A first in human study of SB-743921, a kinesin spindle protein inhibitor, to determine pharmacokinetics, biologic effects and establish a recommended phase II dose.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), safety, pharmacokinetics, and pharmacodynamics of SB-743921 when administered as a 1-h infusion every 21 days to patients with advanced solid tumors or relapsed/refractory lymphoma. METHODS: Patients who failed prior standard therapy or those without any standard options were eligible. Forty-four patients were enrolled using an initial accelerated dose-escalation phase followed by a standard dose-escalation phase. An additional 20 patients were enrolled at the recommended phase II dose to obtain additional safety and pharmacokinetic data. The doses evaluated ranged from 2 to 8 mg/m(2). The pharmacokinetics of SB-743921 was evaluated at 19 time-points over 48 h following during administration during cycle 1. Toxicity was assessed by the NCI Common Terminology Criteria version 3.0. Response evaluation was performed every 6 weeks. RESULTS: The most common and consistent DLT was neutropenia. Other DLTs observed included hypophosphatemia, pulmonary emboli, SVC syndrome, transaminitis, hyponatremia, and hyperbilirubinemia. The MTD of SB-743921 as a 1-h infusion every 21 days was established as 4 mg/m(2). The maximum plasma concentration and area under the plasma concentration time curve appeared to increase proportionally to dose. One durable objective response was seen in a patient with metastatic cholangiocarcinoma who was on treatment 11 months and 6 patients had stable disease for over four cycles. CONCLUSIONS: The recommended phase II dose of SB-743921 on this specific schedule of a 1-h infusion every 3 weeks is 4 mg/m(2). The promising efficacy and lack of severe toxicities in this study warrant the continued development of SB-743921.

Phase I trial of a monoclonal antibody specific for alphavbeta3 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 alpha(v)beta(3) integrin on tumor vasculature has been associated with an aggressive phenotype of several solid tumor types. Murine models have shown that antibodies targeting the alpha(v)beta(3) integrin can affect tumor vasculature and block tumor formation and metastasis. These findings suggest that antibodies directed at alpha(v)beta(3) 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 alpha(v)beta(3) 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 study of docetaxel and topotecan in patients with advanced malignancies.

BACKGROUND: Docetaxel and topotecan are drugs with different mechanisms of action and significant activity against various tumour types. Topotecan may influence docetaxel metabolism by inhibiting the CYP3A4 enzyme. We designed a phase I study to evaluate the maximum tolerated dose of this combination and to assess the impact of pharmacokinetic interactions of the two drugs on toxicity. METHODS: Docetaxel and topotecan were administered intravenously on day 1, and days 1 - 5 respectively, using a phase I dose escalation design. Plasma samples were analysed to determine docetaxel and topotecan concentration by HPLC with subsequent pharmacokinetic analysis using NONMEM. RESULTS: Of the 17 patients enrolled in the trial, 11 had grade 3 and 4 neutropenia and 1 had grade 4 thrombocytopenia. Nonhaematological toxicities were less frequent. The maximum tolerated dose for docetaxel and topotecan were 60 mg/m(2) on day 1 and 0.75 mg/m(2) days 1 - 5, respectively. One patient had stable disease. Subjects with grade >or= 3 haematologic toxicity had higher plasma docetaxel or topotecan area under the curve (AUC) (docetaxel 1.03 +/- 0.11 mg-hr/L versus 0.73 +/- 0.13 mg-hr/L; topotecan 65.8 +/- 14.6 mcg-hr/L versus 41.6 +/- 13.9 mcg-hr/L). There was no additive effect of the AUC of the two drugs on the likelihood of grade >or= 3 haematologic toxicity by multiple logistic regression. CONCLUSION: The dose-limiting toxicity seen with the combination of docetaxel and topotecan was myelosuppression. Future trials will require growth factor support if this combination is pursued.

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. x 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. x 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 perillyl alcohol administered four times daily continuously.

PURPOSE: Previous experience with perillyl alcohol (POH) was with a formulation of 500-mg capsules each containing 250 mg POH and soybean oil. This formulation resulted in the ingestion of large amounts of soybean oil (>10 g/day). Dose-limiting toxicities (DLT) were primarily gastrointestinal. Prior studies also showed no further increase in POH metabolite concentrations with doses of >1600 mg/m2. Therefore, a new formulation of POH was developed (700 mg containing 675 mg POH) in an effort to improve dose and metabolite concentrations delivered and toxicity encountered with chronic dosing. EXPERIMENTAL DESIGN: Eligible patients had refractory solid malignancies. Dose escalation occurred in cohorts of three at the dose levels/dose of 1350 mg, 2025 mg, 2700 mg, 3375 mg and 4050 mg, administered orally four times a day in a 28-day cycle. RESULTS: A group of 19 patients were enrolled. One DLT occurred at dose level 5. This cohort was expanded to six patients, and no further DLT occurred. The maximum tolerated dose was not reached. The predominant toxicity was gastrointestinal. Nausea and vomiting occurred in 63% of patients (12/19, grade 1 in 10). The same proportion of patients (12/19) experienced heartburn and indigestion, primarily grade 1. Although the side effects were mild in nature, three patients withdrew from treatment, citing intolerable gastrointestinal toxicity. The AUCs of POH metabolites did not appear to increase from level 1 to level 2 or change significantly from day 1 to day 29. Inter- and intrapatient variability in metabolite levels was observed. CONCLUSIONS: This reformulation of POH appears to be an improvement upon the prior formulation, by reducing the number of capsules ingested and the degree of gastrointestinal toxicity per dose. It does not appear to offer any metabolite pharmacokinetic advantage. A dose of 2050 mg administered four times daily was easily tolerated. Higher doses can be administered but with increasing gastrointestinal toxicity that limits compliance.

Gemcitabine, Paclitaxel, and piritrexim: a phase I study.

Piritrexim is a new antifolate that has shown activity in methotrexate-resistant tumors. Gemcitabine is an antimetabolite similar in structure to cytosine arabinoside with early studies demonstrating activity in a variety of cancers. It also has apparent synergistic activity with antifolates from initial work in tumor models. Paclitaxel is an antimicrotubule agent that has a wide spectrum of activity against a variety of solid tumors. The combination of gemcitabine, paclitaxel, and piritrexim was assessed in this phase I trial. Thirty patients were enrolled. The starting doses were piritrexim 25 mg orally twice daily (days 1-4, 15-18), paclitaxel 75 mg/m2 (days 1, 15), and gemcitabine 750 mg/m2 (days 1, 15), which then was escalated in a stepwise fashion. Four patients achieved stable disease while on study, whereas one patient with a poorly differentiated neuroendocrine tumor achieved a partial response. The main toxicity was myelosuppression. The maximum tolerated dose was thought to be piritrexim 25 mg orally three times daily (days 1-4), paclitaxel 150 to 175 mg/m2 (days 1, 15), and gemcitabine 1,000 mg/m2 (days 1, 15). The combination of these new antifolates with paclitaxel and gemcitabine appears safe and should be considered for phase II trials in known responsive tumors such as transitional cell carcinomas.

Phase I study of eniluracil, oral 5-fluororacil and gemcitabine in patients with advanced malignancy.

PURPOSE: The objectives of this trial were to assess the maximal tolerated dose and toxicity of the combination of oral eniluracil and 5-fluorouracil and intravenous gemcitabine. PATIENTS AND METHODS: Patients with histologically confirmed, incurable malignancy (solid tumor or lymphoma) refractory to standard therapy or for which no standard therapy exists were enrolled. The treatment plan consisted of weekly gemcitabine for three weeks with twice daily dosing of 5-FU and eniluracil for 21 days beginning on day one of gemcitabine. Cycles repeated on an every four week schedule. The initial cohort received gemcitabine 800 mg/m2, oral 5-FU 0.6 mg/m2 and eniluracil 6.0 mg/m2. RESULTS: Twenty-six patients were enrolled. Eight patients received less than 2 cycles of therapy. Hematologic and gastrointestinal toxicity predominated, with 48% of courses resulted in grade one or two neutropenia. Hematologic toxicity was dose limiting. One treatment related death occurred. CONCLUSIONS: The combination of eniluracil, 5-fluorouracil and gemcitabine offers an oral alternative for 5-FU administration. The recommended phase II dose is gemcitabine 1000 mg/m2, 5FU 1.2 mg/m2 and eniluracil 12 mg/m2.