Administration of pentosan polysulfate to patients with human immunodeficiency virus-associated Kaposi's sarcoma.

BACKGROUND: Neovascularization induced by basic fibroblast growth factor (basic FGF) or FGF-like cytokines is thought to play a substantial role in the pathogenesis of human immunodeficiency virus (HIV)-associated Kaposi's sarcoma. Pentosan polysulfate has been shown to inhibit basic FGF and FGF-like dependent tumor growth both in vitro and in vivo. Moreover, it has been found to inhibit the growth of Kaposi's sarcoma-derived spindle cells in vitro. These observations suggested that pentosan polysulfate might be worth exploring as a potential agent for the treatment of Kaposi's sarcoma. PURPOSE: The purpose of this phase 1 clinical trial was to determine the maximum tolerated dose of pentosan polysulfate in patients with HIV-associated Kaposi's sarcoma and whether or not this compound had activity against this neoplasm. METHODS: Sixteen HIV-seropositive patients with Kaposi's sarcoma received pentosan polysulfate via continuous venous infusion for 3-6 weeks and then received a subcutaneous dose three times per week. Three different doses of pentosan polysulfate were administered: 2 mg/kg per day by infusion followed by 2 mg/kg per dose given subcutaneously (six patients), 3 mg/kg per day by infusion followed by 3 mg/kg per dose given subcutaneously (five patients), and 4 mg/kg per day by infusion followed by 4 mg/kg per dose given subcutaneously (five patients). Five of the 16 patients in the study also received injections of 1 mg of pentosan polysulfate into two different lesions two times a week for 3 weeks, followed by intralesional therapy once weekly. After receiving pentosan polysulfate for 6 weeks, patients were administered 100 mg zidovudine (AZT) orally every 4 hours in conjunction with pentosan polysulfate. RESULTS: The maximally tolerated dose of pentosan polysulfate given by continuous venous infusion was found to be 3 mg/kg per day. No patient had an objective clinical antitumor response to either systemic or intralesional pentosan polysulfate administration; however, three patients had stable Kaposi's sarcoma for 3-27 weeks. No statistically significant effect on CD4 cells or serum HIV p24 antigen was noted during pentosan polysulfate administration. Dose-limiting toxic effects were characterized by anticoagulation and thrombocytopenia and were reversible. CONCLUSION: Pentosan polysulfate was well tolerated in this patient population. However, no objective tumor response or evidence of anti-HIV activity was noted; therefore, no claim of activity can be made in this trial. IMPLICATION: Continued investigation into the use of angiogenesis inhibitors with improved activity and toxicity profiles or different mechanisms of action is warranted.

Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for human leukocyte antigen B (HLA-B) genotype and allopurinol dosing: 2015 update.

The Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for HLA-B*58:01 Genotype and Allopurinol Dosing was originally published in February 2013. We reviewed the recent literature and concluded that none of the evidence would change the therapeutic recommendations in the original guideline; therefore, the original publication remains clinically current. However, we have updated the Supplemental Material and included additional resources for applying CPIC guidelines into the electronic health record. Up-to-date information can be found at PharmGKB (http://www.pharmgkb.org).

Paclitaxel in doxorubicin-refractory or mitoxantrone-refractory breast cancer: a phase I/II trial of 96-hour infusion.

PURPOSE: A phase I study of paclitaxel infused over 96-hours was performed to determine toxicity, maximum-tolerated dose (MTD), and pharmacokinetics in patients with incurable lymphomas and solid tumors. A phase II study was performed at the MTD of paclitaxel in patients with doxorubicin/mitoxantrone-refractory metastatic breast cancer. PATIENTS AND METHODS: In the phase I study, paclitaxel dose levels ranged from 120 to 160 mg/m2, administered on a 21-day cycle. Patients with metastatic breast cancer who had either no response or a partial response (PR) to doxorubicin or mitoxantrone and had measurable disease were eligible for the phase I and II studies. Expression of the multidrug resistance (mdr-1) gene was determined in tumor biopsies by mRNA quantitative polymerase chain reaction. RESULTS: Twelve patients received a total of 73 cycles of paclitaxel on the phase I study. Dose-limiting mucositis and/or grade IV granulocytopenia was reached at 160 mg/m2, and 140 mg/m2 was selected as the phase II dose. Thirty-six consecutive patients with metastatic breast cancer were treated, of whom three were not assessable. The median age was 49 years, with disease in the liver and/or lung in 76%. Patients received a median of two prior regimens for metastatic disease, and 73% had no response to prior doxorubicin or mitoxantrone. Of 33 patients treated with paclitaxel, 16 patients (48%) achieved a PR and five (15%) achieved a minor response (MR). With a median potential follow-up duration of 60 weeks, the median progression-free and overall survival durations were 27 and 43 weeks, respectively. No correlation was found between extent of prior treatment or prior response to doxorubicin/mitoxantrone, and response to paclitaxel. Paclitaxel pharmacokinetics showed a correlation between both granulocyte and mucosal toxicity, and serum steady-state concentrations (Css) more than 0.07 mumol/L. Patients with liver metastases had significantly decreased paclitaxel clearance and higher paclitaxel Css. Levels of mdr-1 were uniformly low in all tumor biopsies studied. CONCLUSION: The recommended phase II dose of paclitaxel is 140 mg/m2 in patients without liver metastases and 105 mg/m2 in patients with liver metastases. Ninety-six-hour infusions of paclitaxel were effective and well tolerated in patients with doxorubicin/mitoxantrone-refractory breast cancer. Prolonged infusion schedules may be more effective than shorter schedules and deserve further study.

Phase II study of paclitaxel in relapsed non-Hodgkin's lymphomas.

PURPOSE: To assess the efficacy and toxicity of paclitaxel administered as a 96-hour infusion to patients with relapsed non-Hodgkin's lymphomas (NHLs). PATIENTS AND METHODS: Eligible patients had relapsed NHL and measurable disease and were considered incurable. Paclitaxel was infused at a dose of 140 mg/m2 every 3 weeks. Premedications to prevent paclitaxel hypersensitivity reactions were not administered and no patients received corticosteroids. Expression of the multidrug resistance (mdr-1) gene was determined in tumor from 17 patients by mRNA quantitative polymerase chain reaction (PCR). RESULTS: Thirty-one patients received a total of 99 cycles of paclitaxel. Two patients were not assessable for response. The median age was 50 years, 71% had stage IV disease, and intermediate/high-grade histology was present in 65% of patients. Patients had received a median of three prior chemotherapy regimens, and 68% of patients had responded to the previous chemotherapy (chemotherapy-sensitive). Of 29 assessable patients, five (17%) achieved a partial response (PR). With a median potential follow-up time of 17 months, the median event-free and overall survival durations were 1.6 and 7.5 months, respectively. No correlation was found between response to paclitaxel and extent of prior treatment or response. The mdr-1 gene was easily detectable in 14 of 17 tumor biopsies, but was low in all but one sample. The most serious toxicity was grade 4 neutropenia, which occurred during 14% of cycles. CONCLUSION: Paclitaxel was well tolerated, but had a low response rate in patients with relapsed NHLs. There was no clear association between response to paclitaxel and extent of our response to prior treatment. Most patients had chemotherapy-sensitive disease, which suggests that the low response rate to paclitaxel was probably not due to general chemotherapy resistance. Paclitaxel provided good palliation in a minority of patients and is a reasonable agent to consider for use in patients who have failed to respond to standard chemotherapy.

Phase I study of paclitaxel in combination with cyclophosphamide and granulocyte colony-stimulating factor in metastatic breast cancer patients.

PURPOSE: In vitro data suggest that prolonged exposure to paclitaxel enhances breast cancer cytotoxicity. Our objective in this phase I study was to determine the tolerability of paclitaxel administered by 72-hour continuous intravenous (i.v.) infusion (CIVI) in combination with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) in the ambulatory setting to metastatic breast cancer patients. PATIENTS AND METHODS: Paclitaxel was administered over 72 hours by CIVI and cyclophosphamide was given daily by i.v. bolus on days 1, 2, and 3, followed by G-CSF every 21 days. The availability of ambulatory infusion pumps and paclitaxel-compatible tubing permitted outpatient administration. RESULTS: Fifty-five patients with metastatic breast cancer who had been previously treated with a median of two prior chemotherapy regimens were entered onto the study. Dose-limiting toxicity of grade 4 neutropenia for longer than 5 days and grade 4 thrombocytopenia occurred in three of five patients treated with paclitaxel 160 mg/m2 CIVI and cyclophosphamide 3,300 mg/m2 followed by G-CSF. The maximum-tolerated dose (MTD) was paclitaxel 160 mg/m2 CIVI and cyclophosphamide 2,700 mg/m2 in divided doses with G-CSF. Nonhematologic toxicities were moderate and included diarrhea, mucositis, and arthalgias. Although hemorrhagic cystitis developed in six patients, recurrence was prevented with i.v. and oral mesna, which permitted continued outpatient delivery. One hundred seventy-four cycles were safely administered in the ambulatory setting using infusional pumps and tubing. Objective responses occurred in 23 (one complete and 22 partial) of 42 patients with bidimensionally measurable disease (55%; 95% confidence interval, 38% to 70%), with a response rate of 73% (11 of 15) seen at the highest dose levels. CONCLUSION: Paclitaxel by 72-hour CIVI with daily cyclophosphamide followed by G-CSF can be administered safely in the ambulatory setting, has acceptable toxicity, and is an active regimen in the treatment of metastatic breast cancer.

Taxol: a history of pharmaceutical development and current pharmaceutical concerns.

Taxol, a unique diterpene anticancer compound derived from the bark of the Taxus brevifolia (Pacific yew) tree, induces cytotoxicity by a novel mechanism of action. An antimicrotubule agent, Taxol promotes the formation and stabilization of the tubulin polymer unlike other anticancer agents that induce microtubule disassembly. Because of its poor aqueous solubility, Taxol is formulated as a solution in 50% Cremophor EL and 50% dehydrated alcohol, USP. The Cremophor EL and dehydrated alcohol vehicle used in the formulation of Taxol creates some interesting challenges for its preparation and administration. The pharmaceutical concerns associated with the preparation and administration of Taxol are discussed.

Adaptive control with feedback strategies for suramin dosing.

Suramin, a drug used in the treatment of parasitic diseases, is currently being evaluated in clinical trials as an antineoplastic agent. The use of therapeutic drug monitoring and adaptive control with feedback in clinical trials of suramin was initially motivated by an association between acute neurologic toxicity and plasma suramin concentrations in excess of 350 micrograms/ml. We have prospectively examined the performance of both two- and three-compartment population pharmacokinetic models in controlling plasma suramin concentrations and have found that a three-compartment model best describes this drug. No correlation was found between the clearance of suramin and creatinine clearance, as had been previously hypothesized. The low systemic clearance of suramin and the number of parameters required to describe the three-compartment model suggest the need for a bayesian approach to the estimation of individual pharmacokinetics.

A pilot study of amiodarone with infusional doxorubicin or vinblastine in refractory breast cancer.

Increasing evidence suggests that P-glycoprotein (Pgp) expression can mediate drug resistance in refractory breast cancer. We studied 33 patients with refractory breast cancer enrolled in a pilot study of oral amiodarone as a Pgp antagonist given in combination with infusional doxorubicin or vinblastine. Whenever possible, tumors were biopsied and Pgp expression was assayed. Patients received either 60 mg/m2 doxorubicin over 96 h or 8.5 mg/m2 vinblastine over 120 h by continuous intravenous infusion. Beginning with the second cycle of chemotherapy, 600-800 mg amiodarone was given orally each day. Patients who experienced toxicity due to amiodarone but were responding to chemotherapy were placed on quinidine. Partial responses were observed in 9 of 33 patients on study and were sometimes observed after the first cycle of chemotherapy, before amiodarone was given, suggesting that some patients may have responded to treatment because of the infusional schedule. Toxicities were primarily the known side effects of the antineoplastic agents and of amiodarone. The major amiodarone toxicity was gastrointestinal, with nausea, vomiting, anorexia, or diarrhea being noted in 21 patients. Biopsy samples were obtained from 29 patients and in 21 cases, viable tumor tissue was present and the results were interpretable. Of the 21 samples, 9 had Pgp expression as determined by immunohistochemical staining; 12 were considered negative. The presence of Pgp expression was associated with an acceleration of the time to treatment failure. Whereas normal-tissue toxicities related to the combination of a Pgp antagonist with chemotherapy were not observed, amiodarone was associated with too many untoward effects to be utilized as a drug resistance-reversing agent.

Clinical overview of the taxanes.

Paclitaxel and docetaxel are taxane antineoplastic agents with broad antitumor activity. Since being introduced, they have become increasingly important in the treatment of a number of major solid tumors. Paclitaxel plus a platinum analog is now considered first-line therapy for advanced ovarian cancer, and both paclitaxel and docetaxel have significant activity as single agents in recurrent ovarian cancer. Docetaxel may be useful in some of these women with ovarian cancer who fail or progress after paclitaxel-containing treatments. Both drugs have significant response rates in the treatment of breast cancer and are options for patients with advanced disease, including anthracycline-refractory disease. Administration of taxanes in new combination regimens and as adjuvant therapy for breast cancer is under investigation; for example, the combination of paclitaxel and doxorubicin is highly active, and comparative studies of taxanes and anthracyclines should help clarify optimal treatment regimens in breast cancer. Both drugs have significant activity alone in the treatment of advanced non-small cell lung cancer (NSCLC) and head and neck cancers. For the former, paclitaxel-cisplatin is now standard treatment in cooperative group combination therapy trials. As a result of its radiosensitizing properties, paclitaxel is undergoing extensive evaluation as combined modality treatment for advanced NSCLC and head and neck cancer. Both taxanes will probably be useful in combination regimens in head and neck cancer. Research is continuing to define further their roles and relative usefulness in other malignancies.

Paclitaxel (taxol).

Paclitaxel is a novel antineoplastic that effects cytotoxicity by promoting intracellular tubulin polymerization and stabilizes abnormal microtubule structures against depolymerization. Although its clinical development had been hampered by misconceptions about its pharmacology, its scarcity, difficulties extracting it from its natural source, formulation problems, and frequent severe hypersensitivity reactions, paclitaxel recently was approved for treatment-refractory ovarian cancer. Two major adverse effects are dosage- and schedule-related myelosuppression and mucositis. Neurotoxicity is directly related to both the individual and cumulative doses. Other relevant toxicities are hypersensitivity reactions, effects on cardiac rate and rhythm, arthralgias and myalgias, generalized hair loss, and mild nausea and emesis. Continuing clinical studies will evaluate paclitaxel as initial therapy for ovarian cancer and its utility in other malignancies. In addition, major efforts are under way to develop alternative sources to increase the availability of taxene analogs and reduce our dependence on yew species.

A continuous-improvement approach for reducing the number of chemotherapy-related medication errors.

A comprehensive, interdisciplinary approach for reducing the number of chemotherapy-related medication errors at the National Institutes of Health Clinical Center, where approximately 8500 doses of chemotherapy agents are dispensed annually, is described. Heightened awareness of the seriousness of chemotherapy-related medication errors prompted formation of an interdisciplinary task force in June 1995 to analyze and improve the hospital's system for ordering, checking, processing, and administering cancer chemotherapy agents. Problems were analyzed and rectified in accordance with the hospital's plan-do-check-act performance-improvement model. Performance monitors for the improvements included a system to record and categorize all chemotherapy-related prescribing errors and a hospital-wide occurrence-reporting system. The task force identified seven major categories in which improvements were needed: protocol development, computer-system enhancements, dose verification, information access, education for health care practitioners, error follow-up, and infusion pumps. Despite the Clinical Center's good safety-net system, 23 modifications were made to the existing system through December 1999. These changes resulted in an overall 23% decrease in prescribing errors and a 53% decrease in serious prescribing errors. The task force membership was recently broadened to include representatives of additional departments where chemotherapy agents are used, and this group recommended more than 20 additional system changes. The changes are being implemented, and their effect on reducing the number of chemotherapy-related errors will be measured. The continuous-improvement process used prospectively by the task force helps ensure that safe chemotherapy practices are instituted uniformly throughout the hospital.

Standardizing the expression and nomenclature of cancer treatment regimens. American Society of Health-System Pharmacist (ASHP), American Medical Association (AMA), American Nurses Association (ANA).

Guidelines for describing cancer chemotherapy regimens in all aspects of drug development, including treatment protocols, order forms, and product labels, are proposed. To complement the approaches to reducing medication errors that have been recommended by ASHP and others, pharmacists at the National Institutes of Health and the National Cancer Institute, with the input of oncology pharmacists from diverse areas of practice, developed guidelines for expressing chemotherapy dosage schedules and treatment regimens. The guidelines present standards that are broadly applicable and can be adopted by other institutions. Clear and unambiguous expression of all medication orders and consistency of treatment descriptions are suggested. Written treatment plans and orders should contain enough information to allow health care providers from diverse disciplines to compare them with published treatment descriptions and investigational protocols and must therefore include planned dosages and schedules expressed in patient-specific units. In general, drug dosages should be expressed as the amount of drug administered from a single container. When ordering drugs that are part of complex or combination-drug regimens, prescribers should write as many of the orders at one time as is possible, so that continuity might be preserved. Standard rules are proposed for describing chemotherapy regimens.

A review of paclitaxel (Taxol) administration, stability, and compatibility issues.

The purpose of this article is to review information relative to the administration, stability, and compatibility of paclitaxel (Taxol, Mead Johnson Oncology Products, Princeton, NJ). The unique formulation used to solubilize paclitaxel has led to an increased awareness of plasticizer-leaching issues, paclitaxel stability in solution, and paclitaxel compatibility with other medications. Particularly with longer paclitaxel infusion schedules (greater than 48 hours), both drug stability in solution and pump apparatus congruence require careful consideration to minimize plasticizer-leaching problems and to ensure optimum drug delivery. Despite knowledge of the physical compatibility of paclitaxel with numerous drugs, a paucity of research has documented the specifics of paclitaxel's chemical compatibility with other medications.

Pharmaceutical issues: preparation, administration, stability, and compatibility with other medications.

In conclusion, paclitaxel, a very active anticancer agent, is dissolved in a polyoxyethylated castor oil/alcohol vehicle, which poses some interesting challenges for drug preparation and administration. Physicians, nurses, and pharmacists should become knowledgeable about solution containers, intravenous administration sets, in-line filters, and access devices compatible with paclitaxel administration. Chemical stability studies show that paclitaxel diluted to clinically used concentrations in customary infusion fluids is stable for at least 27 hours at room temperature, which enables a 24-hour supply to be prepared in a single container. Paclitaxel has been demonstrated to be visually and turbidimetrically compatible with many other drugs during Y-site simulation studies; however, evidence of chemical compatibility for the majority of these combinations is lacking.

Ondansetron: a serotonin receptor (5-HT3) antagonist for antineoplastic chemotherapy-induced nausea and vomiting.

Ondansetron represents a new class of drugs that exert their antiemetic activity by selective inhibition of a serotonin receptor subtype (5-HT3). Ondansetron has marked activity against emesis associated with cisplatin and other highly emetogenic drugs. Compared with high doses of metoclopramide, the antiemetic "gold standard," it demonstrates equal or superior efficacy. Although ondansetron is moderately well absorbed after oral administration, only a parenteral formulation will initially be available. Ondansetron is eliminated almost entirely by hepatic metabolism; less than five percent of an intravenously administered dose is recovered intact in urine. The half-life of ondansetron is approximately 3.5 hours; slightly shorter in children and prolonged in the elderly. Neither clinical efficacy nor adverse effects have correlated with serum concentrations. Ondansetron is generally well tolerated. Clinically relevant adverse effects include headache, diarrhea or constipation, sedation, and transient minor elevations of liver function tests. It is not associated with extrapyramidal reactions. Ondansetron is indicated as prophylaxis for nausea and vomiting associated with emetogenic chemotherapy. Studies to further evaluate and define its use are ongoing.

Goserelin acetate implant: a depot luteinizing hormone-releasing hormone analog for advanced prostate cancer.

Goserelin acetate implant is a newly approved depot formulation of a luteinizing hormone-releasing hormone (LHRH) agonist indicated for palliation of advanced prostate cancer. LHRH superagonists suppress gonadotropin release from the pituitary gland by causing down-regulation of receptors. The sustained-release dosage form contains goserelin acetate dispersed in a biodegradable copolymer matrix and is designed to release active drug over 28 days. Pharmacokinetic studies have demonstrated that, despite nonzero order release of goserelin from the matrix, goserelin acetate implant maintains serum concentrations of testosterone in the range normally found in castrated men (less than 2 nmol/L) throughout the recommended 28-day dosing interval. Response rates similar to those for orchiectomy and estrogen administration have been demonstrated. Combination therapy with either diethylstilbestrol or flutamide has produced favorable results, although the major advantage appears to be a reduction in the tumor flare seen during the first week of LHRH agonist therapy rather than an increase in response rate or survival. Adverse effects are similar to other LHRH agonists and include tumor flare during the first week of therapy, decreased libido, decreased erectile potency, hot flashes, and gynecomastia. In combination with flutamide, additional adverse effects include diarrhea, nausea, vomiting, and elevated hepatic aminotransferases, all of which can be attributed to flutamide administration. Local reactions are minimal; however, some patients require a local anesthetic before goserelin acetate implant injection. The recommended dose is 3.6 mg administered subcutaneously into the upper abdominal wall every 28 days. The average wholesale cost is approximately +320 per month. Formulary addition is recommended.