Pharmacokinetic and pharmacodynamic properties of an oral formulation of the histone deacetylase inhibitor Belinostat (PXD101).

PURPOSE: The primary objective of this sub-study, undertaken as an extension to the previously reported phase-I study, was to explore the feasibility, tolerability and pharmacokinetics (PK) of belinostat when administered by the oral route. Preliminary pharmacodynamic (PD) studies were also performed to enable comparison of the biological effects of the oral and intravenous formulations. PATIENTS AND METHODS: Oral belinostat was administered in a range of doses and schedules (once, twice or thrice daily), on either day 1 or days 1-5, of the second or a subsequent treatment cycle in 15 patients who were included in the phase-I trial of intravenous belinostat. Serial blood samples were collected for PK and PD (histone acetylation) analyses, and the results compared with corresponding analyses following intravenous administration. RESULTS: A total mean daily AUC of 2,767 ± 1,453 ng h/ml (8.7 ± 4.6 µM h) resulted from a dose of 1,000 mg/m(2) once daily (qd). There was no clear evidence of drug accumulation on twice daily dosing (bid); however, a trend towards accumulation was apparent when belinostat was given three times daily (tid). Mean half-life (T½) of a single dose of 1,000 mg/m(2) was 1.5 h (± 0.3 h) and peak levels were reached in an average of 1.9 h (± 0.3 h). The half-life was found to be independent of dose, but a trend towards increasing half-life following multiple dosing was observed. Histone H4 hyperacetylation in PBMCs estimated after oral dosing was comparable to that achieved after intravenous administration. CONCLUSIONS: High doses of oral belinostat, up to 1,000 mg/m(2) bid for 5 consecutive days, have been tolerated in this small study. An oral formulation could lead to enhanced drug exposure and, more importantly, prolonged effects on the intended drug target. Future trials are required to establish the optimal dose and schedule of oral administration of belinostat.

Correcting magnetic probe perturbations on current density measurements of current carrying plasmas.

A method to infer the current density distribution in the current sheath of a plasma focus discharge from a magnetic probe is formulated and then applied to experimental data obtained in a 1.1 kJ device. Distortions on the magnetic probe signal caused by current redistribution and by a time-dependent total discharge current are considered simultaneously, leading to an integral equation for the current density. Two distinct, easy to implement, numerical procedures are given to solve such equation. Experimental results show the coexistence of at least two maxima in the current density structure of a nitrogen sheath.

A phase I study of the safety and pharmacokinetics of the histone deacetylase inhibitor belinostat administered in combination with carboplatin and/or paclitaxel in patients with solid tumours.

BACKGROUND: This phase I study assessed the maximum tolerated dose, dose-limiting toxicity (DLT) and pharmacokinetics of belinostat with carboplatin and paclitaxel and the anti-tumour activity of the combination in solid tumours. METHODS: Cohorts of three to six patients were treated with escalating doses of belinostat administered intravenously once daily, days 1-5 q21 days; on day 3, carboplatin (area under the curve (AUC) 5) and/or paclitaxel (175 mg m(-2)) were administered 2-3 h after the end of the belinostat infusion. RESULTS: In all 23 patients received 600-1000 mg m(-2) per day of belinostat with carboplatin and/or paclitaxel. No DLT was observed. The maximal administered dose of belinostat was 1000 mg m(-2) per day for days 1-5, with paclitaxel (175 mg m(-2)) and carboplatin AUC 5 administered on day 3. Grade III/IV adverse events were (n; %): leucopenia (5; 22%), neutropenia (7; 30%), thrombocytopenia (3; 13%) anaemia (1; 4%), peripheral sensory neuropathy (2; 9%), fatigue (1; 4%), vomiting (1; 4%) and myalgia (1; 4%). The pharmacokinetics of belinostat, paclitaxel and carboplatin were unaltered by the concurrent administration. There were two partial responses (one rectal cancer and one pancreatic cancer). A third patient (mixed mullerian tumour of ovarian origin) showed a complete CA-125 response. In addition, six patients showed a stable disease lasting > or =6 months. CONCLUSION: The combination was well tolerated, with no evidence of pharmacokinetic interaction. Further evaluation of anti-tumour activity is warranted.

A phase I clinical trial of the histone deacetylase inhibitor belinostat in patients with advanced hematological neoplasia.

PURPOSE: To determine the safety, dose-limiting toxicity and maximum tolerated dose (MTD) of the novel hydroxamate histone deacetylase inhibitor belinostat (PXD101) in patients with advanced hematological neoplasms. PATIENTS AND METHODS: Sequential dose-escalating cohorts of three to six patients with hematological malignancies received belinostat administered as a 30-min i.v. infusion on days 1-5 of a 21-d cycle. Experience from a parallel dose-finding study in patients with solid tumors influenced the selection of the final dose. RESULTS: Sixteen patients received belinostat at one of three dose levels: 600 mg/m(2)/d (three patients), 900 mg/m(2)/d (three patients) and 1000 mg/m(2)/d (10 patients), the dose determined to be the MTD in a phase I solid tumor study [Steele et al. (2008) Clin Cancer Res, 14, 804-10]. The most common treatment-related adverse events (all grades) were nausea (50%), vomiting (31%), fatigue (31%) and flushing (31%). No grade 3 or 4 hematological toxicity compared with baseline occurred except one case of grade 3 lymphopenia. There were two related grade 4 adverse events of renal failure observed. Both events occurred in patients with multiple myeloma and had similar characteristics, i.e. an acute episode of decrease in renal function (pre-existing nephropathy in one patient), with a metabolic profile and decrease in tumor burden consistent with tumor lysis syndrome. No other related grade 4 events were noted. The only related grade 3 events noticed in more than one patient were fatigue and neurological symptoms (one patient had status epilepticus in association with uremia and one patient had paresthesia), all other related grade 3 events occurred in single patients. No cardiac events were noted. No complete or partial remissions were noted in these heavily pre-treated (median of four prior regimens) patients. However, five patients, including two patients with diffuse large-cell lymphoma [including one patient with transformed chronic myelocytic leukaemia (CLL)], two patients with CLL and one patient with multiple myeloma, achieved disease stabilization in of two to nine treatment cycles. CONCLUSIONS: Intravenous belinostat at 600, 900 and 1000 mg/m(2)/d is well tolerated by patients with hematological malignancies. The study was carried out in parallel to a similar dose-finding study in patients with solid tumors, in which the MTD was determined to be 1000 mg/m(2)/d days 1-5 in a 21-d cycle. This dose can also be recommended for phase II studies in patients with hematological neoplasms.

Treatment of anthracycline extravasation with Savene (dexrazoxane): results from two prospective clinical multicentre studies.

BACKGROUND: The purpose of this study was to assess the efficacy and tolerability of i.v. dexrazoxane [Savene (EU), Totect (US)] as acute antidote in biopsy-verified anthracycline extravasation. PATIENTS AND METHODS: Two prospective, open-label, single-arm, multicentre studies in patients with anthracycline extravasation were carried out. Patients with fluorescence-positive tissue biopsies were treated with a 3-day schedule of i.v. dexrazoxane (1000, 1000, and 500 mg/m(2)) starting no later than 6 h after the incident. Patients were assessed for efficacy (the possible need for surgical resection) and toxicity during the treatment period and regularly for the next 3 months. RESULTS: In 53 of 54 (98.2%) patients assessable for efficacy, the treatment prevented surgery-requiring necrosis. One patient (1.8%) required surgical debridement. Thirty-eight patients (71%) were able to continue their scheduled chemotherapy without postponement. Twenty-two patients (41%) experienced hospitalisation due to the extravasation. Mild pain (10 patients; 19%) and mild sensory disturbances (nine patients; 17%) were the most frequent sequelae. Haematologic toxicity was common as expected from the fact that the extravasation occurred during a chemotherapy course. Other toxic effects were transient elevation of alanine aminotransferases, nausea, and local pain at the dexrazoxane injection site. CONCLUSION: Dexrazoxane proved to be an effective and well-tolerated acute treatment with only one out of 54 assessable patients requiring surgical resection (1.8%).