PubMed Health⌕ Search

Biomedical subjects

J Baselga

Publications and source records attributed to J Baselga.

At least 19 recordsLinked to original sources
PubMed2003

New drugs and new approaches in metastatic bladder cancer.

The median survival of patients with metastatic cancer of the urothelium who receive best supportive care only in 4-6 months. With the introduction of combination chemotherapy regimens including cisplatin and methotrexate for the management of metastatic urothelial cancer, median overall survival has doubled. Nevertheless, death due to cancer ultimately occurs in more than 80% of these patients, thus more effective therapy is required. The new available treatment modalities range from new combinations of conventional chemotherapeutic agents to combinations incorporating novel drugs like gemcitabine and the taxanes. These new combinations incorporate the new active agents in two, three or multiple drug combinations, administered either in one regimen or sequentially in various combinations and schedules intended to improve the outcome of bladder cancer patients. Ongoing phase III studies will help to define the role of these new combinations in the treatment of advanced bladder cancer. The improved understanding of the molecular biology of urothelial malignancies is helping to define the role of new prognostic indices that can direct the most appropriate choice of treatment for advanced disease. In addition, advances in the molecular biology of urothelial malignancies may allow identification of specific genetic lesions and biochemical pathways upon which future therapeutic approaches can be focused. The integration of newer biologic agents, probably to supplement rather than to supplant chemotherapeutic drugs, should be a primary direction of research with the objective to interfere with multiple aspects of bladder cancer progression.

Antineoplastic Agents↗
PubMed2003

A randomized double-blind multicenter phase III study of fixed-dose single-administration pegfilgrastim versus daily filgrastim in patients receiving myelosuppressive chemotherapy.

BACKGROUND: We evaluated the efficacy of a single fixed 6 mg dose of pegfilgrastim (a pegylated version of filgrastim) per cycle of chemotherapy, compared with daily administration of filgrastim, in the provision of neutrophil support. PATIENTS AND METHODS: Patients (n = 157) were randomized to receive either a single 6 mg subcutaneous (s.c.) injection of pegfilgrastim or daily 5 mg/kg s.c. injections of filgrastim, after doxorubicin and docetaxel chemotherapy (60 mg/m(2) and 75 mg/m(2), respectively). Duration of grade 4 neutropenia, depth of neutrophil nadir, incidence of febrile neutropenia, time to neutrophil recovery and safety information were recorded. RESULTS: A single 6 mg injection of pegfilgrastim was as effective as daily injections of filgrastim for all efficacy measures for all cycles. The mean duration of grade 4 neutropenia in cycle 1 was 1.8 and 1.6 days for the pegfilgrastim and filgrastim groups, respectively. Results for all efficacy end points in cycles 2-4 were consistent with the results from cycle 1. A trend towards a lower incidence of febrile neutropenia was noted across all cycles with pegfilgrastim compared with filgrastim (13% versus 20%, respectively). A single fixed dose of pegfilgrastim was as safe and well tolerated as standard daily filgrastim. CONCLUSIONS: A single fixed dose of pegfilgrastim administered once per cycle of chemotherapy was comparable to multiple daily injections of filgrastim in safely providing neutrophil support during myelosuppressive chemotherapy. Pegfilgrastim may have utility in other clinical settings of neutropenia.

Adult↗
PubMed2003

Randomized, double-blind, multicenter trial comparing two doses of arzoxifene (LY353381) in hormone-sensitive advanced or metastatic breast cancer patients.

BACKGROUND: This randomized, double-blind, phase II study assessed two doses of the selective estrogen receptor modulator arzoxifene in women with advanced breast cancer. The primary end point was to choose the best of two doses of arzoxifene based on the response rate or the clinical benefit rate (CBR). Pharmacokinetics and toxicities were also assessed. PATIENTS AND METHODS: Ninety-two patients with advanced breast cancer received arzoxifene 20 or 50 mg/day. Tumor response was assessed using World Health Organization criteria. Toxicities were graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) system. Pharmacokinetic data were analyzed using the NONMEM software program (GloboMax, Hanover, MD, USA). RESULTS: Response rates in the 20 mg arm were numerically higher than the 50-mg arm according to the investigator (40.5% versus 36.4%) and the independent review panel (42.9% versus 27.3%). CBR was higher in the 20 mg arm according to the investigator (64.3% versus 61.4%) and the independent review panel (59.5% versus 47.7%). Arzoxifene was well tolerated. There were no study drug-related deaths. Mean observed steady-state plasma concentrations of arzoxifene were 3.62 and 7.48 ng/ml for the 20 and 50 mg doses, respectively. CONCLUSIONS: There were no significant differences in efficacy or safety between 20 and 50 mg of arzoxifene. Accordingly, arzoxifene 20 mg/day was selected for further study in patients with breast cancer.

Aged↗
PubMed2002

Phase I safety, pharmacokinetic, and pharmacodynamic trial of ZD1839, a selective oral epidermal growth factor receptor tyrosine kinase inhibitor, in patients with five selected solid tumor types.

PURPOSE: To establish the safety and tolerability of ZD1839 (Iressa), a selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, and to explore its pharmacokinetic and pharmacodynamic effects in patients with selected solid tumor types. PATIENTS AND METHODS: This was a phase I dose-escalating trial of oral ZD1839 150 mg/d to a maximum of 1,000 mg/d given once daily for at least 28 days. Patients with either advanced non-small-cell lung, ovarian, head and neck, prostate, or colorectal cancer were recruited. RESULTS: Eighty-eight patients received ZD1839 (150 to 1,000 mg/d). At 1,000 mg/d, five of 12 patients experienced dose-limiting toxicity (grade 3 diarrhea [four patients] and grade 3 somnolence [one patient]). The most frequent drug-related adverse events (AEs) were acne-like rash (64%) and diarrhea (47%), which were generally mild (grade 1/2) and reversible on cessation of treatment. No change in ZD1839 safety profile was observed with prolonged administration. Pharmacokinetic analysis showed steady-state exposure to ZD1839 in 98% of patients by day 7. Nineteen patients had stable disease and received ZD1839 for >or= 3 months; seven of these patients remained on study drug for >or= 6 months. Serial skin biopsies taken before treatment and at approximately day 28 revealed changes indicative of inhibition of the EGFR signaling pathway. CONCLUSION: ZD1839 was generally well tolerated, with manageable and reversible AEs at doses up to 600 mg/d and dose-limiting toxicity observed at 1,000 mg/d. ZD1839 treatment resulted in clinically meaningful disease stabilization across a range of tumor types and doses. Pharmacodynamic changes in skin confirmed inhibition of EGFR signaling, which was predicted from the mode of action of ZD1839.

Administration, Oral↗
PubMed2002

Feasibility trial of methotrexate-paclitaxel as a second line therapy in advanced urothelial cancer.

To evaluate the clinical value of the concurrent use of methotrexate administered immediately before paclitaxel, we investigated the efficacy and toxicity of this two-drug combination administered as palliative second line therapy in patients with advanced urothelial cancer. The design of the schedule and sequence used was based on our previous preclinical data from a comparative study on sequential combinations of paclitaxel and methotrexate in a human bladder cancer cell line. As a confirmation study, we further extended our analysis of in vitro synergism. Twenty patients with advanced transitional cell carcinoma of the urinary tract previously treated with platinum-based therapy, with adequate renal function and a performance status > or = 60 were considered eligible. They received therapy with methotrexate 30 mg/m2 administered as an intravenous bolus, followed immediately by paclitaxel 175 mg/m2 given as a 3-hr infusion, both on day 1 every 21 days. Therapy was given on a compassionate-use basis until either disease progression was documented or the patient became intolerant to therapy. In vitro data were further analyzed using the median-effect principle and the combination index method. Twenty patients with metastatic (16 patients) or locally advanced disease (four patients) received a median of three cycles of therapy. Of the 19 patients assessable for response, there were six partial responses and seven disease stabilizations with no complete responses. Median duration of response was 3 months (range, 2-7) and median survival was 5 months. Three patients developed grade 3-4 neutropenia, one patient had grade 3 anemia, four patients had grade 2-3 sensory neuropathy, and three patients had myalgias. Eighteen patients developed alopecia. Gastrointestinal toxicity was mild. One patient died after the first cycle due to pulmonary thrombo-embolism and could not be evaluated for response. The synergistic in vitro effect of the concurrent combination was confirmed in analyses performed under mutually exclusive and mutually nonexclusive criteria. In conclusion, the combination of methotrexate and paclitaxel at this dose and sequence is feasible and active as a palliative therapy in patients with advanced urothelial cancer previously treated with platinum-based therapies. This schedule merits further investigation in a phase-II trial.

Adenocarcinoma↗
PubMed2002

Capecitabine (Xeloda) in combination with oxaliplatin: a phase I, dose-escalation study in patients with advanced or metastatic solid tumors.

OBJECTIVES: This phase I, dose-escalation study was conducted to determine the recommended dose of intermittent oral capecitabine in combination with a fixed dose of i.v. oxaliplatin. Secondary objectives included evaluation of the safety profile and antitumor activity. PATIENTS AND METHODS: Twenty-three patients with advanced or metastatic solid tumors received a 21-day regimen of oral capecitabine (500, 825, 1000 or 1250 mg/m2 twice daily, days 1-14) in combination with oxaliplatin (130 mg/m2, 2-h i.v. infusion, day 1). Dose-limiting toxicities were determined during the first treatment cycle, and safety and efficacy were evaluated throughout treatment. RESULTS: The recommended dosing schedule is oral capecitabine 1000 mg/m2 twice daily (days 1-14) with i.v. oxaliplatin 130 mg/m2 (day 1) in a 21-day treatment cycle. The principal dose-limiting toxicity was diarrhea. The most frequent treatment-related adverse events occurring during the study were gastrointestinal (nausea/vomiting, diarrhea) and neurological (dysesthesia, paresthesia). The majority of treatment-related adverse events were mild to moderate in intensity, and no grade 4 adverse events occurred in the 15 patients treated at or below the recommended dose. The most common grade 3/4 laboratory abnormalities were lymphocytopenia (52% of patients), thrombocytopenia (22%; grade 3 only), neutropenia (17%) and hyperbilirubinemia (17%). Among patients treated at or below the recommended dose level (n = 15), only two patients experienced grade 3 neutropenia and no patients experienced grade 4 neutropenia. Partial tumor responses occurred in six patients (26%), including five of nine patients (55%) with colorectal cancer. All responding patients were pretreated with 5-fluorouracil and four responders had received prior irinotecan. CONCLUSIONS: Oral capecitabine with i.v. oxaliplatin is a feasible combination regimen that shows promising antitumor activity in patients with colorectal cancer. There is an ongoing, phase II study to further characterize the safety and efficacy of this combination as first-line therapy for metastatic colorectal cancer, using the recommended dose identified in this study.

Administration, Oral↗
PubMed2001

Metalloprotease-dependent protransforming growth factor-alpha ectodomain shedding in the absence of tumor necrosis factor-alpha-converting enzyme.

Zinc-dependent metalloproteases can mediate the shedding of the extracellular domain of many unrelated transmembrane proteins from the cell surface. In most instances, this process, also known as ectodomain shedding, is regulated via protein kinase C (PKC). The tumor necrosis factor alpha-converting enzyme (TACE) was the first protease involved in regulated protein ectodomain shedding identified. Although TACE belongs to the family of metalloprotease-disintegrins, few members of this family have been shown to participate in regulated ectodomain shedding. In fact, the phenotype of tace-/- cells and that of Chinese hamster ovary cell mutants defective in ectodomain shedding points to the existence of a common PKC-activated ectodomain shedding system, whose proteolytic component is TACE, that acts on a variety of transmembrane proteins. Examples of these proteins include the Alzheimer's disease-related protein beta-amyloid precursor protein (betaAPP) and the transmembrane growth factors protransforming growth factor-alpha (pro-TGF-alpha) and, as shown in this report, proheparin-binding epidermal growth factor-like growth factor (pro-HB-EGF). Here we show that the mercurial compound 4-aminophenylmercuric acetate (APMA), frequently used to activate in vitro recombinant matrix metalloproteases, is an activator of the shedding of betaAPP, pro-HB-EGF, and pro-TGF-alpha. Treatment of tace-/- cells or Chinese hamster ovary shedding-defective mutants with APMA activates the cleavage of pro-TGF-alpha but not that of pro-HB-EGF or betaAPP, indicating that APMA activates TACE and also a previously unacknowledged proteolytic activity specific for pro-TGF-alpha. Characterization of this proteolytic activity indicates that it acts on pro-TGF-alpha located at the cell surface and that it is a metalloprotease active in cells defective in furin activity. In summary, treatment of shedding-defective cell lines with APMA unveils the existence of a metalloprotease activity alternative to TACE with the ability to specifically shed the ectodomain of pro-TGF-alpha.

ADAM Proteins↗
PubMed2001

Activated extracellular signal-regulated kinases: association with epidermal growth factor receptor/transforming growth factor alpha expression in head and neck squamous carcinoma and inhibition by anti-epidermal growth factor receptor treatments.

The expression of the activated mitogen-activated kinases/extracellular signal-regulated kinases (ERKs) ERK1 and ERK2 was characterized in 101 humanhead and neck squamous carcinoma specimens. Activated ERK1/2were detected at different levels in the majority of these tumors, as assayed by immunostaining with an antibody specific for the dually phosphorylated and activated ERK1 and ERK2. ERK1/2 activation levels were higher in tumors with advanced regional lymph node metastasis (P = 0.048) and in relapsed tumors (P = 0.021). The expression of epidermal growth factor (EGF) receptor (P = 0.037), transforming growth factor alpha (TGF-alpha; P < 0.001), and HER2 (P = 0.066; positive trend) correlated with activation of ERK1/2. In a multivariate analysis, both TGF-alpha (P < 0.0001) and HER2 (P = 0.045) were independently correlated with ERK1/2 activation. In turn, activation of ERK1/2 was associated with a higher Ki-67 proliferative index (P = 0.002). In EGF receptor-dependent model cells (A431 and DiFi), a specific EGF receptor tyrosine kinase inhibitor ("Iressa"; ZD1839) and a chimeric anti-EGF receptor antibody ("Cetuximab"; C225) inhibited ERK 1/2 activation at concentrations that inhibited autocrine cell proliferation. In patients on treatment with C225, the activation of ERK1/2 in skin, an EGF receptor-dependent tissue, was lower compared with control skin. Parallel changes were seen in keratinocyte Ki67 proliferation indexes in skin from C225-treated patients. Taken together, these studies provide support for a role of activation of ERK1/2 in head and neck squamous carcinoma and a correlation with EGF receptor/TGF-alpha expression. The inhibition of ERK1/2 activation in vitro and in vivo by compounds targeting the EGF receptor points to the interest of ERK1/2 as potential surrogate markers of EGF-receptor signaling in clinical therapeutic studies.

Adult↗
PubMed2001

Trastuzumab (herceptin), a humanized anti-Her2 receptor monoclonal antibody, inhibits basal and activated Her2 ectodomain cleavage in breast cancer cells.

HER2 is a ligand-less tyrosine kinase receptor of the ErbB family that is frequently overexpressed in breast cancer. It undergoes proteolytic cleavage that results in the release of the extracellular domain and the production of a truncated membrane-bound fragment, p95. We show that HER2 shedding is activated by 4-aminophenylmercuric acetate (APMA), a well-known matrix metalloprotease activator, in HER2-overexpressing breast cancer cells. The HER2 p95 fragment, which appears after APMA-induced cleavage, is phosphorylated. We analyzed 24 human breast cancer specimens, and a phosphorylated M(r) 95,000 HER2 band could be detected in some of them, which indicated that the truncated receptor is also present in vivo. The activation of HER2 shedding by APMA in cells was blocked with batimastat, a broad-spectrum metalloprotease inhibitor. Trastuzumab (Herceptin; Genentech, San Francisco, CA), a humanized monoclonal antibody directed at the HER2 ectodomain, which has been shown to be active in patients with HER2-overexpressing breast cancer, inhibited basal and induced HER2 cleavage and, as a consequence, the generation of phosphorylated p95. This inhibitory effect of trastuzumab was not shared by 2C4, an antibody against a different epitope of the HER2 ectodomain. The inhibition of basal and APMA-induced cleavage of HER2 by trastuzumab preceded antibody-induced receptor down-modulation, which indicated that the effect of trastuzumab on cleavage was not attributable to a decrease in cell-surface HER2 induced by trastuzumab. We propose that the inhibition of HER2 cleavage and prevention of the production of an active truncated HER2 fragment represent a novel mechanism of action of trastuzumab.

Adenocarcinoma↗
PubMed2001

Use of chemotherapy plus a monoclonal antibody against HER2 for metastatic breast cancer that overexpresses HER2.

BACKGROUND: The HER2 gene, which encodes the growth factor receptor HER2, is amplified and HER2 is overexpressed in 25 to 30 percent of breast cancers, increasing the aggressiveness of the tumor. METHODS: We evaluated the efficacy and safety of trastuzumab, a recombinant monoclonal antibody against HER2, in women with metastatic breast cancer that overexpressed HER2. We randomly assigned 234 patients to receive standard chemotherapy alone and 235 patients to receive standard chemotherapy plus trastuzumab. Patients who had not previously received adjuvant (postoperative) therapy with an anthracycline were treated with doxorubicin (or epirubicin in the case of 36 women) and cyclophosphamide alone (138 women) or with trastuzumab (143 women). Patients who had previously received adjuvant anthracycline were treated with paclitaxel alone (96 women) or paclitaxel with trastuzumab (92 women). RESULTS: The addition of trastuzumab to chemotherapy was associated with a longer time to disease progression (median, 7.4 vs. 4.6 months; P<0.001), a higher rate of objective response (50 percent vs. 32 percent, P<0.001), a longer duration of response (median, 9.1 vs. 6.1 months; P<0.001), a lower rate of death at 1 year (22 percent vs. 33 percent, P=0.008), longer survival (median survival, 25.1 vs. 20.3 months; P=0.01), and a 20 percent reduction in the risk of death. The most important adverse event was cardiac dysfunction of New York Heart Association class III or IV, which occurred in 27 percent of the group given an anthracycline, cyclophosphamide, and trastuzumab; 8 percent of the group given an anthracycline and cyclophosphamide alone; 13 percent of the group given paclitaxel and trastuzumab; and 1 percent of the group given paclitaxel alone. Although the cardiotoxicity was potentially severe and, in some cases, life-threatening, the symptoms generally improved with standard medical management. CONCLUSIONS: Trastuzumab increases the clinical benefit of first-line chemotherapy in metastatic breast cancer that overexpresses HER2.

Adult↗
PubMed2001

Interleukin-2 enhances the natural killer cell response to Herceptin-coated Her2/neu-positive breast cancer cells.

The Her2/neu (c-erbB-2) oncogene encodes a 185-kDa protein tyrosine kinase which is overexpressed in 20% of breast adenocarcinomas and is recognized by a humanized anti-Her2/neu monoclonal antibody (mAb) (rhu4D5 or Herceptin). Natural killer (NK) cells are capable of mediating antibody-dependent cell cytotoxicity (ADCC) against antibody-coated targets via their expression of a low-affinity receptor for IgG (FcgammaRIII or CD16). NK cells can be expanded in cancer patients via the administration of low-dose interleukin-2 (IL-2) and become potent cytotoxic effectors following exposure to high doses of IL-2. We tested IL-2-activated NK cells against Her2/neu+ (MCF-7Her2/neu) and Her2/neu- (MDA-468) breast cancer cell lines in a 4-h 51Cr-release cytotoxicity assay in the presence or absence of rhu4D5 mAb (effector : target ratio = 10 : 1). Specific lysis of rhu4D5-coated MCF-7Her2/neu and MDA-468 target cells by IL-2-activated NK cells was 35% and 3%, respectively (p < 0.05). Lysis was less than 5% when targets were treated with either the non-humanized mu4D5 mAb or control huIgG. Lysis of rhu4D5-coated MCF-7Her2/neu cells was inhibited by 80 % when NK cells were pre-treated with an anti-Fc receptor antibody prior to use in the cytotoxicity assay. Enhanced ADCC of MCF-7Her2/neu target cells was seen when the effector cells consisted of mononuclear cells obtained from a patient demonstrating significant expansion of NK cells secondary to therapy with low-dose IL-2. Serum from patients receiving infusions of rhu4D5 mAb could substitute for exogenous antibody in the ADCC assay. NK cells activated by rhu4D5-coated tumor cells in the presence of IL-2 also produced large amounts of IFN-gamma with concomitant up-regulation of cell-surface activation markers CD25 and CD69. These results lend support to the concurrent use of rhu4D5 mAb and IL-2 therapy in patients with cancers that express the Her2/neu oncogene.

Animals↗
PubMed2001

Mechanism of action of trastuzumab and scientific update.

The humanized anti-p185(HER2) monoclonal antibody trastuzumab has been shown to effectively inhibit the growth of HER2-overexpressing breast cancer cells in vivo and in vitro. The treatment of cancer cells with trastuzumab results in downregulation of the HER2 receptor. Further downstream cellular events include the accumulation of the cyclin-dependent kinase inhibitor p27 and cell cycle arrest. In vivo, trastuzumab induces antibody-dependent cellular cytotoxicity. Trastuzumab also inhibits constitutive HER2 cleavage/shedding mediated by metalloproteases. The ability of trastuzumab to inhibit HER2 cleavage may correlate with the clinical anticancer activity of the multifunctional HER2-targeting antibody.

Antibodies, Monoclonal↗
PubMed2001

Pharmacodynamic studies with the epidermal growth factor receptor tyrosine kinase inhibitor ZD1839.

ZD1839 is an orally active, selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that blocks signal transduction pathways implicated in the proliferation and survival of cancer cells, and other host-dependent processes promoting cancer growth. Based on its promising preclinical antitumor activity and favorable toxicity profile, ZD1839 has recently entered clinical trials. A particular challenge in the clinical development of this exciting compound is to explore its biological (pharmacodynamic) activity against the EGFR and receptor-dependent processes in serial biopsies. Such studies might be of assistance in predicting the subset of tumors that will benefit from therapy. They also may prove whether complete EGFR blockade is achieved in vivo. This latest point is particularly relevant because an optimal biological dose (ie, a dose resulting in complete receptor inhibition) would be preferred to the maximally tolerated dose that is being used with conventional nontargeted chemotherapeutic drugs. A series of preclinical studies have identified potentially useful surrogate markers of EGFR activity (eg, phosphorylation of EGFR and downstream receptor-dependent molecules such as mitogen-activated protein kinase [MAPK], Akt, or p27) that could be used as a surrogate marker of ZD1839 efficacy. In various tumor types, such as head and neck squamous carcinoma and gastric and breast adenocarcinoma, a relationship between EGFR and downstream markers (such as phosphorylated MAPK) has been characterized, further supporting the potential of these molecules for pharmacodynamic studies. Preliminary analysis of serial skin biopsies from patients participating in phase I trials has shown that ZD1839 results in substantial changes in EGFR-dependent molecules, such as phosphorylated MAPK, p27, phosphorylated STAT3, and others. Based on these encouraging results, studies assessing activated EGFR, activated MAPK, and other selected markers in phase II trials in tumors from patients treated with ZD1839 are currently planned or ongoing.

Animals↗
PubMed2001

The EGFR as a target for anticancer therapy--focus on cetuximab.

The anti-epidermal-growth-factor-receptor (EGFR) monoclonal antibody cetuximab specifically binds to the EGFR with high affinity, blocking growth-factor binding, receptor activation and subsequent signal-transduction events leading to cell proliferation. Preclinical studies, both in vitro and in vivo, have shown that cetuximab enhances the antitumour effects of chemotherapy as well as radiotherapy by inhibiting cell proliferation, angiogenesis and metastasis and by promoting apoptosis. As of June 2000, 526 patients with advanced solid tumours were treated with cetuximab in phase I/II clinical trials. Analysis of the results of three phase I trials showed that cetuximab has non-linear pharmacokinetics, with saturation of drug-elimination pathways occurring at doses between 200 and 400 mg/m(2). Adverse-event data for 239 patients across most of the completed or ongoing phase I-III trials indicated that the antibody was generally well tolerated. Cetuximab has been evaluated both alone and in combination with radiotherapy and various cytotoxic chemotherapeutic agents in a series of phase I/II studies that primarily treated patients with either head and neck or colorectal cancer. Although not a primary objective of these studies, clinical responses to cetuximab were observed in many patients who had previously failed chemotherapy and/or radiotherapy or were otherwise unlikely to achieve a therapeutic outcome. Based on these promising results, additional phase II and phase III trials are currently underway in head and neck and colorectal cancer.

Antibodies, Monoclonal↗