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Biomedical subjects

Jose Baselga

Publications and source records attributed to Jose Baselga.

At least 19 recordsLinked to original sources
PubMed2007

2-year follow-up of trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer: a randomised controlled trial.

BACKGROUND: Trastuzumab--a humanised monoclonal antibody against HER2--has been shown to improve disease-free survival after chemotherapy in women with HER2-positive early breast cancer. We investigated the drug's effect on overall survival after a median follow-up of 2 years in the Herceptin Adjuvant (HERA) study. METHODS: HERA is an international multicentre randomised trial that compared 1 or 2 years of trastuzumab treatment with observation alone after standard neoadjuvant or adjuvant chemotherapy in women with HER2-positive node positive or high-risk node negative breast cancer. 5102 women participated in the trial; we analysed data from 1703 women who had been randomised for treatment with trastuzumab for 1 year and 1698 women from the control group, with median follow-up of 23.5 months (range 0-48 months). The primary endpoint of the trial was disease-free survival. Here, we assess overall survival, a secondary endpoint. Analyses were done on an intent-to-treat basis. This trial is registered with the European Clinical Trials Database, number 2005-002385-11. FINDINGS: 97 (5.7%) patients randomised to observation alone and 58 (3.4%) patients randomised to 1 year of treatment with trastuzumab were lost to follow-up. 172 women stopped trastuzumab prematurely. 59 deaths were reported for trastuzumab and 90 in the control group. The unadjusted hazard ratio (HR) for the risk of death with trastuzumab compared with observation alone was 0.66 (95% CI 0.47-0.91; p=0.0115). 218 disease-free survival events were reported with trastuzumab compared with 321 in the control group. The unadjusted HR for the risk of an event with trastuzumab compared with observation alone was 0.64 (0.54-0.76; p<0.0001). INTERPRETATION: Our results show that 1 year of treatment with trastuzumab after adjuvant chemotherapy has a significant overall survival benefit after a median follow-up of 2 years. The emergence of this benefit after only 2 years reinforces the importance of trastuzumab in the treatment of women with HER2-positive early breast cancer.

Adult↗
PubMed2007

4E-binding protein 1, a cell signaling hallmark in breast cancer that correlates with pathologic grade and prognosis.

PURPOSE: Cell signaling pathways include a complex myriad of interconnected factors from the membrane to the nucleus, such as erbB family receptors and the phosphoinositide-3-kinase/Akt/mTOR and Ras-Raf-ERK cascades, which drive proliferative signals, promote survival, and regulate protein synthesis. EXPERIMENTAL DESIGN: To find pivotal factors in these pathways, which provide prognostic information in malignancies, we studied 103 human breast tumors with an immunohistochemical profile, including total and phosphorylated (p) proteins: human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor, extracellular signal-regulated kinase 1/2, Akt, 4E-binding protein 1 (4EBP1), eukaryotic initiation factor 4E, phosphorylated ribosomal protein S6 kinase 1, phosphorylated ribosomal protein S6, and Ki67. Western blot and reverse lysate protein arrays were also done in a subset of tumors. RESULTS: Significantly, activation of the phosphoinositide-3-kinase/Akt/mTOR cascade was detected in a high proportion of tumors (41.9%). Tumors with HER2 overexpression showed higher p-Akt as compared with negative tumors (P < 0.001). Levels of p-Akt correlated with the downstream molecules, p-4EBP1 (P = 0.001) and p-p70S6K (P = 0.05). Although 81.5% of tumors expressed p-4EBP1, in 16.3% of these tumors, concomitant activation of the upstream factors was not detected. Interestingly, p-4EBP1 was mainly expressed in poorly differentiated tumors (P < 0.001) and correlated with tumor size (P < 0.001), presence of lymph node metastasis (P = 0.002), and locoregional recurrences (P = 0.002). Coexpression of p-4EBP1 and p-eIF4G correlated with a high tumor proliferation rate (P = 0.012). CONCLUSION: In this study, p-4EBP1 was the main factor in signaling pathways that associate with prognosis and grade of malignancy in breast tumors. Moreover, p-4EBP1 was detected in both HER2-positive and HER2-negative tumors. This factor seems to be a channeling point at which different upstream oncogenic alterations converge and transmit their proliferative signal, modulating protein translation.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Phosphorylated 4E binding protein 1: a hallmark of cell signaling that correlates with survival in ovarian cancer.

BACKGROUND: Growth factor receptors and cell signaling factors play a crucial role in human carcinomas and have been studied in ovarian tumors with varying results. Cell signaling involves multiple pathways and a myriad of factors that can be mutated or amplified. Cell signaling is driven through the mammalian target of rapamycin (mTOR) and extracellular regulated kinase (ERK) pathways and by some downstream molecules, such as 4E binding protein 1 (4EBP1), eukaryotic initiation factor 4E, and p70 ribosomal protein S6 kinase (p70S6K). The objectives of this study were to analyze the real role that these pathways play in ovarian cancer, to correlate them with clinicopathologic characteristics, and to identify the factors that transmit individual proliferation signals and are associated with pathologic grade and prognosis, regardless specific oncogenic alterations upstream. METHODS: One hundred twenty-nine ovarian epithelial tumors were studied, including 20 serous cystadenomas, 7 mucinous cystadenomas, 11 serous borderline tumors, 16 mucinous borderline tumors, 29 serous carcinomas, 16 endometrioid carcinomas, 15 clear cell carcinomas, and 15 mucinous carcinomas. Tissue microarrays were constructed, and immunohistochemistry for the receptors epidermal growth factor receptor (EGFR) and c-erb-B2 was performed and with phosphorylated antibodies for protein kinase B (AKT), 4EBP1, p70S6K, S6, and ERK. RESULTS: Among 129 ovarian neoplasms, 17.8% were positive for c-erb-B2, 9.3% were positive for EGFR, 47.3% were positive for phosphorylated AKT (p-AKT), 58.9% were positive for p-ERK, 41.1% were positive for p-4EBP1, 26.4% were positive for p70S6K, and 15.5% were positive for p-S6. Although EGFR, p-AKT, and p-ERK expression did not differ between benign, borderline, or malignant tumors, c-erb-B2, p-4EBP1, p-p70S6K, and p-S6 were expressed significantly more often in malignant tumors. Only p-4EBP1 expression demonstrated prognostic significance (P = .005), and only surgical stage and p-4EBP1 expression had statistical significance in the multivariate analysis. CONCLUSIONS: In patients with ovarian carcinoma, significant expression of p-4EBP1 was associated with high-grade tumors and a poor prognosis, regardless other oncogenic alterations upstream. This finding supports the study of this factor as a hallmark or pivotal factor in cell signaling in ovarian carcinoma that may crucial in the transmission of the proliferation cell signal and may reflect the real oncogenic role of this pathway in ovarian tumors.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Targeting tyrosine kinases in cancer: the second wave.

One of the most exciting developments in cancer research in recent years has been the clinical validation of molecularly targeted drugs that inhibit the action of pathogenic tyrosine kinases. Treatment of appropriately selected patients with these drugs can alter the natural history of their disease and improve survival. The clinical validation of these "first-generation" tyrosine kinase inhibitors has been the prelude to a second wave of advances in molecular targeting that is expected to further change the way we classify and treat cancer. Efforts are now being directed at identifying the tumor subtypes and patients who will benefit the most from these drugs. In addition, new compounds that circumvent acquired resistance to the first-generation tyrosine kinase inhibitors are being tested in patients with refractory disease. Agents directed against new molecular targets are also being explored.

Antibodies, Monoclonal↗
PubMed2006

Reduction of cytosolic p27(Kip1) inhibits cancer cell motility, survival, and tumorigenicity.

We generated a p27(Kip1) mutant (p27deltaNLS) that localized exclusively in cell cytosol. Expression of p27deltaNLS in MCF7 breast cancer cells down-regulated RhoA and increased motility, survival, and Akt levels without an effect on cell cycle distribution. RNA interference of p27 in U87 glioma cells, which express p27 predominantly in the cytoplasm, inhibited motility and survival. Conversely, knockdown of p27 in COS7 cells, with >95% nuclear p27 expression, accelerated proliferation but had no effect on motility or survival. U87 cells in which p27 had been eliminated by RNA interference exhibited lower Akt levels, shorter Akt turnover, and markedly impaired tumorigenicity in vivo. These xenografts were less invasive and exhibited increased apoptosis compared with p27-expressing tumors. Expression of cytosolic p27 in primary human breast carcinomas correlated linearly with Akt content as measured by immunohistochemistry. These data suggest that cytoplasmic p27 can exert oncogenic functions by modulating Akt stability, cell survival, and tumorigenicity.

Amino Acid Sequence↗
PubMed2006

Radiotherapy plus cetuximab for squamous-cell carcinoma of the head and neck.

BACKGROUND: We conducted a multinational, randomized study to compare radiotherapy alone with radiotherapy plus cetuximab, a monoclonal antibody against the epidermal growth factor receptor, in the treatment of locoregionally advanced squamous-cell carcinoma of the head and neck. METHODS: Patients with locoregionally advanced head and neck cancer were randomly assigned to treatment with high-dose radiotherapy alone (213 patients) or high-dose radiotherapy plus weekly cetuximab (211 patients) at an initial dose of 400 mg per square meter of body-surface area, followed by 250 mg per square meter weekly for the duration of radiotherapy. The primary end point was the duration of control of locoregional disease; secondary end points were overall survival, progression-free survival, the response rate, and safety. RESULTS: The median duration of locoregional control was 24.4 months among patients treated with cetuximab plus radiotherapy and 14.9 months among those given radiotherapy alone (hazard ratio for locoregional progression or death, 0.68; P=0.005). With a median follow-up of 54.0 months, the median duration of overall survival was 49.0 months among patients treated with combined therapy and 29.3 months among those treated with radiotherapy alone (hazard ratio for death, 0.74; P=0.03). Radiotherapy plus cetuximab significantly prolonged progression-free survival (hazard ratio for disease progression or death, 0.70; P=0.006). With the exception of acneiform rash and infusion reactions, the incidence of grade 3 or greater toxic effects, including mucositis, did not differ significantly between the two groups. CONCLUSIONS: Treatment of locoregionally advanced head and neck cancer with concomitant high-dose radiotherapy plus cetuximab improves locoregional control and reduces mortality without increasing the common toxic effects associated with radiotherapy to the head and neck. (ClinicalTrials.gov number, NCT00004227.)

Adult↗
PubMed2006

mTOR inhibition induces upstream receptor tyrosine kinase signaling and activates Akt.

Stimulation of the insulin and insulin-like growth factor I (IGF-I) receptor activates the phosphoinositide-3-kinase/Akt/mTOR pathway causing pleiotropic cellular effects including an mTOR-dependent loss in insulin receptor substrate-1 expression leading to feedback down-regulation of signaling through the pathway. In model systems, tumors exhibiting mutational activation of phosphoinositide-3-kinase/Akt kinase, a common event in cancers, are hypersensitive to mTOR inhibitors, including rapamycin. Despite the activity in model systems, in patients, mTOR inhibitors exhibit more modest antitumor activity. We now show that mTOR inhibition induces insulin receptor substrate-1 expression and abrogates feedback inhibition of the pathway, resulting in Akt activation both in cancer cell lines and in patient tumors treated with the rapamycin derivative, RAD001. IGF-I receptor inhibition prevents rapamycin-induced Akt activation and sensitizes tumor cells to inhibition of mTOR. In contrast, IGF-I reverses the antiproliferative effects of rapamycin in serum-free medium. The data suggest that feedback down-regulation of receptor tyrosine kinase signaling is a frequent event in tumor cells with constitutive mTOR activation. Reversal of this feedback loop by rapamycin may attenuate its therapeutic effects, whereas combination therapy that ablates mTOR function and prevents Akt activation may have improved antitumor activity.

Cell Line, Tumor↗
PubMed2006

Epidermal growth factor receptor targeting in cancer.

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase of the ErbB family that is abnormally activated in many epithelial tumors. Several mechanisms lead to the receptor's aberrant activation that is observed in cancer, including receptor overexpression, mutation, ligand-dependent receptor dimerization, and ligand-independent activation. Two classes of anti-EGFR agents are currently approved for the treatment of patients with cancer: cetuximab, a monoclonal antibody directed at the extracellular domain of the receptor, and gefitinib and erlotinib, oral, low-molecular-weight (MW), adenosine triphosphate (ATP)-competitive inhibitors of the receptor's tyrosine kinase. Anti-EGFR monoclonal antibodies have demonstrated activity in the therapy of advanced colorectal carcinoma and in a variety of epithelial tumor types, including head and neck cancer and non-small cell lung cancer (NSCLC). The development of low MW, anti-EGFR tyrosine kinase inhibitors (TKIs) has been focused until recently on NSCLC, although responses have been reported for other types of cancer. Erlotinib was the only agent approved based on demonstrating improved survival, which was observed in patients with advanced NSCLC who previously had been treated with chemotherapy. Recent major advances in the EGFR field include the discovery of EGFR somatic mutations in NSCLC that have important implications for biology, treatment, clinical trial design, and methods for mutation detection. Clinical and survival benefits with anti-EGFR agents have been demonstrated in additional tumor types such as head and neck and pancreatic carcinomas. New agents with clinical activity are entering the clinic and new combinatorial approaches with anti-EGFR agents are being explored. Major efforts are, belatedly, attempting to identify molecular markers that can predict patients more likely to respond to anti-EGFR therapy.

Antibodies, Monoclonal↗
PubMed2005

Trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer.

BACKGROUND: Trastuzumab, a recombinant monoclonal antibody against HER2, has clinical activity in advanced breast cancer that overexpresses HER2. We investigated its efficacy and safety after excision of early-stage breast cancer and completion of chemotherapy. METHODS: This international, multicenter, randomized trial compared one or two years of trastuzumab given every three weeks with observation in patients with HER2-positive and either node-negative or node-positive breast cancer who had completed locoregional therapy and at least four cycles of neoadjuvant or adjuvant chemotherapy. RESULTS: Data were available for 1694 women randomly assigned to two years of treatment with trastuzumab, 1694 women assigned to one year of trastuzumab, and 1693 women assigned to observation. We report here the results only of treatment with trastuzumab for one year or observation. At the first planned interim analysis (median follow-up of one year), 347 events (recurrence of breast cancer, contralateral breast cancer, second nonbreast malignant disease, or death) were observed: 127 events in the trastuzumab group and 220 in the observation group. The unadjusted hazard ratio for an event in the trastuzumab group, as compared with the observation group, was 0.54 (95 percent confidence interval, 0.43 to 0.67; P<0.0001 by the log-rank test, crossing the interim analysis boundary), representing an absolute benefit in terms of disease-free survival at two years of 8.4 percentage points. Overall survival in the two groups was not significantly different (29 deaths with trastuzumab vs. 37 with observation). Severe cardiotoxicity developed in 0.5 percent of the women who were treated with trastuzumab. CONCLUSIONS: One year of treatment with trastuzumab after adjuvant chemotherapy significantly improves disease-free survival among women with HER2-positive breast cancer. (ClinicalTrials.gov number, NCT00045032.)

Adult↗
PubMed2005

Maintaining normal hemoglobin levels with epoetin alfa in mainly nonanemic patients with metastatic breast cancer receiving first-line chemotherapy: a survival study.

PURPOSE: To evaluate the effect on survival and quality of life of maintaining hemoglobin (Hb) in the range of 12 to 14 g/dL with epoetin alfa versus placebo in women with metastatic breast cancer (MBC) receiving first-line chemotherapy. PATIENTS AND METHODS: Eligible patients were randomly assigned to receive epoetin alfa 40,000 U once weekly or placebo for 12 months. Study drug was initiated if baseline Hb was < or = 13 g/dL or when Hb decreased to < or = 13g/dL during the study. The primary end point was 12-month overall survival (OS). RESULTS: The study drug administration was stopped early in accordance with a recommendation from the Independent Data Monitoring Committee because of higher mortality in the group treated with epoetin alfa. Enrollment had been completed, with 939 patients enrolled (epoetin alfa, n = 469; placebo, n = 470). Most patients had Hb more than 12 g/dL at baseline (median Hb, 12.8 g/dL) or during the study. From the final analysis, 12-month OS was 70% for epoetin alfa recipients and 76% for placebo recipients (P = .01). Optimal tumor response and time to disease progression were similar between groups. The reason for the difference in mortality between groups could not be determined from additional subsequent analyses involving both study data and chart review. CONCLUSION: In this trial, the use of epoetin alfa to maintain high Hb targets in women with MBC, most of whom did not have anemia at the start of treatment, was associated with decreased survival. Additional research is required to clarify the potential impact of erythropoietic agents on survival when the Hb target range is 10 to 12 g/dL.

Adult↗
PubMed2005

A multicenter phase II trial of ZD6474, a vascular endothelial growth factor receptor-2 and epidermal growth factor receptor tyrosine kinase inhibitor, in patients with previously treated metastatic breast cancer.

PURPOSE: To determine the efficacy and safety of ZD6474, an orally available inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase with additional activity against the epidermal growth factor receptor (EGFR) tyrosine kinase, in patients with previously treated metastatic breast cancer. PATIENTS AND METHODS: Eligible patients had histologically confirmed metastatic breast cancer and had received prior treatment with an anthracycline and taxane; measurable disease was required. Patients were enrolled sequentially into one of two dose cohorts, 100 or 300 mg orally once daily; 28 days defined one cycle. The primary end point was objective response rate; pharmacokinetics and serial pharmacodynamic studies were obtained. RESULTS: Forty-six patients were enrolled between May 2002 and April 2003, and 44 were evaluable for response. Diarrhea was the most commonly reported toxicity and seemed dose related (grade >/=2: 4.5% and 37.5% in the 100 and 300 mg cohorts, respectively). Rash was reported by 26% of patients but was never worse than grade 2. Seven patients in the 300 mg cohort had asymptomatic grade 1 prolongation of the QTc interval. Hypertension requiring treatment was not reported. There were no objective responses; one patient in the 300 mg cohort had stable disease >/=24 weeks. All patients in the 300 mg cohort and 90% of patients in the 100 mg cohort achieved steady-state concentrations exceeding the IC(50) for VEGF inhibition in preclinical models. CONCLUSION: ZD6474 monotherapy was generally well tolerated but had limited monotherapy activity in patients with refractory metastatic breast cancer.

Adult↗
PubMed2004

Tyrosine kinase inhibitors: why does the current process of clinical development not apply to them?

The robust clinical activity of imatinib and trastuzumab for treatment of chronic myeloid leukemia, gastrointestinal stromal tumors, and breast cancer has demonstrated that blocking pathogenic tyrosine kinases can alter the natural history of human tumors. On the other hand, EGF receptor inhibitors have shown overall modest activity. The contrast in the development of these agents implies that both molecular target dependence and patient selection are essential for the successful outcome of this process. We will contrast lessons derived from the development of inhibitors of Abl, c-Kit, HER2/neu (erbB2), and EGFR, highlight successes and limitations in the field, and propose new approaches for clinical development of tyrosine kinase inhibitor therapy.

Antibodies, Monoclonal↗
PubMed2003

Pilot trial of trastuzumab starting with or after the doxorubicin component of a doxorubicin plus paclitaxel regimen for women with HER2-positive advanced breast cancer.

PURPOSE: Combining trastuzumab with doxorubicin and paclitaxel (AT) is attractive because of the activity of AT and survival improvements observed when trastuzumab is added to either agent in HER2-positive metastatic breast cancer. This pilot study evaluates the efficacy and cardiac tolerability of AT followed by paclitaxel with trastuzumab started with AT or paclitaxel alone and investigates pharmacokinetic interactions. EXPERIMENTAL DESIGN: Two cohorts of 16 patients were enrolled. Cohort 1 received three cycles of AT (60/150 mg/m2) plus trastuzumab (4 mg/kg initial dose followed by 2 mg/kg), initiated concomitantly with doxorubicin, followed by nine cycles of paclitaxel (80 mg/m2) plus trastuzumab and then trastuzumab alone. Cohort 2 was treated with the same regimen, but trastuzumab was initiated with paclitaxel after AT. Cardiac function, pharmacokinetic interactions, and efficacy were evaluated. RESULTS: Median baseline left ventricular ejection fraction (LVEF) was 62% (range, 57-74%) and 66% (range, 57-77%) in cohorts 1 and 2, respectively. Most patients had an absolute decrease in LVEF. Congestive heart failure was not observed. LVEF in three patients decreased to <50% but recovered despite continued treatment. Response rates were 87.5% in both cohorts (cohort 1:2 complete response, 12 partial response; cohort 2:3 complete response, 11 partial response). No unexpected side effects were observed. Pharmacokinetics of paclitaxel and its metabolites and of doxorubicin were similar without and with trastuzumab. CONCLUSIONS: Trastuzumab administered with AT followed by weekly paclitaxel alone is highly active whether trastuzumab is initiated with AT or paclitaxel. Congestive heart failure was not observed, and LVEF decreases were reversible. Further studies of this regimen are warranted.

Adult↗
PubMed2003

Status of epidermal growth factor receptor antagonists in the biology and treatment of cancer.

The epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor of the ErbB family that is abnormally activated in many epithelial tumors. Receptor activation leads to recruitment and phosphorylation of several downstream intracellular substrates, leading to mitogenic signaling and other tumor-promoting cellular activities. In human tumors, receptor overexpression correlates with a more aggressive clinical course. Taken together, these observations indicate that the EGFR is a promising target for cancer therapy. Monoclonal antibodies directed at the ligand-binding extracellular domain and low-molecular weight inhibitors of the receptor's tyrosine kinase are currently in advanced stages of clinical development. These agents prevent ligand-induced receptor activation and downstream signaling, which results in cell cycle arrest, promotion of apoptosis, and inhibition of angiogenesis. They also enhance the antitumor effects of chemotherapy and radiation therapy. In patients, anti-EGFR agents can be given safely at doses that fully inhibit receptor signaling, and single-agent activity has been observed against a variety of tumor types, including colon carcinoma, non-small-cell lung cancer, head and neck cancer, ovarian carcinoma, and renal cell carcinoma. Although antitumor activity is significant, responses have been seen in only a minority of the patients treated. In some clinical trials, anti-EGFR agents enhanced the effects of conventional chemotherapy and radiation therapy. Ongoing research efforts are directed at the selection of patients with EGFR-dependent tumors, identification of the differences among the various classes of agents, and new clinical development strategies.

Antibodies, Monoclonal↗
PubMed2003

Phase II trial of antiepidermal growth factor receptor antibody C225 in patients with advanced renal cell carcinoma.

Fifty-five patients with metastatic renal cell carcinoma (RCC) were treated on a multicenter, single-arm Phase II trial. Patients received single-agent Cetuximab (C225) administered by intravenous infusion at a loading dose of 400 or 500 mg/m2 followed by weekly maintenance doses at 250 mg/m2. None of the patients treated with C225 achieved either a complete or partial response. The median time to progression was 57 days. The most frequently reported grade 3 or 4 toxicity treatment-related adverse events were acne (17%) and rash or dry skin (4%). The lack of clinical response or suggestion of prolonging time to progression compared to historical data with interferon-alfa supports no further study of single-agent C225 in patients with metastatic RCC.

Adult↗