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 investigation of a cytostatic calcium influx inhibitor in patients with refractory cancers.

Carboxyamido-triazole (CAI) is a synthetic inhibitor of non-excitable calcium channels that reversibly inhibits angiogenesis, tumor cell proliferation, and metastatic potential. Inhibition of calcium influx and calcium-dependent events is a potential common mechanism underlying these effects of CAI. The cytostatic and antiangiogenic properties of CAI led to its development for clinical investigation. In a Phase I clinical trial open to patients with refractory solid tumors, 49 patients received p.o. administered CAI daily or every other day. Two oral formulations, PEG-400 CAI solution and a gelatin capsule containing CAI in PEG-400, were tested. All administered dosages of CAI yielded plasma concentration at or above the range demonstrated to be effective in inhibiting signaling and cancer progression in vitro and in preclinical models (1 microgram/ml, 2.3 microM). Toxicity of p.o. administered CAI most commonly consisted of dose-related grade 1-2 nausea, vomiting, and occasional anorexia. CAI administration at bedtime ameliorated gastrointestinal complaints in many patients; others required addition of simple antiemetic regimens, usually consisting of metoclopropamide or prochlorperazine. Gastrointestinal complaints were the cause for compliance-limiting toxicity at 175 mg/m2/day of the liquid formulation and 125 mg/m2/day of the gelatin capsule formation. Reversible and rare sensory axonal neuropathy (grade 3, 1 patient) and neutropenia (grade 4, 1 patient) were dose-limiting toxicities observed at the 330 mg/m2 every-other-day liquid CAI dose level. No evidence of cumulative end organ damage or central nervous system injury was observed. Disease stabilization and improvement in performance status was observed. Disease stabilization and improvement in performance status was observed in 49% of evaluable patients who had disease progression before CAI. Disease stabilization and associated improvement in performance status was seen in patients with renal cell carcinoma (7 months), pancreaticobiliary carcinomas (3, 5, and 5 months), melanoma (7 months), ovarian cancer (7 months), and non-small cell lung cancer (3 months). The recommended Phase II doses from this trial are 150 mg/m2/day in the liquid formation and 100 mg/m2/day in the gelatin capsule formation.

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 and II study of high-dose ifosfamide, carboplatin, and etoposide with autologous bone marrow rescue in lymphomas and solid tumors.

PURPOSE: High-dose chemotherapy produces durable disease-free remissions in a minority of patients with resistant lymphomas and solid tumors. In an attempt to improve on the available regimens, ifosfamide, carboplatin, and etoposide (ICE) were selected for a new high-dose regimen because of their favorable spectrum of nonhematopoietic toxicity and evidence of synergy in in vitro systems. PATIENTS AND METHODS: Forty-one patients with drug-resistant Hodgkin's and non-Hodgkin's lymphomas, and breast and testicular cancers were entered onto a phase I and II trial of a single course of ICE with autologous bone marrow rescue. Before transplantation, all patients received combination chemotherapy until maximal tumor response was achieved. RESULTS: Patients received total doses of ifosfamide from 10 to 18 g/m2, carboplatin from 0.9 to 1.98 g/m2, and etoposide from 0.6 to 1.5 g/m2 administered during a 4-day period, with a maximum-tolerated dose (MTD) of ifosfamide 16 g/m2, carboplatin 1.8 g/m2, and etoposide 1.5 g/m2. The dose-limiting toxicities included irreversible renal, cardiac, and CNS dysfunction. There were three toxic deaths (7%), and all occurred above the MTD. Thirteen patients who were treated at the MTD tolerated the regimen well; reversible renal dysfunction and grade 2 mucositis commonly were observed. Of 23 heavily pretreated patients with persistent disease at the time of transplant, 10 (43%) achieved complete remissions (CRs) and 11 (48%) achieved partial remissions (PRs). Hodgkin's and non-Hodgkin's lymphoma patients who were treated at or below the MTD had a median potential follow-up of 11.9 months, and 12-month progression-free survivals of 62% and 48%, respectively. CONCLUSION: High-dose ICE with bone marrow rescue was well tolerated with a high response rate, and should be considered for further testing.

Phase I study of paclitaxel as a radiation sensitizer in the treatment of mesothelioma and non-small-cell lung cancer.

PURPOSE: To determine the maximum-tolerated dose (MTD) and dose-limiting toxicities of paclitaxel with concurrent thoracic irradiation in patients with malignant pleural mesothelioma and locally advanced non-small-cell lung cancer (NSCLC) using a 120-hour continuous infusion regimen. A secondary objective was to assess the effect of paclitaxel on the cell cycle through serial tumor biopsies. PATIENTS AND METHODS: Paclitaxel was administered as a 120-hour (5-day) continuous infusion repeated every 3 weeks during the course of radiation therapy. The starting dose of paclitaxel was 90 mg/m2. Doses were escalated at 15-mg/m2 increments in successive cohorts of three patients. In NSCLC patients, radiation was delivered to the primary tumor and regional lymph nodes for a total tumor dose of 6,120 cGy. In mesothelioma patients, hemithoracic irradiation was delivered as the initial treatment field with a conedown to the tumor volume for a total dose of 5,760 to 6,300 cGy. Tumor biopsies were obtained, if possible, before and during paclitaxel treatment. RESULTS: Thirty patients were entered onto this study through three dose levels (from 90 mg/m2 to 120 mg/m2). The MTD was determined to be 105 mg/m2. The dose-limiting toxicity was grade 4 neutropenia (two patients). Grade 2 gastrointestinal (GI) toxicity (nausea and vomiting) was also observed at 120 mg/m2. Three of 30 patients developed a hypersensitivity reaction. Six patients had grade 2 lung injury manifested by a persistent cough that required antitussives. Five patients underwent tumor biopsies. None of the patients showed a significant block of cells in mitosis (G2/M) after paclitaxel infusion. CONCLUSION: The MTD of paclitaxel, when administered as a 120-hour continuous infusion with concurrent radiotherapy, was determined to be 105 mg/m2. The dose-limiting toxicity was neutropenia. Continuous infusion paclitaxel administered with large field irradiation of the lung is well tolerated and deserves continued evaluation.

Phase I study of infusional paclitaxel in combination with the P-glycoprotein antagonist PSC 833.

PURPOSE: PSC 833 (valspodar) is a second-generation P-glycoprotein (Pgp) antagonist developed to reverse multidrug resistance. We conducted a phase I study of a 7-day oral administration of PSC 833 in combination with paclitaxel, administered as a 96-hour continuous infusion. PATIENTS AND METHODS: Fifty patients with advanced cancer were enrolled onto the trial. PSC 833 was administered orally for 7 days, beginning 72 hours before the start of the paclitaxel infusion. Paclitaxel dose reductions were planned because of the pharmacokinetic interactions known to occur with PSC 833. RESULTS: In combination with PSC 833, maximum-tolerated doses were defined as paclitaxel 13.1 mg/m(2)/d continuous intravenous infusion (CIVI) for 4 days without filgrastim, and paclitaxel 17.5 mg/m(2)/d CIVI for 4 days with filgrastim support. Dose-limiting toxicity for the combination was neutropenia. Statistical analysis of cohorts revealed similar mean steady-state concentrations (C(pss)) and areas under the concentration-versus-time curve (AUCs) when patients received paclitaxel doses of 13.1 or 17.5 mg/m(2)/d for 4 days with PSC 833, as when they received a paclitaxel dose of 35 mg/m(2)/d for 4 days without PSC 833. However, the effect of PSC 833 on paclitaxel pharmacokinetics varied greatly among individual patients, although a surrogate assay using CD56+ cells suggested inhibition of Pgp was complete or nearly complete at low concentrations of PSC 833. Responses occurred in three of four patients with non-small-cell lung cancer, and clinical benefit occurred in five of 10 patients with ovarian carcinoma. CONCLUSION: PSC 833 in combination with paclitaxel can be administered safely to patients provided the paclitaxel dose is reduced to compensate for the pharmacokinetic interaction. Surrogate studies with CD56+ cells indicate that the maximum-tolerated dose for PSC 833 gives serum levels much higher than those required to block Pgp. The variability in paclitaxel pharmacokinetics, despite complete inhibition of Pgp in the surrogate assay, suggests that other mechanisms, most likely related to P450, contribute to the pharmacokinetic interaction. Future development of combinations such as this should include strategies to predict pharmacokinetics of the chemotherapeutic agent. This in turn will facilitate dosing to achieve comparable CPss and AUCs.

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.

Phase I/II study of 72-hour infusional paclitaxel and doxorubicin with granulocyte colony-stimulating factor in patients with metastatic breast cancer.

PURPOSE: We conducted a phase I/II trial of concurrently administered 72-hour infusional paclitaxel and doxorubicin in combination with granulocyte colony-stimulating factor (G-CSF) in patients with previously untreated metastatic breast cancer and bidimensionally measurable disease. PATIENTS AND METHODS: We defined the maximum-tolerated dose (MTD) of concurrent paclitaxel and doxorubicin administration and then studied potential pharmacokinetic interactions between the two drugs. Forty-two patients who had not received prior chemotherapy for metastatic breast cancer received 296 total cycles of paclitaxel and doxorubicin with G-CSF. RESULTS: The MTD was determined to be paclitaxel 180 mg/m2 and doxorubicin 60 mg/m2 each by 72-hour infusion with G-CSF. Diarrhea was the dose-limiting toxicity (DLT) of this combination, with three of three patients developing abdominal computed tomographic (CT) scan evidence of typhlitis (cecal thickening) at the dose level above the MTD. All patients developed grade 4 neutropenia (absolute neutrophil count [ANC] < 500 microL), generally less than 5 days in duration. This combination was generally safely administered at dose levels at or below the MTD. The overall response rate was 72% (28 of 39 patients; 95% confidence interval [CI], 55% to 85%), with 8% complete responses (CRs) (three of 39; 95% CI, 2% to 21%) and a median response duration of 9 months. The median overall survival time for all patients is 23 months, with a median follow-up duration of 28 months. Pharmacokinetic studies showed that administration of paclitaxel and doxorubicin together by 72-hour infusion did not affect the steady-state concentrations of either drug. CONCLUSION: Concurrent 72-hour infusional paclitaxel and doxorubicin can be administered safely, but is associated with significant toxicity. The overall response rate of this combination in untreated metastatic breast cancer patients is similar to that achieved with other doxorubicin-based combination regimens. The modest complete response rate achieved suggests that this schedule of paclitaxel and doxorubicin administration does not produce significant additive or synergistic cytotoxicity against breast cancer.

Pilot trial of the safety, tolerability, and retinoid levels of N-(4-hydroxyphenyl) retinamide in combination with tamoxifen in patients at high risk for developing invasive breast cancer.

PURPOSE: N-(4-hydroxyphenyl) retinamide (¿4-HPR, Fenretinide; R.W. Johnson Pharmaceutical Research Institute, Springhouse, PA) and tamoxifen (TAM) have synergistic antitumor and chemopreventive activity against mammary cancer in preclinical studies. We performed a pilot study of this combination in women at high risk for developing breast cancer. PATIENTS AND METHODS: Thirty-two women were treated with four cycles of 4-HPR, 200 mg orally (PO) for 25 days of each 28-day cycle, and TAM, 20 mg PO once daily for 23 months beginning after 1 month of 4-HPR alone. Tolerability, dark adaptometry, tissue biopsies, and retinoid plasma concentrations (Cp) were evaluated. RESULTS: Symptomatic reversible nyctalopia developed in two patients (6%) on 4-HPR, but 16 (73%) of 22 patients had reversible changes in dark adaptation, which correlated with relative decrease in Cp retinol (P

Phase I crossover study of paclitaxel with r-verapamil in patients with metastatic breast cancer.

PURPOSE: We conducted a phase I crossover study of escalating doses of both paclitaxel (Taxol; Bristol-Myers, Squibb, Princeton, NJ) and r-verapamil, the less cardiotoxic stereoisomer, in heavily pretreated patients with metastatic breast cancer. PATIENTS AND METHODS: Twenty-nine patients refractory to paclitaxel by 3-hour infusion were treated orally with r-verapamil every 4 hours starting 24 hours before the same-dose 3-hour paclitaxel infusion and continuing for a total of 12 doses. Once the maximum-tolerated dose (MTD) of the combination was determined, seven additional patients who had not been treated with either drug were evaluated to determine whether the addition of r-verapamil altered the pharmacokinetics of paclitaxel. Consenting patients had tumor biopsies for P-glycoprotein (Pgp) expression before receiving paclitaxel and after becoming refractory to paclitaxel therapy. RESULTS: The MTD of the combination was 225 mg/m2 of r-verapamil every 4 hours with paclitaxel 200 mg/m2 by 3-hour infusion. Dose-limiting hypotension and bradycardia were observed in three of five patients treated at 250 mg/m2 r-verapamil. Fourteen patients received 32 cycles of r-verapamil at the MTD as outpatient therapy without developing cardiac toxicity. The median peak and trough serum verapamil concentrations at the MTD were 5.1 micromol/L (range, 1.9 to 6.3), respectively, which are within the range necessary for in vitro modulation of Pgp-mediated multidrug resistance (MDR). Increased serum verapamil concentrations and cardiac toxicity were observed more frequently in patients with elevated hepatic transaminases and bilirubin levels. Hematologic toxicity from combined paclitaxel and r-verapamil was significantly worse compared with the previous cycle of paclitxel without r-verapamil. In the pharmacokinetic analysis, r-verapamil delayed mean paclitaxel clearance and increased mean peak paclitaxel concentrations. CONCLUSION: r-Verapamil at 225 mg/m2 orally every 4 hours can be given safely with paclitaxel 200 mg/m2 by 3-hour infusion as outpatient therapy and is associated with serum levels considered active for Pgp inhibition. The addition of r-verapamil significantly alters the toxicity and pharmacokinetics of paclitaxel.

Pharmacokinetics of orally administered carboxyamido-triazole, an inhibitor of calcium-mediated signal transduction.

Carboxyamido-triazole (CAI), inhibits proliferation, invasion, and metastatic potential of a number of cancer cell lines at concentrations greater than 0.4 microgram/ml. The objective of this study was to characterize the pharmacokinetic profile from the first Phase I clinical trial of CAI for the single test dose and multiple daily dosing schedule. Two different p.o. formulations (liquid and gelcap) of CAI were administered. Thirty-nine patients with cancer were enrolled. The dose escalation schema was 100, 125, and 150 mg/m2/day and 200 and 330 mg/m2 every other day of the liquid formulation, plus 100 and 125 mg/m2/day and 200 mg/m2 every other day of the gelcap. The CAI pharmacokinetics are best described by a two-compartment open linear model. The gelcap was more rapidly absorbed than the liquid [time to maximum plasma concentration (Tmax) = 2.06 +/- 1.02 versus 5.31 +/- 3.59 h, P2 = 0.0012] which resulted in higher peak plasma concentrations. There was no evidence of saturable elimination as the dose was increased. The mean steady-state peak concentration was 5.1 +/- 1.0 microgram/ml for the 150 mg/m2/day multiple daily dosing regimen. The terminal half-life of CAI was relatively prolonged, 111 h, and the total body p.o. clearance was low (1.87 liters/h). The peak concentration for all dose levels explored was greater than the targeted concentration suggested by in vitro data for activity. Thus, these data suggest that an effective cytostatic exposure of CAI may be obtained with daily or every other day dosing without severe toxicity.

A phase I trial of carboxyamido-triazole and paclitaxel for relapsed solid tumors: potential efficacy of the combination and demonstration of pharmacokinetic interaction.

PURPOSE: Preclinical and clinical investigation of the combination of the antiangiogenesis/anti-invasion agent carboxyamido-triazole (CAI) administered with the cytotoxic agent paclitaxel (PAX). EXPERIMENTAL DESIGN: Colony-forming assays were used to test the activity of CAI plus PAX on A2780 human ovarian cancer. The sequence of CAI followed by PAX (CAI>Pax) was modeled in nude mice to test for potential additive toxicity. The Phase I clinical dose escalation schema tested p.o. administered CAI in PEG-400 (50-100 mg/m(2)) or micronized CAI (250 mg/m(2)) for 8 days followed by a 3-h infusion of PAX (110-250 mg/m(2)) every 21 days. Patients were assessed for toxicity, pharmacokinetics of CAI and PAX, and disease outcome. RESULTS: In preclinical studies, CAI>Pax was additive in A2780 human ovarian cancer cell lines when CAI (1 or 5 microM) preceded subtherapeutic doses of PAX. CAI did not reverse PAX resistance and collateral resistance to CAI was documented in PAX-resistant cells. CAI>PAX administration had no overt additive toxicity in nude mice. Thirty-nine patients were treated on a dose-escalation Phase I trial using daily oral CAI for 8 days followed by the PAX infusion. Pharmacokinetic analysis revealed that PAX caused an acute increase in circulating CAI concentrations in a dose-dependent fashion. No additive or cumulative toxicity was observed, and grade 3 nonhematological toxicity was rare. Three partial responses and two minor responses were observed. CONCLUSIONS: The sequential combination of CAI and PAX is well tolerated, and the activity observed suggests that further study of the combination is warranted.

A phase I study of topotecan followed sequentially by doxorubicin in patients with advanced malignancies.

Inhibitors of topoisomerase I and topoisomerase II have demonstrated synergy when administered sequentially in several tumor models while having a diminished antitumor effect when given concurrently. To explore the potential for clinical sequence-dependent synergy, we instituted a Phase I study of topotecan (a topoisomerase I inhibitor) followed by doxorubicin (a topoisomerase II inhibitor) in patients with advanced malignancies. Thirty-three patients with advanced malignancies or malignancies for whom no standard therapy exists were entered into the study. Topotecan was administered in escalating doses by 72-h continuous infusion on days 1, 2, and 3, followed by a bolus of doxorubicin given on day 5. To explore the hematological toxicity associated with this sequence, bone marrow aspirates were obtained both prior to the topotecan infusion and immediately prior to the doxorubicin in 10 patients to determine by fluorescence-activated cell sorting analysis whether CD34+ cell synchronization was occurring using this sequential schedule. Dose-limiting hematological toxicity occurred at the first dose-level in three of six patients. Therefore, we defined the maximum-tolerated dose (MTD) below our starting dose-level. Further dose-escalation and a new MTD were defined with the addition of granulocyte-colony stimulating factor (G-CSF). The MTD was, therefore, topotecan 0.35 mg/m2/day continuous i.v. infusion on days 1, 2, and 3, followed by doxorubicin 45 mg/m2 on day 5 without G-CSF, whereas the MTD with G-CSF was topotecan 0.75 mg/m2/day by 72-h continuous i.v. infusion, followed by doxorubicin 45 mg/m2 i.v. bolus on day 5. Ten patients with paired bone marrow aspirates obtained before topotecan and before doxorubicin administrations were available for evaluation. In 7 of 10 patients, there was an increase (16.6 +/- 2.9% to 25.0 +/- 3.5%; P < 0.02) in the proportion of CD34+ cells in S-phase 24 h after the topotecan infusion and prior to doxorubicin compared to the pretreatment values, whereas 1 patient had a decrease in the proportion of CD34+ cells in S phase and 2 patients had no change. Topotecan and doxorubicin with this sequence and schedule can be given safely; the dose-limiting toxicity is hematological toxicity. Alterations in the fraction of hematopoietic progenitor CD34+ cells in S-phase may account for the increased granulocytopenia and thrombocytopenia observed at relatively low dose levels of the combination with and without G-CSF.

A Phase I study of raltitrexed, an antifolate thymidylate synthase inhibitor, in adult patients with advanced solid tumors.

The purpose of this study was to perform a Phase I trial of raltitrexed, a selective inhibitor of thymidylate synthase, and to determine the pharmacokinetic and toxicity profiles as a function of raltitrexed dose. Fifty patients with advanced solid tumors and good performance status were treated with raltitrexed as a 15-min i.v. infusion every 3 weeks, at doses escalating from 0.6 to 4.5 mg/m2. Asthenia, neutropenia, and hepatic toxicity were the most common dose-limiting toxicities in this largely pretreated patient population, but they occurred during the initial cycle in only one of nine patients treated with 4.0 mg/m2 and in two of nine patients treated with 4.5 mg/m2. Only 2 of 13 patients treated with 3.5 mg/m2 ultimately experienced unacceptable toxicity after three and seven cycles, compared with 42 and 56% of patients receiving 4.0 and 4.5 mg/m2 after medians of three and two cycles, respectively. The maximum raltitrexed plasma concentration and the area under the plasma concentration-time curve increased in proportion to dose. Raltitrexed clearance was independent of dose and was associated with the estimated creatinine clearance. Asthenia, neutropenia, and hepatic transaminitis were dose-related and tended to occur more frequently when patients received three or more cycles of therapy. A 3-week treatment interval was feasible in the majority of patients at all doses. Although 4.0 mg/m2 appeared to be a safe starting dose in this pretreated patient population, about half who received two or more courses ultimately experienced dose-limiting toxicity. A dose of 3.5 mg/m2 was well tolerated in most patients.

Paclitaxel chemotherapy after autologous stem-cell transplantation and engraftment of hematopoietic cells transduced with a retrovirus containing the multidrug resistance complementary DNA (MDR1) in metastatic breast cancer patients.

The MDR1 multidrug resistance gene confers resistance to natural-product anticancer drugs including paclitaxel. We conducted a clinical gene therapy study to determine whether retroviral-mediated transfer of MDR1 in human hematopoietic cells would result in stable engraftment, and possibly expansion, of cells containing this gene after treatment with myelosuppressive doses of paclitaxel. Patients with metastatic breast cancer who achieved a complete or partial remission after standard chemotherapy were eligible for the study. Hematopoietic stem cells (HSCs) were collected by both peripheral blood apheresis and bone marrow harvest after mobilization with a single dose of cyclophosphamide (4 g/m2) and daily filgrastim therapy (10 microg/kg/day). After enrichment for CD34+ cells, one-third of each collection was incubated ex vivo for 72 h with a replication-incompetent retrovirus containing the MDR1 gene (G1MD) in the presence of stem-cell factor, interleukin 3, and interleukin 6. The remaining CD34+ cells were stored without further manipulation. All of the CD34+ cells were reinfused for hematopoietic rescue after conditioning chemotherapy with ifosfamide, carboplatin, and etoposide regimen. After hematopoietic recovery, patients received six cycles of paclitaxel (175 mg/m2 every 3 weeks). Bone marrow and serial peripheral blood samples were obtained and tested for the presence of the MDR1 transgene using a PCR assay. Six patients were enrolled in the study and four patients received infusion of genetically altered cells. The ex vivo transduction efficiency, estimated by the PCR assay, ranged from 0.1 to 0.5%. Three of the four patients demonstrated engraftment of cells containing the MDR1 transgene. The estimated percentage of granulocytes containing the MDR1 transgene ranged from a maximum of 9% of circulating nucleated cells down to the limit of detection of 0.01%. One patient remained positive for the MDR1 transgene throughout all six cycles of paclitaxel therapy, whereas the other 2 patients showed a decrease in the number of cells containing the transgene to undetectable levels. Despite the low level of engraftment of MDR1-marked cells, a correlation was observed between the relative number of granulocytes containing the MDR1 transgene and the granulocyte nadir after paclitaxel therapy. No adverse reactions to the genetic manipulation procedures were detected. Therefore, engraftment of human HSCs transduced with the MDR1 gene can be achieved. However, the overall transduction efficiency and stable engraftment of gene-modified HSCs must be improved before MDR1 gene therapy and in vivo selection with anticancer drugs can be reliably used to protect cancer patients from drug-related myelosuppression.

Retroviral mediated transfer of the human multidrug resistance gene (MDR-1) into hematopoietic stem cells during autologous transplantation after intensive chemotherapy for metastatic breast cancer.

Patients with metastatic breast cancer will receive 4-5 cycles of induction chemotherapy on one of the ongoing Medicine Branch protocols. Patients achieving at least a partial response, and who do not have evidence of bone marrow involvement and who do not have metastatic bone disease, will undergo PBSC and bone marrow harvest when hematologic recovery has occurred. Patients who have not achieved a PR, but who are responding to therapy, may be treated with additional cycles of therapy in an attempt to achieve a PR. Such patients will be eligible for transplant if a PR is obtained. 70% of the bone marrow and PBSC will be cryopreserved. The CD34+ subpopulation from the remaining 30% of the bone marrow and PBSC harvest will be obtained using an anti-CD34+ antibody and immunoabsorption column. The bone marrow and peripheral blood CD34 cells will be transduced with a retroviral vector expressing the human MDR-1 cDNA. Patients with positive bone scans or histologic evidence of bone marrow involvement will be excluded from the gene transfer component of the protocol. The MDR-1 transduced CD34 cells will be reinfused along with the non-transduced bone marrow and PBSC into patients following high dose ICE chemotherapy. Serial peripheral blood and bone marrow samples will be obtained to study hematopoietic reconstitution with MDR-1 transduced cells. Patients with residual or progressive disease after ABMT will be treated with taxol or vinblastine. In these relapsed patients, peripheral blood and bone marrow samples will be obtained to study whether chemotherapy amplifies the proportion of hematopoietic cells containing the MDR-1 provirus. We will monitor the nadir blood counts of each patient receiving salvage chemotherapy for evidence of myeloprotection and correlate this data with changes in the mean proviral copy number. Sites of relapsed tumor will be biopsied to test for the presence of the MDR-1 provirus.

Phase I study of Taxol, doxorubicin, plus granulocyte-colony stimulating factor in patients with metastatic breast cancer.

The objective of this phase I trial was to determine the maximal tolerated dose (MTD) of Taxol and doxorubicin administered as a simultaneous intravenous infusion over 72 hours every 21 days. Granulocyte-colony stimulating factor (G-CSF) 10 micrograms/kg, was administered on days 4-18 of each cycle. The treated population consisted of metastatic breast cancer patients previously untreated with chemotherapy for metastatic disease, who had not received doxorubicin in the adjuvant setting and who had bidimensionally measurable disease. The MTD was determined to be 75 mg/m2 of doxorubicin and 160 mg/m2 of Taxol. The dose-limiting toxicity of the combination was clinical typhlitis in three of three patients. Other significant toxicities included grade 3 diarrhea at the higher dose levels and grade 4 neutropenia in all patients. Eighteen patients were treated on this initial phase I study. The overall response rate was 62%, with 6% complete responses and 56% partial responses. The combination of doxorubicin and Taxol by 72-hour continuous infusion with G-CSF is an active regimen in patients with 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.