Napabucasin Drug-Drug Interaction Potential, Safety, Tolerability, and Pharmacokinetics Following Oral Dosing in Healthy Adult Volunteers.

Napabucasin is an orally administered reactive oxygen species generator that is bioactivated by the intracellular antioxidant nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1. Napabucasin induces cell death in cancer cells, including cancer stem cells. This phase 1 study (NCT03411122) evaluated napabucasin drug-drug interaction potential for 7 cytochrome P450 (CYP) enzymes and the breast cancer resistance protein transporter/organic anion transporter 3. Healthy volunteers who tolerated napabucasin during period 1 received probe drugs during period 2, and in period 3 received napabucasin (240 mg twice daily; days 1-11) plus a phenotyping cocktail containing omeprazole (CYP2C19), caffeine (CYP1A2), flurbiprofen (CYP2C9), bupropion (CYP2B6), dextromethorphan (CYP2D6), midazolam (CYP3A) (all oral; day 6), intravenous midazolam (day 7), repaglinide (CYP2C8; day 8), and rosuvastatin (breast cancer resistance protein/organic anion transporter 3; day 9). Drug-drug interaction potential was evaluated in 17 of 30 enrolled volunteers. Napabucasin coadministration increased the area under the plasma concentration-time curve from time 0 extrapolated to infinity (geometric mean ratio [90% confidence interval]) of caffeine (124% [109.0%-141.4%]), intravenous midazolam (118% [94.4%-147.3%]), repaglinide (127% [104.7%-153.3%]), and rosuvastatin (213% [42.5%-1068.3%]) and decreased the area under the plasma concentration-time curve from time 0 extrapolated to infinity of dextromethorphan (71% [47.1%-108.3%]), bupropion (79% [64.6%-97.0%]), and hydroxybupropion (45% [15.7%-129.6%]). No serious adverse events/deaths were reported. Generally, napabucasin is not expected to induce/inhibit drug clearance to a clinically meaningful degree.

Mass balance and pharmacokinetics of an oral dose of 14 C-napabucasin in healthy adult male subjects.

This phase 1, open-label study assessed14 C-napabucasin absorption, metabolism, and excretion, napabucasin pharmacokinetics, and napabucasin metabolites (primary objectives); safety/tolerability were also evaluated. Eight healthy males (18-45 years) received a single oral 240-mg napabucasin dose containing ~100 µCi14 C-napabucasin. Napabucasin was absorbed and metabolized to dihydro-napabucasin (M1; an active metabolite [12.57-fold less activity than napabucasin]), the sole major circulating metabolite (median time to peak concentration: 2.75 and 2.25 h, respectively). M1 plasma concentration versus time profiles generally mirrored napabucasin; similar arithmetic mean half-lives (7.14 and 7.92 h, respectively) suggest M1 formation was rate limiting. Napabucasin systemic exposure (per Cmax and AUC) was higher than M1. The total radioactivity (TRA) whole blood:plasma ratio (AUClast : 0.376; Cmax : 0.525) indicated circulating drug-related compounds were essentially confined to plasma. Mean TRA recovery was 81.1% (feces, 57.2%; urine, 23.8%; expired air, negligible). Unlabeled napabucasin and M1 recovered in urine accounted for 13.9% and 11.0% of the dose (sum similar to urine TRA recovered); apparent renal clearance was 8.24 and 7.98 L/h. No uniquely human or disproportionate metabolite was quantified. Secondary glucuronide and sulfate conjugates were common urinary metabolites, suggesting napabucasin was mainly cleared by reductive metabolism. All subjects experienced mild treatment-emergent adverse events (TEAEs), the majority related to napabucasin. The most commonly reported TEAEs were gastrointestinal disorders. There were no clinically significant laboratory, vital sign, electrocardiogram, or physical examination changes. Napabucasin was absorbed, metabolized to M1 as the sole major circulating metabolite, and primarily excreted via feces. A single oral 240-mg dose was generally well tolerated.

A phase I and pharmacokinetic study of ganetespib (STA-9090) in advanced hepatocellular carcinoma.

BACKGROUND: Ganetespib (STA-9090) is an Hsp90 inhibitor that downregulates VEGFR, c-MET, HER2, IGF-IR, EGFR, and other Hsp90 client proteins involved in hepatocarcinogenesis, thereby making it an attractive therapy for HCC. This Phase I study was performed to establish the safety, tolerability, recommended Phase 2 dose (RP2D), and preliminary clinical activity of ganetespib in previously treated patients with advanced HCC. METHODS: Patients with advanced HCC, Child-Pugh A cirrhosis, progression on or intolerance to sorafenib, and ECOG PS ≤ 1 were enrolled in a standard 3x3 dose escalation study at doses of 100 mg/m(2), 150 mg/m(2), and 200 mg/m(2) IV given on days 1, 8, and 15 of each 28-day cycle. Objective response by RECIST version 1.1 criteria was evaluated by CT/MRI every 8 weeks. RESULTS: Fourteen patients were enrolled in this trial and received at least one dose of the study drug. Of the 14 patients: median age, 57 years old; male 71 %; Asian 36 %; HCC etiology (HBV 36 %, HCV 43 %, Hemachromatosis 7 %, unknown 21 %); Child Pugh Class (A 93 %, B 7 %); median number of prior treatments 2; median baseline AFP 70.1 ng/mL. The RP2D was determined to be 200 mg/m(2). The most commonly seen AEs were diarrhea (93 %), fatigue (71 %), AST elevation (64 %), and hyperglycemia (64 %). The most common Gr 3/4 AEs were hyperglycemia (21 %) and lipasemia (21 %). One (7 %) patient had a fatal AE, septic shock, within 30 days of receiving the study drug. One dose-limiting toxicity, grade 3 lipasemia, was observed at the 100 mg/m(2) dose. Pharmacokinetics studies showed a t1/2, CL, Tmax, and Vss of 6.45 h, 48.28 L/h (25.56 L/h/m(2)), 0.76 h, and 191 L (100.4 L/m(2)), respectively. No objective responses were seen; one patient (7 %) had stable disease at 16 weeks. Median time to progression was 1.8 months, and median overall survival was 7.2 months. CONCLUSION: Ganetespib had a manageable safety profile in patients with advanced HCC who had progressed on at least one line of systemic therapy. The pharmacokinetic profile showed that ganetespib exposure in patients with mild hepatic dysfunction is similar to that seen in patients with normal liver function. Ganetespib showed limited clinical benefit in patients with advanced HCC in this phase I trial.

A first in human, safety, pharmacokinetics, and clinical activity phase I study of once weekly administration of the Hsp90 inhibitor ganetespib (STA-9090) in patients with solid malignancies.

BACKGROUND: This phase I study investigated the maximum tolerated dose (MTD), safety, pharmacokinetics and antitumor activity of ganetespib in patients with solid malignancies. METHODS: Patients were enrolled in cohorts of escalating ganetespib doses, given as 1 hour IV infusion, once weekly for 3 weeks, followed by a 1-week rest until disease progression or unacceptable toxicity. Endpoints included safety, pharmacokinetic and pharmacodynamic parameters and preliminary clinical activity. RESULTS: Fifty-three patients were treated at doses escalating from 7 to 259 mg/m(2). The most common adverse events were Grade 1 and 2 diarrhea, fatigue, nausea or vomiting. Dose-limiting toxicities (DLT) observed were: one Grade 3 amylase elevation (150 mg/m(2)), one Grade 3 diarrhea and one Grade 3 and one Grade 4 asthenia (259 mg/m(2)). The MTD was 216 mg/m(2) and the recommended phase 2 dose was established at 200 mg/m(2) given IV at Days 1, 8, and 15 every 4 weeks. There was a linear relationship between dose and exposure. Plasma HSP70 protein levels remained elevated for over a week post treatment. Disease control rate (objective response and stable disease at ≥ 16 weeks) was 24.4%. CONCLUSIONS: Ganetespib is well tolerated as a weekly infusion for 3 of every 4 weeks cycle. The recommended phase II dose is 200 mg/m(2), and is associated with an acceptable tolerability profile. TRIAL REGISTRATION: NCT00687934.

Phase 1 clinical results with tandutinib (MLN518), a novel FLT3 antagonist, in patients with acute myelogenous leukemia or high-risk myelodysplastic syndrome: safety, pharmacokinetics, and pharmacodynamics.

Tandutinib (MLN518/CT53518) is a novel quinazoline-based inhibitor of the type III receptor tyrosine kinases: FMS-like tyrosine kinase 3 (FLT3), platelet-derived growth factor receptor (PDGFR), and KIT. Because of the correlation between FLT3 internal tandem duplication (ITD) mutations and poor prognosis in acute myelogenous leukemia (AML), we conducted a phase 1 trial of tandutinib in 40 patients with either AML or high-risk myelodysplastic syndrome (MDS). Tandutinib was given orally in doses ranging from 50 mg to 700 mg twice daily The principal dose-limiting toxicity (DLT) of tandutinib was reversible generalized muscular weakness, fatigue, or both, occurring at doses of 525 mg and 700 mg twice daily. Tandutinib's pharmacokinetics were characterized by slow elimination, with achievement of steady-state plasma concentrations requiring greater than 1 week of dosing. Western blotting showed that tandutinib inhibited phosphorylation of FLT3 in circulating leukemic blasts. Eight patients had FLT3-ITD mutations; 5 of these were evaluable for assessment of tandutinib's antileukemic effect. Two of the 5 patients, treated at 525 mg and 700 mg twice daily, showed evidence of antileukemic activity, with decreases in both peripheral and bone marrow blasts. Tandutinib at the MTD (525 mg twice daily) should be evaluated more extensively in patients with AML with FLT3-ITD mutations to better define its antileukemic activity.

Comparison of the pharmacokinetics of lansoprazole 15- and 30-mg sachets for suspension versus intact capsules.

OBJECTIVE: The pharmacokinetic profiles of single doses of lansoprazole 15- and 30-mg sachets for suspension were compared with those of corresponding doses of lansoprazole oral capsules. METHODS: Healthy adult male and female subjects were randomized (1:1 ratio) into 2 Phase 1, open-label, single-dose, 2-sequence, 2-period complete crossover studies. In the first study, each subject received 1 lansoprazole 15-mg sachet mixed with water and 1 lansoprazole 15-mg oral capsule; in the second study, each subject received 1 lansoprazole 30-mg sachet mixed with water and 1 lansoprazole 30-mg oral capsule. Administration of the 2 formulations was separated by a washout period of > or =7 days. Blood samples were collected before and after each administration to assess the pharmacokinetic parameters of lansoprazole and bioequivalence between suspension and capsule. RESULTS: Thirty-six subjects (19 males, 17 females) with a mean (SD) age of 32.0 (9.6) years and mean (SD) body weight of 68.6 (10.5) kg received lansoprazole 15 mg. Thirty-six subjects (22 males, 14 females) with a mean (SD) age of 38.0 (8.3) years and mean (SD) body weight of 75.1 (9.7) kg received lansoprazole 30 mg. The pharmacokinetic parameters of the 15- and 30-mg lansoprazole sachets for suspension were similar to those of the corresponding doses of the oral capsules. The mean (SD) values for C(max) and AUC from time 0 to infinity (AUC(0-infinity) for the lansoprazole 15-mg sachet (591.9 [242.3] ng/mL and 1614 [2065] ng.h/mL, respectively) did not differ significantly from those for the lansoprazole 15-mg capsules (578.6 [275.2] ng/mL and 1620 [2290] ng.h/mL, respectively). These parameters also did not differ significantly between the lansoprazole 30-mg sachet and 30-mg capsule: mean (SD) C(max), 1103 (428.3) and 1077 (465.6) ng/mL, respectively; mean (SD) AUC(0-infinity), 2655 (1338) and 2669 (1311) ng.h/mL, respectively. The 90% Cls for C(max) and AUC(0-infinity) ratios were contained within the 0.80 to 1.25 equivalence range, supporting bioequivalence. CONCLUSIONS: These findings suggest that the 15- and 30-mg lansoprazole sachets for suspension are bioequivalent to the corresponding doses of oral capsules. The sachet for suspension may provide an alternative route of administration to patients who have difficulty swallowing solid oral formulations.

The Effects of Lansoprazole on the Disposition of Antipyrine and Indocyanine Green in Normal Human Subjects.

This study was designed to evaluate the potential effects of acute and chronic daily oral doses of lansoprazole (60 mg) on the disposition of antipyrine, an almost completely metabolized low hepatic extraction compound, and indocyanine green, a hepatically secreted compound with high extraction ratio. The study utilized a randomized, placebo-controlled, double-blind, two-period crossover design. Sixteen of 18 subjects completed all phases of the study. Both antipyrine (10 mg kg(minus sign1)) and indocyanine green (0.5 mg kg(minus sign1)) were administered as single intravenous bolus doses on Days 1 and 7 of lansoprazole or placebo dosing. Acute exposure to lansoprazole had no statistically significant effects on the plasma pharmacokinetics of indocyanine green or antipyrine. After the seventh dose, there was a small but statistically significant reductions in indocyanine green total body clearance (CL), and elimination rate constant of 10.6% and 8%, respectively. Additionally, a small statistically significant reduction (8.6%) in antipyrine volume of distribution was detected. No other plasma antipyrine pharmacokinetic parameters were changed with concomitant lansoprazole administration. About a 12% increase in the recovery of one of the major antipyrine urine metabolites (NORA) was detected. Overall, this study demonstrates little or no effect of lansoprazole on the pharmacokinetics of antipyrine and indocyanine green.