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Biomedical subjects

S B Kaye

Publications and source records attributed to S B Kaye.

At least 289 records · Page 16Linked to original sources

A phase 1 and pharmacokinetic study of didox: a ribonucleotide reductase inhibitor.

A phase 1 study of a new ribonucleotide reductase inhibitor, didox, was performed by administration of escalating doses of the drug by slow i.v. injection. Thirty-four patients with unresponsive metastatic carcinoma received the drug. There were 13 escalations of dosage, from a starting dose of 192 mg m-2 to 10 g m-2. Dose limiting toxicity was encountered at 7.5 g m-2 where disturbances of hepatic and renal function were observed, in addition to severe gastrointestinal toxicity. Pharmacokinetic studies showed that a peak level of didox was achieved within 5 minutes of injection. At 1,728 mg m-2 the data best fitted a 2 compartment open model, with a mean serum alpha t1/2 of 5.2 min, with a beta t1/2 of 41.3 min. Less than 10% of the drug was excreted unchanged in the urine and the majority of this excretion was within 6 h. Didox can therefore be safely given by slow i.v. injection at a dose of 6 g m-2.

Adult↗

Antitumour activity and pharmacokinetics of niosome encapsulated adriamycin in monolayer, spheroid and xenograft.

Niosomes are multilamellar vesicles formed from nonionic surfactants of the alkyl or dialkyl polyglycerol ether class and cholesterol. Adriamycin has been trapped within vesicles prepared from a monoalkyl triglycerol ether and its activity compared with adriamycin solution in human lung tumour cells grown in monolayer and spheroid culture and in tumour xenografted nude mice. The activity of the encapsulated adriamycin in vitro is maintained with similar clonogenic survival curves following treatment of monolayers and identical growth delays following spheroid exposure. The pharmacokinetics of adriamycin are altered in vivo in human lung tumour-bearing nude mice, when it is administered in niosomal form. There is prolonged release of drug from the plasma compartment with significantly lower peak levels; lower peak cardiac adriamycin concentrations with a shorter tissue half-life and decreased cardiac AUC and a greater degree of hepatic metabolism to inactive 7-deoxyaglycones. The tumour peak drug level and AUC was similar irrespective of the mode of administration of adriamycin. The growth delay (i.e. the time taken for the tumour volume to double) was significantly longer for adriamycin (15 days) and niosomal adriamycin (11 days) than for control (5.8 days). It is possible that the therapeutic ratio of adriamycin could be enhanced by administration in niosomal form.

Animals↗

A pilot study of carboplatin (JM8, CBDCA) and chlorambucil in combination for advanced ovarian cancer.

Forty-six patients with previously untreated, advanced ovarian cancer received carboplatin (JM8, CBDCA) and chlorambucil (CLB) to assess the efficacy and toxicity of this combination. Carboplatin 300 mg m-2 was given on day 1 with CLB 10 mg daily for 7, 10 or 14 days; 6 treatment courses were given at 4-6 weekly intervals in the absence of disease progression. Tumour response was assessed, where possible, by restaging laparotomy after 6 treatment cycles. Five complete and 16 partial remission were seen in 37 evaluable patients giving an overall response rate of 57%. The median survival of all patients was 15 months. The major toxicity was myelosuppression. Nausea and vomiting were generally minor (WHO, grades I or II) and most courses were given on an outpatient basis. Leucopenia was the major factor causing treatment delays, particularly with the 10 and 14 day CLB regimens. Thrombocytopenia was minimal in the early chemotherapy cycles but the data suggest that cumulative toxicity may occur. This combination may provide a satisfactory degree of efficacy with less toxicity than cisplatin-based regimens.

Adult↗

Pharmacokinetics and anti-emetic efficacy of BRL43694, a new selective 5HT-3 antagonist.

Twenty patients receiving a variety of emetogenic cytotoxics (including cisplatin in 5) were given a single i.v. infusion of 40 micrograms kg-1 of BRL43694 (as the hydrochloride salt) in successive groups of 3-4 patients between 0-6 hours after chemotherapy. Eleven patients were completely protected from vomiting; 9 had mild to moderate nausea and vomiting, but none severe enough to require alternative anti-emetic 'rescue'. In 4 of the patients in whom BRL43694 was delayed until 4-6 h after chemotherapy, vomiting had already begun; in each case immediate termination of vomiting occurred when BRL43694 was infused. No adverse effects attributable to the anti-emetic were observed. Mean pharmacokinetic parameters in 14 patients in whom plasma assay data are available were: Maximum observed concentration = 30.7 ng ml-1; terminal phase half-life = 8.96 h; total body clearance = 0.376 (1 h-1) kg-1; apparent volume of distribution = 2.85 l kg-1. This study shows BRL43694 to be an effective and well tolerated anti-emetic. Further studies aimed at defining an optimal dose and schedule for use against the most emetogenic cytotoxics are in progress.

Adolescent↗

Cancer support groups--who joins and why?

Tak Tent is a cancer support organisation consisting of 14 groups of which 11 are based in Scotland. In 1985, a survey was conducted among those attending the Scottish groups. 146 (79%) of the groups' members completed survey questionnaires. The results showed that Tak Tent's membership mainly comprised cancer patients (36%), relatives of patients (34%) and professionals involved in cancer care (21%). Women outnumbered men 3 to 1 and most of the membership belonged to social classes I, II or III. The groups appeared to be meeting their members' expectations of them to varying degrees. Respondents were satisfied that group membership had allowed them to make new friends, find out more about cancer and meet others facing similar difficulties. They were less certain that participation in a group had enabled them to learn how to cope better with cancer, share their problems with others or provide support for others to the extent they had anticipated.

Adult↗

Results of treatment of non seminomatous germ cell tumours; 122 consecutive cases in the West of Scotland, 1981-1985.

Between January 1981 and December 1985, 122 patients with non-seminomatous germ cell tumours (NSGT) were seen at a regional referral centre. Of these, a total of 98 patients received chemotherapy for metastatic disease. Treatment was given within collaborative EORTC Urology group studies, all of which involved cis-platin-containing schedules. Ninety patients had tumours of testicular origin, and their 2 year actuarial survival rate is 91%; 8 had tumours of extragonadal origin and their 2 year actuarial survival is 25%. Patients with testicular tumours were subdivided by volume of metastatic disease using the recommendations of the Testicular Cancer Subgroup of the MRC Urological Cancer Working Party and survival was significantly worse in the group with very large volume metastatic disease (VLVM, 57%) compared with the groups with large volume metastases (LVM, 100%) and small volume metastases (SVM, 98%). There were 31 patients with Stage I disease at presentation; of these 6 were treated by prophylactic abdominal radiotherapy and 25 were managed by a policy of surveillance only. Seven of these Stage I patients (23%) relapsed with metastatic disease (median 8 months); all have been successfully treated with chemotherapy. These data confirm that the majority of patients now presenting with metastatic NSGCT are curable with chemotherapy, but that a small proportion with very large volume metastases or extragonadal tumours require alternative chemotherapy schedules.

Antineoplastic Combined Chemotherapy Protocols↗

Cytotoxic drug penetration studies in multicellular tumour spheroids.

1. The three-dimensional structure of human lung tumour spheroids conferred a degree of resistance to the anthracyclines adriamycin, 4'-deoxydoxorubicin, daunomycin and daunomycin-low density lipoprotein complex in comparison with cells grown as a monolayer, as assessed by delayed growth and clonogenic cell survival. 2. 4'-Deoxydoxorubicin induced a longer growth delay and greater clonogenic cell kill than adriamycin in spheroids, although it was no more cytotoxic in monolayer. 3. Fluorescent microscopy demonstrated that the more lipophilic analogues partitioned into the spheroid more rapidly and to a greater degree than adriamycin. 4. The spheroid model demonstrated that penetration is an important aspect of resistance to anthracycline drugs, and this approach may represent a better in vitro system for testing lipophilic analogues of cytotoxic drugs.

Antibiotics, Antineoplastic↗

Potential advances in combination chemotherapy for advanced testicular cancer.

An interim analysis of the current EORTC studies in advanced testicular cancer indicates that (a) for low volume metastatic disease the addition of bleomycin (B) to etoposide (E) and cisplatinum (P) may not be necessary, and (b) for high volume metastatic disease the alternating schedule of PVB/BEP is not superior to treatment with BEP. Future studies will subdivide patients into 3 groups. Those with low volume metastatic disease will receive EP using 2 dose schedules for cisplatin. Those with high volume metastases will receive either BEP or etoposide, ifosfamide and cisplatinum (VIP). Those with ultra-high volume metastases will receive BOP/VIP, possibly randomised against another intensive chemotherapy schedule.

Antineoplastic Combined Chemotherapy Protocols↗

Phase I and pharmacokinetic study of flavone acetic acid.

Flavone acetic acid is the second in a series of compounds based on the flavonoid aglycone ring structure to be clinically evaluated in malignant disease. Preclinical studies have indicated that a minimum plasma level of 150 micrograms/ml is required before therapeutic efficacy (in a wide range of experimental tumors) is seen in mice; both in vitro and in vivo studies also suggest that the duration of drug exposure is crucial in determining activity. Thus a Phase I trial has been performed in a total of 54 patients using 3 schedules, i.e., a 1-, 3-, and 6-h infusion. In each case, treatment was given once weekly for a minimum of 3 weeks. The maximum tolerated doses were 6.4, 6.4, and 10.0 g/m2, respectively. Dose limiting toxicity was denoted by an intense feeling of warmth and flushing with a 1-h infusion, hypotension with a 3-h infusion, and hypotension and diarrhea with a 6-h infusion. No objective responses were seen in this Phase I trial. The recommended doses for Phase II trials of flavone acetic acid in Europe are 4.8 g/m2 over 1 h or 8.6 g/m2 over 6 h. At these doses the peak plasma concentrations obtained are 650 and 388 micrograms/ml, respectively. Total drug exposure (assessed by an area under the curve greater than 100 micrograms/ml) was approximately 50% greater for the 6-h schedule. This Phase I trial indicates that peak plasma concentrations associated with experimental activity are achievable in humans, although optimal drug exposure times have not yet been defined.

Adult↗

Multivariate analysis of prognostic factors in patients with disseminated nonseminomatous testicular cancer: results from a European Organization for Research on Treatment of Cancer Multiinstitutional Phase III Study.

Univariate and multivariate linear logistic regression analyses of potential prognostic variables have been performed for 163 patients with disseminated nonseminomatous testicular cancer, treated with cisplatin, vinblastine, and bleomycin in a multicenter study of the European Organization for Research on Treatment of Cancer Genito-Urinary Tract Cancer Cooperative Group. With a multivariate analysis, four prognostic groups with complete responder rates of 100, 89, 41, and 18%, respectively, were identified based on three prognostic factors: trophoblastic elements in the primary tumor, serum concentration of alpha-fetoprotein, and lung metastases by size and number. However, with a univariate analysis the logarithm of the beta subunit of human chorionic gonadotrophin (BHCG) was the single most important factor. This model aids the physician in selecting prospectively good risk patients who are candidates for low toxicity chemotherapy and poor risk patients with whom innovative treatment should be attempted.

Analysis of Variance↗

Comparative cardiotoxicity and antitumour activity of doxorubicin (adriamycin) and 4'-deoxydoxorubicin and the relationship to in vivo disposition and metabolism in the target tissues.

4'-Deoxydoxorubicin (4'-DOX) is an analogue of the anticancer drug Adriamycin (ADR) believed to lack its cardiotoxicity. Bioreduction to a semi-quinone free radical has been implicated in the etiology of ADR induced cardiotoxicity. We have studied (in a rat model) acute cardiotoxicity (after 16 mg/kg i.v. of both drugs), antitumour activity (after 5 mg/kg i.v.) and the relationship to disposition and metabolism in the target tissues (after 5 mg/kg i.v.). 7-Deoxyaglycones, which are considered inactive lipophilic metabolites derived from ADR semi-quinone, were utilised as markers of in vivo tissue free radical generation. Both drugs produced toxicity of equal severity to hearts after 24 hr, associated with high cardiac levels of 7-deoxyaglycones in the case of ADR (AUC0-48 hr, micrograms/g X hr: ADR, 47; ADR 7-deoxyaglycone (ADR-DONE), 24; and adriamycinol 7-deoxyaglycone (AOL-DONE), 35) compared to low cardiac levels of 7-deoxyaglycones but a times five higher peak cardiac concentration of parent drug in the case of 4'-DOX (AUC0-48 hr, micrograms/g X hr: 4'-DOX, 68; 4'-DOX-DONE, 3.8; and 4'-DOL-DONE, 0.8). 4'-DOX displayed superior antitumour activity to ADR against the MC 40A sarcoma growing sub-cutaneously, achieving higher concentrations of parent drug in tumour (AUC0-48 hr, micrograms/g X hr: 4'-DOX, 150; ADR, 60). There was an absence of 7-deoxyaglycones of both drugs in the tumour. These data suggest that drug bioreduction is involved principally only in ADR induced cardiotoxicity and that the level of unchanged parent drug achieved in the tumour is the most important pharmacokinetic determinant of antitumour activity for both ADR and 4'-DOX.

Animals↗

Phase II clinical and pharmacological study of oral 4-demethoxydaunorubicin in advanced non-pretreated small cell lung cancer.

4-Demethoxydaunorubicin (4-DMDNR) is an oral anthracycline with antitumour activity demonstrated in a number of clinical studies. We have assessed the usefulness of 4-DMDNR in 16 patients with advanced small cell lung cancer, none of whom had received previous chemotherapy. There were no complete or partial responders among the 14 evaluable patients, but 9 patients showed a minor radiographic improvement and 6 reported transient symptomatic improvement. Side effects were mostly minor or moderate, although one patient succumbed to septicaemia during neutropenia following treatment. There was no evidence of cardiotoxicity in any patient. Pharmacological studies were undertaken in 8 patients. A previously undescribed metabolite, identified as the 7-deoxyaglycone of 4-demethoxydaunorubicinol, was detected in 3 patients and these 3 patients all showed some anti-tumor response.

Administration, Oral↗

Method for the determination of 4-demethoxydaunorubicin, its quinone and hydroquinone metabolites in human plasma and urine by high-performance liquid chromatography.

4-Demethoxydaunorubicin (4-DMDNR) is a new orally active analogue of daunorubicin (DNR). We have developed a high-performance liquid chromatography (HPLC) method capable of separating and identifying 4-DMDNR, five possible fluorescent quinone metabolites and three possible non-fluorescent hydroquinone metabolites. Methods are described for high-yield synthesis of reference metabolites. The limit of detection of the fluorescence assay was less than 1 ng/ml after extraction of 1 ml plasma or urine with chloroform/propan-2-ol (2:1), with coefficients of variation in k' (HPLC column capacity factors) of less than 3% throughout the day. Efficiency of the extraction method described exceeded 80% in control experiments. Blood and urine samples were analysed from four cancer patients who had received 50 mg/m2 orally as three divided doses every 8 h. A typical urinary profile of the drug and its metabolites was: parent drug, 13%; 4-demethoxydaunorubicinol (4-DMDNOL), 80%; 4-DMDNR 7-hydroxyaglycone, 4% and 4-DMDNOL 7-hydroxyaglycone, 3%. 4-DMDNOL was the major metabolite detected in plasma. A further metabolite identified as the 7-deoxyaglycone of 4-DMDNOL was detected in plasma of two patients at concentrations equal to or greater than the parent drug. In the other two patients no trace of the metabolite was detected.

Carcinoma, Small Cell↗

Aspects of cytotoxic drug penetration, with particular reference to anthracyclines.

Experimental data, particularly derived from tumour spheroids, indicate that drug penetration barriers may be an important determinant of cytotoxic drug efficacy, even in spheroids of only a few hundred microns in diameter. Clinically, tumour masses of this size would equate with those micrometastases which are the target of adjuvant chemotherapy in a wide range of tumour types. It is apparent, therefore, that even at this relatively early stage of the metastatic process, which ultimately proves to be fatal in many patients, measures aimed at improving drug penetration may prove to be crucial in improving the therapeutic efficacy of cytotoxic agents.

Animals↗

Occurrence of circulating 7-deoxyaglycone metabolites of 4'-deoxydoxorubicin in man.

In five cancer patients we have determined the pharmacokinetics of 4'-deoxydoxorubicin (4'-DOX), its alcoholic metabolite 4'-deoxydoxorubicinol and the occurrence of circulating 7-deoxyaglycone metabolites. The 7-deoxyaglycone of the alcohol metabolite, the major aglycone of Adriamycin (ADR) present in man, was not detected in any serum sample. The 7-deoxyaglycone of the parent drug, which appears in concentrations in excess of 30 ng/ml after ADR administration, was detected in only 2/5 patients in trace amounts. These preliminary data indicate a difference in biotransformation between ADR and 4'-DOX despite their close structural similarities.

Biotransformation↗