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Biomedical subjects

W P Petros

Publications and source records attributed to W P Petros.

At least 19 recordsLinked to original sources

Phase I/II trial of intravenous Doxil and whole abdomen hyperthermia in patients with refractory ovarian cancer.

OBJECTIVE: A phase I/II study of Doxil combined with whole abdomen hyperthermia was conducted in patients with refractory ovarian cancer. Liposomal doxorubicin combined with hyperthermia has been shown to increase both liposomal delivery and drug extravasation into tumour xenografts resulting in enhanced cytotoxic effects. PATIENTS AND METHODS: Thirty patients with either recurrent or persistent epithelial ovarian cancer were enrolled. All patients had either measurable or assessable disease. Patients received intravenous (IV) Doxil at a dose of 40 mg m-2 as a 1-h infusion followed by whole abdomen hyperthermia. The phase I portion of the study was performed to determine the maximal tolerated dose (MTD) of hyperthermia. Quality of life (QoL) was performed at baseline, prior to each cycle and every 3 months. Plasma pharmacokinetic studies were performed with the first cycle. RESULTS: Ten patients participated in the phase I portion of the study which demonstrated that the MTD of hyperthermia was 60 min after either average vaginal and rectal temperatures of 40 degrees C had been achieved or after 30 min of power application, whichever was shorter. All 30 patients were either paclitaxel and/or platinum resistant initially or developed resistant disease. The median number of prior chemotherapeutic regimens was three (range 2-8) and six patients had been previously treated with Doxil. There were three partial responses for a response rate of 10% (95% CI: [2%, 27%]) and eight patients (27%; 95% CI: [12%, 46%]) had disease stabilization. The median time to progression or death was 3.4 months (95% CI: [2.6, 5.2]) and the median survival was 10.8 months (95% CI: [8.8, 17.4]). Twelve patients (40%) experienced palmar-plantar erythrodysesthesia (PPE), but only four (13%) experienced grade 3-4 PPE toxicity. Doxil systemic exposure was higher in those with grade 3-4 PPE compared to those with no PPE. None of the patients had grade 3-4 thermal toxicity due to hyperthermia. QoL was not decreased in patients responding to therapy. CONCLUSIONS: Therapy with intravenous Doxil and whole abdomen hyperthermia for patients with platinum/paclitaxel resistant ovarian cancer is feasible and does not negatively impact quality of life.

Aged↗

Intraneoplastic polymer-based delivery of cyclophosphamide for intratumoral bioconversion by a replicating oncolytic viral vector.

rRp450 is an oncolytic herpesvirus that expresses the CYP2B1 cDNA, responsible for bioconverting cyclophosphamide (CPA) into the active metabolites 4-hydroxyCPA/aldophosphamide (AP). However, formal proof of prodrug activation is lacking. We report that activation of CPA in cells infected with rRp450 generates a time-dependent increase of diffusible 4-hydroxyCPA/AP. For in vivo applications, a CPA-impregnated polymer was implanted into human tumor xenografts inoculated with rRp450. The area under the curve for 4-hydroxyCPA/AP was 806 microg/g of tumor tissue/h when CPA was administered via intraneoplastic polymer and 3 microg/g of tumor tissue/h when CPA was administered i.p. Therefore, (a) a lytic virus expressing a "suicide" gene can activate a prodrug; and (b) within rRp450-infected tumor, more prolonged and higher concentrations of activated metabolites are generated by intraneoplastic compared with systemic administration of prodrug.

Animals↗

Efficacy of liposomes and hyperthermia in a human tumor xenograft model: importance of triggered drug release.

The tumor drug concentrations, drug distributions, and therapeutic efficacies achieved by three fundamentally different liposomes, nonthermosensitive liposome (NTSL), traditional thermosensitive liposome (TTSL), and low temperature sensitive liposome (LTSL); free doxorubicin (DOX); and saline in combination with hyperthermia (HT) were directly compared in a human tumor xenograft model. NTSL is a nonthermosensitive liposome in the physiological temperature range, TTSL is a traditional thermosensitive liposome that triggers in the range of approximately 42-45 degrees C and releases drug over approximately 30 min, and LTSL is a new low temperature sensitive liposome that triggers in the range of approximately 39-40 degrees C and releases drug in a matter of seconds. Because of the different attributes of the liposomes, it was possible to delineate the relative importance of liposome drug encapsulation, HT cytotoxicity, HT-drug interaction, HT-induced liposomal delivery, and HT-triggered liposomal drug release in achieving antitumor activity. Athymic nude mice bearing the FaDu human tumor xenograft were given a single i.v. dose of 5 mg/kg of DOX (free drug or liposome encapsulated), and the tumors were then heated to either 34 degrees C or 42 degrees C for 1 h at 34 degrees C. All treatment groups were similar, achieving low concentrations of DOX (0-4.5 ng/mg). At 42 degrees C, the LTSL (25.6 ng/mg) achieved the highest DOX concentration (P < 0.04), but all three liposomal formulations (7.3-25.6 ng/mg) were higher than saline or DOX (0-0.7 ng/mg; P < 0.02). LTSL + HT was also the only group that resulted in significant amounts of DNA-bound DOX (silver nitrate-extractable fraction; P < 0.02). Tumor tissue sections were visualized for DOX fluorescence to investigate the local distribution of the drug in the tumor and confirm the relative drug concentrations based on fluorescence intensity. There was relatively little fluorescence seen with treatment groups at 34 degrees C. At 42 degrees C, the LTSL showed the most DOX fluorescence (P < 0.01), and the fluorescence, although not homogeneous, was pervasive throughout the tumor sections. Therapeutic efficacy of treatments was determined from tumor growth time. At 34 degrees C, the only treatment group significantly better than the saline group (9.8 days) was the NTSL group, with a growth time of 20.9 days (P < 0.02). At 42 degrees C, all three liposomal formulations were more efficacious than DOX. LTSL + HT had the longest growth time (51.4 days) and the most number of local controls at 60 days (six of nine tumors). With HT, the DOX concentrations and fluorescence were tightly correlated with tumor growth delay, indicating that adequate (increased) drug delivery can be predictive of therapeutic effect. Overall, the LTSL + HT group showed the largest DOX concentration, the highest and most pervasive DOX fluorescence, and the most antitumor effect. Thus, HT-triggered liposomal drug release may account for the largest differential therapeutic effect and demonstrates the importance of rapid drug release from the drug carriers at the tumor site.

Animals↗

Pharmacokinetics and bioequivalence of a combined oral formulation of eniluracil, an inactivator of dihydropyrimidine dehydrogenase, and 5-fluorouracil in patients with advanced solid malignancies.

BACKGROUND: This study was performed to evaluate the pharmacokinetics, bioequivalence, and feasibility of a combined oral formulation of 5-flurouracil (5-FU) and eniluracil (Glaxo Wellcome Inc., Research Triangle Park, North Carolina), an inactivator of dihydropyrimidine dehydrogenase (DPD). The rationale for developing a combined eniluracil/5-FU formulation oral dosing form is to simplify treatment with these agents, which has been performed using separate dosing forms, and decrease the probability of severe toxicity and/or suboptimal therapeutic results caused by inadvertently high or conversely insufficient 5-FU dosing. PATIENTS AND METHODS: The trial was a randomized, three-way crossover bioequivalence study of three oral dosing forms of eniluracil/5-FU tablets in adults with solid malignancies. Each period consisted of two days of treatment and a five- to seven-day washout phase. Eniluracil at a dose of 20 mg, which results in maximal DPD inactivation, was administered twice daily on the first day and in the evening on the second day of each of the three treatments. On the morning of the second day, all patients received a total eniluracil dose of 20 mg orally and a total 5-FU dose of 2 mg orally as either separate tablets (treatment A) or combined eniluracil/5-FU tablets in two different strengths (2 tablets of eniluracil/5-FU at a strength (mg/mg) of 10/1 (treatment B) or 8 tablets at a strength of 2.5/0.25 (treatment C)). The pharmacokinetics of plasma 5-FU, eniluracil, and uracil, and the urinary excretion of eniluracil, 5-FU, uracil, and alpha-fluoro-beta-alanine (FBAL), were studied. To determine the bioequivalence of the combined eniluracil/5-FU dosing forms compared to the separate tablets, an analysis of variance on pharmacokinetic parameters reflecting eniluracil and 5-FU exposure was performed. RESULTS: Thirty-nine patients with advanced solid malignancies had complete pharmacokinetic studies performed during treatments A, B, and C. The pharmacokinetics of eniluracil and 5-FU were similar among the three types of treatment. Both strengths of the combined eniluracil/5-FU dosing form and the separate dosing forms were bioequivalent. Mean values for terminal half-life, systemic clearance, and apparent volume of distribution for oral 5-FU during treatments A/B/C were 5.5/5.6/5.6 hours, 6.6/6.6/6.5 liters/hour, and 50.7/51.5/50.0 liters, respectively. The intersubject coefficient of variation for pharmacokinetic variables reflecting 5-FU exposure and clearance in treatments ranged from 23% to 33%. The urinary excretion of unchanged 5-FU over 24 hours following treatments A, B, and C averaged 52.2%, 56.1%, and 50.8'%, of the administered dose of 5-FU, respectively. Parameters reflecting DPD inhibition, including plasma uracil and urinary FBAL excretion following treatments A, B, and C were similar. Toxicity was generally mild and similar following all three types of treatments. CONCLUSIONS: The pharmacokinetics of 5-FU and eniluracil were similar and met bioequivalence criteria following treatment with the separate oral formulations of 5-FU and eniluracil and two strengths of the combined formulation. The availability of a combined eniluracil/5-FU oral dosing form will likely simplify dosing and decrease the probability of severe toxicity or suboptimal therapeutic results caused by an inadvertent 5-FU overdose or insufficient 5-FU dosing in the case of separate oral formulations, thereby enhancing the overall feasibility and 0therapeutic index of oral 5-FU therapy.

Administration, Oral↗

Pulmonary toxicity of induction chemotherapy prior to standard or high-dose chemotherapy with autologous hematopoietic support.

We closely followed the pulmonary function of 150 consecutive high-risk breast cancer patients who underwent standard induction CAF (cyclophosphamide, doxorubicin, 5-fluorouracil) chemotherapy, followed by randomization to either standard-dose CPB (cyclophosphamide, cisplatin, bischloroethylnitrosourea [BCNU]) chemotherapy (SDC) or to high-dose CPB chemotherapy (HDC) with autologous bone marrow transplantation (ABMT) and peripheral blood progenitor cell support (PBPCS). Previously, we have described a delayed pulmonary toxicity syndrome (DPTS) which characterizes the pulmonary dysfunction after HDC and ABMT in this patient population. However, little is known concerning the role induction chemotherapy plays in its development. We found that after three cycles of induction CAF, the mean diffusing capacity of the lungs for carbon monoxide (DL(CO)) significantly decreased by 12.6%. Additionally, in patients receiving HDC, the mean DL(CO) further decreased to a nadir of 55.2 +/- 14.1% which was significantly lower than those receiving SDC (nadir: 80.7 +/- 12.3%). DPTS occurred in 72% of patients receiving HDC as compared with only 4% of patients receiving SDC. All individuals diagnosed with DPTS were treated with prednisone and the 2-yr follow-up of pulmonary function revealed a gradual improvement in mean DL(CO) such that there were no differences between HDC and SDC groups at the end of the study. No mortality was attributable to pulmonary toxicity in either group. After induction chemotherapy, but before HDC, bronchoalveolar lavage (BAL) demonstrated significant elevations in interleukin-6 (IL-6), IL-8, neutrophils, and lymphocytes. We conclude that induction CAF produces asymptomatic pulmonary dysfunction and inflammation which may prime the lungs for further injury by HDC and predispose to the development of DPTS. Fortunately, in this specific ABMT patient population, the early and judicious use of prednisone appears to improve pulmonary function in patients who develop DPTS.

Adenocarcinoma↗

Phase I study of Doxil and vinorelbine in metastatic breast cancer.

BACKGROUND: Vinorelbine and Doxil (liposomal doxorubicin) are active chemotherapeutic agents in metastatic breast cancer. A phase I study was designed to evaluate combination therapy. PATIENTS AND METHODS: Thirty women with metastatic breast cancer were enrolled. Dose-limiting toxicity was determined through a dose escalation scheme, and defined for the first treatment cycle, only. Pharmacokinetic studies were performed during the first cycle of treatment. RESULTS: In the first cohort of Doxil 30 mg/m2 day 1 and vinorelbine 25 mg/m2 days 1 and 8, patients experienced severe neutropenia. Vinorelbine administration was changed thereafter to days 1 and 15 of each cycle. Dose limiting toxicity was observed at Doxil 50 mg/m2 and vinorelbine 25 mg/m2. Doxil 40 mg/m2 and vinorelbine 30 mg/m2 was defined as the maximally tolerated dose. Few toxicities (principally neutro penia) were seen at this dose level, with the notable absence of significant nausea, vomiting, or alopecia. Though 63% of patients had received prior anthracycline-based chemotherapy, only one patient developed grade 2 cardiac toxicity. Pharmacokinetic studies revealed prolonged exposure to high doxorubicin concentrations for several days following Doxil administration. CONCLUSIONS: Combination chemotherapy with Doxil and vinorelbine affords treatment with two active drugs in women with metastatic breast cancer, and appears to have a favorable toxicity profile. A schedule of Doxil 40 mg/m2 day 1 and vinorelbine 30 mg/m2 days 1 and 15 given every 28 days is recommended for phase II studies.

Antineoplastic Combined Chemotherapy Protocols↗

Administration and pharmacokinetics of high-dose cyclophosphamide with hemodialysis support for allogeneic bone marrow transplantation in acute leukemia and end-stage renal disease.

We report a patient with pre-existing end-stage renal disease (ESRD) who underwent successful matched related donor allogeneic bone marrow transplantation for AML in second complete remission (CR2) using conditioning with high-dose cyclophosphamide (CY, 60 mg/kg/day x 2) and TBI (165 cGy twice daily x 4 days). The timing of hemodialysis after high-dose CY was extrapolated from available data on the pharmacokinetics of high-dose CY and hemodialysis clearance of conventional dose CY and its metabolites. Pharmacokinetic analyses indicated that the elimination of high-dose CY and its alkylating metabolites is impaired in ESRD but is cleared with hemodialysis. The patient's early post-transplant course was uncomplicated, and WBC and platelet engraftment occurred by day +22. Bone marrow examination on day +25 showed trilineage engraftment with no AML; cytogenetics showed 100% donor karyotype. The patient remains in remission with 100% donor karyotype at 3 years post transplant. Clinical results indicate that the administration of high-dose CY is feasible with hemodialysis support for patients with ESRD.

Adult↗

Prognostic and predictive factors for patients with metastatic breast cancer undergoing aggressive induction therapy followed by high-dose chemotherapy with autologous stem-cell support.

PURPOSE: We performed a retrospective review to determine predictive and prognostic factors in patients with metastatic breast cancer who received induction therapy, and, if they responded to treatment, high-dose chemotherapy. PATIENTS AND METHODS: Patients with metastatic breast cancer received induction therapy with doxorubicin, fluorouracil, and methotrexate (AFM). Partial responders then received immediate high-dose chemotherapy, whereas those who achieved complete remission were randomized to immediate or delayed high-dose chemotherapy with hematopoietic stem-cell support. We performed a retrospective review of data from these patients and used Cox proportional hazards regression models for analyses. RESULTS: The overall response rate for the 425 patients enrolled was 74% (95% confidence interval, 70% to 78%). Multivariate analysis of data from all 425 patients revealed that positive estrogen receptor status (P =.0041), smaller metastatic foci (</= 2 v > 2 cm) (P =. 0165), a longer disease-free interval from initial diagnosis to diagnosis of metastases (</= 2 v > 2 years) (P =.0051), and prior treatment with tamoxifen (P =.0152) were good prognostic signs for overall survival. Patients who had received prior adjuvant therapy (P =.0001) and those who developed liver metastases (P =.0001) had decreased long-term survival. In the subgroup of responders to AFM induction, multivariate analysis showed that those with visceral metastases did less well (P =.0006), as did patients who had received prior adjuvant therapy (P =.0023). However, those who had received tamoxifen therapy in the adjuvant setting did better (P =. 0143). CONCLUSION: The chance for long-term remission with induction therapy with AFM and high-dose chemotherapy is increased for hormone receptor positive-patients with nonvisceral metastases who have not received prior adjuvant chemotherapy and have long disease-free intervals.

Adult↗

Irinotecan therapy in adults with recurrent or progressive malignant glioma.

PURPOSE: To determine the activity, toxicity, and pharmacokinetics of irinotecan (CPT-11, Camptosar; Pharmacia & Upjohn, Kalamazoo, MI) in the treatment of adults with progressive, persistent, or recurrent malignant glioma. PATIENTS AND METHODS: Patients with progressive or recurrent malignant gliomas were enrolled onto this study between October 1996 and August 1997. CPT-11 was given as a 90-minute intravenous (i.v.) infusion at a dose of 125 mg/m2 once weekly for 4 weeks followed by a 2-week rest, which comprised one course. Plasma concentrations of CPT-11 and its metabolites, SN-38 and SN-38 glucuronide (SN-38G), were determined in a subset of patients. RESULTS: All 60 patients who enrolled (36 males and 24 females) were treated with CPT-11 and all were assessable for toxicity, response, and survival. Pharmacokinetic data were available in 32 patients. Nine patients (15%; 95% confidence interval, 6% to 24%) had a confirmed partial response, and 33 patients (55%) achieved stable disease lasting more than two courses (12 weeks). Toxicity observed during the study was limited to infrequent neutropenia, nausea, vomiting, and diarrhea. CPT-11, SN-38, and SN-38G area under the plasma concentration-time curves through infinite time values in these patients were approximately 40%, 25%, and 25%, respectively, of those determined previously in patients with metastatic colorectal cancer not receiving antiepileptics or chronic dexamethasone treatment. CONCLUSION: Response results document that CPT-11, given with a standard starting dose and treatment schedule, has activity in patients with recurrent malignant glioma. However, the low incidence of severe toxicity and low plasma concentrations of CPT-11 and SN-38 achieved in this patient population suggest that concurrent treatment with anticonvulsants and dexamethasone enhances drug clearance.

Adult↗

Two instruments to determine activated partial thromboplastin time: implications for heparin monitoring.

STUDY OBJECTIVE: To measure the difference in therapeutic ranges of activated partial thromboplastin time (APTT) between two laboratory devices. DESIGN: Prospective, controlled laboratory study. SETTING: University-affiliated hospital. PATIENTS: Thirty inpatients receiving intravenous unfractionated heparin for treatment of myocardial infarction, unstable angina, deep venous thrombosis, or pulmonary embolism. INTERVENTIONS: Therapeutic APTT ranges were determined by a portable (whole blood assay) and a central laboratory device (plasma assay) based on heparin serum concentrations. They were compared with APTT ranges equivalent to 1.5-2.5 times the mean normal determination. MEASUREMENTS AND MAIN RESULTS: The central laboratory and portable devices produced therapeutic ranges of 61-93 and 56-73 seconds, respectively. Both differed from conventional therapeutic ratios of 1.5-2.5 times the mean normal (41-68 sec). Mean absolute APTT differences between instruments were statistically significant (12 +/- 20 sec, p<0.006), and 58% of paired APTT values differed by more than 10 seconds. CONCLUSION: A fixed APTT ratio as a goal for monitoring unfractionated heparin may result in significant underanticoagulation. Individual therapeutic APTT ranges must be reported for each instrument if more than one is used for heparin monitoring.

Adult↗

Pharmacokinetic interaction between ondansetron and cyclophosphamide during high-dose chemotherapy for breast cancer.

PURPOSE: Both ondansetron and cyclophosphamide are thought to be metabolized by hepatic microsomal processes. The purpose of this study was to evaluate the potential pharmacokinetic interactions between ondansetron and high-dose alkylating agent chemotherapy. METHODS: A total of 54 breast cancer patients receiving high-dose cyclophosphamide, cisplatin and carmustine were treated prospectively in four sequential cohorts. Cohorts I and II received continuous infusions of both ondansetron and prochlorperazine, and cohorts III and IV received a continuous infusion of ondansetron alone at the same doses. All patients received lorazepam every 4 h. A group of 75 matched historical controls had received a continuous infusion of prochlorperazine with lorazepam. Pharmacokinetic monitoring of each drug used in the high-dose chemotherapy regimen was conducted. RESULTS: Median AUCs of cyclophosphamide in patients receiving ondansetron (73.6 mg/ml x min) were lower than those of the control patients (88.3 mg/ml x min, n = 75, P = 0.0004), but the median cisplatin AUC was approximately 10% higher and no difference in the disposition of carmustine was demonstrated. Patients treated with ondansetron displayed a higher frequency of headaches than the controls. The frequency of achieving complete emetic control was greater in the ondansetron + prochlorperazine groups compared to the ondansetron alone groups and was greater in both these groups than in the prochlorperazine alone group on the first day of therapy only. CONCLUSION: Ondansetron altered the systemic exposure to cyclophosphamide when these agents were administered concomitantly. Ondansetron did not substantially improve overall emetic control when used alone but may improve control in combination with prochlorperazine. Future randomized studies are needed to delineate the effect of ondansetron on the disposition of the active cyclophosphamide metabolites so that clinical implications can be addressed.

Antiemetics↗

Reduced mortality following bone marrow transplantation for breast cancer with the addition of peripheral blood progenitor cells is due to a marked reduction in veno-occlusive disease of the liver.

Clinical trials involving breast cancer in the Duke University Bone Marrow Transplant Program were evaluated to assess the association between type of hematopoietic support and treatment-related morbidity/mortality. Case histories of patients treated with high-dose chemotherapy and hematopoietic rescue on three separate protocols between 1986 and 1994 were reviewed. This included 307 patients with stage IV disease and 85 patients with high-risk (10 or more positive axillary lymph nodes) stage II or III disease. One hundred and twenty-eight of these patients were rescued with autologous bone marrow (BM) alone and 264 additionally received autologous peripheral blood progenitor cells (PBPC). The 100 day transplant-related mortality rate in those patients who received BM alone was 20.3%, with an overall mortality rate due to the high-dose chemotherapy procedure of 24.2%. The PBPC-treated group experienced a 100 day transplant-related mortality of only 6.1% and an overall trans-plant- related mortality of 10.2%. Sixteen of 31 deaths were attributed to veno-occlusive disease (VOD) in the group that received BM alone compared to only one VOD-related death in the PBPC group. These data demonstrate a marked improvement in transplant-related mortality which is related to the use of PBPC. This effect has been almost entirely due to a reduction in mortality from hepatic veno-occlusive disease.

Adult↗

New modified fluorescence polarization immunoassay does not falsely elevate vancomycin concentrations in patients with end-stage renal disease.

Recent literature has urged caution in the interpretation of vancomycin serum concentrations in patients with end-stage renal disease (ESRD), because falsely elevated levels in excess of 70% have been reported with the most commonly used fluorescence polarization immunoassay (FPIA). The purpose of this study was to evaluate the performance of a recently modified FPIA assay for use in patients with ESRD, in comparison to high-performance liquid chromatography (HPLC) and an enzyme-mediated immunoassay technique (EMIT). Serum vancomycin samples were prospectively collected from adults with ESRD undergoing chronic hemodialysis. Each sample was stored at -70 degrees C until analyzed in duplicate by FPIA, EMIT, and HPLC. In an in vitro experiment, blank serum samples with 15 microg/ml vancomycin were spiked with increasing amounts of CDP and analyzed in duplicate with the modified FPIA assay. When compared to HPLC, no statistically significant difference was found in patients with ESRD with the use of the modified FPIA assay (mean concentrations, HPLC 14.92 microg/ml, FPIA 15.96 microg/ml), with FPIA exhibiting a positive bias of 0.64 microg/ml and a precision of +/-3.49 microg/ml (n = 18, p = 0.44). The mean EMIT concentration was 18.34 microg/ml, with a positive bias of 3.43 microg/ml and a precision of +/-5.17 microg/ml (p < 0.01). The addition of increasing amounts of CDP to vancomycin in vitro resulted in concentrations similar to those expected in the absence of significant cross-reactivity with the modified FPIA assay. The modified FPIA assay is a satisfactory tool for monitoring vancomycin serum concentrations in patients with ESRD undergoing hemodialysis. Results obtained with EMIT were not as precise as with FPIA.

Adolescent↗

Delayed pulmonary toxicity syndrome following high-dose chemotherapy and bone marrow transplantation for breast cancer.

We have intensely followed 45 consecutive women who underwent high-dose chemotherapy (cyclophosphamide/cisplatin/BCNU) and autologous bone marrow transplant (HDC/ABMT) for primary breast cancer with pulmonary function testing and computed tomography at regular intervals up to 126 wk (median follow-up, 72 wk). Our results show a high incidence of interstitial pneumonitis requiring steroids (64%), but no deaths due to pulmonary toxicity. The DL(CO) reaches a nadir of 58.2 +/- SEM 3.4 (expressed as a percent of baseline value) 15-18 wk following HDC/ABMT, and marginally improves with time. To a much lesser extent, vital capacity is reduced with a parallel drop in FEV1, suggesting mild restrictive changes without significant obstruction. Patients who develop pulmonary symptoms of cough or dyspnea have a corresponding significantly greater and earlier decline in DL(CO). Chest computed tomography was neither sensitive nor specific for diagnosing pulmonary toxicity. For patients who received steroids for pulmonary toxicity, there was a subsequent improvement in DL(CO) of 17.1% (p = 0.0001). Because our patients do not fit with the recent definition of idiopathic pulmonary syndrome (IPS), we propose the term delayed pulmonary toxicity syndrome (DPTS) to better describe the milder form of lung toxicity seen in our patient population. We were unable to correlate the severity of DPTS with age, tobacco use, baseline pulmonary function, or systemic exposure to BCNU, cyclophosphamide, or cisplatin. These data suggest that factor(s) other than, or in addition to, chemotherapy systemic exposure can contribute to DPTS. Furthermore, early identification and institution of systemic corticosteroids may improve lung function.

Adult↗

Pharmacokinetics and clinical impact of all-trans retinoic acid in metastatic breast cancer: a phase II trial.

PURPOSE: The purpose of this trial was to evaluate tumor cytoreduction by all-trans retinoic acid (ATRA) in patients with metastatic breast cancer and to characterize the initial pharmacokinetics of this agent. METHODS: The study was a single institution, phase II study. The treatment regimen consisted of ATRA administered orally at a dose of 50 mg/m2 three times a day for 14 consecutive day of a 21-day cycle. Cycles were repeated until disease progression, unacceptable toxicity or patient withdrawal. Plasma samples were obtained following the first dose of ATRA for pharmacokinetic analysis. RESULTS: A total of 17 patients with metastatic breast cancer were enrolled in the study, and 14 completed at least one cycle of therapy and were evaluable for response. One patient achieved a partial response in soft tissue of 4 months duration. Three patients had stable disease for 4, 2, and 2 months duration. The remainder had progressive disease. ATRA was reasonably well tolerated. Pharmacokinetic analysis revealed a high degree of interpatient variability in systemic exposure following the initial dose of ATRA. CONCLUSIONS: We conclude, that in the dose and schedule tested, ATRA does not have significant activity in patients with hormone-refractory, metastatic breast cancer. Future studies should focus on more intensive investigation of those individuals with very high or low ATRA initial systemic exposure in the hope of expanding our understanding of ATRA's clinical pharmacology, ultimately leading to improved efficacy.

Administration, Oral↗

Characterization of the mechanisms of busulfan resistance in a human glioblastoma multiforme xenograft.

Busulfan is an alkylating agent commonly used in the treatment of chronic myelogenous leukemia and in combination with cyclophosphamide in preparation for allogeneic bone marrow transplantation. Serial treatment of a childhood high-grade glioma xenograft (D-456 MG) with busulfan resulted in a busulfan-resistant xenograft, D-456 MG(BR). Cross-resistance to 1,3-bis(2-chloroethyl)-1-nitrosourea was seen but not resistance to cyclophosphamide or CPT-11. Cytoplasmic levels of glutathione in D-456 MG(BR) were approximately one-half those found in D-456 MG. This depletion could not be explained by levels of glutathione-S-transferase, or by amplification, rearrangement, or increased levels of transcript of gamma-glutamylcysteine synthetase. Furthermore, depletion of glutathione in D-456 MG did not alter busulfan activity. Quantitation of busulfan levels in D-456 MG and D-456 MG(BR) xenografts following treatment of mice at the dose lethal to 10% of the animals demonstrated that significantly lower levels of drug were achieved in D-456 MG(BR). These studies suggest that alterations in drug transport or metabolism of busulfan may play a role in the resistance of D-456 MG(BR) to this alkylator.

Animals↗

A phase I trial of recombinant human interleukin-1 beta (OCT-43) following high-dose chemotherapy and autologous bone marrow transplantation.

We studied the effects of escalating doses of recombinant human IL-1 beta in patients receiving high-dose chemotherapy and ABMT for metastatic breast cancer or malignant melanoma. Sixteen patients received IL-1 beta, 4 to 32 ng/kg/day administered subcutaneously for 7 days beginning 3 h after bone marrow infusion. Three patients at the highest dose level also received G-CSF following completion of IL-1 beta. All patients completed the 7 days of therapy. The majority of patients experienced chills and fever following one or more injections, and seven had severe pain at the injection site. There was one episode of hypotension and one episode of transient confusion at the highest dose level; other significant toxicity was not identified. Recovery of neutrophils to > 0.5 x 10(9)l and platelet transfusion independence occurred at a median of 23 and 22 days, respectively, which was comparable to historical controls. The mean number of bone marrow colony-forming unit granulocyte-macrophage (CFU-GM) per 10(5) mononuclear cells on day +21 post-ABMT was more than twice that of control patients or patients receiving G-CSF or GM-CSF. A linear correlation was found between the dose of IL-1 beta and endogenous concentrations of several cytokines. These patients also displayed significantly higher concentrations of endogenous G-CSF compared to historical controls receiving GM-CSF. While IL-1 beta was moderately toxic and had no effect on recovery of peripheral blood counts after ABMT, the increased number of bone marrow CFU-GM suggests that the addition of G- or GM-CSF to a short course of IL-1 beta may accelerate hematologic recovery.

Adult↗