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Biomedical subjects

G Blackledge

Publications and source records attributed to G Blackledge.

At least 19 recordsLinked to original sources
PubMed2004

Gefitinib ('Iressa', ZD1839) and new epidermal growth factor receptor inhibitors.

The epidermal growth factor receptor (EGFR) is a promising target for cancer therapy and a number of EGFR-targeted agents have been developed. Those most advanced in development are the EGFR tyrosine kinase inhibitors gefitinib ('Iressa', ZD1839) and erlotinib ('Tarceva', OSI-774), and the monoclonal antibody cetuximab ('Erbitux', IMC-C225). This review provides a clinical overview of these agents, highlighting their antitumour activities in different tumour types. Epidermal growth factor receptor-targeted agents are generally well tolerated and are not typically associated with the severe adverse events often seen with cytotoxic chemotherapy. Gefitinib is the agent with the most extensive clinical experience, particularly in non-small-cell lung cancer (NSCLC). Recently, gefitinib became the first-approved EGFR-targeted agent, for use in patients with previously treated advanced NSCLC in Japan, the USA and other countries. Further studies are required to explore the full potential of these novel agents either as monotherapy or combination therapy.

Antibodies, Monoclonal↗
PubMed2001

Growth factors and their receptors: new targets for prostate cancer therapy.

Stimulation of the signal transduction pathway of the epidermal growth-factor receptor (EGFR) tyrosine kinase family of receptors in tumor cells enhances cellular proliferation, prevents apoptosis, and promotes tumor-cell mobility, adhesion, and invasion. Therapeutic approaches used to target the EGFR and its signal transduction cascade include (1) monoclonal antibodies (eg, cetuximab [IMC-C225]) directed against the extracellular binding domain of the receptor; and (2) trastuzumab, a monoclonal antibody binding to the HER2 receptor; immunotoxin conjugates use an antibody directed against EGFR joined to a cell toxin. All are in clinical trials for a number of cancers, including prostate cancer. Antisense strategies are in preclinical development. Low-molecular-weight inhibitors of the EGFR tyrosine kinase also in clinical development include OSI-774, PD182905, PKI-166, CI-1033, and ZD1839. ZD1839 has shown encouraging results in patients with prostate cancer in phase 1 trials. mn

Antibodies, Bispecific↗
PubMed2001

[Comparison of management of advanced cancer in various organs].

The management of advanced cancer presents the greatest challenge to physicians involved in oncology. There will usually be a large burden of disease; cure is unlikely; and the needs of the patient in terms of pain control and palliation will also be important over and above the direct treatment of the disease. Different issues will arise depending on the site and pathological type of the cancer. Increasingly over the past few years, treatment protocols and guidelines have been developed for different cancers, but these can only be rough guides rather than definite treatment recommendations. Additionally in most cancers advanced disease offers the opportunity for evaluation of new treatments in Phase II studies and other trials. With the new generation of molecular targeted therapies, such as EGFR inhibitors, striking results are being seen in advanced disease that compare favourably with what has been seen previously. Other agents such as those which attack the tumour vasculature may also have promise in this setting. Palliation is also an important aspect of the management of advanced disease, and pain control in particular is an important component of patient management. In summary, the treatment of advanced disease provides a test bed for new agents, but this need to develop better cancer therapies must be balanced against patient needs for a pain-free and comfortable end to life.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Anti-EGF receptor therapy.

The epidermal growth factor receptor (EGFR) signalling pathway contributes to a number of processes important to tumour progression, including cell proliferation, apoptosis, angiogenesis and metastatic spread. EGFR signalling is thought to be an important cell survival mechanism in hormone-resistant prostate cancer. ZD1839 ('Iressa') is an orally active, selective EGFR-tyrosine kinase inhibitor (EGFR-TKI) which blocks signal transduction pathways implicated in promoting cancer growth. In preclinical studies, ZD1839 alone, and in combination with cytotoxic agents, produced reversible growth inhibition and growth delay in a wide range of tumour cell lines and human tumour xenografts. Preliminary results from phase I trials in patients with advanced disease suggest that ZD1839 has an acceptable tolerability profile and promising clinical efficacy in patients with a variety of tumour types, including hormone-resistant prostate cancer, where new treatment strategies are needed. Prostate Cancer and Prostatic Diseases (2000) 3, 296-302

Journal Article↗
PubMed2000

[Development of molecular targeting drugs for the treatment of cancer-therapeutic potential and issues to be addressed in global development].

A survey of cancer treatment in a sample of hospitals > 100 beds conducted in 1998 compared with experience in the US showed that good progress has been achieved in Japan in the screening and early treatment of gastric cancer, and that the prognosis for breast cancer is better than in the West. Although in the past, the cytotoxic therapies available to physicians in Japan vs the West have been different, recent acceleration of regulatory review will result in a convergence of treatment paradigms and some improvement in acute response in many tumour types. However, world wide there is a need for new improved therapies in all cancers evaluated. Particular needs are in the management of NSCLC, advanced disease and cancers which form micrometastases. The eventual hope is that cancer can be turned from a lethal disease into a chronic disease where patients maintain a good QOL. Apart from anti hormonal therapies, the usual approach has been to kill the cancerous cells. However, the new approaches to intervening in the growth and migration of cancerous cells or the host tissue response by molecular targeting offer the promise of achieving a step change in therapy. Although EGF tyrosine Kinase inhibitors such as ZD 1839 have been shown to cause a conventional tumour response in NSCLC, many of these new approaches are unlikely to show a short term response even if they have the capacity to affect tumour development and increase disease free survival. Some compounds will require combination therapy with a conventional cytotoxic or radiotherapy to show their full benefit. For conventional cytotoxics, the usual approach to development has been to select the maximum tolerated dose and then evaluate the efficacy in advanced disease. However, for the new approaches which will not have such severe dose limiting toxicities, it will be necessary to select a surrogate marker of the intended biological effect to select the optimal biological dose (OBD) and dose regimen in phase I/II studies for further evaluation in phase II or III studies which are designed to show the expected patient benefit. The tumour target, the stage of the disease and the possible need for concomitant therapy will also have to be considered according to the mechanism of action of the product.

Angiogenesis Inhibitors↗
PubMed1998

New developments in cancer treatment with the novel thymidylate synthase inhibitor raltitrexed ('Tomudex').

Following the demonstration of efficacy, tolerability and quality-of-life benefits of raltitrexed ('Tomudex'), principally in advanced colorectal but also in other cancers, an extensive evaluation of combination therapy with other agents in patients with colorectal and other tumour types is being undertaken. This work has been prompted by preclinical observations of enhanced activity of raltitrexed when coadministered with other cytotoxic agents or radiotherapy and by preliminary results showing the activity of raltitrexed in patients with cancers other than colorectal. Raltitrexed is currently being investigated as monotherapy in phase I and II cancer studies, including head and neck cancer, hormone-resistant prostate cancer, paediatric and adult leukaemias and solid tumours, and soft tissue sarcoma. In addition, phase I clinical trials are evaluating the drug in combination with taxanes (paclitaxel) in solid tumours, anthracyclines (doxorubicin) in gastric carcinoma, topoisomerase I inhibitors (CPT-11) and 5-fluorouracil (both infusion and bolus regimens) in advanced colorectal cancer, platinum compounds (oxaliplatin and cisplatin) in a variety of tumours and radiotherapy in rectal cancer. Preliminary reports indicate good tolerability and acceptability of the combinations being investigated, with no dose-limiting toxicity being reported to date, and some early indications of efficacy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

A randomised comparison of 'Casodex' (bicalutamide) 150 mg monotherapy versus castration in the treatment of metastatic and locally advanced prostate cancer.

OBJECTIVES: To evaluate the efficacy and tolerability of 'Casodex' monotherapy (150 mg daily) for metastatic and locally advanced prostate cancer. METHODS: A total of 1,453 patients with either confirmed metastatic disease (M1), or T3/T4 non-metastatic disease with elevated prostate-specific antigen (M0) were recruited into one of two identical, multicentre, randomised studies to compare 'Casodex' 150 mg/day with castration. The protocols allowed for combined analysis. RESULTS: At a median follow-up period of approximately 100 weeks for both studies, 'Casodex' 150 mg was found to be less effective than castration in patients with metastatic disease (M1) at entry (hazard ratio of 1.30 for time to death) with a difference in median survival of 6 weeks. In symptomatic M1 patients, 'Casodex' was associated with a statistically significant improvement in subjective response (70%) compared with castration (58%). Analysis of a validated quality-of-life questionnaire proved an advantage for 'Casodex' in sexual interest and physical capacity. 'Casodex' had a substantially lower incidence of hot flushes compared to castration (6-13% compared with 39-44%) and the most commonly reported adverse events were those expected for a potent antiandrogen. However, in patients with M0 disease at entry, the data are still immature with only 13% of M0 patients having died. An initial analysis of this immature data has suggested that the results in these patients may be different to those obtained in patients with M1 disease. A further survival analysis in patients with M0 disease is therefore planned when the data are more mature. CONCLUSIONS: 'Casodex' 150 mg is less effective than castration in patients with M1 disease. However, 'Casodex' has shown a benefit in terms of quality of life and subjective response when compared to castration and has an acceptable tolerability profile. Thus 'Casodex' 150 mg monotherapy is an option for patients with M1 prostate cancer for whom surgical or medical castration is not indicated or is not acceptable.

Aged↗
PubMed1996

Bicalutamide: a new antiandrogen for use in combination with castration for patients with advanced prostate cancer.

Maximum androgen blockade, a relatively recent development in the treatment of prostate cancer, combines medical or surgical castration with antiandrogen therapy. A large randomized study comparing the non-steroidal antiandrogen, bicalutamide, with flutamide, each in combination with luteinizing hormone-releasing hormone (LHRH) analogs, showed that after a median follow-up of 49 weeks, the time to treatment failure was significantly longer for the bicalutamide patients compared with the flutamide patients (p = 0.005). After a median follow up to 95 weeks, bicalutamide in combination with LHRH analog therapy produced at least equivalent efficacy with flutamide in combination with LHRH analog therapy in terms of time to treatment failure and equivalent efficacy in terms of survival. The tolerability profile of bicalutamide, as based on reported findings and a literature review, indicates a superior tolerability to that of currently available antiandrogens, particularly with respect to diarrhea with a low incidence of treatment-related withdrawals.

Adult↗
PubMed1993

Cyclophosphamide versus ifosfamide: a randomized phase II trial in adult soft-tissue sarcomas. The European Organization for Research and Treatment of Cancer [EORTC], Soft Tissue and Bone Sarcoma Group.

Ifosfamide (5 g/m2) was compared with its parent analogue cyclophosphamide (1.5 g/m2) in a randomized phase II study. Both drugs were given by 24-h intravenous (i.v.) infusion every 3 weeks along with i.v. bolus infusions of mesna (400 mg/m2), which was given every 4 h for nine administrations. Eligibility criteria included an age of 15-75 years, biopsy-proven advanced metastatic soft-tissue sarcoma, and a World Health Organization performance status of 0-2. Exclusion criteria were prior treatment with classic alkylating agents, a creatinine level of > 150 mumol/l, a bilirubin level of > 20 mumol/l, a leukocyte cell count of < 3.5 x 10(9)/l, and a platelet count of < 100 x 10(9)/l. A total of 171 patients were entered, 24 of whom were ineligible and 12, inevaluable, leaving 135 patients evaluable. In all, 67 patients were treated with cyclophosphamide, and the overall response rate was 7.5%. All responders to cyclophosphamide were patients who had not received prior chemotherapy (13% of 38 patients). Another 68 patients were given ifosfamide, 18% of whom responded to treatment. Of the 28 ifosfamide-treated patients who had received prior chemotherapy, 7% were responders. The response rate for the remaining 40 patients was 25%. The higher overall response rate (P = 0.13) obtained with less myelosuppression in ifosfamide-treated patients suggests that this agent may have advantages over cyclophosphamide in combination therapy.

Adolescent↗
PubMed1993

Ifosfamide plus doxorubicin in previously untreated patients with advanced soft-tissue sarcoma.

The objective of this phase II trial was to assess the therapeutic activity and toxicity of doxorubicin plus ifosfamide in previously untreated patients with advanced soft-tissue sarcoma. Treatment consisted of an intravenous bolus injection of doxorubicin at a dose of 50 mg/m2 followed by a 24-h infusion of ifosfamide at 5 g/m2 plus mesna, with therapy being repeated every 3 weeks until disease progression or unacceptable toxicity occurred. Of the 203 patients entered, 175 were evaluable for response. The overall response rate was 35% (95% confidence interval, 28%-42%), with 9% of patients achieving complete responses and 26% showing partial responses. The median time to progression was 29 weeks for all evaluable patients and 67, 40, and 28 weeks for complete and partial responders and patients with stable disease, respectively. The median duration of survival was 58 weeks. Myelosuppression was the dose-limiting toxicity, resulting in leukopenia (World Health Organization grades 3 and 4) in 73% of the evaluable patients. Other side effects were rare and usually well manageable.

Adolescent↗
PubMed1992

Single agent high-dose cisplatin (200 mg m-2) treatment in ovarian carcinoma.

Twenty patients with epithelial ovarian carcinoma were treated with high-dose cisplatin 200mg m-2. Patients were to receive three cycles at 21 day intervals. Treatment was stopped if severe myelosuppression or any neurotoxicity occurred. Overall, eight (40%) of patients responded with a complete response in five (25%). Four of 16 (25%) previously treated patients responded. The median duration of response was 44 weeks (range 6-130). In patients previously treated there was a significant association (P < 0.002) between response and a remission free interval of 52 weeks or more from primary chemotherapy. Toxicity was assessable in 18 patients. Alopecia and nausea/vomiting were common. Myelosuppression was recorded in nine patients delaying planned administration in eight of 35 cycles. Five patients developed anaemia and six thrombocytopenia. Neurotoxicity affected seven patients and varying degrees of tinnitus six patients. Neurotoxicity and myelosuppression were indications for cessation of treatment in 8 patients receiving less than three cycles. Analysis revealed no significant association between toxicity and prior cisplatin exposure, age or the amount of high-dose cisplatin administered. This series reveals that it is possible to achieve good response rates using high-dose cisplatin without encountering debilitating neurotoxicity.

Adult↗
PubMed1992

Experience with ifosfamide in the EORTC Soft Tissue and Bone Sarcoma Group.

The Soft Tissue and Bone Sarcoma Group of the European Organization on Research and Treatment of Cancer has conducted a number of studies of chemotherapy in advanced disease over the past 15 years. Following the discovery that the CYVADIC regimen (cyclophosphamide/vincristine/doxorubicin/dimethyl imidazole carboxamide) was less active than had been reported originally, the individual components of CYVADIC were studied. This showed that doxorubicin had considerable activity and that ifosfamide 5 g/m2 given over 24 hours was at least as active as cyclophosphamide. Subsequent studies have therefore centered on a combination of doxorubicin and ifosfamide. A large randomized trial showed no significant benefit of doxorubicin/ifosfamide over single-agent doxorubicin, but the doses of doxorubicin were different. More recently, using bone marrow growth factors, it has been possible to increase the doxorubicin dose to that given as a single agent and also maintain the ifosfamide dose. This is now being tested in a randomized trial to determine whether improved response rates and other indicators of outcome will be seen.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Interferon-alpha 2b in the treatment of follicular lymphoma: preliminary results of a trial in progress.

Since 1985 the combination of chlorambucil (10 mg daily, initially for six weeks, then alternating fortnights for 12 weeks) and interferon-alpha 2b (Schering-Plough; 2 x 10(6) U/m2 three times weekly by subcutaneous injection for 18 weeks) has been compared in a randomised trial with chlorambucil alone in previously untreated patients with stage III or IV follicular lymphoma. Responding patients have subsequently been randomised to receive maintenance interferon-alpha 2b or no further treatment. Of the 124 treated patients, 108 are evaluable for response with a median follow-up of 30 months. The major toxicity was myelosuppression which was more frequent with chlorambucil and IFN alpha 2b in combination than with chlorambucil alone (P less than 0.01). There was no treatment-related mortality. Actuarial survival at three years is 75% for all patients, regardless of therapy. There was no significant difference in response rate according to initial therapy. For the 60 patients achieving a good response to initial therapy who have entered the second part of the trial, there has been a significant prolongation of remission duration in favour of maintenance IFN-alpha 2b (median not yet reached versus two years for the 'no treatment' arm, P less than 0.015). Fewest relapses have been seen in patients who received IFN-alpha 2b throughout. Accrual to this trial continues; this preliminary analysis indicates that maintenance IFN-alpha 2b may extend remission duration in follicular lymphoma.

Adult↗
PubMed1991

Doxorubicin plus ifosfamide with rhGM-CSF in the treatment of advanced adult soft-tissue sarcomas: preliminary results of a phase II study from the EORTC Soft-Tissue and Bone Sarcoma Group.

Doxorubicin and ifosfamide are the two most active agents used in the treatment of advanced inoperable soft-tissue sarcoma, but their use in combination produces dose-limiting myelosuppression. To explore the feasibility of combining optimal doses of both drugs, doxorubicin (75 mg/m2) and ifosfamide (5 g/m2) were given every 3 weeks with recombinant human granulocyte/macrophage-colony-stimulating factor (rhGM-CSF; 250 micrograms m-2 day-1) by subcutaneous injection for up to 14 days after each course. A total of 52 patients with progressive metastatic soft-tissue sarcoma were entered, none having received prior chemotherapy. One patient was ineligible and received no treatment after registration. Preliminary analysis of six cycles of chemotherapy revealed that the full protocol dose intensity had been administered to the majority of patients. Although the median leucocyte and neutrophil counts did not fall with subsequent courses of chemotherapy, the duration of neutropenia increased with each course delivered. Cumulative thrombocytopenia was a major dose-limiting toxicity and was the main reason for any dose modifications that occurred. Although 26 patients experienced infections after one or more courses of treatment, in only 7 was admission required for parenteral antibiotics. One patient died as a result of septicaemia after the first cycle of treatment. To date, there have been 22 responses (43%) with 8% complete remissions. It appears that the administration of rhGM-CSF allows this high-dose regime of chemotherapy to be given safely and the early encouraging response rate adds support to the concept that increasing the dose of doxorubicin improves the outlook for patients with advanced soft-tissue sarcomas.

Adult↗
PubMed1991

Short-duration (three cycles) cisplatin combination chemotherapy with alkylating agent consolidation in advanced epithelial ovarian cancer.

Forty-eight patients with advanced epithelial ovarian cancer were treated with a two-part cytotoxic regimen consisting of three cycles of cisplatin-based induction therapy followed by five cycles of escalating doses of cyclophosphamide, all given at 3-weekly intervals. The total cisplatin dose was 225 mg/m2. Seventeen patients with optimal primary surgery received chemotherapy only, while 17 of the 31 patients with suboptimal primary surgery underwent optimal interval cytoreductive surgery at the end of induction (cisplatin) therapy. Median survival for all patients was 15.4 months. Median survival was 15 months for patients with optimal primary surgery and 22 months for patients who had optimal secondary cytoreduction. Only 10 patients suffered WHO grade 3 or greater toxicity during therapy. This study suggests that the total dose of cisplatin can be reduced for patients with advanced ovarian carcinoma, resulting in reduced overall toxicity, without compromising response or response duration. A randomized trial to test this concept is now underway.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Phase II study of nimustine in metastatic soft tissue sarcoma. European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group.

The EORTC Soft Tissue and Bone Sarcoma Group has conducted a phase II trial in 33 eligible patients with metastatic soft tissue sarcoma with nimustine 100 mg/m2 every 6 weeks. In 31 evaluable patients there were 3 (10%) partial responses lasting 4.5, 6 and 7.5 months, and 5 cases of stable disease. 12 patients had progressive disease and 11 patients early progressive disease. Toxicity consisted mainly of leukopenia and thrombocytopenia and nausea and vomiting. It is concluded that nimustine has only minor activity in soft tissue sarcoma.

Adult↗
PubMed1991

EORTC joint ventures in quality control: treatment-related variables and data acquisition in chemotherapy trials.

In multicentre studies, non-compliance with the protocol may limit the chances of reaching a correct conclusion. A procedure to examine the administration of chemotherapy in multicentre EORTC protocols has been developed. General aspects are covered in a mailed questionnaire on the prescription of drugs with rounding up or down of dosages, local facilities for preparation and the procedure for preparation and administration. More detail is collected during a quality control site visit. Ten centres have been visited and there was significant variation between centres in the organisation of chemotherapy administration. However, more striking differences were noted between the type and quality of hospital files. The lack of systematic recording of sequence, timing and doses of chemotherapy and, in particular, treatment related toxicity, is a major difficulty limiting the effectiveness of quality control. These shortcomings emphasise the need for standardisation of some aspects of case records and a suggested check-list has been drafted.

Antineoplastic Agents↗