Dona Alberti

Phase I Pharmacokinetic and Pharmacodynamic Study of Recombinant Human Endostatin in Patients With Advanced Solid Tumors

PURPOSE Endostatin is the first endogenous angiogenesis inhibitor to enter clinical trials. Laboratory investigations with endostatin have indicated broad antitumor activity coupled with remarkably low toxicity. A phase I trial of recombinant human endostatin was designed to evaluate toxicity and explore biologic effectiveness in patients with refractory solid tumors. PATIENTS AND METHODS Endostatin was administered as a 1-hour intravenous infusion given daily for a 28-day cycle. A starting dose of 30 mg/m2 was explored with subsequent dose escalations of 60, 100, 150, 225, and 300 mg/m2. Assessment of serum pharmacokinetics was performed on all 21 patients. Western blot assay and mass spectroscopy were employed to evaluate endostatin metabolism. Circulating levels of endogenous proangiogenic growth factors were examined. Tumor and tumor blood supply were imaged by dynamic computed tomography (CT), magnetic resonance imaging, ultrasound, and positron emission tomography. RESULTS Endostatin given on this schedule was essentially free of significant drug-related toxicity. Two transient episodes of grade 1 rash were observed. No clinical responses were observed. Endostatin pharmacokinetics were linear with dose, and serum concentrations were achieved that are associated with antitumor activity in preclinical models. No aggregate effect on circulating proangiogenic growth factors were seen, although several patients exhibited persistent declines in vascular endothelial growth factor levels while enrolled in the study. A few patients demonstrated changes in their dynamic CT scans suggestive of a decline in microvessel density, although overall, no consistent effect of endostatin on tumor vasculature was seen. CONCLUSION Endostatin given daily as a 1-hour intravenous infusion was well tolerated without dose-limiting toxicity at doses up to 300 mg/m2.

Safety and Immunological Efficacy of a DNA Vaccine Encoding Prostatic Acid Phosphatase in Patients With Stage D0 Prostate Cancer

PURPOSE Prostatic acid phosphatase (PAP) is a prostate tumor antigen. We have previously demonstrated that a DNA vaccine encoding PAP can elicit antigen-specific CD8+ T cells in rodents. We report here the results of a phase I/IIa trial conducted with a DNA vaccine encoding human PAP in patients with stage D0 prostate cancer. PATIENTS AND METHODS Twenty-two patients were treated in a dose-escalation trial with 100 microg, 500 microg, or 1,500 microg plasmid DNA, coadministered intradermally with 200 microg granulocyte-macrophage colony-stimulating factor as a vaccine adjuvant, six times at 14-day intervals. All patients were observed for 1 year after treatment. RESULTS No significant adverse events were observed. Three (14%) of 22 patients developed PAP-specific IFN gamma-secreting CD8+ T-cells immediately after the treatment course, as determined by enzyme-linked immunospot. Nine (41%) of 22 patients developed PAP-specific CD4+ and/or CD8+ T-cell proliferation. Antibody responses to PAP were not detected. Overall, the prostate-specific antigen (PSA) doubling time was observed to increase from a median 6.5 months pretreatment to 8.5 months on-treatment (P = .033), and 9.3 months in the 1-year post-treatment period (P = .054). CONCLUSION The demonstration that a DNA vaccine encoding PAP is safe, elicits an antigen-specific T-cell response, and may be associated with an increased PSA doubling time suggests that a multi-institutional phase II trial designed to evaluate clinical efficacy is warranted.

A Phase I Trial of Perifosine (NSC 639966) on a Loading Dose/Maintenance Dose Schedule in Patients with Advanced Cancer

Perifosine (NSC 639966) is a synthetic, substituted heterocyclic alkylphosphocholine that acts primarily at the cell membrane targeting signal transduction pathways. Early clinical trials were limited because of dose-limiting gastrointestinal toxicity, and parenteral dosing of this class of agents is not possible because of their hemolytic properties; therefore, related compounds with an improved therapeutic index were developed. Toxicity was minimized and efficacy improved by using a loading dose/maintenance dose schedule, and therefore, this schedule was carried into clinical trials. This phase I trial enrolled 42 patients with incurable solid malignancies. The starting doses were 100 mg p.o. × four doses (every 6 hours) load followed by a 50 mg p.o. once daily maintenance dose with escalation of either component in successive dose levels. No treatment related deaths occurred. The maximum-tolerated dose was determined to be 150 mg p.o. × four doses load and 100 mg p.o. once daily maintenance. Dose-limiting toxicities such as nausea, diarrhea, dehydration, and fatigue were seen early during the loading phase and were surmountable with the use of prophylactic 5-HT3 receptor antagonists, dexamethasone, and loperamide. Toxicities during the chronic phase were difficult to manage and, given that pharmacokinetic data showed biologically active serum concentrations (based on preclinical data), raised the question of less frequent maintenance dosing. Pharmacokinetic data confirmed the maintenance of stable drug levels with chronic dosing and the long half-life. One partial response was seen, as were multiple patients with stable disease beyond course 2. These results suggest perifosine activity in sarcoma and perhaps renal cell carcinoma (stable disease in two patients who continued for 6 and 14 courses), thus justifying additional investigation of this agent in a phase II sarcoma trial.

Phase I Trial of a Monoclonal Antibody Specific for αvβ3 Integrin (MEDI-522) in Patients with Advanced Malignancies, Including an Assessment of Effect on Tumor Perfusion

At present, a variety of agents targeting tumor angiogenesis are under clinical investigation as new therapies for patients with cancer. Overexpression of the αvβ3 integrin on tumor vasculature has been associated with an aggressive phenotype of several solid tumor types. Murine models have shown that antibodies targeting the αvβ3 integrin can affect tumor vasculature and block tumor formation and metastasis. These findings suggest that antibodies directed at αvβ3 could be investigated in the treatment of human malignancies. The current phase I dose escalation study evaluated the safety of MEDI-522, a monoclonal antibody specific for the αvβ3 integrin, in patients with advanced malignancies. Twenty-five patients with a variety of metastatic solid tumors were treated with MEDI-522 on a weekly basis with doses ranging from 2 to 10 mg/kg/wk. Adverse events were assessed weekly; pharmacokinetic studies were done; and radiographic staging was done every 8 weeks. In addition, dynamic computed tomography imaging was done at baseline and at 8 weeks in patients with suitable target lesions amenable to analysis, to potentially identify the effect of MEDI-522 on tumor perfusion. Treatment was well tolerated, and a maximum tolerated dose was not identified by traditional dose-limiting toxicities. The major adverse events observed were grade 1 and 2 infusion-related reactions (fever, rigors, flushing, injection site reactions, and tachycardia), low-grade constitutional and gastrointestinal symptoms (fatigue, myalgias, and nausea), and asymptomatic hypophosphatemia. Dynamic computed tomography imaging suggested a possible effect on tumor perfusion with an increase in contrast mean transit time from baseline to the 8-week evaluation with increasing doses of MEDI-522. No complete or partial responses were observed. Three patients with metastatic renal cell cancer experienced prolonged stable disease (34 weeks, >1 and >2 years) on treatment. With this weekly schedule of administration, and in the doses studied, MEDI-522 seems to be without significant toxicity, may have effects on tumor perfusion, and may have clinical activity in renal cell cancer. These findings suggest the MEDI-522 could be further investigated as an antiangiogenic agent for the treatment of cancer.

Phase I Trial of 2-Methoxyestradiol NanoCrystal Dispersion in Advanced Solid Malignancies

Purpose: 2-Methoxyestradiol (2ME2; Panzem) is an endogenous, estradiol-17β metabolite that at pharmacologic doses exerts antimitotic and antiangiogenic activities. Studies with a 2ME2 capsule formulation showed limited oral bioavailability. We report the results of a phase I study using a NanoCrystal Dispersion formulation of 2ME2 (2ME2 NCD). Experimental Design: Patients with refractory solid tumors received 2ME2 NCD orally. Patients received drug either every 6 hours (part A) or every 8 hours (part B). Doses were escalated in successive cohorts until the maximum tolerated dose (MTD) was identified. The primary objective was identifying the MTD. Secondary objectives were to evaluate the plasma pharmacokinetics of 2ME2 and efficacy. Results: In part A, 16 patients received a median of 4 cycles of 2ME2 NCD. Dose-limiting toxicities (DLT) included fatigue (2), hypophosphatemia (2), increased alanine aminotransferase (1), and muscle weakness (1). Trough levels at steady-state reached the minimum effective concentration in all cohorts. The MTD was determined to be 1,000 mg orally every 6 hours. In part B, 10 patients received a median of 1 cycle. DLTs included elevated γ-glutamyltransferase (1), hyponatremia (1), fatigue (1), and anorexia (1). An MTD could not be defined for part B because 4 of 10 patients had DLTs at the initial dose level and dose reduction was not pursued. Thirteen patients had stable disease (A, 11; B, 2); there were no confirmed responses. Conclusion: For 2ME2 NCD, the MTD and recommended phase II regimen is 1,000 mg orally every 6 hours. Treatment was generally well-tolerated.

A Phase I and Pharmacologic Trial of Two Schedules of the Proteasome Inhibitor, PS-341 (Bortezomib, Velcade), in Patients with Advanced Cancer

Purpose: To define the toxicities, pharmacodynamics, and clinical activity of the proteasome inhibitor, PS-341 (bortezomib), in patients with advanced malignancies. Patients and Methods: Twenty-eight patients (14 male and 14 female) received PS-341 twice weekly for 4 of 6 weeks (schedule I). Because toxicity necessitated dose omissions on this schedule, 16 additional patients (12 male and 4 female) received PS-341 twice weekly for 2 of every 3 weeks (schedule II). A total of 73 courses of treatment was given (median, 2; range, 1-4). Inhibition of 20S proteasome activity in peripheral blood mononuclear cells (PBMC) and accumulation of proteasome-targeted polypeptides in tumor tissue were evaluated as pharmacodynamic markers of PS-341 activity. Results: The most common toxicity was thrombocytopenia, which was dose limiting at 1.7 mg/m2 (schedule I) and 1.6 mg/m2 (schedule II), respectively. Sensory neuropathy was dose-limiting in a patient in schedule I. Grade ≥3 toxicities for schedule I were constipation, fatigue, myalgia, and sensory neuropathy. Grade ≥3 toxicities for schedule II were dehydration resulting from diarrhea, nausea and vomiting, fatigue, hypoglycemia, and hypotension. The maximum tolerated dose was 1.5 mg/m2 for both schedules. Reversible dose-dependent decreases in 20S proteasome activity in PBMCs were observed, with 36% inhibition at 0.5 mg/m2, 52% at 0.9 mg/m2, and 75% at 1.25 mg/m2. Accumulation of proteasome-targeted polypeptides was detected in tumor samples after treatment with PS-341. A patient with multiple myeloma had a partial response. Conclusion: PS-341 given 1.5 mg/m2 twice weekly for 2 of every 3 weeks is well tolerated and should be further studied.

Phase II trial of perillyl alcohol (NSC 641066) administered daily in patients with metastatic androgen independent prostate cancer

Objective. We conducted a phase II multicenter trial of perillyl alcohol in patients with advanced hormone refractory prostate cancer (HRPC). The primary endpoint was to evaluate the 6-month progression-free survival given the potential cytostatic nature of the drug. Secondary objectives included assessing acute and chronic toxicities, as well as measuring objective response rates. Methods. Patients with metastatic androgen-independent prostate cancer that failed at least one prior chemotherapeutic or experimental regimen were eligible. Perillyl alcohol was administered orally at 1200 mg/m2/dose four times daily and continued until disease progression or development of unacceptable toxicity. Results. Fifteen patients were eligible. Six patients received less than one cycle (4 weeks) of drug, four of which stopped because of drug intolerance. Only six patients received more than two cycles of therapy and were considered evaluable for response. Main toxicity included grade 1–2 gastrointestinal intolerance (nausea/vomiting in 60% of the patients) and fatigue (47%). One patient developed a grade 4 hypokalemia that was felt likely attributable to the drug. No objective responses were seen. All patients either progressed or withdrew from the study secondary to drug intolerance before the 6-month time period. Conclusion. Perillyl alcohol administered at this dose and formulation did not have any objective clinical activity in this patient population.

Randomized, Double-Blinded Phase II Evaluation of Docetaxel with or without Doxercalciferol in Patients with Metastatic, Androgen-Independent Prostate Cancer

Purpose: Docetaxel is standard of care for androgen-independent prostate cancer (AIPC). Doxercalciferol (1α-hydroxyvitamin D2) had modest activity in phase I/II trials. Preclinical data support combining vitamin D analogues with docetaxel to treat AIPC. Experimental Design: Chemotherapy-naive men with metastatic AIPC were randomized 1:1 to receive, on a 4-week cycle, docetaxel (35 mg/m2 i.v., days 1, 8, and 15) with or without doxercalciferol (10 μg orally, days 1-28). The primary end point was prostate-specific antigen (PSA) response. Secondary end points were progression-free survival, overall survival, objective response, and toxicity. Survival was analyzed as intent to treat. Results: Seventy patients were randomized. Median follow-up was 17.6 months (range, 3.3-45.2). PSA response rate was 46.7% [95% confidence interval (95% CI), 30-64] in the doxercalciferol arm and 39.4% (95% CI, 25-56) with placebo (P = 0.560). Median progression-free survival in the doxercalciferol arm was 6.17 months (95% CI, 4.20-10.7) versus 6.20 months (95% CI, 4.83-9.07) with placebo (P = 0.764). Median overall survival in the doxercalciferol arm was 17.8 months (95% CI, 14.9-23.6) versus 16.4 months (95% CI, 11.9-23.8) with placebo (P = 0.383). Twenty-four patients in the doxercalciferol arm and 23 in the placebo arm were evaluable for objective response. No complete responses were observed. Partial objective response rate was 12.5% with doxercalciferol versus 8.7% with placebo (P = 0.672). Rate of grade ≥3 toxicity was 46% with doxercalciferol versus 42% with placebo (P = 0.785). Conclusions: Daily doxercalciferol with weekly docetaxel did not enhance PSA response rate or survival. Toxicity was similar between arms. Despite the disappointing results of this study, other vitamin D analogues remain under active investigation.

A phase I study of gemcitabine, 5-fluorouracil and leucovorin in patients with advanced, recurrent, and/or metastatic solid tumors

Introduction: This was a dose escalation phase I trial designed to establish the MTD (maximum tolerated dose) and toxicity profile of the combination of gemcitabine, leucovorin and 5-fluorouracil (5-FU).Methods: Standard eligibility criteria were required for patients with advanced malignancy to enrol. Gemcitabine was escalated from an initial dose of 800 mg/m2. Gemcitabine was administered prior to leucovorin (25 mg/m2) followed by bolus 5-FU (600 mg/m2) every week for 3 weeks followed by 1 week of rest.Results: Of 21 patients enrolled, 20 were eligible for MTD determination. Patients received a median of three 4-week cycles of chemotherapy (range: 1 to 8 cycles). Toxicity was predominantly hematologic or gastroenterologic. Four dose levels were studied. At a gemcitabine dose of 1,500 mg/m2 systemic symptoms of fatigue accompanied hematologic toxicity and patients refused further therapy. At 1,250 mg/m2, full dose intensity was not delivered during the first cycle in 7 of 8 patients treated. Therefore, 1,000 mg/m2 was established as the recommended phase II dose for gemcitabine in this study. Antitumor activity was seen at all dose levels.Conclusions: The combination of gemcitabine, leucovorin and 5-FU was tolerable at full doses of all 3 drugs with an expected toxicity profile. Recommended phase II dose for gemcitabine was 1,000 mg/m2. Initial evidence of clinical activity was seen in a variety of tumor types.

Clinical and biologic effects of combination therapy with gamma‐interferon and tumor necrosis factor

Tumor necrosis factor (TNF) and gamma‐interferon (γ‐IFN) are cytokines with synergistic biologic and antiproliferative effects in vitro and in mouse models. The biologic effects of the combination of TNF and γ‐IFN, however, have not been studied well in humans. A Phase I trial was conducted of TNF and γ‐IFN therapy in 24 patients with advanced malignancies to determine the tolerability of the combination and the biologic effects of TNF and γ‐IFN in vivo. Both TNF and γ‐IFN were administered as 30‐minute intravenous infusions three times per week. Doses of TNF ranged from 25 to 100 μg/m2; all patients received 100 μg/m2 of γ‐IFN. Dose‐limiting toxicity consisted primarily of orthostatic hypotension and constitutional symptoms. The maximum tolerated dose level (MTDL) of 50 μg/m2 of TNF and 100 μg/m2 of IFN‐γ was less than the maximum tolerated dose (MTD) observed in previous Phase I trials of γ‐IFN and TNF alone. Biologic responses were studied in seven patients treated at the MTDL. Serum interleukin‐2 receptor levels and neopterin secretion were enhanced significantly 24 hours after therapy (P = 0.002); enhancement of monocyte Fc receptor levels had borderline statistical significance (P = 0.07). With the exception of the mean fluorescent intensity on monocytes positive for histocompatibility antigen HLA‐DR (P = 0.03), HLA Class I and II cell surface protein expression was not increased. The combination significantly enhanced indoleamine dioxygenase activity and serum β2‐microglobulin expression (P < 0.04) but not 2′,5′‐oligoadenylate synthetase activity, bactericidal function, or chemiluminescence. These results were compared retrospectively with those observed in previous Phase I trials of γ‐IFN and TNF alone. The combination of TNF and γ‐IFN significantly increased urinary kynurenine levels more than either TNF alone or γ‐IFN alone. Given the limitations inherent in any retrospective analysis, however, the enhancement in the other biologic parameters measured at the MTDL during this trial did not differ significantly from the changes observed at the MTD of either TNF or γ‐IFN alone. It was concluded that the combination of TNF and γ‐IFN, when administered at the MTDL of the combination, does not offer any enhancement in biologic responses over either agent alone.