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Biomedical subjects

A Lipton

Publications and source records attributed to A Lipton.

At least 73 records · Page 4Linked to original sources
PubMed1994

Pamidronate in the treatment of bone metastases: results of 2 dose-ranging trials in patients with breast or prostate cancer.

Four intravenous regimens of pamidronate (Aredia) were evaluated for palliative treatment of bone metastases in 2 randomized open-label trials in patients with breast cancer (n = 61) or prostate cancer (n = 58). In breast cancer patients, administration of pamidronate 60 mg every 4 weeks, 60 mg every 2 weeks, or 90 mg every 4 weeks for 3 months resulted in statistically and clinically significant reductions in bone pain, with accompanying decreases in biochemical markers of bone turnover; a regimen of 30 mg every 2 weeks was not effective. Healing of bone lesions was observed in 25% of breast cancer patients. In prostate cancer patients, the same regimens of pamidronate produced reductions in bone pain, but no dose-response relationship was apparent. Moreover, there were no consistent changes in biochemical indices in these patients, and no healing of bone lesions occurred. The different response to pamidronate in those 2 patient populations may reflect the different severity of metastatic disease at baseline. Side effects of pamidronate were mild and transient in both studies.

Adult↗
PubMed1993

The effects of long term fadrozole hydrochloride treatment in patients with advanced stage breast cancer.

Fadrozole hydrochloride at a dose of 2 mg b.i.d. has been shown to be an effective aromatase inhibitor in advanced stage breast cancer patients as determined by its ability to significantly suppress endogenous estrogen biosynthesis over a 12-week period. Continued suppression of circulating estrogen levels over a prolonged period has not yet been examined in published reports. In this study, we report the extended use of fadrozole hydrochloride at a maintenance dose of 2 mg b.i.d. in a cohort of 11 patients extending to 973 days of therapy. Results show that the degree of suppression of plasma and urinary estrogens was maintained in all patients throughout the extended period of drug use. Continued estradiol suppression of over 50% or greater from baseline was observed, as was continued suppression of estrone to over 80% from baseline. Cortisol determinations after 9 months of treatment showed no suppression from baseline. The aldosterone values and responses to cortrosyn stimulation continued to be suppressed as first noted following the initial 3 months of the core clinical trial. Objective tumor response noted in the core clinical trial did not change until disease progression. These findings suggest that fadrozole hydrochloride maintains its ability to suppress the aromatase enzyme during long term use. No observable escape from suppression of plasma and urinary estrogens occurred during prolonged treatment.

Adrenocorticotropic Hormone↗
PubMed1993

The efficacy of CGS 20267 in suppressing estrogen biosynthesis in patients with advanced stage breast cancer.

The pharmacologic inhibition of aromatase activity has been the focus of clinical trials in patients with advanced stage breast cancer. Recent developments with imidazole compounds that inhibit aromatase activity suggest their clinical use as potent inhibitors of estrogen biosynthesis in postmenopausal breast cancer patients. In this Phase I, open-label, dose-range finding study, we examined the inhibitory potency of CGS 20267 on blood and urine levels of estradiol, estrone and estrone sulfate in 8 patients with metastatic breast cancer. Studies included evaluation of adrenal and thyroid function to look for evidence of general hydroxylase inhibition at dose levels effective for aromatase blockade. Patients were administered CGS 20267 at doses of 0.1 and 0.25 mg, once a day in ascending doses over a 12-week period. Preliminary data reveal that CGS 20267 elicits a striking suppression in plasma estradiol, estrone and estrone sulphate which was observed in some patients as quickly as within 24 h of the first dose. Estrogen suppression of over 90% was achieved within 2 weeks of therapy. No alterations in either baseline or ACTH (cortrosyn) stimulated cortisol and aldosterone levels were observed through the 12 weeks of therapy. In addition, 24 h urine sodium and potassium values were not appreciably altered during therapy. We conclude that CGS 20267 is a potent, specific inhibitor of estrogen biosynthesis in postmenopausal patients with metastatic breast cancer and effectively reduces blood and urine estrogens to undetectable levels.

Aldosterone↗
PubMed1993

Interleukin-2 and interferon-alpha-2a outpatient therapy for metastatic renal cell carcinoma.

The combination of interleukin-2 (IL-2) and interferon-alpha-2a (IFN-alpha-2a) has synergistic bioactivity in numerous preclinical model systems. Thirty-nine patients with metastatic renal cell cancer were treated with continuous intravenous infusion IL-2 for 4-5 days plus intramuscular IFN-alpha-2a 2-3 days a week for 4 consecutive weeks. A 2- to 4-week rest period was permitted after each 4 weeks of treatment. Thirty-one of the 39 patients were assessable for response determination. Response rate (six complete+seven partial remissions) was 33.3% for all patients, or 41.9% when the analysis was restricted to the 31 evaluable patients. Three patients were unable to tolerate treatment due to anorexia, weight loss, and severe fatigue. This therapy was relatively well tolerated in the outpatient setting in the other patients despite fever, chills, fatigue, anorexia, and weight loss. There was no correlation of response with site of metastases or bulk of disease.

Adult↗
PubMed1993

Subcutaneous interleukin-2 plus interferon alfa-2a in metastatic renal cancer: an outpatient multicenter trial.

PURPOSE: A prospective multicenter phase II trial was undertaken to define the activity of a low-dose subcutaneous regimen of interleukin-2 (IL-2) and interferon alfa-2a (IFN) in patients with metastatic renal cancer. PATIENTS AND METHODS: Between December 1990 and October 1991, 42 patients with metastatic renal cancer who had received no prior immunotherapy were treated with IL-2 (4 x 10(6) U) days 1 through 4 and IFN (9 x 10(6) U) day 1 and 4 each week of a 4-week treatment course followed by a 2-week rest period. Maximum duration of therapy was 1 year. Concomitant therapy with acetaminophen, diphenhydramine, and indomethacin was recommended. Treatment was administered on an outpatient basis. RESULTS: With a median follow-up duration of 18 months, responses occurred in five of 42 patients (12%; 95% confidence interval [Cl], 2% to 22%). One pathologic complete remission, one surgical complete remission, and three partial remissions occurred. Toxicity was modest, with a symptom complex of rash, fever, anorexia, fatigue, mild weight loss, lymphocytosis, and eosinophilia occurring in 85% to 90% of patients. Renal dysfunction (creatinine > 2 mg/dL) occurred in 19% of patients, while three patients (7%) refused further IL-2 and IFN. No toxic deaths occurred. The median survival duration was 14.5 months. CONCLUSION: This outpatient low-dose subcutaneous regimen induced mild toxicity, a modest response rate, and an excellent median survival duration in previously untreated patients. Phase III trials are now needed to compare IL-2 plus IFN with IL-2 alone or to various IL-2/IFN regimens. However, the major task is to identify unique new agents with activity in renal cancer.

Adult↗
PubMed1993

Increased urinary excretion of pyridinium cross-links in cancer patients.

Pyridinoline (PYD) and deoxypyridinoline (DPD), two collagen-based cross-links found in bone, were measured by high-performance liquid chromatography in urine samples from 65 control subjects and 97 patients with either untreated or progressive cancer. Patients with cancer had significantly (P < 0.001) higher urine concentrations of PYD and DPD than did control subjects. Both cross-links were increased in cancer patients with and without clinically detectable bone metastases, although patients with bone and liver involvement had higher mean concentrations. The mean concentrations of both cross-links were also significantly higher in the urine samples of inpatients than in an outpatient ambulatory population. These findings suggest that the measurement of PYD and DPD in urine may be useful in assessing bone metastases and bone resorption in cancer patients.

Adult↗
PubMed1992

Prognostic value of breast cancer aromatase.

The estrogen receptor, progesterone receptor, and intratumoral aromatase content of 127 breast carcinomas were determined. Patients whose tumor contained either estrogen or progesterone receptors had a longer disease-free interval, but no difference in survival was observed. Measurable aromatase activity was detected in 78 of 113 (69%) tumors. There was no relationship between aromatase activity and disease-free interval or survival.

Aromatase↗
PubMed1992

Hormonal and immunological regulation of 2', 5'-oligoadenylate synthetase activity in human peripheral blood mononuclear cells.

A newly developed method for assaying 2', 5'-oligoadenylate (2, 5A) synthetase activity by polyacrylamide gel electrophoresis was applied to peripheral blood mononuclear cells (PBMC) from normal subjects, HIV-positive subjects, and renal cell carcinoma (RCC) patients. Sex differences were observed in 2, 5A synthetase activity of PBMC from normal young adults, males having eightfold higher activities of this enzyme than females. Moreover, compared to values for postmenopausal (PM) females receiving estrogen replacement, untreated PM females had higher activities. Collectively, these results suggest that estrogen downregulates 2, 5A synthetase activity. Activities of 2, 5A synthetase were investigated in two disease states associated with altered immune function. In one patient with AIDS-related Kaposi's sarcoma, interferon-alpha (IFN-alpha) therapy increased 2, 5A synthetase activity twofold. In addition, combined therapy with interleukin-2 (IL-2) and IFN-alpha increased 2, 5A synthetase activities in eight of nine patients with RCC. Therefore, in patients receiving immunotherapy with IL-2 and IFN-alpha, our new assay could contribute to evaluation of immune stimulation. In general, studies in vitro confirmed these observations; however, exposure of PBMC from RCC patients revealed that in vitro IL-2 failed to induce this enzyme activity as it did in PBMC from normal volunteers.

2',5'-Oligoadenylate Synthetase↗
PubMed1991

Corynebacterium parvum versus bacille Calmette-Guérin adjuvant immunotherapy of stage II malignant melanoma.

Two separate studies have been reported comparing Corynebacterium parvum and bacille Calmette-Guérin (BCG) as adjuvant immunotherapy for stage II melanoma patients (The Milton S. Hershey Medical Center, 48 patients; Southeastern Cancer Study Group [SECSG], 162 patients). As the criteria for patient selection and drugs used were similar, we have pooled the data to analyze the effects of these two treatments. Both studies used BCG (Tice, Chicago, IL) 3 x 10(8) live organisms per treatment by Tine technique and C parvum (Burroughs-Wellcome, Triangle Park, NC) subcutaneous at a dose of 4 mg/m2 (SECSG) or 5 micrograms/m2 (Hershey) per treatment. The only difference in these studies was the frequency of immunization, with patients in Hershey receiving 22 doses and the SECSG patients receiving 55 doses during the 2-year period of treatment. Kaplan-Meier life-table analysis for the 210 patients shows a prolonged disease-free interval for patients treated with C parvum (P = .02, two-sided Mantel procedure). In similar fashion, patients treated with C parvum had an improved survival rate (from all causes) when compared with BCG-treated patients (P = .012). An analysis of the results for the 170 patients for which the number of positive nodes was available was performed using Cox's model, with nodes as a stratification variable and with covariates of place, treatment, age, and sex. In this analysis, an observed benefit for C parvum on the disease-free interval had a P value of .37 while the benefit of C parvum on the survival times (from all causes) had a P value of .04. When the same analysis was performed using only patients aged younger than 60 years, the observed benefit of C parvum on disease-free interval had a P value of .08 and the benefit of C parvum on survival times (from all causes) had a P value of .008.

Adjuvants, Immunologic↗
PubMed1991

Specificity of low dose fadrozole hydrochloride (CGS 16949A) as an aromatase inhibitor.

CGS 16949A (fadrozole hydrochloride), a potent cytochrome P450-mediated steroidogenesis inhibitor, blocks aromatase at low doses, but other biosynthetic steps at higher concentrations. Recent studies demonstrated inhibition of C11-hydroxylase, corticosterone methyloxidase-II, and deoxycorticosterone to corticosterone conversion with this agent at some-what higher concentrations than those required for blockade of aromatase. Based upon phase I studies, we postulated that relatively selective inhibition of aromatase might be possible if sufficiently low doses of CGS 16949A were used. A phase II study in 54 postmenopausal women with metastatic breast cancer examined the effects of low dose CGS 16949A on estrogen, mineralocorticoid, and glucocorticoid secretion. Two dose schedules and two dose levels were chosen based upon our prior dose escalation protocol study. Plasma estrone, estradiol, and estrone sulfate as well as urinary estrone and estradiol fell equally with 1.8-4 mg CGS 16949A given either on a twice daily or three times daily dose schedule. Isotopic kinetic studies demonstrated an 84% decrease in the rate of conversion of androstenedione to estrone to 0.40 +/- 0.07% (patients receiving 1.8-4 mg CGS 16949A daily). With these three regimens, basal levels of aldosterone and cortisol did not change significantly over a 12-week period of observation. Clinical examination, plasma electrolytes, and urinary sodium/potassium ratios suggested no biological evidence of mineralo-corticoid deficiency. ACTH-stimulated cortisol concentrations, however, were blunted at each dose level compared to pretreatment values. Nonetheless, peak responses exceeded 550 nmol/L, or a basal to peak difference of 190 nmol/L or greater, in 97% of instances. This probably reflected inhibition of C11-hydroxylase, since basal and ACTH-stimulated levels of 11-deoxycortisol were increased in response to CGS 16949A. Androstenedione and 17 alpha-hydroxyprogesterone also exhibited an upward trend in response to drug treatment. ACTH-stimulated aldosterone levels were blunted to a greater extent than those of cortisol, probably as a reflection of corticosterone methyloxidase type II blockade. Overall, the results suggest that CGS 16949A, at doses of 1.8-2 mg daily, blocks aromatase effectively and does not produce clinically important inhibition of cortisol or aldosterone biosynthesis. Thus, this agent can probably be used safely without glucocorticoid or mineralocorticoid supplementation.

17-alpha-Hydroxyprogesterone↗
PubMed1990

Somatostatin analogues in the treatment of breast and prostate cancer.

Newly developed somatostatin analogues may be useful agents in the treatment of breast and prostate cancer. Potential mechanisms of antitumor action include suppression of circulating levels of trophic hormones and growth factors as well as direct effects at the tumor level, potentially involving autocrine/paracrine mechanisms. Pilot clinical trials conducted in heavily pretreated women with advanced breast cancer indicate that SMS 201-995 (Sandostatin R) has minimal toxicity and moderately suppresses stimulated growth hormone secretion and basal somatomedin-C level. Somatostatin analogues have also been found to retard the growth of experimental prostate cancer, particularly when used in combination with LHRH analogues. The therapeutic efficacy of these compounds used alone or in combination with other agents in the treatment of breast and prostate cancer remains to be established in larger clinical trials involving less heavily pretreated patients.

Antineoplastic Agents↗
PubMed1990

A phase I trial of CGS 16949A. A new aromatase inhibitor.

CGS 16949A is a new, nonsteroidal competitive inhibitor of the aromatase enzyme. In this Phase I trial, 16 heavily pretreated postmenopausal patients with metastatic breast cancer were treated with escalating doses of CGS 16949A from 0.6 to 16 mg total daily oral dose. No hematologic, biochemical, or significant clinical toxicity was encountered. Endocrinologic and pharmacologic data were available from 12 of these patients. Maximum inhibition of estrogen biosynthesis was observed at a dose of 2 mg CGS 16949A daily. At this dose, the inhibition of estrogen biosynthesis was equivalent to 1000 mg aminoglutethimide (AG). The fall in plasma and urinary estrogens without a concomitant drop in androgens confirmed the specific blockade of aromatase activity. At doses of 4 to 16 mg daily, CGS 16949A appeared to inhibit the C21-hydroxylase enzyme as well. The t1/2 of CGS 16949A in the circulation was 10.5 hours. Of 16 evaluable patients there were two partial responses and seven patients with stable disease.

Adult↗
PubMed1990

Phase I study of interleukin-2 and interferon alfa-2a as outpatient therapy for patients with advanced malignancy.

Twenty-six patients were treated in this phase I study with the combination of interleukin-2 (IL2) administered as a continuous infusion and interferon alfa-2a (IFN alpha-2a) administered intramuscularly to patients in an outpatient setting. The maximum-tolerated dose of both agents given as outpatient therapy was 2 x 10(6) U/m2 days 1 to 5 of IL2 and 9 x 10(6) U/m2 days 1, 3, and 5 of IFN alpha-2a for 4 consecutive weeks. A 2- to 4-week rest period was permitted after each 4 weeks of treatment. Fatigue was the treatment-limiting toxicity, and serious clinical or laboratory abnormalities occurred infrequently during this study. Patients with colon cancer metastatic to the liver tolerated treatment worse than patients with other tumors. Twelve of the 15 patients with renal cell cancer were assessable for response determinations. Of these 12 patients, three exhibited complete tumor regression, three have had partial objective regression, and three patients experienced stabilization of rapidly progressive disease. This therapy appears to be well tolerated in an outpatient treatment setting and shows significant activity against advanced renal cell cancer.

Adult↗
PubMed1990

The pharmacodynamic inhibition of estrogen synthesis by fadrozole, an aromatase inhibitor, and its pharmacokinetic disposition.

In this dose-ranging phase I study, the relationship between in vivo androgen to estrogen conversion kinetics and plasma concentrations of fadrozole was investigated in postmenopausal women receiving therapy with this aromatase inhibitor. Patients received ascending doses, ranging from 0.3-8 mg fadrozole twice daily, each for a period of 2 weeks. Drug kinetics and endocrine effects were evaluated specifically for the 2- and 8-mg twice daily treatment regimens. The in vivo activity of the drug was demonstrated by the suppression of estrone and estradiol biosynthesis from testosterone and androstenedione, respectively. The drug inhibitory constant, KI, for the estrone synthetic pathway, was 3.0 ng/mL (13.4 nmol/L) and was of similar magnitude as that determined under in vitro conditions. The KI for the estradiol synthetic pathway was 5.3 ng/mL (23.7 nmol/L). The disparity between KI values may indicate that the two pathways are not equivalent in terms of their inhibition by fadrozole. Pharmacokinetic data demonstrated tha the drug was rapidly absorbed after oral dosing, with peak plasma concentrations achieved in median times of 1 and 2 h, respectively, for the 2- and 8-mg twice daily treatment regimens. The average half-life and oral clearance values were 10.5 h and 621 mL/min, respectively. Oral clearance was independent of dose.

Aged↗
PubMed1990

The effects of CGS 16949A, an aromatase inhibitor on adrenal mineralocorticoid biosynthesis.

The family of cytochrome P450 enzymes that mediates steroid hydroxylations are distinct but structurally related proteins. Inhibitors of these steroidogenic steps generally exhibit only relative and dose-related specificity. We evaluated an imidazole, cytochrome P450-related inhibitor, CGS 16949A, in postmenopausal patients with metastatic breast cancer. While a relatively specific aromatase inhibitor at daily dosages of 1-2 mg, CGS 16949A significantly blunted cortisol responses to ACTH at a dose of 16 mg daily. To further evaluate other inhibitory effects of this drug, we determined blood levels of aldosterone (ALDO) and 18-hydroxycorticosterone and their respective urinary metabolites, tetrahydroaldosterone and tetrahydro-18-hydroxy-11-dehydrocorticosterone in 16 postmenopausal women receiving CGS 16949A. At a dose of 16 mg/day, CGS 16949A produced significant (P less than 0.001) suppression of both basal and ACTH-stimulated ALDO production. This was accompanied by a significant rise in the blood 18-hydroxycorticosterone/ALDO ratio (11.4 +/- 0.19; normal, less than 2; P less than 0.001), consistent with a corticosterone methyloxidase type II inhibition. A similar significant elevation (7.5 +/- 1.2; normal, less than 5; P less than 0.001) in the urinary tetrahydro-18-hydroxy-11-dehydrocorticosterone/tetrahydroaldosterone ratio was also observed. These results suggest that CGS 16949A is a potent inhibitor of the corticosterone methyloxidase type II enzyme at a dose of 16 mg daily. At doses of 1-2 mg daily, CGS 16949A blocks aromatase without altering basal aldosterone production and, thus, exhibits dose-related specificity.

18-Hydroxycorticosterone↗
PubMed1990

FAM chemotherapy +/- aminoglutethimide in the treatment of pancreatic carcinoma.

Human pancreas contains receptors for estrogens and androgens as well as aromatase activity. FAM chemotherapy was administered to 14 patients with pancreatic cancer (seven at Stage IV). The median survival of these patients was 24.4 +/- 4.8 weeks. FAM chemotherapy plus aminoglutethimide/hydrocortisone (AG/HC) (250 mg bid AG + 20 mg bid HC) was administered to 14 patients (seven at stage IV). The median survival of this group was 17.3 +/- 2.9 weeks (P = 0.74 vs FAM alone). We conclude that addition of AG/HC does not add to the survival of patients with carcinoma of the pancreas treated with chemotherapy.

Aminoglutethimide↗
PubMed1989

A phase I study of hepatic arterial infusion using difluoromethylornithine.

Ten patients with metastatic disease to the liver were treated with difluoromethylornithine (DFMO) administered by continuous hepatic arterial infusion. Two of nine evaluable patients had an objective partial response. Stable disease was recorded in three patients. Ototoxicity was encountered in all patients who received a daily dose of DFMO equal to or greater than 1.0 g/m2.

Adult↗