A phase Ib/II and pharmacokinetic study of EP0057 (formerly CRLX101) in combination with weekly paclitaxel in patients with recurrent or persistent epithelial ovarian, fallopian tube, or primary peritoneal cancer.

BACKGROUND: EP0057 (formerly CRLX101) is an investigational nanoparticle-drug conjugate (NDC) of a cyclodextrin-based polymer backbone plus camptothecin, a topoisomerase-1 inhibitor. Prior studies showed efficacy in recurrent or persistent, epithelial ovarian, fallopian tube or primary peritoneal cancer (EOC). METHODS: This phase Ib/2 trial assessed safety and efficacy of EP0057 Q2W plus weekly paclitaxel in patients with EOC. The recommended phase 2 dose (RP2D) was identified using a 3+3 design. The single-arm phase 2 assessed overall response (ORR) per RECIST 1.1 in patients previously treated with bevacizumab. Secondary objectives included progression free survival (PFS) and duration of response. RESULTS: The RP2D was established as 15 mg/m2 EP0057 Q2W plus 80 mg/m2 paclitaxel administered 3 weeks on/1 week off. Nine patients enrolled on phase 1b, with no DLTs; 21 additional patients enrolled on phase 2. All completed >1 cycle. Median age was 62 (44-76) years, 57% ≥3 prior therapies. For the primary analysis, 6/19 patients with prior bevacizumab had confirmed responses (ORR=31.6% (95% CI: 15.4% to 54.0%)) including one complete response (CR). Median PFS was 5.4 months. Most common grade 3/4 adverse events attributed to treatment were decreased neutrophil count (13, 43%) and anemia (3, 10%). CONCLUSIONS: Although the observed ORR was not statistically better than the historical control rate, EP0057 remains an interesting option for treatment of recurrent EOC. EP0057 exhibits high plasma drug retention, slow clearance, and controlled slow release of CPT from the polymer when administered alone and with paclitaxel. (NCT02389985) 242 words.

Final report on serial phase II trials of all-intraperitoneal chemotherapy with or without bevacizumab for women with newly diagnosed, optimally cytoreduced carcinoma of Müllerian origin.

BACKGROUND: Intraperitoneal (IP) chemotherapy can improve outcomes for women with optimally cytoreduced epithelial ovarian cancer but toxicities are a concern. We conducted 2 phase 2 trials of an IV/IP regimen using carboplatin and paclitaxel without (Trial A) and with bevacizumab (Trial B). METHODS: Both trials consisted of carboplatin AUC 6 day 1, and paclitaxel 60 mg/m2 on days 1,8, 15 of a 21-day cycle; in Trial B, patients received IV bevacizumab 15 mg/kg every cycle starting cycle 2. Chemotherapy was administered IV for cycle 1 and then IP for all subsequent cycles. Primary objectives included safety and tolerability, pathologic CR rate (Trial A), and the rate of completion of IP cycles of therapy (Trial B). Progression-free (PFS), overall survival (OS), and pharmacokinetic analysis were secondary endpoints. RESULTS: 81 patients were treated on both trials (n = 40 and 41 in trials A and B, respectively). Median age for trials A and B was 59 (range, 36-76) and 55 (range, 19-69) years, respectively. 68% and 85% of patients, respectively for A and B, completed at least 4 cycles of treatment in both trials. Treatment with bevacizumab resulted in higher rates of grade 3 fatigue (37 versus 33%) and grade 3-4 diarrhea (22 versus 8%). Median PFS was 23.5 (95%CI 16.2-35.3) and 25 (95%CI 16.4-42.7) months, respectively; median OS was 68 (95%CI 49.5-NR) and 79.7 (95%CI 59.0-79.7) months, respectively for Trial A and B. CONCLUSIONS: Weekly administered IP carboplatin and IP paclitaxel is tolerable and safe with similar activity with and without concommittant bevacizumab in these 2 trials.

Long-term outcome of a pediatric-inspired regimen used for adults aged 18-50 years with newly diagnosed acute lymphoblastic leukemia.

On the basis of the data suggesting that adolescents and young adult patients with acute lymphoblastic leukemia (ALL) have improved outcomes when treated on pediatric protocols, we assessed the feasibility of treating adult patients aged 18-50 years with ALL with the DFCI Pediatric ALL Consortium regimen utilizing a 30-week course of pharmacokinetically dose-adjusted E. coli L-asparaginase during consolidation. Between 2002 and 2008, 92 eligible patients aged 18-50 years were enrolled at 13 participating centers. Seventy-eight patients (85%) achieved a complete remission (CR) after 1 month of intensive induction therapy. With a median follow-up of 4.5 years, the 4-year disease-free survival (DFS) for the patients achieving a CR was 69% (95% confidence interval (CI) 56-78%) and the 4-year overall survival (OS) for all eligible patients was 67% (95% CI 56-76%). The 4-year DFS for the 64 patients who achieved a CR and were Philadelphia chromosome negative (Ph-) was 71% (95% CI 58-81%), and for all 74 Ph- patients the 4-year OS was 70% (95% CI 58-79%). We conclude that a pediatric-like treatment strategy for young adults with de novo ALL is feasible, associated with tolerable toxicity, and results in improved outcomes compared with historical regimens in young adult patients with ALL.

Oncolytic herpes simplex virus expressing yeast cytosine deaminase: relationship between viral replication, transgene expression, prodrug bioactivation.

Yeast cytosine deaminase (yCD) is a well-characterized prodrug/enzyme system that converts 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU), and has been combined with oncolytic viruses. However, in vivo studies of the interactions between 5-FC bioactivation and viral replication have not been previously reported, nor have the kinetics of transgene expression and the pharmacokinetics of 5-FC and 5-FU. We constructed a replication-conditional Herpes simplex virus 1 (HSV-1) expressing yCD and examined cytotoxicity when 5-FC was initiated at different times after viral infection, and observed that earlier 5-FC administration led to greater cytotoxicity than later 5-FC administration in vitro and in vivo. In animal models, 12 days of 5-FC administration was superior to 6 days, but dosing beyond 12 days did not further enhance efficacy. Consistent with the dosing-schedule results, both viral genomic DNA copy number and viral titers were observed to peak on Day 3 after viral injection and gradually decrease thereafter. The virus is replication-conditional and was detected in tumors for as long as 2 weeks after viral injection. The maximum relative extent of yCD conversion of 5-FC to 5-FU in tumors was observed on Day 6 after viral injection and it decreased progressively thereafter. The observation that 5-FU generation within tumors did not lead to appreciable levels of systemic 5-FU (<10 ng ml⁻¹) is important and has not been previously reported. The approaches used in these studies of the relationship between the viral replication kinetics, transgene expression, prodrug administration and anti-tumor efficacy are useful in the design of clinical trials of armed, oncolytic viruses.

Phase I trial of sorafenib in patients with recurrent or progressive malignant glioma.

Sorafenib is an inhibitor of multiple kinases that has demonstrated antiproliferative and antiangiogenic activity in a number of in vitro and in vivo model systems. A phase I study was conducted to determine the maximum tolerated dose (MTD) of sorafenib in patients with recurrent malignant glioma. Sorafenib was given orally, twice a day (BID), continuously in 28-day cycles. The dose was escalated in 2 groups of patients stratified by use of enzyme-inducing antiseizure drugs (± EIASDs). Dose-limiting toxicity (DLT) was defined as any grades 3-4 nonhematological toxicity, grade 4 hematological toxicity, and febrile neutropenia. The number of evaluable patients enrolled in the +EIASD and -EIASD arms were 23 and 24, respectively. DLTs were predominantly dermatological and gastrointestinal effects, as observed in previous clinical trials of sorafenib. The MTD was 600 mg BID for patients receiving EIASDs and 800 mg BID for those who were not. The plasma pharmacokinetics of sorafenib were not significantly affected by the concurrent administration of EIASDs. The MTD of sorafenib given orally BID on a continuous basis was established as 600 mg BID in patients with malignant glioma who were concurrently receiving EIASDs and 800 mg BID in those who were not. Further evaluation is warranted of sorafenib at the recommended MTD against recurrent or progressive malignant glioma in combination with other molecularly targeted drugs or in the newly diagnosed setting concurrent with chemoradiation.

Ecteinascidin-743 (ET-743) for chemotherapy-naive patients with advanced soft tissue sarcomas: multicenter phase II and pharmacokinetic study.

PURPOSE: To evaluate the response rate, toxicity profile, and pharmacokinetics of ecteinascidin-743 (ET-743) as first-line therapy in patients with unresectable advanced soft tissue sarcoma (STS). PATIENTS AND METHODS: Thirty-six patients with STS were enrolled onto the study between September 1999 and August 2000. Patients were treated with 1.5 mg/m2 of ET-743 given as a 24-hour continuous intravenous (IV) infusion every 21 days. Pharmacokinetic sampling was performed in 23 patients. RESULTS: One complete and five partial responses were achieved in 35 assessable patients for an overall response rate of 17.1% (95% CI, 6.6% to 33.6%). In addition, one patient had a minor response, leading to an overall clinical benefit of 20%. Neutropenia and transaminitis were the main grade 3 to 4 toxicities, which occurred in 33% and 36% of the patients. The estimated 1-year progression-free and overall survival rates were 21% (95% CI, 11% to 41%) and 72% (95% CI, 59% to 88%), respectively. Total body clearance (L/h) was not significantly correlated with body-surface area (r = -0.28; P = .21). Mild hepatic impairment or the extent of prior cytotoxic therapy does not seem to contribute significantly to the high interpatient variability (49%) in the clearance of this drug. Severity of treatment-related toxicity was not correlated with pharmacokinetic variables. CONCLUSION: ET-743 demonstrates clinical activity as first-line therapy against STS with acceptable toxicity. Additional studies to establish empirical dosing guidelines may be necessary to improve the safety of the drug in patients with varying degrees of hepatic dysfunction and definitively establish the role of ET-743 for patients with these malignancies.

Phase II and pharmacokinetic study of ecteinascidin 743 in patients with progressive sarcomas of soft tissues refractory to chemotherapy.

PURPOSE: To assess the efficacy of the marine-derived alkaloid ecteinascidin 743 (ET-743) in patients with soft tissue sarcomas that progressed despite prior conventional chemotherapy and to characterize the pharmacokinetic profiles of ET-743 in this patient population. PATIENTS AND METHODS: Thirty-six previously treated soft tissue sarcoma patients from three institutions received ET-743 as a 24-hour continuous intravenous (IV) infusion at a dose of 1,500 microg/m(2) every 3 weeks. Pharmacokinetic studies were also performed. Patients were restaged every two cycles for response by objective criteria. RESULTS: Objective responses were observed in three patients, with one complete response and two partial responses, for an overall response rate of 8% (95% CI, 2% to 23%). Responses were durable for up to 20 months. Two minor responses (43% and 47% tumor reduction) were observed, for an overall clinical benefit rate of 14%. The predominant toxicities were neutropenia and self-limited transaminitis of grade 3 to 4 severity in 34% and 26% of patients, respectively. The estimated 1-year time to progression and overall survival rates were 9% (95% CI, 3% to 27%) and 53% (95% CI, 39% to 73%), respectively. The maximum observed plasma concentration and total plasma clearance of ET-743 (mean +/- standard deviation), 1.04 +/- 0.48 ng/mL and 35.6 +/- 16.2 L/h/m(2), respectively, were consistent with previously reported values from phase I studies of the drug given as a 24-hour IV infusion. CONCLUSION: ET-743 is a promising new option for the management of several histologic subtypes of sarcoma. Durable objective responses were obtained in a subset of sarcoma patients with disease progression despite prior chemotherapy. Additionally, the relatively high survival rate noted in this series of previously treated patients further justifies development of this agent.

Determination of procarbazine in human plasma by liquid chromatography with electrospray ionization mass spectrometry.

Procarbazine is a cytotoxic chemotherapeutic agent used in the treatment of lymphomas and brain tumors. Its pharmacokinetic behavior remains poorly understood even though more than 30 years have elapsed since the drug was approved for clinical use. To characterize the pharmacokinetics of procarbazine in brain cancer patients during a phase I trial, a method for determining the drug in human plasma by reversed-phase high-performance liquid chromatography (HPLC) with electrospray ionization mass spectrometry (ESI-MS) was developed and thoroughly validated. Plasma samples were prepared for analysis by precipitating proteins with trichloroacetic acid and washing the protein-free supernatant with methyl tert-butyl ether to remove excess acid. The solution was separated on a Luna C-18 analytical column using methanol-25 mM ammonium acetate buffer, pH 5.1 (22:78, v/v) as the mobile phase at 1.0 ml/min. A single-quadrupole mass spectrometer with an electrospray interface was operated in the selected-ion monitoring mode to detect the [M+H](+) ions at m/z 222.2 for procarbazine and at m/z 192.1 for the internal standard (3-dimethylamino-2-methylpropiophenone). Procarbazine and the internal standard eluted as sharp, symmetrical peaks with retention times (mean+/-S.D.) of 6.3+/-0.1 and 9.9+/-0.3 min, respectively. Calibration curves of procarbazine hydrochloride in human plasma at concentrations ranging from 0.5 to 50 ng/ml exhibited excellent linearity. The mean absolute recovery of the drug from plasma was 102.9+/-1.0%. Using a sample volume of 150 microl, procarbazine was determined at the 0.5 ng/ml (1.9 nM) lower limit of quantitation with a mean accuracy of 105.2% and an interday precision of 3.60% R.S.D. on 11 different days over 5 weeks. During this same time interval, the between-day accuracy for determining quality control solutions of the drug in plasma at concentrations of 2.0, 15 and 40 ng/ml ranged from 97.5 to 98.2% (mean+/-S.D., 97.9+/-0.4%) and the precision was 3.8-6.2% (mean+/-S.D., 5.1+/-1.2%). Stability characteristics of the drug were thoroughly evaluated to establish appropriate conditions to process, store and prepare clinical specimens for chromatographic analysis without inducing significant chemical degradation. The sensitivity achieved with this assay permitted the plasma concentration-time profile of the parent drug to be accurately defined following oral administration of standard doses to brain cancer patients.

Quantitative analysis of the novel depsipeptide anticancer drug Kahalalide F in human plasma by high-performance liquid chromatography under basic conditions coupled to electrospray ionization tandem mass spectrometry.

Kahalalide F (KF) is a novel cyclic depsipeptide anticancer drug, which has shown anticancer activity both in vitro and in vivo especially against human prostate cancer cell lines. To characterize the pharmacokinetics of KF during a phase I clinical trial in patients with androgen refractory prostate cancer, a method was developed and validated for the quantitative analysis of KF in human plasma using high-performance liquid chromatography (HPLC) coupled to positive electrospray ionization tandem mass spectrometry (ESI-MS/MS). Microbore reversed-phase liquid chromatography (LC) performed with mobile phases containing trifluoroacetic acid, an additive commonly used for separating peptides, resulted in substantial suppression of the signal for KF on ESI-MS/MS. An alternative approach employing a basic mobile phase provided an excellent response for KF when detected in the positive ion mode. Plasma samples were prepared for LC MS/MS by solid-phase extraction on C(18) cartridges. The LC separation was performed on a Zorbax Extend C(18) column (150 x 2.1 mm i.d., particle size 5 micro m) with acetonitrile -10 mM aqueous ammonia (85 : 15, v/v) as the mobile phase, at a flow-rate of 0.20 ml min(-1). A butyric acid analogue of KF was used as the internal standard. The lower limit of quantitation (LLQ) using a 500 micro l sample volume was 1 ng ml(-1) and the linear dynamic range extended to 1000 ng ml(-1). The inter-assay accuracy of the assay was -15.1% at the LLQ and between -2.68 and -9.05% for quality control solutions ranging in concentration from 2.24 to 715 ng ml(-1). The inter-assay precision was 9.91% or better at these concentrations. The analyte was stable in plasma under all relevant conditions evaluated and for a period of 16 h after reconstituting plasma extracts for LC analysis at ambient temperature.

A phase II study of weekly paclitaxel in elderly patients with advanced non-small cell lung cancer.

PURPOSE: Our aim was to evaluate the efficacy, toxicity, and pharmacokinetic behavior of single-agent paclitaxel given weekly to elderly patients with lung cancer. EXPERIMENTAL DESIGN: Previously untreated patients with stage IIIB/IV non-small cell lung cancer were eligible for the study if they were at least 70 years of age and had preserved organ function. Paclitaxel was administered over 1 h at a dose of 90 mg/m(2) for 6 consecutive weeks on an 8-week cycle. The pharmacokinetics of paclitaxel were assessed during the first and sixth week of therapy in a subgroup of eight patients. RESULTS: A total of 35 patients (median age, 76 years; range, 70-85) were enrolled. The overall response rate was 23%. Median time to failure was 5.2 months, whereas the median survival time was 10.3 months. Survival rates after 1 and 2 years were 45 and 22%, respectively. Grade 3/4 toxicities included neutropenia (5.8%), hyperglycemia (17.6%), neuropathy (5.8%), and infection (8.8%). Two patients died from treatment-related toxicity. There was no significant difference (P = 0.18) between the total body clearance of paclitaxel on the first (17.4 +/- 2.9 liters/h/m(2), mean +/- SD) and sixth (15.8 +/- 4.1 liters/h/m(2)) week of therapy. CONCLUSION: Paclitaxel administered as a weekly 1-h infusion at a dose of 90 mg/m(2) is a safe and effective therapy for elderly patients with advanced non-small cell lung cancer. Its pharmacokinetics in elderly patients do not appear to differ from historical data for younger patients, and there was no suggestion of a change in drug clearance after repeated weekly dosing.

Plasma pharmacokinetics and bioavailability of 1-(2-chloroethyl)-3-sarcosinamide-1-nitrosourea after intravenous and oral administration to mice and dogs.

PURPOSE: Chloroethylnitrosoureas are among the most widely used chemotherapeutic agents for the treatment of brain tumors. SarCNU (1-(2-chloroethyl)3-sarcosinamide-1-nitrosourea) is an investigational nitrosourea analogue that has shown greater antitumor activity and a more favorable toxicity profile than 1,3-bis(2-chloroethyl)-1-nitrosourea in preclinical studies. The purpose of the present study was to characterize the plasma pharmacokinetics and oral bioavailability of SarCNU in mice and dogs treated by intravenous infusion and gastric intubation. METHODS: SarCNU was administered to mice by i.v. injection or orally at doses ranging from 10 to 100 mg/kg. Plasma samples were obtained from groups of five animals at each time-point at intervals ranging from 3 min to 2.5 h after dosing. A group of three male beagle dogs were treated with Sar CNU 10 mg/kg given both by i.v. infusion and orally in a crossover design. The concentration of SarCNU in plasma was measured by high-performance liquid chromatography. RESULTS: During the initial 90 min after i.v. injection to mice, SarCNU was eliminated from plasma in a monoexponential manner with a mean half-life of 9.8 +/- 0.8 min. The total plasma clearance was 47.3 +/- 8.7 ml/min per kg and the apparent volume of distribution was 0.7 +/- 0.1 l/kg. SarCNU exhibited linear pharmacokinetic behavior following both i.v. and oral administration of doses ranging from approximately 10 to 100 mg/kg. Peak plasma levels provided by a dose of 100 mg/kg given by the i.v. and oral routes were 142.4 microg/ml (0.5 min) and 27.8 microg/ml (9.8 min), respectively. The mean oral bioavailability of the drug was 57.3 +/- 12.6% in mice. In comparison, the disposition of SarCNU in dogs after rapid i.v. injection was biexponential, with half-lives of 5.4 +/- 8.4 min and 40.8 +/- 9.0 min for the initial and terminal disposition phases, respectively. Mean values of the total plasma clearance and apparent volume of distribution were 17.8 +/- 1.8 ml/min per kg and 1.1 +/- 0.3 l/kg, respectively. The Cmax was 18.5 +/- 6.5 microg/ml after i.v. injection and 8.5 0.4 microg/ml after oral administration of a 10 mg/kg dose. Oral bioavailability of the drug in dogs (71.7 +/- 21.2%) was greater than that observed in mice. CONCLUSIONS: SarCNU exhibited linear and consistent pharmacokinetics in mice and dogs with very good oral bioavailability in both species. These findings support the rationale for evaluating SarCNU given by the oral route of administration in phase I clinical trials.

A Phase I-II study of 96-hour infusional topotecan and paclitaxel for patients with recurrent Müllerian tumors.

BACKGROUND: Topotecan and paclitaxel are schedule dependent chemotherapeutic agents with activity against ovarian carcinoma. A Phase I-II study in which both drugs were administered concurrently by 96-hour, continuous, intravenous infusion was performed to determine the maximum tolerated dose (MTD), toxicities, pharmacokinetics, and efficacy of the combination. METHODS: Women with ovarian or primary peritoneal carcinoma and documented recurrent disease were eligible for the study. The dose of topotecan was escalated from 1.6 mg/m(2) while maintaining the paclitaxel dose constant at 100 mg/m(2). Plasma concentrations of both drugs were monitored daily during the first cycle of therapy. RESULTS: Forty-five patients with a median age of 54 years (range, 42-70 years) received 181 cycles of therapy. Five patients were recruited to each of four dose levels (topotecan 1.6 mg/m(2), 2.0 mg/m(2), 2.8 mg/m(2), and 3.6 mg/m(2)), and an additional 25 patients were treated at the MTD (Phase II). Neutropenia and thrombocytopenia became dose limiting toxicities (DLT) at the fourth dose level. Emesis, mucositis, peripheral neuropathy, diarrhea, and alopecia were mild. Twenty patients (44%) had line-related occlusion, thrombosis, or infection. The mean values (+/- standard deviation) of the apparent steady-state plasma concentrations at the Phase II doses were 2.3 nM +/- 0.5 nM for topotecan lactone, 5.6 nM +/- 2.1 nM for total topotecan, and 40.1 nM +/- 16.8 nM for paclitaxel. There were seven partial responses (Phase II) contributing to an objective response rate of 28% and a median survival time of 11.7 months (range, 0.6-20.1 months). CONCLUSIONS: Topotecan at a dose of 2.8 mg/m(2) and paclitaxel at a dose of 100 mg/m(2) administered by concurrent, 96-hour, continuous intravenous infusions shows activity against tumors of Müllerian origin.

A phase II trial of the cyclin-dependent kinase inhibitor flavopiridol in patients with previously untreated stage IV non-small cell lung cancer.

PURPOSE: Flavopiridol is a potent cyclin-dependent kinase inhibitor with preclinical activity against non-small cell lung cancer (NSCLC), inhibiting tumor growth in vitro and in vivo by cytostatic and cytotoxic mechanisms. A Phase II trial was conducted to determine the activity and toxicity of flavopiridol in untreated patients with metastatic NSCLC. EXPERIMENTAL DESIGN: A total of 20 patients were treated with a 72-h continuous infusion of flavopiridol every 14 days at a dose of 50 mg/m(2)/day and a concentration of 0.1-0.2 mg/ml. Dose escalation to 60 mg/m(2)/day was permitted if no significant toxicity occurred. Response was initially assessed after every two infusions; patients treated longer than 8 weeks were then assessed after every four infusions. Plasma levels of flavopiridol were measured daily during the first two infusions to determine steady-state concentrations. RESULTS: This study was designed to evaluate a total of 45 patients in two stages. However, because no objective responses were seen in the first 20 patients, the early-stopping rule was invoked, and patient accrual was halted. In four patients who received eight infusions, progression was documented at 15, 20, 40, and 65 weeks, respectively. The most common toxicities included grade 1 or 2 diarrhea in 11 patients, asthenia in 10 patients, and venous thromboses in 7 patients. The mean +/- SD steady-state concentration of drug during the first infusion was 200 +/- 89.9 nM, sufficient for cytostatic effects in in vitro models. CONCLUSIONS: At the current doses and schedule, flavopiridol does not have cytotoxic activity in NSCLC, although protracted periods of disease stability were observed with an acceptable degree of toxicity.

Phase I and pharmacokinetic study of ecteinascidin 743 administered as a 72-hour continuous intravenous infusion in patients with solid malignancies.

Ecteinascidin 743 (ET-743) is a cytotoxic tetrahydroisoquinoline alkaloid that covalently binds to DNA in the minor groove. The in vitro chemosensitivity of cancer cells to ET-743 is markedly enhanced by prolonging the duration of exposure to the drug. A Phase I study of ET-743 given as a 72-h continuous i.v. infusion every 21 days was performed. Characteristics of the 21 adult patients with refractory solid tumors enrolled in the study were as follows: (a) 12 men; (b) 9 women; (c) median age, 59 years; (d) Eastern Cooperative Oncology Group performance status < or = 1, 20 patients; and (e) two prior regimens of chemotherapy, 7 patients. Dose limiting toxicity (DLT) was defined by typical criteria, except that grade 3 transaminitis did not constitute a DLT. There were no DLTs in the six patients evaluated at the first two dose levels of 600 and 900 microg/m2. Reversible grade 4 transaminitis occurred in two of nine patients after treatment with the first cycle of therapy at the third dose level of 1200 microg/m2. Another patient experienced grade 4 rhabdomyolysis, renal failure requiring hemodialysis, grade 4 neutropenia, and grade 3 thrombocytopenia during the second cycle of therapy with this dose. The maximum tolerated dose was 1200 microg/m2, and an additional six patients were enrolled at an intermediate dose level of 1050 microg/m2. This well-tolerated dose was established as the recommended Phase II dose. The disposition of ET-743 was distinctly biexponential, and a departure from linear pharmacokinetic behavior was evident at the 1200-microg/m2 dose level. Pharmacokinetic parameters determined at 1050 microg/m2 were (mean +/- SD): maximum plasma concentration, 318 +/- 147 pg/ml; initial disposition phase half-life, 9.0 +/- 10.3 min; terminal phase half-life, 69.0 +/- 56.7 h; and total plasma clearance, 28.4 +/- 22.5 liters/h/m2. Prolonged systemic exposure to concentrations of the agent that are cytotoxic in vitro were achieved. Toxicity of the drug is clearly schedule-dependent, because increasing the duration of infusion from 3 or 24 h to 72 h results in decreased myelosuppression and comparable hepatotoxicity. Although there were no objective responses to therapy, clear evidence of antitumor activity was observed in a patient with epithelioid mesothelioma, as confirmed by positron emission tomography studies. A Phase II trial to assess the efficacy of ET-743 against this highly refractory neoplasm has been initiated on the basis of this observation. The therapeutically optimal administration schedule remains to be established, inasmuch as there have been indications of activity against a variety of tumors during Phase I studies when the drug was infused over times ranging from 1 to 72 h. Characterizing the pharmacokinetics of ET-743 during the course of Phase II trials and Phase I combination studies is recommended to assure that this promising new anticancer drug can be used with an acceptable margin of safety.

Phase I clinical trial of 7-cyanoquinocarcinol (DX-52-1) in adult patients with refractory solid malignancies.

PURPOSE: A phase I study of the antitumor antibiotic 7-cyanoquinocarcinol, DX-52-1, was conducted in patients with refractory solid malignancies. This study sought to determine the maximum tolerated dose and principal toxicities of this agent and to characterize its pharmacokinetic behavior. METHODS: Patients were required to have adequate bone marrow, renal and hepatic function. DX-52-1 was administered by i.v. continuous infusion over a 6-h period each week for four consecutive weeks followed by a 2-week rest period, which constituted one cycle of treatment. RESULTS: Initial dose levels were 3, 6, and 10 mg/m2. An intermediate dose level of 8 mg/m2 was added after acceptable toxicity was observed at the 6 mg/m2 dose level, but dose-limiting toxicities, including life-threatening ones, were seen at the 10 mg/m2 dose level in all three patients. The maximum tolerated dose (MTD) was subsequently determined to be 6 mg/m2. Because a clear pattern of toxicities was not initially evident, a larger than usual number of additional patients (16) were enrolled at the MTD to better distinguish toxicities due to the study drug from those secondary to the patients' underlying malignancies. Even at the MTD, the drug was poorly tolerated, with gastrointestinal toxicities (abdominal pain, nausea, vomiting and increased liver function tests) predominating and dose-limiting. Pharmacokinetic studies revealed that the mean maximum plasma concentration of DX-52-1 in patients evaluated at the MTD (138.8 +/- 59.3 ng/ml, n = 19) was considerably lower than the concentrations required for cytostatic or cytotoxic activity against sensitive human tumor cell lines in vitro. Further, the weekly dose intensity of the most efficacious treatment schedule identified during in vivo antitumor efficacy studies was 60 times greater than the 6 mg/m2 weekly dose tolerated by cancer patients. None of the 33 patients participating in this study, including the 22 patients evaluated at the MTD, had any response to treatment. CONCLUSION: Given the poor tolerability, the inability to achieve drug levels necessary to inhibit in vitro or in vivo tumor growth, and the lack of any responses in our study, DX-52-1, as given by this schedule, does not appear to warrant further investigation in phase II studies.

A phase I clinical and pharmacokinetic study of the dolastatin analogue cemadotin administered as a 5-day continuous intravenous infusion.

PURPOSE: The dolastatins are a class of naturally occurring cytotoxic peptides which function by inhibiting microtubule assembly and tubulin polymerization. Cemadotin is a synthetic analogue of dolastatin 15 with potent antiproliferative and preclinical antitumor activity. This report describes a phase I study to evaluate the administration of cemadotin to adult cancer patients by a 5-day continuous intravenous (CIV) infusion. METHODS: All patients had histologically confirmed refractory solid tumors. The dose was escalated from an initial level of 2.5 mg/m2 (0.5 mg/m2 daily) according to a modified Fibonacci algorithm. A minimum of three patients was evaluated at each dose level until the maximum tolerated dose (MTD) was established. Treatment was repeated every 21 days until patients were removed from the study due to toxicity or disease progression. Drug-related toxicities were evaluated and graded by the U.S. National Cancer Institute's Common Toxicity Criteria. A radioimmunoassay (RIA) that detected both the parent drug and its metabolites with an intact N-terminal region of the molecule was used for pharmacokinetic studies. RESULTS: Twenty heavily pretreated patients received a total of 40 courses of cemadotin over five dose levels ranging from 2.5 to 17.5 mg/m2. Reversible dose-related neutropenia was the principal dose-limiting toxicity and 12.5 mg/m2 was established as the MTD. Nonhematologic toxicities attributed to the drug were moderate, and there was no evidence of the cardiovascular toxicity noted in the prior phase I studies of cemadotin given IV as a 5-min injection or 24-h infusion. There were no objective antitumor responses. Time courses of the cemadotin RIA equivalent concentration in whole blood were defined in 14 patients during the first cycle of therapy. The RIA-detectable species exhibited apparent first-order pharmacokinetics across the entire range of doses. The mean +/- SD of the observed steady-state blood concentration at the 12.5 mg/m2 MTD was 282 +/- 7 nM (n = 3). Blood levels decayed monoexponentially following the end of the infusion, with a mean half-life of 13.2 +/- 4.3 h (n = 14) in all patients. Mean values (n = 14) of the total blood clearance and apparent volume of distribution at steady state were 0.52 +/- 0.09 lh/m2 and 9.9 +/- 3.3 l/m2, respectively. CONCLUSIONS: The cardiotoxic effects of cemadotin were completely avoided by administering it as a 120-h CIV infusion. Thus. cardiovascular toxicity appears to be associated with the magnitude of the peak blood levels of the parent drug or its metabolites, whereas myelotoxicity is related to the duration of time that blood levels exceed a threshold concentration. Nevertheless, the data acquired during the extensive clinical experience with cemadotin requires careful examination to assess whether advancing this compound into disease-oriented efficacy studies is merited.

Characterization of a novel degradation product of 2,2'-dithiobis[N-isoleucylbenzamide], an inhibitor of HIV nucleocapsid protein zinc fingers.

Zinc finger motifs have been found to be important in a variety of protein structures including transcription factors and viral nucleocapsid proteins. Recently, it was demonstrated that various aromatic disulfides effectively remove the metal ion from the zinc finger, resulting in an alteration of tertiary structure in this region of the protein, thereby inhibiting transcription. Among these compounds, 2,2'-dithiobis[N-isoleucylbenzamide] exhibits activity against human immunodeficiency virus (HIV)-type 1 in vitro and has been selected for preclinical development as an anti-HIV agent. Analysis of this agent by reversed-phase high-performance liquid chromatography (HPLC) indicated a significant quantity of two additional compounds. Identifying the parent disulfide was accomplished by scanning eluting peaks with positive ion thermospray ionization (TSP) mass spectrometry (MS). Solution-induced disproportionation of the disulfide into its sulfhydryl monomer was demonstrated by treating the drug with dithiothreitol (DTT) prior to HPLC analysis. TSP-MS analysis of the remaining chromatographic peak suggested a molecular weight of 265, which, with 1H-nuclear magnetic resonance (NMR) data of the isolated material, allowed us to elucidate the chemical structure as N-isoleucyl-benzisothiazolone. Contact with stainless steel, such as that employed in an HPLC system, was found to accelerate degradation of the parent disulfide to the benzisothiazolone.

A Phase I study of continuous infusion doxorubicin and paclitaxel chemotherapy with granulocyte colony-stimulating factor for relapsed epithelial ovarian cancer.

A Phase I study of paclitaxel and doxorubicin administered as concurrent 96-h continuous i.v. infusion was performed to determine the maximum tolerated dose (MTD), principal toxicities, and pharmacokinetics of this combination in women with relapsed epithelial ovarian cancer. The paclitaxel dose was fixed at 100 mg/m2 (25 mg/m2/day for 4 days). The dose of doxorubicin was escalated from 30 mg/m2 (7.5 mg/m2/day for 4 days) in increments of 10 mg/m2 until dose-limiting toxicity was observed. All patients received granulocyte colony-stimulating factor 5 microg/kg/day prophylactically. Apparent steady-state plasma levels of both drugs were determined in the final cohort of patients treated at the MTD. A total of 17 patients received 52 cycles of therapy. The median age was 58 years, and all patients had previously received one to five different regimens (median, 2) of chemotherapy, including both platinum and paclitaxel. The treatment was tolerated well, with grade 1-2 nausea being the most frequent side effect (73% of cycles). Anemia, neutropenia, thrombocytopenia, and mucositis became dose limiting at the fourth dose level, defining the MTD of doxorubicin in this regimen as 50 mg/m2. There were four partial responses and one complete response in 15 evaluable patients. Apparent steady-state plasma concentrations (mean +/- SD) of paclitaxel and doxorubicin in the three patients treated at the MTD were 33.9 +/- 12.5 nM and 15.7 +/- 1.3 nM, respectively. Paclitaxel and doxorubicin by continuous infusion is a well-tolerated and active chemotherapy regimen for recurrent ovarian cancer.

Disappearance of endogenous luteinizing hormone is prolonged in postmenopausal women.

Pituitary secretion of LH is increased after menopause, but it is not known whether changes in LH clearance also contribute to elevated serum levels. To determine whether the disappearance of endogenous LH is decreased in postmenopausal women (PMW), compared with normal cycling women, GnRH receptor blockade was used to inhibit endogenous secretion of LH and the glycoprotein free alpha-subunit (FAS), and the decline of serum levels was monitored. The NAL-GLU GnRH antagonist ([Ac-D-2Nal1,D-4ClPhe2, D-3Pal3,Arg5,D-4-p-methoxybenzoyl-2-aminobutyric acid6,D-Ala10]GnRH) was administered s.c., at doses of 5, 15, 50, and 150 microg/kg, to 15 euthyroid PMW in 21 studies. Blood was sampled every 10 min, for 4 h before and 8 h after a single sc injection of the GnRH antagonist, followed by hourly samples, ending at 20 h after injection. Results of the maximally suppressive doses (50 and 150 microg/kg) were compared with those of 24 normal cycling women in the early follicular phase and late follicular phase or early luteal phase, and 8 women at the midcycle surge (MCS), who also received these doses of the GnRH antagonist. The best fit curve describing the decay of hormone serum levels after maximal GnRH receptor blockade was determined by nonlinear regression analysis. The elimination of both LH and FAS, after GnRH receptor blockade, exhibited apparent first-order kinetics characterized by a single exponential phase. No differences were seen in percent suppression or half-lives (t1/2) of LH or FAS, between the 50- and 150-microg/kg antagonist doses, in any of the subject populations; and percent suppression of LH was similar across all groups. The t1/2 of LH was prolonged in PMW (139 +/- 35 min, mean +/- est. SD), in comparison with both the MCS (78 +/- 20 min; P < 0.0005) and other cycle stages (57 +/- 28 min; P < 0.0001). However, the disappearance of FAS was not different in PMW, compared with MCS or other cycle stages (t1/2 = 51 +/- 26, 41 +/- 12, and 41 +/- 19 min, respectively). Our conclusions were: 1) Disappearance of endogenous LH after GnRH receptor blockade is significantly prolonged in PMW, compared with the MCS or other cycle stages; 2) The disappearance of FAS is not altered in PMW, suggesting that differences in the disappearance of LH relate to LH microheterogeneity rather than systemic factors.

Adaptation of solid phase extraction to an automated column switching method for online sample cleanup as the basis of a facile and sensitive high-performance liquid chromatographic assay for paclitaxel in human plasma.

An improved method for assaying paclitaxel in human plasma by high-performance liquid chromatography (HPLC) with UV detection at 227 nm has been developed by adapting previously reported sample preparation methods and chromatographic conditions to facilitate semi-automated sample cleanup using a column switching technique. Manual sample manipulations were limited to isolating the drug and internal standard from plasma (1.0 ml) by liquid-liquid extraction using tert-butyl methyl ether. The sample extract was initially loaded onto a short cartridge column containing a cyanopropyl stationary phase. During the predetermined time interval that the drug and internal standard eluted from the cartridge, 1.50-2.20 min, a fully automated 6-position switching valve was used to direct the effluent onto an octylsilica analytical column. The same mobile phase, composed of acetonitrile-methanol-ammonium acetate buffer (pH 5.0; 20 mM) (76:19:105, v/v/v) and delivered at flow rate of 1.0 ml/min, was used for both separations. The overall retention times of paclitaxel and the internal standard were 10.9 and 18.1 min, respectively. The analytical method was thoroughly validated for quantitating paclitaxel in plasma at concentrations ranging from 6 to 586 nM (5-500 ng/ml). The lowest concentration of paclitaxel measured with acceptable day-to-day accuracy (100.2%) and precision (RSD 11.7%, n = 21, 5 months) was 6 nM (5 ng/ml). The sensitivity and selectivity of the assay proved to be more than adequate for monitoring steady-state plasma concentrations of the drug when administered to cancer patients as a 96 h continuous intravenous infusion in combination with other anticancer agents, such as doxorubicin and topotecan. Moreover, the heart-cutting procedure prevented the problematic introduction of interfering nonpolar plasma components onto the analytical column, thereby enhancing sample throughput while decreasing the technical demands of the assay. The method was found to be extremely reproducible and robust during extended use for the routine analysis of plasma specimens acquired from several clinical trials.