Veliparib in combination with whole brain radiation therapy in patients with brain metastases: results of a phase 1 study.

Veliparib, a potent, oral PARP inhibitor, potentiates the antitumor activity of radiation therapy and crosses the blood-brain barrier. This was a phase 1 dose-escalation study evaluating the safety, and secondarily the antitumor activity of veliparib in combination with whole brain radiation therapy (WBRT) in patients with brain metastases, in order to power future trials. Patients with brain metastases from primary solid tumors were treated with WBRT (30.0 or 37.5 Gy in 10 or 15 fractions) and veliparib (escalating doses of 10-300 mg, orally BID). Safety and tumor response were assessed. Observed survival was compared to predicted survival based on a published nomogram. Eighty-one patients (median age 58 years) were treated. The most common primary tumor types were non-small cell lung (NSCLC; n = 34) and breast cancer (n = 25). The most common AEs deemed possibly related to veliparib (AEs, ≥15 %) were fatigue (30 %), nausea (22 %), and decreased appetite (15 %). Fatigue (5 %), hypokalemia and hyponatremia (3 % each) were the only Grade 3/4 AEs deemed possibly related to veliparib observed in ≥2 patients. Although this was an uncontrolled study, preliminary efficacy results were better than predicted: the median survival time (MST, 95 % CI) for the NSCLC subgroup was 10.0 mo (3.9-13.5) and for the breast cancer subgroup was 7.7 mo (2.8-15.0) compared to a nomogram-model-predicted MST of 3.5 mo (3.3-3.8) and 4.9 mo (4.2-5.5). The addition of veliparib to WBRT did not identify new toxicities when compared to WBRT alone. Based on encouraging safety and preliminary efficacy results, a randomized, controlled phase 2b study is ongoing.

Field assessment of active ingredient quantity in pharmaceutical tablets with limited calibration of near infrared spectra: An application to ciprofloxacin tablets.

Portable near-infrared (NIR) spectrophotometers have emerged as valuable tools for identifying substandard and falsified pharmaceuticals (SFPs). Integration of these devices with chemometric and machine learning models enhances their ability to provide quantitative chemical insights. However, different NIR spectrophotometer models vary in resolution, sensitivity, and responses to environmental factors such as temperature and humidity, necessitating instrument-specific libraries that hinder the wider adoption of NIR technology. This study addresses these challenges and seeks to establish a robust approach to promote the use of NIR technology in post-market pharmaceutical analysis. We developed support vector machine and partial least squares regression models based on binary mixtures of lab-made ciprofloxacin and microcrystalline cellulose, then applied the models to ciprofloxacin dosage forms that were assayed with high performance liquid chromatography (HPLC). A receiver operating characteristic (ROC) analysis was performed to set spectrophotometer independent NIR metrics to evaluate ciprofloxacin dosage forms as "meets standard," "needs HPLC assay," or "fails standard." Over 200 ciprofloxacin tablets representing 50 different brands were evaluated using spectra acquired from three types of NIR spectrophotometer with 85% of the prediction agreeing with HPLC testing. This study shows that non-brand-specific predictive models can be applied across multiple spectrophotometers for rapid screening of the conformity of pharmaceutical active ingredients to regulatory standard.

Preclinical discovery of candidate genes to guide pharmacogenetics during phase I development: the example of the novel anticancer agent ABT-751.

OBJECTIVE: ABT-751, a novel orally available antitubulin agent, is mainly eliminated as inactive glucuronide (ABT-751G) and sulfate (ABT-751S) conjugates. We performed a pharmacogenetic investigation of ABT-751 pharmacokinetics using in-vitro data to guide the selection of genes for genotyping in a phase I trial of ABT-751. METHODS: UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT) enzymes were screened for ABT-751 metabolite formation in vitro. Forty-seven cancer patients treated with ABT-751 were genotyped for 21 variants in these genes. RESULTS: UGT1A1, UGT1A4, UGT1A8, UGT2B7, and SULT1A1 were found to be involved in the formation of inactive ABT-751 glucuronide (ABT-751G) and sulfate (ABT-751S). SULT1A1 copy number (>2) was associated with an average 34% increase in ABT-751 clearance (P=0.044), an 18% reduction in ABT-751 AUC (P=0.045), and a 50% increase in sulfation metabolic ratios (P=0.025). UGT1A8 rs6431558 was associated with a 28% increase in glucuronidation metabolic ratios (P=0.022), and UGT1A4*2 was associated with a 65% decrease in ABT-751 C trough (P=0.009). CONCLUSION: These results might represent the first example of a clinical pharmacokinetic effect of the SULT1A1 copy number variant on the clearance of a SULT1A1 substrate. A-priori selection of candidate genes guided by in-vitro metabolic screening enhanced our ability to identify genetic determinants of interpatient pharmacokinetic variability.

A phase I study of ABT-751, an orally bioavailable tubulin inhibitor, administered daily for 21 days every 28 days in pediatric patients with solid tumors.

PURPOSE: To determine the toxicity profile, dose-limiting toxicities (DLT), and maximum tolerated dose (MTD) of ABT-751 administered orally once daily for 21 days, repeated every 28 days in a pediatric population. EXPERIMENTAL DESIGN: Patients who were < or = 18 years with relapsed or refractory solid tumors and who were able to swallow capsules were eligible. The starting dose was 75 mg/m(2)/d (n = 3) and was escalated to 100 (n = 6), 130 (n = 5), and 165 (n = 3) mg/m(2)/d in cohorts of three to six patients. The MTD was determined from DLTs occurring during the first treatment cycle. RESULTS: Nineteen children (median age, 13 years; range, 5-18 years) were enrolled, and 17 were evaluable for toxicity. Diagnoses included neuroblastoma (n = 9), sarcomas (n = 9), and other solid tumors (n = 1). DLTs included fatigue, sensory neuropathy, transient hypertension, neutropenia, thrombocytopenia, nausea, vomiting, dehydration, abdominal pain, and constipation. The MTD of ABT-751 administered daily for 21 days every 28 days was 100 mg/m(2)/d. Non-DLT at the MTD included bone marrow suppression, gastrointestinal toxicities (anorexia, abdominal pain, nausea, vomiting, and constipation), and sensory and motor neuropathies. The median number of cycles administered was one (range, one to five). Tolerance of repeated treatment cycles was poor. CONCLUSION: Fatigue, hematologic, and gastrointestinal toxicities limited the tolerability of ABT-751 administered to children on the once daily for 21 days every 28 days schedule. The MTD in children with solid tumors (100 mg/m(2)/d daily for 21 days) was similar to the recommended dose in adults with solid tumors (200 mg fixed dose) receiving the same dosing schedule.

The pharmacokinetics and safety of ABT-751, a novel, orally bioavailable sulfonamide antimitotic agent: results of a phase 1 study.

PURPOSE: Microtubules play a critical role in many cellular functions, including cell division and mitosis. ABT-751 is a novel sulfonamide antimitotic that binds to the colchicine site on beta-tubulin that leads to a block in the cell cycle at the G2M phase, resulting in cellular apoptosis. ABT-751 was investigated in this phase 1 trial designed to assess its maximum tolerated dose (MTD), dose-limiting toxicity (DLT), tolerability, and pharmacokinetics. EXPERIMENTAL DESIGN: ABT-751 was administered on a daily (q.d.) or twice daily (b.i.d.) oral schedule for 7 days every 3 weeks to 39 patients with refractory solid tumors. Toxicity was monitored weekly. Plasma and urine ABT-751 and metabolite pharmacokinetics were determined. RESULTS: The MTD for the q.d. schedule was 250 mg/d. DLTs during cycle 1 were abdominal pain, constipation, and fatigue. The MTD on the b.i.d. schedule was 150 mg. Cycle 1 of therapy with the 175 mg b.i.d. schedule was tolerated without DLT. However, six of seven patients reported grade 3 toxicity (ileus, constipation, abdominal pain, or fatigue), which occurred in cycle 2 or 3. ABT-751 was absorbed after oral administration with an overall mean T(max) of about 2 hours. The pharmacokinetics of ABT-751 were dose-proportional and time-independent. There was minimal accumulation of ABT-751 after multiple q.d. and b.i.d. doses. Efficacious concentrations, as determined from preclinical models (0.5-1.5 microg/mL), were achieved in all subjects. ABT-751 metabolism occurred primarily by glucuronidation and sulfation. No complete or partial tumor responses were noted, but one patient had a minor response, and four patients had stable disease lasting at least 6 months. CONCLUSIONS: The MTD and recommended phase 2 doses for ABT-751 were 250 mg q.d. and 150 mg b.i.d. on a 7-day schedule given every 3 weeks, due to subsequent cycle toxicities at 175 mg b.i.d. dosing. Toxicities were abdominal pain, constipation, and neuropathy.

A phase 1 study of ABT-751, an orally bioavailable tubulin inhibitor, administered daily for 7 days every 21 days in pediatric patients with solid tumors.

PURPOSE: To determine the toxicity profile, dose-limiting toxicities, and maximum tolerated dose of ABT-751 administered orally once daily for 7 days, repeated every 21 days. EXPERIMENTAL DESIGN: Patients who were 40% higher than the maximum tolerated dose in adults receiving the same dosing schedule.

Effect of veliparib (ABT-888) on cardiac repolarization in patients with advanced solid tumors: a randomized, placebo-controlled crossover study.

PURPOSE: Veliparib (ABT-888) is an orally bioavailable potent inhibitor of poly(ADP-ribose) polymerase (PARP)-1 and PARP-2. This phase 1 study evaluated the effect of veliparib on corrected QT interval using Fridericia's formula (QTcF). METHODS: Eligible patients with advanced solid tumors received single-dose oral veliparib (200 mg or 400 mg) or placebo in a 6-sequence, 3-period crossover design. The primary endpoint was the difference in the mean baseline-adjusted QTcF between 400 mg veliparib and placebo (∆∆QTcF) at six post-dose time points. Absence of clinically relevant QTcF effect was shown if the 95 % upper confidence bound (UCB) for the mean ∆∆QTcF was <10 ms for all time points. An exposure-response analysis was also performed. RESULTS: Forty-seven patients were enrolled. Maximum mean ∆∆QTcF of veliparib 400 mg was 6.4 ms, with a 95 % UCB of 8.9 ms; for veliparib 200 mg, the maximum mean ∆∆QTcF was 3.6 ms, with a 95 % UCB of 6.1 ms. No patient had a QTcF value >480 ms or change from baseline in QTcF interval >30 ms. Treatment-emergent adverse events (TEAEs) were experienced by 36.2, 48.9, and 47.8 % of patients while receiving veliparib 200 mg, veliparib 400 mg, and placebo, respectively. Most common TEAEs were nausea (12.8 %) and myalgia (8.5 %) after veliparib 200 mg, nausea (8.5 %) and vomiting (8.5 %) after veliparib 400 mg, and nausea (6.5 %) after placebo. CONCLUSIONS: Single-dose veliparib (200 mg or 400 mg) did not result in clinically significant QTc prolongation and was well tolerated in patients with advanced solid tumors.

Pharmacokinetics of orally administered ABT-751 in children with neuroblastoma and other solid tumors.

PURPOSE: To describe the pharmacokinetics of orally administered ABT-751 and its conjugated metabolites in children with neuroblastoma and other solid tumors and to relate pharmacokinetic parameters to toxicity and therapeutic outcomes. METHODS: Patients (median age, 11 years) with neuroblastoma (n = 37) or other solid tumors (n = 25) had pharmacokinetic sampling after the first dose of ABT-751 (75-250 mg/m(2)/day) on a 7-day or 21-day schedule. ABT-751 and its glucuronide and sulfate metabolites were quantified with an HPLC/MS/MS assay. Pharmacokinetic parameters were derived with non-compartmental methods. The relative bioavailability of more water soluble capsule and suspension formulations was assessed. RESULTS: ABT-751 peaked in plasma at 2 h and declined monoexponentially with a t (1/2) of 5.1 h. The apparent clearance was 33 ml/min/m(2) and was age-independent. The AUC(0-infinity) increased in proportion to the dose, and at 200 mg/m(2) the median AUC(0-infinity) was 91 mcg h/ml and the C (ave) was 3.9 mcg/ml. Inter-and intra-patient variability was low. The metabolites were detected in plasma 30 min post-dose and peaked 3-5 h after the dose. The glucuronide:sulfate molar AUC(0-infinity) ratio was 0.57. Less than 1% of the dose was excreted in urine as parent drug; 13% of the dose was excreted as sulfate metabolite and 10% as glucuronide metabolite. The relative bioavailability of the water soluble capsule and suspension formulations was 105 and 93%, respectively. AUC(0-infinity) was higher in patients experiencing dose-limiting toxicity. CONCLUSIONS: Oral ABT-751 pharmacokinetics was dose-proportional and age-independent with minimal intra- and inter-patient variability in children.