A Phase I study of intermittently dosed vorinostat in combination with bortezomib in patients with advanced solid tumors.

BACKGROUND: Accumulating evidence shows evidence of efficacy with the combination of vorinostat and bortezomib in solid tumors. We previously examined a once-daily continuous dosing schedule of vorinostat in combination with bortezomib which was well tolerated in cycles 1 and 2; however, there was concern regarding the tolerability through multiple cycles. This study was conducted to evaluate an intermittent dosing schedule of vorinostat with bortezomib. METHODS: Vorinostat was initially administered orally twice daily on days 1-14 with bortezomib IV on days 1, 4, 8, and 11 of a 21 day cycle. Two DLTs (elevated ALT and fatigue) were observed at dose level 1, thus the protocol was amended to administer vorinostat intermittently twice daily on days 1-4 and 8-11. RESULTS: 29 patients were enrolled; 13 men and 16 women. Common cancer types included sarcoma, pancreatic, colorectal, GIST, and breast. The most common Grade 3-4 toxicities at any dose level included thrombocytopenia, fatigue, increased ALT, elevated INR, and diarrhea. DLTs in the intermittent dosing scheduled included thrombocytopenia and fatigue. The Cmax and AUC for the intermittent dosing regimen were similar to those observed in the daily dosing. In this heavily pretreated population, stable disease was observed in patients with sarcoma, colorectal adenocarcinoma and GIST. CONCLUSIONS: The MTD was established at vorinostat 300 mg BID on days 1-4 and 8-11 and bortezomib 1.3 mg/m(2) IV on days 1, 4, 8, and 11 of a 21 day cycle. Tolerability was not improved with the intermittent dosing schedule of vorinostat when compared to continuous dosing.

A phase I study of AT-101 with cisplatin and etoposide in patients with advanced solid tumors with an expanded cohort in extensive-stage small cell lung cancer.

BACKGROUND: A phase I, dose-escalation study of AT-101 with cisplatin and etoposide was conducted to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), safety and pharmacokinetics in patients with advanced solid tumors, with an expanded cohort in patients with extensive-stage small cell lung cancer (ES-SCLC) to assess preliminary activity. METHODS: In the dose escalation portion, increasing doses of AT-101 were administered orally BID on days 1-3 along with cisplatin on day 1 and etoposide on days 1-3 of a 21 day cycle. At the RP2D, an additional 7 patients with untreated ES-SCLC were enrolled. RESULTS: Twenty patients were enrolled in the dose-escalation cohort, and 7 patients with ES-SCLC were enrolled in the expanded cohort. The MTD/RP2D was established at AT-101 40 mg BID days 1-3 with cisplatin 60 mg/m2 and etoposide 120 mg/m2 on day 1 of a 21 day cycle with pegfilgrastim support. Two DLTs of neutropenic fever were seen at dose level 1. After the addition of pegfilgrastim, no additional DLTs were observed. Grade 3/4 treatment-related toxicities included: diarrhea, increased AST, neutropenia, hypophosphatemia, hyponatremia, myocardial infarction and pulmonary embolism. No apparent PK interactions were observed between the agents. Preliminary activity was observed with PRs in patients with ES-SCLC, high-grade neuroendocrine tumor, esophageal cancer and NSCLC. CONCLUSIONS: AT-101 with cisplatin and etoposide is well tolerated with growth factor support. Anti-tumor activity was observed in a variety of cancers including ES-SCLC, supporting further investigation with BH-3 mimetics in combination with standard chemotherapy for ES-SCLC.

A phase I study of vorinostat in combination with bortezomib in patients with advanced malignancies.

BACKGROUND: A phase I study to assess the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK) and antitumor activity of vorinostat in combination with bortezomib in patients with advanced solid tumors. METHODS: Patients received vorinostat orally once daily on days 1-14 and bortezomib intravenously on days 1, 4, 8 and 11 of a 21-day cycle. Starting dose (level 1) was vorinostat (400 mg) and bortezomib (0.7 mg/m(2)). Bortezomib dosing was increased using a standard phase I dose-escalation schema. PKs were evaluated during cycle 1. RESULTS: Twenty-three patients received 57 cycles of treatment on four dose levels ranging from bortezomib 0.7 mg/m(2) to 1.5 mg/m(2). The MTD was established at vorinostat 400 mg daily and bortezomib 1.3 mg/m(2). DLTs consisted of grade 3 fatigue in three patients (1 mg/m(2),1.3 mg/m(2) and 1.5 mg/m(2)) and grade 3 hyponatremia in one patient (1.5 mg/m(2)). The most common grade 1/2 toxicities included nausea (60.9%), fatigue (34.8%), diaphoresis (34.8%), anorexia (30.4%) and constipation (26.1%). Objective partial responses were observed in one patient with NSCLC and in one patient with treatment-refractory soft tissue sarcoma. Bortezomib did not affect the PKs of vorinostat; however, the Cmax and AUC of the acid metabolite were significantly increased on day 2 compared with day 1. CONCLUSIONS: This combination was generally well-tolerated at doses that achieved clinical benefit. The MTD was established at vorinostat 400 mg daily × 14 days and bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11 of a 21-day cycle.

Phase I trial of motexafin gadolinium and doxorubicin in the treatment of advanced malignancies.

PURPOSE: To assess the safety, maximum-tolerated dose (MTD), and dose-limiting toxicities (DLT), of motexafin gadolinium (MGd), given in combination with doxorubicin, in patients with advanced solid tumors. STUDY DESIGN: The combination of MGd and doxorubicin was administered every 28 days (cycle 1) and then every 21 days (subsequent cycles). The dose of MGd, given daily for 3 days, was escalated from 1.0 mg/kg/d to 3.3 mg/kg/d, while the dose of doxorubicin was held at 30 mg/m². RESULTS: Fifteen patients received 37 cycles of treatment, for a median of 2 cycles per patient (range 0-6 cycles). Three patients (20%) completed 6 cycles of therapy. The MTD was identified as MGd, 2 mg/kg/day and doxorubicin, 30 mg/m². Dose limiting toxicities included grade 3 hypertension, pneumonia, bacteremia, and elevated GGT. Serious adverse events also included pulmonary embolism and urinary tract infection requiring hospitalization. There was no exacerbation of cardiac toxicity. No patients attained a response to treatment. Six patients (54%) had stable disease. The median time to disease progression, or to last assessment, was 49 days (range 8-195 days). CONCLUSIONS: The combination of MGd and doxorubicin was fairly well tolerated. However, due to emerging preclinical data suggesting that MGd inhibits ribonucleotide reductase, further development of the combination of MGd plus doxorubicin is not recommended.

A dose escalation, safety, and tolerability study of MN-029 in patients with advanced solid tumors.

PURPOSE: To assess the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), safety, and tolerability of MN-209, a novel vascular disrupting agent, in patients with advanced solid tumors. STUDY DESIGN: MN-029 was administered weekly for three consecutive weeks out of four; two cycles were planned. Dose escalation proceeded by 100% per toxicity criteria. Intra-patient dose escalation was permitted. RESULTS: Twenty patients received a total of 151 infusions of MN-029. No DLTs or grade 4 toxicities occurred. The most common adverse events were nausea, vomiting, arthralgias, and headache. One patient developed acute substernal chest pain 4 days after his first dose of MN-029 and was removed from the study. An MTD was not determined. The recommended phase II dose was identified as 180 mg/m(2)/week. One patient with advanced pancreatic cancer attained a partial response lasting 10 weeks. CONCLUSIONS: MN-029 was well tolerated in this schedule. Further development of this class of agents is warranted, especially in combination with other anti-cancer treatments.

Phase I trial of 2-methoxyestradiol NanoCrystal dispersion in advanced solid malignancies.

PURPOSE: 2-methoxyestradiol (2ME2; Panzem) is an endogenous, estradiol-17beta 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 gamma-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 pharmacokinetic and pharmacodynamic correlative study of the antisense Bcl-2 oligonucleotide g3139, in combination with carboplatin and paclitaxel, in patients with advanced solid tumors.

PURPOSE: This phase I trial assessed the safety and tolerability of G3139 when given in combination with carboplatin and paclitaxel chemotherapy. The effect of G3139 treatment on Bcl-2 expression in peripheral blood mononuclear cells (PBMC) and paired tumor biopsies was also determined. EXPERIMENTAL DESIGN: Patients with advanced solid malignancies received various doses of G3139 (continuous i.v. infusion days 1-7), carboplatin (day 4), and paclitaxel (day 4), repeated in 3-week cycles, in a standard cohort-of-three dose-escalation schema. Changes in Bcl-2/Bax transcription/expression were assessed at baseline and day 4 (prechemotherapy) in both PBMCs and paired tumor biopsies. The pharmacokinetic interactions between G3139 and carboplatin/paclitaxel were measured. RESULTS: Forty-two patients were evaluable for safety analysis. Primary toxicities were hematologic (myelosuppression and thrombocytopenia). Dose escalation was stopped with G3139 at 7 mg/kg/d, carboplatin at area under the curve of 6, and paclitaxel at 175 mg/m(2) due to significant neutropenia seen in cycle 1 and safety concerns in further escalating chemotherapy in this phase I population. With G3139 at 7 mg/kg/d, 13 patients underwent planned tumor biopsies, of which 12 matched pairs were obtained. Quantitative increases in intratumoral G3139 with decreases in intratumoral Bcl-2 gene expression were seen. This paralleled a decrease in Bcl-2 protein expression observed in PBMCs. CONCLUSIONS: Although the maximal tolerated dose was not reached, the observed toxicities were consistent with what one would expect from carboplatin and paclitaxel alone. In addition, we show that achievable intratumoral G3139 concentrations can result in Bcl-2 down-regulation in solid tumors and PBMCs.

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 (1 alpha-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 microg 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 > or =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 trial of gemcitabine in combination with patupilone in patients with advanced solid tumors.

INTRODUCTION: Chemotherapy regimens including gemcitabine in combination with microtubule inhibitors such as docetaxel and paclitaxel have wide clinical application. Patupilone is a novel tubulin-polymerizing agent with activity against paclitaxel-resistant cell lines. We conducted a phase I trial to assess the maximum tolerated dose, dose limiting toxicity (DLT) and antitumor activity of gemcitabine and patupilone. METHODS: Patients with refractory solid tumors enrolled in cohorts of three. Cohorts received fixed doses of gemcitabine (1,000 or 750 mg/m(2)) along with escalating doses of patupilone (1.5-3 mg/m(2)) on days 1 and 8 of a 21-day cycle. RESULTS: Twenty-seven patients received a total of 99 courses of treatment on study. Hematologic toxicity in the first cohort required a modification of the protocol to decrease the gemcitabine dose. Subsequent patients received gemcitabine 750 mg/m(2) and escalating doses of patupilone from 1.5 to 3 mg/m(2). DLTs were grade 3 asthenia and grade 3 dehydration. There was also one treatment-related death due to neutropenic infection. Other clinically significant toxicities were persistent asthenia and persistent nausea. Four patients, one each with pancreatic cancer, esophageal carcinoma, cholangiocarcinoma and gallbladder carcinoma, experienced a partial response. CONCLUSIONS: The dose-limiting toxicities of gemcitabine and patupilone were asthenia and dehydration. Dose reductions also occurred due to persistent fatigue that was not dose-limiting. However, patients with advanced malignancies were able to tolerate gemcitabine and patupilone at doses that resulted in clinical benefit. The recommended phase II dose for this schedule is gemcitabine 750 mg/m(2) and patupilone 1.5 mg/m(2) on days 1 and 8 of a 21-day cycle.

Effect of medical castration on CYP3A4 enzyme activity using the erythromycin breath test.

PURPOSE: Testosterone administration can lead to increased antipyrine clearance in humans. Medical or surgical castration is a standard treatment of progressive prostate carcinoma, but the effect of the subsequent fall of testosterone concentrations upon drug metabolism has not been reported. METHODS: Eleven men with a biopsy-proven diagnosis of progressive prostate cancer were enrolled after providing informed consent. CYP3A4 activity was determined using the erythromycin breath test (EBT) in each patient prior to their beginning with an LHRH-agonist (leuprolide or goserelin). No patients had elected to undergo orchiectomy during the period of subject accrual. Each subject underwent a second EBT 2 months after beginning LHRH suppression. Blood samples were collected at these time points to determine changes in testosterone and leutinizing hormone. RESULTS: All subjects had a predictable drop in serum testosterone concentrations over the 8-week course of the study, but concentrations in three did not fall below castrate levels (<50 ng/dl). There was no statistically significant change in CYP3A4 activity using the EBT method (p = 0.88). The extent and direction of changes in CYP3A4 activity was highly variable, with three subjects experiencing an increase in activity, and five demonstrating a decrease in activity. CONCLUSION: There is no clinically significant change in CYP3A4 activity after medical castration. No changes in the clearance of docetaxel or other CYP3A4 substrates are likely during and after medical castration. Although similar findings are expected after orchiectomy, we were not able to test this presumption because of patient preference for medical castration.

Electron paramagnetic resonance study of peripheral blood mononuclear cells from patients with refractory solid tumors treated with Triapine.

The metal chelator Triapine, 3-aminopyridine-2-carboxaldehyde thiosemicarbazone, is a potent inhibitor of ribonucleotide reductase. EPR spectra consistent with signals from Fe-transferrin, heme, and low-spin iron or cupric ion were observed in peripheral blood mononuclear cells (PBMCs) obtained from patients treated with Triapine. One signal that is unequivocally identified is the signal for Fe-transferrin. It is hypothesized that Fe uptake is blocked by reactive oxygen species generated by FeT(2) or CuT that damage transferrin or transferrin receptor. A potential source for the increase in the heme signal is cytochrome c released from the mitochondria. These results provide valuable insight into the in vivo mechanism of action of Triapine.

Phase I trial of weekly paclitaxel and BMS-214662 in patients with advanced solid tumors.

PURPOSE: To assess the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacodynamics, and antitumor activity of continuous weekly-administered paclitaxel and BMS-214662, a novel farnesyl transferase inhibitor. EXPERIMENTAL DESIGN: Patients were treated every week as tolerated with i.v. paclitaxel (fixed dose, 80 mg/m(2)/wk) administered over 1 h followed by i.v. BMS-214662 (escalating doses, 80-245 mg/m(2)/wk) over 1 h starting 30 min after completion of paclitaxel. RESULTS: Twenty-six patients received 94 courses (one course, 21 days) of study treatment. Two patients received five courses of BMS-214662 as a weekly 24-h infusion (209 mg/m(2)/wk). The most common toxicities were grade 1 to 2 nausea/vomiting and/or diarrhea. DLTs observed at or near the MTD (200 mg/m(2)/wk) were grade 4 febrile neutropenia with sepsis occurring on day 2 of course 1 (245 mg/m(2)/wk), reversible grade 3 to 4 serum transaminase increases on day 2, and grade 3 diarrhea (200 and 245 mg/m(2)/wk). Objective partial responses were observed in patients with pretreated head and neck, ovarian, and hormone-refractory prostate carcinomas, and leiomyosarcoma. The observed pharmacokinetics of paclitaxel and BMS-214662 imply no interaction between the two. Significant inhibition (>80%) of farnesyl transferase activity in peripheral mononuclear cells was observed at the end of BMS-214662 infusion. CONCLUSIONS: Pretreated patients with advanced malignancies can tolerate weekly paclitaxel and BMS-214662 at doses that achieve objective clinical benefit. Due to multiple DLTs occurring at the expanded MTD, the recommended phase 2 dose and schedule is paclitaxel (80 mg/m(2) over 1 h) and BMS-214662 (160 mg/m(2) over 1 h) administered weekly.

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.

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 > or =3 toxicities for schedule I were constipation, fatigue, myalgia, and sensory neuropathy. Grade > or =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 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.

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 II study of 1alpha-hydroxyvitamin D(2) in the treatment of advanced androgen-independent prostate cancer.

PURPOSE: In this single institution Phase II trial, we evaluated the efficacy of the vitamin D analogue, 1alpha-OH-D(2), in patients with advanced hormone-refractory prostate cancer. EXPERIMENTAL DESIGN: The patients initially received 1alpha-OH-D(2) at 12.5 micro g p.o. every day, which was dose adjusted for hypercalcemia. Given the cytostatic nature of the drug, the primary study end point was progression-free survival for a minimum of 6 months. The secondary end point was further characterization of drug toxicity. RESULTS: A total of 26 patients was enrolled. Using the intent-to-treat population, stable disease was seen for an average of 19.2 weeks (median 12 weeks, range 3-108 weeks). Twenty patients were evaluable for response. The one patient that achieved disease stabilization for >2 years elected to come off-study because of patient preference. His last disease evaluation showed no evidence of progression. No objective responses were seen. Previous and ongoing clinical observations strongly imply that PSA could be a misleading surrogate marker for clinical effect with this type of drug. Therefore, prostate-specific antigen was not used as a marker for disease response. Toxicity was as expected with mild hypercalcemia and associated symptoms like constipation and prerenal azotemia seen in some patients. Six (30%) evaluable patients experienced stable disease for >6 months, suggesting possible cytostatic activity. CONCLUSION: The results of this and other trials suggest further clinical investigation in this disease with vitamin D analogues alone or in combination with other agents, such as chemotherapy, should be pursued.

Phase I clinical and pharmacokinetic study of NSC 655649, a rebeccamycin analogue, given in both single-dose and multiple-dose formats.

PURPOSE: NSC 655649 was given in both single- and multiple-dose formats, to characterize maximum tolerated dose (MTD), toxicity, and pharmacokinetic profile. EXPERIMENTAL DESIGN: Patients with advanced malignancies were treated with escalating doses of NSC 655649 in either a single-dose format (step 1) or a multiple-dose format (step 2). In step 1, NSC 655649 was given as a 30-60 min infusion. In step 2, the NSC 655649 dose was divided into three consecutive daily doses. Plasma and urine were sampled to assess the pharmacokinetic and excretory characteristics of NSC 655649. A total of 12 patients were enrolled at the MTD for the purpose of gender equity. RESULTS: Forty-three patients were treated with NSC 655649 for a total of 108 cycles in step 1, and 26 patients were treated for a total of 41 cycles in step 2. The MTD for both steps 1 and 2 was determined to be 572 mg/m(2). Myelosuppression was the dose-limiting toxicity. Local venous irritation was generally grade 1-2 in severity but could only be adequately prevented by administration of study drug through central i.v. access. One patient with adenocarcinoma of unknown primary experienced a partial response on step 1. Four patients experienced stable disease of >100 days duration. CONCLUSIONS: NSC 655649 may be safely given at an MTD of 572 mg/m(2) in both single-dose and multiple-dose formats. Optimally, this drug should be administered through central i.v. access.

Phase I and pharmacokinetic study of a micronized formulation of carboxyamidotriazole, a calcium signal transduction inhibitor: toxicity, bioavailability and the effect of food.

PURPOSE: This Phase I study was conducted to evaluate the toxicity profile and determine the maximum tolerated dose (MTD) of an oral micronized formulation of the signal transduction inhibitor carboxyamidotriazole (CAI). Bioavailability of the micronized formulation relative to a gelatin capsule (gelcap) formulation was assessed. The effects of food intake and timing on CAI steady-state plasma concentrations (C(ss)) were also investigated. EXPERIMENTAL DESIGN: Patients received continuous daily CAI (28-day cycles). Starting dose was 150 mg/m(2) daily and escalations were by 50 mg/m(2) increments. The first three patients enrolled were given test doses of the original gelcap formulation and two different micronized formulations to determine relative bioavailability. Toxicity and pharmacokinetic assessments were performed weekly. Additional cohorts were added after MTD determination to assess the effect of food intake and duration of fast on CAI C(ss). RESULTS: The micronized formulation was absorbed more slowly than the gelcap formulation. Twenty-nine patients were enrolled in the dose-escalation portion of the study. After dose escalation to 300 mg/m(2), dose-limiting neurotoxicities occurred including reversible vision loss in two patients. Other toxicities were mild. The final MTD was 150 mg/m(2). Pharmacokinetics appeared linear with significant inter- and intrapatient variability. Patients with C(ss) of > or = 4.0 mg/liter were more likely to have neurotoxicity. Nine patients with renal cell cancer and one with hepatocellular cancer had prolonged stable disease. CAI plasma concentrations were higher when taken with food. CONCLUSIONS: Micronized CAI was well tolerated at the MTD of 150 mg/m(2). Higher doses were limited by significant neurotoxicity. The variability in CAI pharmacokinetics may be partially attributable to concomitant food intake and timing of the dose.

Phase I clinical and pharmacokinetic study of oral penclomedine (NSC 338720) in adults with advanced solid malignancy.

Penclomedine is a synthetic alpha-picoline derivative that has shown antitumor activity both in preclinical development and in Phase I work using an i.v. preparation. The main toxicities seen in those studies were dose dependent and mainly neurocerebellar, with hematological toxicity being far less severe. This Phase I trial of p.o. penclomedine was conducted to potentially alter the toxicity profile and to avoid the neurological side effects seen with i.v. penclomedine. Eligibility criteria included microscopic confirmation of a solid malignancy or lymphoma with a lack of effective anticancer therapy. Twenty patients were enrolled. The median age was 60.5 years, and the median performance status was one. All but one patient had received prior systemic therapy. The starting dose of penclomedine was 200 mg/m(2) p.o. for 5 days, and was escalated according to a traditional Fibonacci sequence until the maximum tolerated dose (MTD) was observed. No treatment-related deaths were observed during the study. The MTD was determined to be 800 mg/m(2) p.o. for 5 days. Dose-limiting toxicities included mainly neurocerebellar symptoms such as ataxia and dysmetria, but neurocortical symptoms, such as confusion, were seen as well. Myelosuppression was less common and resulted in the discontinuation of therapy in only two patients. Pharmacokinetics show that the observed MTD is consistent with the i.v. preparations, and that the bioavailability of p.o. penclomedine is 49 +/- 18%. This regimen can be considered for additional studies in patients with intracranial neoplasms, because good central nervous system penetration is evident. Further development of penclomedine metabolites, such as 4-O-demethylpenclomedine, should be considered to minimize dose-limiting neurotoxicity.