fraction (LVEF) ≥ 55% at study entry following neoadjuvant chemotherapy with or without radiotherapy. This 8-year median follow-up analysis considered patients randomly assigned to 2 years or 1 year of trastuzumab or observation., Results: The as-treated safety population for 2 years of trastuzumab (n = 1,673), 1 year of trastuzumab (n = 1,682), and observation (n = 1,744) is reported. Cardiac adverse events leading to discontinuation of trastuzumab occurred in 9.4% of patients in the 2-year arm and 5.2% of patients in the 1-year arm. Cardiac death, severe congestive heart failure (CHF), and confirmed significant LVEF decrease remained low in all three arms. The incidence of severe CHF (0.8%, 0.8%, and 0.0%, respectively) and confirmed significant LVEF decrease (7.2%, 4.1%, and 0.9%, respectively) was significantly higher in the 2-year and 1-year trastuzumab arms compared with the observation arm. Severe CHF was the same for 2-year and 1-year trastuzumab. Of patients with confirmed LVEF decrease receiving 2-year trastuzumab, 87.5% reached acute recovery. Of patients with confirmed LVEF decrease receiving 1-year trastuzumab, 81.2% reached acute recovery., Conclusion: Long-term assessment at 8-year median follow-up confirms the low incidence of cardiac events for trastuzumab given sequentially after chemotherapy and radiotherapy, and cardiac events were reversible in the vast majority of patients., (© 2014 by American Society of Clinical Oncology.)

Purpose: This phase I, first-in-human study evaluated the safety, maximum-tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and preliminary efficacy of SAR245409, an inhibitor of pan-Class I phosphoinositide 3-kinase (PI3K) and mTOR, administered orally once or twice daily in patients with advanced solid tumors., Experimental Design: Eighty-three patients received SAR245409. Doses ranged from 15 to 120 mg twice daily, and 70 to 100 mg once daily. A 3+3 dose-escalation design was used to determine the MTD. Patients were evaluated for adverse events and response. Assessments included pharmacokinetic, pharmacodynamic impact of SAR245409 on PI3K pathway signaling in hair sheath cells, skin and tumor, and characterization of tumor molecular alterations., Results: The MTDs were 50 mg twice daily and 90 mg once daily. The most frequent treatment-related adverse events were nausea (36.1%), diarrhea (21.7%), vomiting (19.3%), and decreased appetite (16.9%). The most frequent treatment-related grade 3/4 adverse events were increases in alanine aminotransferase (6.0%) and aspartate aminotransferase (4.8%). SAR245409 had a relatively short plasma half-life (2.96-7.52 hours). At MTDs, once- and twice-daily regimens yielded similar mean steady-state plasma exposure. A reduction in PI3K and mTORC1/mTORC2 pathway signaling was observed in serial hair sheath cells, skin, and tumor samples. Best response was stable disease in 48% of evaluable patients; seven patients had minor tumor regression. Twelve patients with stable disease were treated for ≥16 weeks. No trend was observed correlating tumor molecular alteration with antitumor activity., Conclusion: SAR245409 had a manageable safety profile, demonstrated reduced PI3K and mTORC1/mTORC2 pathway signaling and was associated with clinically relevant stable disease., (©2014 AACR.)

Background: In our randomised, controlled, phase 3 trial NeOAdjuvant Herceptin (NOAH) trial in women with HER2-positive locally advanced or inflammatory breast cancer, neoadjuvant trastuzumab significantly improved pathological complete response rate and event-free survival. We report updated results from our primary analysis to establish the long-term benefit of trastuzumab-containing neoadjuvant therapy., Methods: We did this multicentre, open-label, randomised trial in women with HER2-positive locally advanced or inflammatory breast cancer. Participants were randomly assigned (1:1), by computer program with a minimisation technique, to receive neoadjuvant chemotherapy alone or with 1 year of trastuzumab (concurrently with neoadjuvant chemotherapy and continued after surgery). A parallel group with HER2-negative disease was included and received neoadjuvant chemotherapy alone. Our primary endpoint was event-free survival. Analysis was by intention to treat. This study is registered at www.controlled-trials.com, ISRCTN86043495., Findings: Between June 20, 2002, and Dec 12, 2005, we enrolled 235 patients with HER2-positive disease, of whom 118 received chemotherapy alone and 117 received chemotherapy plus trastuzumab. 99 additional patients with HER2-negative disease were included in the parallel cohort. After a median follow-up of 5.4 years (IQR 3.1-6.8) the event-free-survival benefit from the addition of trastuzumab to chemotherapy was maintained in patients with HER2-positive disease. 5 year event-free survival was 58% (95% CI 48-66) in patients in the trastuzumab group and 43% (34-52) in those in the chemotherapy group; the unadjusted hazard ratio (HR) for event-free survival between the two randomised HER2-positive treatment groups was 0.64 (95% CI 0.44-0.93; two-sided log-rank p=0.016). Event-free survival was strongly associated with pathological complete remission in patients given trastuzumab. Of the 68 patients with a pathological complete response (45 with trastuzumab and 23 with chemotherapy alone), the HR for event-free survival between those with and without trastuzumab was 0.29 (95% CI 0.11-0.78). During follow-up only four cardiovascular adverse events were regarded by the investigator to be drug-related (grade 2 lymphostasis and grade 2 lymphoedema, each in one patient in the trastuzumab group, and grade 2 thrombosis and grade 2 deep vein thrombosis, each in one patient in the chemotherapy-alone group)., Interpretation: These results show a sustained benefit in event-free survival from trastuzumab-containing neoadjuvant therapy followed by adjuvant trastuzumab in patients with locally advanced or inflammatory breast cancer, and provide new insight into the association between pathological complete remission and long-term outcomes in HER2-positive disease., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

In 2009 a prospective, randomized Phase II trial (NCT00842998) was initiated to evaluate the activity of HER2-targeting agents without chemotherapy (CT) in HER2-positive metastatic breast cancer (MBC) patients. The primary tumors of the patients enrolled in this study offered a unique opportunity to identify biomarkers that could predict durable clinical benefit from CT-free anti-HER2 therapy. Patients with HER2-positive MBC were randomized to trastuzumab or lapatinib as first-line therapy. CT was added to anti-HER2 therapy in patients failing to achieve tumor regression at the 8-week evaluation and in those progressing at any time. Expression analysis of 105 selected genes was performed from formalin-fixed paraffin-embedded primary tumor samples. The research-based PAM50 intrinsic subtypes were also identified. Additionally, quantitative HER2 (H2T) and p95HER2 (p95) protein expression were evaluated by HERmark® and VeraTag® assay, respectively. Predictors of persistence on protocol (PP) were studied by Cox univariate and multivariate analysis. Nineteen patients were enrolled. Median overall survival was 43 months and median PP was 3.8 months (0.8-38.8+), with 4 patients (21.1%) persisting on single agent trastuzumab or lapatinib for longer than 12 mo (14.9-38.8 + mo). Seventeen patients were evaluable for PP. Gene expression analysis revealed that high expression of the 17q12-21 amplicon genes HER2 and GRB7, and the PAM50 HER2-enriched intrinsic profile, were significantly associated with longer PP. Conversely, high expression of luminal-related genes such as PGR, MDM2 or PIK3CA, or the PAM50 luminal intrinsic profile correlated with reduced PP. Moreover, increasing H2T/p95 ratio was found to be significantly associated with longer PP (HR 0.56 per 2-fold increase in H2T/p95, P = 0.0015). Our data suggest that patients belonging to the "HER2-enriched" subtype and/or having high H2T/p95 protein expression ratio are exquisitely sensitive to anti-HER2 agents. MBC patients with these tumors could be candidates for studies aimed at establishing chemotherapy-free regimens., (Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Purpose: SAR245408 is a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor. This phase I study determined the maximum tolerated dose (MTD) of two dosing schedules [first 21 days of a 28-day period (21/7) and continuous once-daily dosing (CDD)], pharmacokinetic and pharmacodynamic profiles, and preliminary efficacy., Experimental Design: Patients with refractory advanced solid malignancies were treated with SAR245408 using a 3 + 3 design. Pharmacokinetic parameters were determined after single and repeated doses. Pharmacodynamic effects were evaluated in plasma, hair sheath cells, and skin and tumor biopsies., Results: Sixty-nine patients were enrolled. The MTD of both schedules was 600 mg; dose-limiting toxicities were maculopapular rash and hypersensitivity reaction. The most frequent drug-related adverse events included dermatologic toxicities, diarrhea, nausea, and decreased appetite. Plasma pharmacokinetics showed a median time to maximum concentration of 8 to 22 hours, mean terminal elimination half-life of 70 to 88 hours, and 5- to 13-fold accumulation after daily dosing (first cycle). Steady-state concentration was reached between days 15 and 21, and exposure was dose-proportional with doses up to 400 mg. SAR245408 inhibited the PI3K pathway (∼40%-80% reduction in phosphorylation of AKT, PRAS40, 4EBP1, and S6 in tumor and surrogate tissues) and, unexpectedly, also inhibited the MEK/ERK pathway. A partial response was seen in one patient with advanced non-small cell lung cancer. Eight patients were progression-free at 6 months. Pharmacodynamic and clinical activity were observed irrespective of tumor PI3K pathway molecular alterations., Conclusions: SAR245408 was tolerable at doses associated with PI3K pathway inhibition. The recommended phase II dose of the capsule formulation is 600 mg administered orally with CDD.

Purpose: We investigated the pattern of rash, diarrhea, and hepatic adverse events (AEs) secondary to lapatinib and their association with age and pathologic complete response (pCR) in the Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimisation (NeoALLTO) phase III trial., Patients and Methods: Patients with HER2-positive early breast cancer were randomly assigned to receive lapatinib (Arm A), trastuzumab (Arm B), or their combination (Arm C) for 6 weeks followed by the addition of paclitaxel for 12 weeks before surgery. We investigated the frequency and time to developing each AE according to age (≤ 50 v > 50 years) and their association with pCR in a logistic regression model adjusted for age, hormone receptors, tumor size, nodal status, planned breast surgery, completion of lapatinib administration, and treatment arm., Results: Only patients randomly assigned to arms A and C were eligible (n = 306). Younger patients (≤ 50 years) experienced significantly more rash compared with older patients (74.4% v 47.9%; P < .0001). Diarrhea and hepatic AEs were observed in 78.8% and 41.2% of patients, respectively, with no differences in rate or severity or time of onset according to age. Early rash (ie, before starting paclitaxel) was independently associated with a higher chance of pCR, mainly in patients older than 50 years (odds ratio [OR] = 3.76; 95% CI, 1.69 to 8.34) but not in those ≤ 50 years (OR = 0.92; 95% CI, 0.45 to 1.88; P for interaction = .01). No significant association was observed between pCR and diarrhea or hepatic AEs., Conclusion: Our results indicate that the frequency and clinical relevance of lapatinib-related rash is largely dependent on patient age.

The traditional drug development process in breast cancer based on large phase III studies has serious limitations and needs a major overhaul. Searching for new approaches, the testing of novel agents in the preoperative (neoadjuvant) setting approach offers a potentially rapid and efficient strategy for drug development utilizing pathologic complete response (path CR), a surrogate marker for survival, as the primary endpoint. In addition, neoadjuvant studies allow the assessment of drug effects on the target (pharmacodynamic response) and the development of predictive biomarkers of response. Molecular profiling of the residual tumor in the surgical specimen may also provide insights into actionable mechanisms of resistance. Recognizing the potential of neoadjuvant trials for drug development, the U.S. Food and Drug Administration (FDA) recently announced consideration of neoadjuvant trials for accelerated drug approval in early breast cancer, particularly for tumors with high risk of recurrence and unfavorable prognosis, and provided accelerated approval to neoadjuvant pertuzumab in September 2013. The FDA has emphasized that while improvement in path CR could be utilized for "accelerated" approval, improvement in survival will still need to be demonstrated for "regular" approval. Key considerations in conduct of such neoadjuvant drug development trials include (i) study design such as utilization of biomarker stratified design to evaluate a biomarker that could enrich response, (ii) definition of path CR, (iii) distribution of factors that influence path CR between the treatment arms, (iv) prespecified plan for follow-up to obtain data on survival, and (v) safety as it involves a patient population with curable disease. In the years to come, we anticipate an increase in the number of neoadjuvant trials testing novel therapies that hopefully will open a new path in bringing efficacious new therapies to patients with breast cancer., (©2013 AACR.)

Background: Trastuzumab has established efficacy against breast cancer with overexpression or amplification of the HER2 oncogene. The standard of care is 1 year of adjuvant trastuzumab, but the optimum duration of treatment is unknown. We compared 2 years of treatment with trastuzumab with 1 year of treatment, and updated the comparison of 1 year of trastuzumab versus observation at a median follow-up of 8 years, for patients enrolled in the HERceptin Adjuvant (HERA) trial., Methods: The HERA trial is an international, multicentre, randomised, open-label, phase 3 trial comparing treatment with trastuzumab for 1 and 2 years with observation after standard neoadjuvant chemotherapy, adjuvant chemotherapy, or both in 5102 patients with HER2-positive early breast cancer. The primary endpoint was disease-free survival. The comparison of 2 years versus 1 year of trastuzumab treatment involved a landmark analysis of 3105 patients who were disease-free 12 months after randomisation to one of the trastuzumab groups, and was planned after observing at least 725 disease-free survival events. The updated intention-to-treat comparison of 1 year trastuzumab treatment versus observation alone in 3399 patients at a median follow-up of 8 years (range 0-10) is also reported. This study is registered with ClinicalTrials.gov, number NCT00045032., Findings: We recorded 367 events of disease-free survival in 1552 patients in the 1 year group and 367 events in 1553 patients in the 2 year group (hazard ratio [HR] 0·99, 95% CI 0·85-1·14, p=0·86). Grade 3-4 adverse events and decreases in left ventricular ejection fraction during treatment were reported more frequently in the 2 year treatment group than in the 1 year group (342 [20·4%] vs 275 [16·3%] grade 3-4 adverse events, and 120 [7·2%] vs 69 [4·1%] decreases in left ventricular ejection fraction, respectively). HRs for a comparison of 1 year of trastuzumab treatment versus observation were 0·76 (95% CI 0·67-0·86, p<0·0001) for disease-free survival and 0·76 (0·65-0·88, p=0·0005) for overall survival, despite crossover of 884 (52%) patients from the observation group to trastuzumab therapy., Interpretation: 2 years of adjuvant trastuzumab is not more effective than is 1 year of treatment for patients with HER2-positive early breast cancer. 1 year of treatment provides a significant disease-free and overall survival benefit compared with observation and remains the standard of care., Funding: F Hoffmann-La Roche (Roche)., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Purpose: Fibroblast growth factor receptor 1 (FGFR1) and FGFR2 amplifications are observed in approximately 10% of breast cancers and are related to poor outcomes. We evaluated whether dovitinib (TKI258), an inhibitor of FGFR1, FGFR2, and FGFR3, presented antitumor activity in FGFR-amplified breast cancers., Experimental Design: Preclinical activity of dovitinib was evaluated in both breast cancer cell lines and an FGFR1-amplified xenograft model (HBCx2). Dovitinib was then evaluated in a phase II trial that included 4 groups of patients with human EGF receptor 2-negative metastatic breast cancer on the basis of FGFR1 amplification and hormone receptor (HR) status. FGFR1 amplification was assessed by silver in situ hybridization. Preplanned retrospective analyses assessed predictive value of FGFR1, FGFR2, and FGF3 amplifications by quantitative PCR (qPCR)., Results: Dovitinib monotherapy inhibits proliferation in FGFR1- and FGFR2-amplified, but not FGFR-normal, breast cancer cell lines. Dovitinib also inhibits tumor growth in FGFR1-amplified breast cancer xenografts. Eighty-one patients were enrolled in the trial. Unconfirmed response or stable disease for more than 6 months was observed in 5 (25%) and 1 (3%) patient(s) with FGFR1-amplified/HR-positive and FGFR1-nonamplified/HR-positive breast cancer. When qPCR-identified amplifications in FGFR1, FGFR2, or FGF3 were grouped to define an FGF pathway-amplified breast cancer in HR-positive patients, the mean reduction in target lesions was 21.1% compared with a 12.0% increase in patients who did not present with FGF pathway-amplified breast cancer., Conclusion: Dovitinib showed antitumor activity in FGFR-amplified breast cancer cell lines and may have activity in breast cancers with FGF pathway amplification., (©2013 AACR.)

The PI3K signaling pathway regulates diverse cellular processes, including proliferation, survival, and metabolism, and is aberrantly activated in human cancer. As such, numerous compounds targeting the PI3K pathway are currently being clinically evaluated for the treatment of cancer, and several have shown some early indications of efficacy in breast cancer. However, resistance against these agents, both de novo and acquired, may ultimately limit the efficacy of these compounds. Here, we have taken a systematic functional approach to uncovering potential mechanisms of resistance to PI3K inhibitors and have identified several genes whose expression promotes survival under conditions of PI3K/mammalian target of rapamycin (PI3K/mTOR) blockade, including the ribosomal S6 kinases RPS6KA2 (RSK3) and RPS6KA6 (RSK4). We demonstrate that overexpression of RSK3 or RSK4 supports proliferation upon PI3K inhibition both in vitro and in vivo, in part through the attenuation of the apoptotic response and upregulation of protein translation. Notably, the addition of MEK- or RSK-specific inhibitors can overcome these resistance phenotypes, both in breast cancer cell lines and patient-derived xenograft models with elevated levels of RSK activity. These observations provide a strong rationale for the combined use of RSK and PI3K pathway inhibitors to elicit favorable responses in breast cancer patients with activated RSK.

Purpose: To evaluate the benefit of adjuvant trastuzumab in patients diagnosed with human epidermal growth factor receptor 2 (HER2) -positive invasive lobular carcinoma (ILC) enrolled onto the Herceptin Adjuvant (HERA) trial., Patients and Methods: Patients randomly assigned to receive one year of trastuzumab and one year of observation in the HERA trial were included (n = 3,401). Centrally reviewed estrogen receptor (ER), progesterone receptor (PgR), and HER2 copy numbers were used. First site-specific relapse pattern was evaluated for ILC and invasive ductal carcinoma (IDC). The magnitude of trastuzumab benefit was assessed using the Cox proportional hazards model for disease-free survival (DFS) and overall survival (OS)., Results: Median follow-up time was 4 years. A total of 187 ILC and 3,213 IDC patients were included. High Allred scores (6 to 8) were more common in patients with ILC than IDC for both ER (36.9% v 22.7%) and PgR (44.1% v 28.5%). A trend toward decreased HER2 copy number was observed in the ILC group. The ILC and IDC subgroups had similar patterns of first site of disease relapse. DFS hazard ratios (HRs) comparing 1 year of trastuzumab versus observation were 0.63 for ILC (95% CI, 0.34 to 1.15) and 0.77 for IDC (95% CI, 0.67 to 0.89; P for interaction = .49). The OS HRs comparing 1 year of trastuzumab versus observation were 0.60 for ILC (95% CI, 0.27 to 1.31) and 0.86 for IDC (95% CI, 0.71 to 1.06; P for interaction = .29)., Conclusion: In this retrospective analysis, there was no suggestion that patients in the ILC cohort experienced a different magnitude of benefit from adjuvant trastuzumab than those in the IDC cohort.

Background: Breast Cancer Trials of Oral Everolimus 2 (BOLERO-2), a phase III study in postmenopausal women with estrogen receptor-positive breast cancer progressing despite nonsteroidal aromatase inhibitor therapy, showed statistically significant benefits with adding everolimus to exemestane. Moreover, in preclinical studies, mammalian target of rapamycin inhibition was associated with decreased osteoclast survival and activity. Exploratory analyses in BOLERO-2 evaluated the effect of everolimus on bone marker levels and progressive disease in bone., Methods: Patients were treated with exemestane (25mg/day) and randomized (2:1) to everolimus (10mg/day; combination) or placebo (exemestane only). Exploratory endpoints included changes in bone turnover marker levels vs baseline and progressive disease in bone, defined as unequivocal progression of a preexisting bone lesion or the appearance of a new bone lesion., Results: Baseline disease characteristics were well balanced between arms (N = 724); baseline bisphosphonate use was not (43.9% combination vs 54.0% exemestane only). At a median of 18 months of follow-up, median progression-free survival (primary endpoint) was statistically significantly longer with the combination vs exemestane only (Cox proportional hazard ratio = 0.45, 95% confidence interval = 0.38 to 0.54; log-rank, 1-sided P < .0001). Bone marker levels at 6 and 12 weeks increased with exemestane only, as expected, but decreased with the combination. The cumulative incidence rate of progressive disease in bone was lower in the combination arm. Bone-related adverse events occurred with similar frequency in both arms (3.3% combination vs 4.2% exemestane only)., Conclusion: These exploratory analyses suggest that everolimus has beneficial effects on bone turnover and progressive disease in bone in patients receiving exemestane for hormone receptor-positive breast cancer progressing during/after nonsteroidal aromatase inhibitor therapy.

Extensive preclinical experimentation has conceptually changed the way we perceive breast cancer, with the wide spectrum of genomic alterations governing its malignant progression now being recognized. Functional genomics has helped us identify important genetic defects that can be pharmaceutically targeted in the setting of metastatic disease. Rationally chosen combination regimens are now under clinical investigation. Recent data underline the functional importance of the tumour-associated stroma, with several candidate molecular targets now emerging. Data elucidating a cellular hierarchy within the breast cancer cellular compartment support the existence of a therapy-resistant subpopulation of breast cancer stem cells. Identification of the developmental pathways that dictate their malignant phenotype and use of high-throughput screening techniques are leading to new therapeutic avenues. In this Review, we present the biological rationale for the clinical development of more than 15 different classes of targeted agents in breast cancer, along with evidence supporting rational combinations. However, metastatic breast cancer resembles a Darwinian evolutionary system, with 'driver' mutations and epigenetic changes determining clonal selection according to branching trajectories. This evolution is reflected in the molecular heterogeneity of the disease and poses severe impediments to the successful clinical development of emerging targeted agents.

Purpose: In this first-in-human study of AEE788, a tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR), HER-2, and VEGFR-2, a comprehensive pharmacodynamic program was implemented in addition to the evaluation of safety, pharmacokinetics, and preliminary efficacy of AEE788 in cancer patients., Experimental Design: Patients with advanced, solid tumors received escalating doses of oral AEE788 once daily. Primary endpoints were to determine dose-limiting toxicities (DLTs) and maximum-tolerated dose (MTD). A nonlinear model (Emax model) was used to describe the relationship between AEE788 exposure and target-pathway modulation in skin and tumor tissues., Results: Overall, 111 patients were treated (25 to 550 mg/day). DLTs included rash and diarrhea; MTD was 450 mg/day. Effects on biomarkers correlated to serum AEE788 concentrations. The concentration at 50% inhibition (IC(50)) for EGFR in skin (0.033 μmol/L) and tumor (0.0125 μmol/L) were similar to IC(50) in vitro suggesting skin may be surrogate tissue for estimating tumor EGFR inhibition. No inhibition of p-MAPK and Ki67 was observed in skin vessels at ≤ MTD. Hence, AEE788 inhibited EGFR, but not VEGFR, at doses ≤ MTD. A total of 16 of 96 evaluable patients showed a >10% shrinkage of tumor size; one partial response was observed., Conclusion: Our pharmacodynamic-based study showed effective inhibition of EGFR, but not of VEGFR at tolerable AEE788 doses. Emax modeling integrated with biomarker data effectively guided real-time decision making in the early development of AEE788. Despite clinical activity, target inhibition of only EGFR led to discontinuation of further AEE788 development., (©2012 AACR.)

Background: Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate incorporating the human epidermal growth factor receptor 2 (HER2)-targeted antitumor properties of trastuzumab with the cytotoxic activity of the microtubule-inhibitory agent DM1. The antibody and the cytotoxic agent are conjugated by means of a stable linker., Methods: We randomly assigned patients with HER2-positive advanced breast cancer, who had previously been treated with trastuzumab and a taxane, to T-DM1 or lapatinib plus capecitabine. The primary end points were progression-free survival (as assessed by independent review), overall survival, and safety. Secondary end points included progression-free survival (investigator-assessed), the objective response rate, and the time to symptom progression. Two interim analyses of overall survival were conducted., Results: Among 991 randomly assigned patients, median progression-free survival as assessed by independent review was 9.6 months with T-DM1 versus 6.4 months with lapatinib plus capecitabine (hazard ratio for progression or death from any cause, 0.65; 95% confidence interval [CI], 0.55 to 0.77; P<0.001), and median overall survival at the second interim analysis crossed the stopping boundary for efficacy (30.9 months vs. 25.1 months; hazard ratio for death from any cause, 0.68; 95% CI, 0.55 to 0.85; P<0.001). The objective response rate was higher with T-DM1 (43.6%, vs. 30.8% with lapatinib plus capecitabine; P<0.001); results for all additional secondary end points favored T-DM1. Rates of grade 3 or 4 adverse events were higher with lapatinib plus capecitabine than with T-DM1 (57% vs. 41%). The incidences of thrombocytopenia and increased serum aminotransferase levels were higher with T-DM1, whereas the incidences of diarrhea, nausea, vomiting, and palmar-plantar erythrodysesthesia were higher with lapatinib plus capecitabine., Conclusions: T-DM1 significantly prolonged progression-free and overall survival with less toxicity than lapatinib plus capecitabine in patients with HER2-positive advanced breast cancer previously treated with trastuzumab and a taxane. (Funded by F. Hoffmann-La Roche/Genentech; EMILIA ClinicalTrials.gov number, NCT00829166.).

Background: This phase I dose-escalation study investigated the maximum tolerated dose (MTD), safety, pharmacokinetics, pharmacodynamics (PDs), and preliminary antitumor activity of BGT226, a potent, oral dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin inhibitor., Patients and Methods: Fifty-seven patients with advanced solid tumors received BGT226 2.5-125 mg/day three times weekly (TIW). Dose escalation was guided by an adaptive Bayesian logistic regression model with overdose control. Assessments included response per RECIST, [18F]-fluorodeoxyglucose uptake, and phosphorylated-S6 in skin and paired tumor samples., Results: Three patients (125 mg cohort) had dose-limiting toxic effects (grade 3 nausea/vomiting, diarrhea). BGT226-related adverse events included nausea (68%), diarrhea (61%), vomiting (49%), and fatigue (19%). BGT226 demonstrated rapid absorption, variable systemic exposure, and a median half-life of 6-9 h. Seventeen patients (30%) had stable disease (SD) as best response. Nine patients had SD for ≥16 weeks. Thirty patients (53%) achieved stable metabolic disease as assessed by [18F]-fluorodeoxyglucose-positron emission tomography; however, no correlation between metabolic response and tumor shrinkage according to computed tomography was observed. PD changes suggested PI3K pathway inhibition but were inconsistent., Conclusions: The MTD of BGT226 was 125 mg/day TIW, and the clinically recommended dose was 100 mg/day TIW. Limited preliminary antitumor activity and inconsistent target inhibition were observed, potentially due to low systemic exposure.

Purpose: Aurora A kinase (AAK) is a key regulator of mitosis and a target for anticancer drug development. This phase I study investigated the safety, pharmacokinetics, and pharmacodynamics of MLN8237 (alisertib), an investigational, oral, selective AAK inhibitor, in 59 adults with advanced solid tumors., Experimental Design: Patients received MLN8237 once daily or twice daily for 7, 14, or 21 consecutive days, followed by 14 days recovery, in 21-, 28-, or 35-day cycles. Dose-limiting toxicities (DLT) and the maximum-tolerated dose (MTD) for the 7- and 21-day schedules were determined. Pharmacokinetic parameters were derived from plasma concentration-time profiles. AAK inhibition in skin and tumor biopsies was evaluated and antitumor activity assessed., Results: Neutropenia and stomatitis were the most common DLTs. The MTD for the 7- and 21-day schedules was 50 mg twice daily and 50 mg once daily, respectively. MLN8237 absorption was fast (median time to maximum concentration, 2 hours). Mean terminal half-life was approximately 19 hours. At steady state, pharmacodynamic effects were shown by accumulation of mitotic and apoptotic cells in skin, and exposure-related increases in numbers of mitotic cells with characteristic spindle and chromosomal abnormalities in tumor specimens, supporting AAK inhibition by MLN8237. Stable disease was observed and was durable with repeat treatment cycles, administered over 6 months, in 6 patients, without notable cumulative toxicity., Conclusions: The recommended phase II dose of MLN8237 is 50 mg twice daily on the 7-day schedule, which is being evaluated further in a variety of malignancies, including in a phase III trial in peripheral T-cell lymphoma., (©2012 AACR.)

Background: Elderly breast cancer patients are usually excluded from clinical trials. Nevertheless, with the increasing use of trastuzumab, there is a need to address trastuzumab-related cardiotoxicity in this population., Patients and Methods: Records for patients ≥ 70 years treated with trastuzumab since 2005 were reviewed. New York Heart Association classification was used to document symptomatic cardiotoxicity. Asymptomatic cardiotoxicity was defined as an absolute drop ≥ 10% with a final left ventricular ejection fraction < 50% or an absolute drop > 20%., Results: Forty-five patients, median age 75.9 years (range 70-92), were identified. Three of 24 (12.5%) early breast cancer patients and 5 of 21 (23.8%) with advanced disease experienced asymptomatic cardiotoxicity. Four of 45 patients (8.9%), all with advanced breast cancer, developed symptomatic congestive heart failure. All but one of them recovered in a median time of 5 weeks (range 3-21). Patients with trastuzumab-related cardiotoxicity presented more often with cardiovascular risk factors, such as history of cardiac disease (33% versus 9.1%, P = 0.017) and diabetes (33.3% versus 6.1%, P = 0.010), compared with those without., Conclusions: Elderly breast cancer patients with a history of cardiac disease and/or diabetes treated with trastuzumab have an increased incidence of cardiotoxicity. Continuous cardiac monitoring is especially advised in this population.

Background: Pertuzumab, a human epidermal growth factor receptor (HER) 2 dimerization inhibitor, has demonstrated promising efficacy in combination with trastuzumab in patients with metastatic breast cancer. As HER signaling pathways are not only involved in oncogenesis, but also in myocardial homeostasis, an analysis of cardiac safety data was undertaken in a large group of patients treated with pertuzumab., Patients and Methods: A complete database of patients treated with full-dose pertuzumab was used to describe the incidence of asymptomatic left ventricular systolic dysfunction (LVSD) and symptomatic heart failure (HF)., Results: Information for 598 unique patients was available for the current analysis. Of the patients treated with pertuzumab alone (n = 331) or pertuzumab in combination with a non-anthracycline-containing cytotoxic (n = 175) or trastuzumab (n = 93), 23 (6.9%), 6 (3.4%), and 6 (6.5%), respectively, developed asymptomatic LVSD and 1 (0.3%), 2 (1.1%), and 1 (1.1%), respectively, displayed symptomatic HF. None of the 15 patients receiving both pertuzumab and erlotinib demonstrated LVSD., Conclusions: Patients treated with pertuzumab experienced relatively low levels of asymptomatic LVSD or symptomatic HF. There was no notable increase in cardiac side-effects when pertuzumab was given in combination with other anticancer agents.

Purpose: We studied the safety, tolerability, and recommended dose of BMS-599626, an orally bioavailable inhibitor of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases., Patients and Methods: Patients with advanced solid tumors that expressed epidermal growth factor receptor (EGFR) and/or HER-2 were recruited and enrolled in a phase I, open-label, dose escalation trial of oral BMS-599626 starting at 100 mg/day given once daily for at least 28 days., Results: Forty-five patients received BMS-599626 (100-660 mg/day). Dose-limiting toxic effects were reported at 660 mg/day (grade 3 elevation of hepatic transaminases [two patients] and QTc interval prolongation [one patient]), therefore the recommended maximum tolerated dose was 600 mg/day. The most frequent drug-related toxic effects were diarrhea (30% of patients), anorexia (13%), asthenia (30%), and cutaneous toxic effects, including skin rash (30%). Pharmacokinetic analysis demonstrated C(max) and exposure to BMS-599626 in patients increased with dose. Eleven patients had stable disease and received BMS-599626 for ≥ 4 months. Serial skin and tumor biopsies taken before and after treatment revealed expected changes in pharmacodynamic biomarkers, indicating that the EGFR and HER-2 pathways were affected. Positron emission tomography imaging showed a metabolic response in 2 of 10 patients evaluated., Conclusion: BMS-599626 was generally well tolerated, with disease stabilization across a range of tumor types and doses.

Recent advances in tumor genetics and drug development have led to the generation of a wealth of anticancer targeted therapies. A few recent examples indicate that these drugs are mainly, if not exclusively, active against tumors of a particular genotype that can be identified by a diagnostic test, usually by detecting a somatic alteration in the tumor DNA. However, for the majority of targeted therapies in development, there are still no clinical tools to determine which patients are most likely to benefit or, alternatively, be resistant de novo to these novel agents or drug combinations.

Background: ES-285 (Spisulosine) is a novel marine compound with antitumor activity in preclinical studies. A phase I study was performed in patients with advanced solid tumors to determine the maximum tolerated dose (MTD), establish a safety profile, and to evaluate pharmacokinetics and efficacy of the drug., Patients and Methods: Thirty patients from two centers were treated with a three-hour ES-285 intravenous infusion for five consecutive days, every 3 weeks. Eleven dose levels were explored., Results: No dose-limiting toxicity (DLT) occurred from 2 to 81 mg/m²/day. Three patients had DLT, one each at dose levels 160, 120 and 100 mg/m²/day; all had grade 4 transaminase increases, one of whom (160 mg/m²/day) had concomitant grade 4 hepatitis and grade 3 bilirubin elevation. The MTD of this regimen was not reached due to early termination of the ES-285 phase I program, but was considered to be 80 to 100 mg/m²/day. Other toxicities included mild to moderate asthenia, nausea, vomiting, anemia, lymphopenia, and injection site reaction. Pharmacokinetic analyses showed dose proportionality on Days 1 and 5, a wide distribution and a long half-life. Seven patients (five with colorectal cancer) had stable disease (1.2-4.1 months), lasting for more than 3 months in three patients., Conclusions: Liver enzyme elevations were dose limiting for ES-285 in this administration schedule. Low antitumor activity was observed.

Purpose: We conducted a phase I dose-escalation study to characterize the safety, efficacy, pharmacokinetic (PK), and pharmacodynamic properties of RG7160 (GA201), a humanized and glycoengineered immunoglobulin G(1) anti-epidermal growth factor receptor (EGFR) monoclonal antibody with enhanced antibody-dependent cell-mediated cytotoxicity., Patients and Methods: Seventy-five patients with advanced EGFR-positive solid tumors received RG7160 (50 to 1,400 mg) administered every week, every 2 weeks, or every 3 weeks. Dose escalation followed a three-plus-three trial design., Results: No maximum-tolerated dose was reached for any dosing schedule. Common adverse events (AEs) included rash (80% of patients), infusion-related reactions (77%), and hypomagnesemia (56%). Grades 3 and 4 AEs were rash (grade 3, 25%), infusion-related reaction (grade 3, 7%; grade 4, 1%), paronychia (grade 3, 3%), and hypomagnesemia (grade 3, 1%; grade 4, 1%). RG7160 exposure increased greater than proportionally over the 50- to 400-mg dose range (with greater than proportional decline in clearance) and approximately dose proportionally above 400 mg (where clearance plateaued). A marked reduction in circulating natural killer cells and increased infiltration of immune effector cells into skin rash were seen. Clinical efficacy included one complete response and two partial responses in patients with colorectal cancer (including one with KRAS mutation) and disease stabilization in 27 patients., Conclusion: RG7160 had an acceptable safety profile with manageable AEs and demonstrated promising efficacy in this heavily pretreated patient cohort. On the basis of modeling of available PK parameters, the RG7160 dose selected for part two of this study is 1,400 mg on days 1 and 8 followed by 1,400 mg every 2 weeks.

Hsp90 facilitates the maturation and stability of numerous oncoproteins, including HER2. The aim of this study was to assess the antitumor activity of the Hsp90 inhibitor IPI-504 in trastuzumab-resistant, HER2-overexpressing breast cancer cells. Therapy with trastuzumab, IPI-504, and the combination of trastuzumab and IPI-504 was evaluated in trastuzumab-sensitive and trastuzumab-resistant cells. Inhibition of protein targets, cell proliferation, and tumor growth was assessed in vitro and in xenograft models. IPI-504 inhibited proliferation of both trastuzumab-sensitive and trastuzumab-resistant cells. Administration of IPI-504 markedly reduced total levels of HER2 and Akt, as well as phosphorylated Akt and mitogen-activated protein kinase (MAPK), to an equal extent in trastuzumab-sensitive and trastuzumab-resistant cells. IPI-504, used as single agent or in combination with trastuzumab, also inhibited in vivo the growth of both trastuzumab-sensitive and -resistant tumor xenografts. As a mechanism for the observed antitumor activity, IPI-504 resulted in a marked decrease in the levels of HER2, Akt, p-Akt, and p-MAPK in trastuzumab-resistant xenografts as early as 12 hours after a single dose of IPI-504. IPI-504-mediated Hsp90 inhibition may represent a novel therapeutic approach in trastuzumab refractory HER2-positive breast cancer.

Background: Treatment with adjuvant trastuzumab for 1 year improves disease-free survival and overall survival in patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. We aimed to assess disease-free survival and overall survival after a median follow-up of 4 years for patients enrolled on the Herceptin Adjuvant (HERA) trial., Methods: The HERA trial is an international, multicentre, randomised, open-label, phase 3 trial comparing treatment with trastuzumab for 1 and 2 years with observation after standard neoadjuvant, adjuvant chemotherapy, or both in patients with HER2-positive early breast cancer. The primary endpoint was disease-free survival. After a positive first interim analysis at a median follow-up of 1 year for the comparison of treatment with trastuzumab for 1 year with observation, event-free patients in the observation group were allowed to cross over to receive trastuzumab. We report trial outcomes for the 1-year trastuzumab and observation groups at a median follow-up of 48·4 months (IQR 42·0-56·5) and assess the effect of the extensive crossover to trastuzumab. Our analysis was by intention-to-treat. The HERA trial is registered with the European Clinical Trials Database, number 2005-002385-11., Findings: The HERA trial population comprised 1698 patients randomly assigned to the observation group and 1703 to the 1-year trastuzumab group. Intention-to-treat analysis of disease-free survival showed a significant benefit in favour of patients in the 1-year trastuzumab group (4-year disease-free survival 78·6%) compared with the observation group (4-year disease-free survival 72·2%; hazard ratio [HR] 0·76; 95% CI 0·66-0·87; p<0·0001). Intention-to-treat analysis of overall survival showed no significant difference in the risk of death (4-year overall survival 89·3%vs 87·7%, respectively; HR 0·85; 95% CI 0·70-1·04; p=0·11). Overall, 885 patients (52%) of the 1698 patients in the observation group crossed over to receive trastuzumab, and began treatment at median 22·8 months (range 4·5-52·7) from randomisation. In a non-randomised comparison, patients in the selective-crossover cohort had fewer disease-free survival events than patients remaining in the observation group (adjusted HR 0·68; 95% CI 0·51-0·90; p=0·0077). Higher incidences of grade 3-4 and fatal adverse events were noted on 1-year trastuzumab than in the observation group. The most common grade 3 or 4 adverse events, each in less than 1% of patients, were congestive cardiac failure, hypertension, arthralgia, back pain, central-line infection, hot flush, headache, and diarrhoea., Interpretation: Treatment with adjuvant trastuzumab for 1 year after chemotherapy is associated with significant clinical benefit at 4-year median follow-up. The substantial selective crossover of patients in the observation group to trastuzumab was associated with improved outcomes for this cohort., Funding: F Hoffmann-La Roche, Michelangelo Foundation., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Mutations in the TP53 gene are a feature of 50% of all reported cancer cases. In the other 50% of cases, the TP53 gene itself is not mutated but the p53 pathway is often partially inactivated. Cancer therapies that target specific mutant genes are proving to be highly active and trials assessing agents that exploit the p53 system are ongoing. Many trials are aimed at stratifying patients on the basis of TP53 status. In another approach, TP53 is delivered as a gene therapy; this is the only currently approved p53-based treatment. The p53 protein is overexpressed in many cancers and p53-based vaccines are undergoing trials. Processed cell-surface p53 is being exploited as a target for protein-drug conjugates, and small-molecule drugs that inhibit the activity of MDM2, the E3 ligase that regulates p53 levels, have been developed by several companies. The first MDM2 inhibitors are being trialed in both hematologic and solid malignancies. Finally, the first agent found to restore the active function of mutant TP53 has just entered the clinic. Here we discuss the basis of these trials and the future of p53-based therapy.