Evaluation of the Mass Balance and Metabolic Profile of Futibatinib in Healthy Participants.

Futibatinib, a selective, irreversible fibroblast growth factor receptor 1-4 inhibitor, was recently approved for FGFR2 rearrangement-positive cholangiocarcinoma. This Phase I study evaluated the mass balance and metabolic profile of 14 C-futibatinib single oral 20-mg dose in healthy participants (n = 6). Futibatinib was rapidly absorbed; median time to peak drug concentration was 1.0 hours. The mean elimination half-life in plasma was 2.3 hours for futibatinib, and 11.9 hours for total radioactivity. Mean recovery of total radioactivity was 70% of the dose, with 64% recovered in feces and 6% in urine. The major excretion route was fecal; negligible levels were excreted as parent futibatinib. Futibatinib was the most abundant plasma component, comprising 59% of circulating radioactivity (CRA). The most abundant metabolites were cysteinylglycine-conjugated futibatinib in plasma (13% CRA) and reduction of desmethyl futibatinib in feces (17% of dose). In human hepatocytes, 14 C-futibatinib metabolites included glucuronide and sulfate of desmethyl futibatinib, whose formation was inhibited by 1-aminobenzotriazole (a pan-cytochrome P450 inhibitor), and glutathione- and cysteine-conjugated futibatinib. These data indicate the primary metabolic pathways of futibatinib are O-desmethylation and glutathione conjugation, with cytochrome P450 enzyme-mediated desmethylation as the main oxidation pathway. 14 C-futibatinib was well tolerated in this Phase 1 study.

Evaluation of the Cytochrome P450 3A and P-glycoprotein Drug-Drug Interaction Potential of Futibatinib.

Futibatinib, a selective, irreversible fibroblast growth factor receptor 1-4 inhibitor, is being investigated for tumors harboring FGFR aberrations and was recently approved for the treatment of FGFR2 fusion/rearrangement-positive intrahepatic cholangiocarcinoma. In vitro studies identified cytochrome P450 (CYP) 3A as the major CYP isoform in futibatinib metabolism and indicated that futibatinib is likely a P-glycoprotein (P-gp) substrate and inhibitor. Futibatinib also showed time-dependent inhibition of CYP3A in vitro. Phase I studies investigated the drug-drug interactions of futibatinib with itraconazole (a dual P-gp and strong CYP3A inhibitor), rifampin (a dual P-gp and strong CYP3A inducer), or midazolam (a sensitive CYP3A substrate) in healthy adult participants. Compared with futibatinib alone, coadministration of futibatinib with itraconazole increased futibatinib mean peak plasma concentration and area under the plasma concentration-time curve by 51% and 41%, respectively, and coadministration of futibatinib with rifampin lowered futibatinib mean peak plasma concentration and area under the plasma concentration-time curve by 53% and 64%, respectively. Coadministration of midazolam with futibatinib had no effect on midazolam pharmacokinetics compared with midazolam administered alone. These findings suggest that concomitant use of dual P-gp and strong CYP3A inhibitors/inducers with futibatinib should be avoided, but futibatinib can be concomitantly administered with other drugs metabolized by CYP3A. Drug-drug interaction studies with P-gp-specific substrates and inhibitors are planned.

Effect of Futibatinib on Cardiac Repolarization: Results of a Randomized, Controlled, Double-Blind, QT/QTc, Phase 1 Study in Healthy Subjects.

Futibatinib, a fibroblast growth factor receptor (FGFR) 1-4 inhibitor, is being investigated for FGFR-aberrant tumors. A 4-period, crossover, phase 1 thorough QT/QTc study compared effects on Fridericia heart rate-corrected QT (QTcF) interval of single doses of futibatinib 20 and 80 mg (therapeutic and supratherapeutic doses, respectively), placebo, and moxifloxacin (positive control) in healthy subjects. The study objective was to assess the time-matched difference in change from baseline in QTcF (ddQTcF) between futibatinib and placebo. In addition, changes from baseline in QTcF and other electrocardiogram (ECG) parameters, pharmacokinetics, ECG morphology, and safety were assessed. Forty-eight subjects were randomized. ddQTcF upper limits of 2-sided 90%CIs remained <10 milliseconds (clinical threshold) for both futibatinib doses at all time points (range, 2.0-4.5 milliseconds). Assay sensitivity was demonstrated by lower limits of 2-sided 97.5%CIs of the dQTcF difference between moxifloxacin and placebo of >5 milliseconds. Futibatinib exposure increased in a dose-dependent manner, and no significant relationship was detected between plasma futibatinib concentration and ddQTcF. There were no significant effects on heart rate, other ECG parameters, or ECG morphology. No serious adverse events occurred. Futibatinib did not prolong QTcF or affect other cardiac measures at therapeutic or supratherapeutic doses.

Evaluation of Potential Food Effects and Drug Interactions With Lansoprazole in Healthy Adult Volunteers Receiving Futibatinib.

Futibatinib, an oral, irreversible fibroblast growth factor receptor (FGFR) 1-4 inhibitor, is being evaluated for FGFR-aberrant tumors. Two open-label phase 1 studies evaluated the effects of high-fat, high-calorie food and concomitant proton pump inhibitors (PPIs; lansoprazole) on single-dose futibatinib (20 mg) pharmacokinetics and safety in healthy adults. In the food effect study (N  =  17), subjects received futibatinib under fed and fasted conditions, separated by a 7-day washout. In the PPI study (N  =  20), subjects received futibatinib alone, underwent a 2-day washout, and then received lansoprazole 60 mg once daily for 5 days, with futibatinib also administered on day 5. Under fed versus fasted conditions, futibatinib bioavailability was 11.2% lower (area under the plasma concentration-time curve from time 0 to infinity geometric mean ratio 88.8%; 90% confidence interval, 79.8%-98.9%), and median time to maximum plasma concentration was significantly delayed (4.0 vs 1.5 hours; P < .0001). There were no significant differences in futibatinib exposure between futibatinib plus lansoprazole and futibatinib alone. No serious adverse events occurred in either study. These findings suggest that food and PPIs are unlikely to have clinically meaningful impacts on futibatinib bioavailability. Thus, futibatinib may be used with or without food and concomitantly with acid-reducing agents.

Effects of Strong CYP2C8 or CYP3A Inhibition and CYP3A Induction on the Pharmacokinetics of Brigatinib, an Oral Anaplastic Lymphoma Kinase Inhibitor, in Healthy Volunteers.

In vitro data support involvement of cytochrome P450 (CYP)2C8 and CYP3A4 in the metabolism of the anaplastic lymphoma kinase inhibitor brigatinib. A 3-arm, open-label, randomized, single-dose, fixed-sequence crossover study was conducted to characterize the effects of the strong inhibitors gemfibrozil (of CYP2C8) and itraconazole (of CYP3A) and the strong inducer rifampin (of CYP3A) on the single-dose pharmacokinetics of brigatinib. Healthy subjects (n = 20 per arm) were administered a single dose of brigatinib (90 mg, arms 1 and 2; 180 mg, arm 3) alone in treatment period 1 and coadministered with multiple doses of gemfibrozil 600 mg twice daily (BID; arm 1), itraconazole 200 mg BID (arm 2), or rifampin 600 mg daily (QD; arm 3) in period 2. Compared with brigatinib alone, coadministration of gemfibrozil with brigatinib did not meaningfully affect brigatinib area under the plasma concentration-time curve (AUC0-inf ; geometric least-squares mean [LSM] ratio [90%CI], 0.88 [0.83-0.94]). Coadministration of itraconazole with brigatinib increased AUC0-inf (geometric LSM ratio [90%CI], 2.01 [1.84-2.20]). Coadministration of rifampin with brigatinib substantially reduced AUC0-inf (geometric LSM ratio [90%CI], 0.20 [0.18-0.21]) compared with brigatinib alone. The treatments were generally tolerated. Based on these results, strong CYP3A inhibitors and inducers should be avoided during brigatinib treatment. If concomitant use of a strong CYP3A inhibitor is unavoidable, the results of this study support a dose reduction of brigatinib by approximately 50%. Furthermore, CYP2C8 is not a meaningful determinant of brigatinib clearance, and no dose modifications are needed during coadministration of brigatinib with CYP2C8 inhibitors.

The Effect of a High-Fat Meal on the Pharmacokinetics of Brigatinib, an Oral Anaplastic Lymphoma Kinase Inhibitor, in Healthy Volunteers.

Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, received accelerated approval in the United States for the treatment of patients with metastatic ALK+ non-small-cell lung cancer who have progressed on or are intolerant to crizotinib. A clinical study was conducted to assess the effect of food on brigatinib pharmacokinetics (PK). Healthy subjects received a single oral dose of brigatinib 180 mg (2 × 90-mg tablets) after a 10-hour fast or after a high-fat meal in a 2-period, 2-sequence crossover study. Plasma samples for PK characterization were collected over 168 hours postdose. Twenty-four subjects were enrolled (mean age 44 years; 58% male), with 21 included in the PK-evaluable population. Brigatinib peak concentration was reduced by 13% under fed (high-fat meal) versus fasted conditions, with no effect on area under the concentration-time curve. The median time to peak concentration of brigatinib was longer under fed conditions (5 hours) than in fasted conditions (2 hours). Treatment-emergent adverse events were similar under fasted (48%) and fed (46%) conditions and were of mild intensity. Consumption of a high-fat meal decreased the rate of brigatinib oral absorption but had no impact on the extent of absorption, thereby supporting brigatinib administration without regard to meals. These recommendations are reflected in the US prescribing information for brigatinib.

Evaluation of the effect of multiple doses of rifampin on the pharmacokinetics and safety of ponatinib in healthy subjects.

Ponatinib, an oral tyrosine kinase inhibitor with significant activity in heavily pretreated patients with chronic myeloid leukemia, is a CYP3A4 substrate. This open-label, nonrandomized, fixed-order crossover study evaluated the effect of multiple oral doses of rifampin, a strong CYP3A4 inducer, on the pharmacokinetics of ponatinib (45 mg, single dose). Twenty healthy adults received ponatinib on day 1, rifampin 600 mg alone on days 8-13, 15, and 16, and rifampin 600 mg with ponatinib on day 14. Rifampin decreased maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve (AUC) from time zero to time of last measurable concentration (AUC0-t ) and from time zero to infinity (AUC0-∞ ) of ponatinib by 42%, 59%, and 63%, respectively, with no effect on time to Cmax . The limits of the 90% confidence intervals of the estimated geometric mean ratios of ponatinib Cmax , AUC0-t , and AUC0-∞ did not fall within the 80-125% margins for equivalence, suggesting a statistically significant interaction. Coadministration of ponatinib with strong CYP3A4 inducers should be avoided unless the benefit outweighs the possible risk of ponatinib underexposure, because the safety of ponatinib dose increases has not been studied in this context.

Evaluation of pharmacokinetics and safety of ponatinib in subjects with chronic hepatic impairment and matched healthy subjects.

PURPOSE: This study evaluated the effects of chronic hepatic impairment on the single-dose pharmacokinetics (PK) of the tyrosine kinase inhibitor ponatinib. METHODS: Subjects (n = 16) had Child-Pugh class A (mild, n = 6), B (moderate, n = 6), or C (severe, n = 4) hepatic impairment and were matched with healthy controls (n = 8). Each subject received a single oral dose of ponatinib 30 mg under fasting conditions, and PK parameters were assessed in blood samples collected through 96 h post-dose. RESULTS: Ponatinib maximum plasma concentrations (C max) were observed after 5-6 h in Child-Pugh A, Child-Pugh B, and healthy subjects, and after ~3 h in Child-Pugh C subjects. The estimated % geometric mean ratios for C max, area under the plasma concentration-time curves from time zero to last observation (AUC0-t ) and to infinity (AUC0-∞) suggested a slightly lower exposure in Child-Pugh B (61.4, 89.1, and 90.6%, respectively) and Child-Pugh C subjects (62.8, 77.1, and 79.4%) versus healthy subjects. Child-Pugh A subjects had similar estimated % geometric mean ratio for C max (106.7%), and slightly greater estimated % geometric mean ratios for AUC0-t (133.0%) and AUC0-∞ (122.8%), versus healthy subjects. Mean elimination half-life was extended in subjects with hepatic impairment (43-47 vs 36 h). Ponatinib was generally well tolerated. A single serious AE (pancreatitis) in the Child-Pugh C group resolved with treatment. DISCUSSION: As no major differences in ponatinib single-dose PK were observed in patients with hepatic impairment versus healthy subjects, a reduction of ponatinib starting dose in these patients is not necessary, but caution is recommended when administering ponatinib to these patients.

A clinical study to examine the potential effect of lansoprazole on the pharmacokinetics of bosutinib when administered concomitantly to healthy subjects.

BACKGROUND: Bosutinib is an orally bioavailable, dual Src and Abl tyrosine kinase inhibitor approved in the USA for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia following development of resistance or intolerance to prior therapy. In vitro studies demonstrated that bosutinib displays pH-dependent aqueous solubility, suggesting that concomitant administration of agents that alter gastric pH could affect bosutinib absorption. OBJECTIVES: The objectives of this study were to evaluate the effect of lansoprazole, a gastric proton pump inhibitor, on the pharmacokinetics and safety of bosutinib. METHODS: This open-label, non-randomized, phase I study involved inpatients and outpatients at a single site. The study participants were healthy men or women of non-childbearing potential aged 18-50 years. Each subject received bosutinib 400 mg on Day 1, lansoprazole 60 mg on Day 14, and bosutinib 400 mg co-administered with lansoprazole 60 mg on Day 15 under fasting conditions. The main outcome measure was the effect of multiple doses of lansoprazole on the pharmacokinetic profile of a single oral dose of bosutinib. RESULTS: A total of 24 healthy male subjects were enrolled. Co-administration with lansoprazole decreased the mean maximum plasma concentration (C(max)) of bosutinib from 70.2 to 42.9 ng/mL, and the total area under the plasma concentration-time curve (AUC) from 1,940 to 1,470 ng·h/mL. Log-transformed bosutinib pharmacokinetic parameters indicated significant between-treatment differences; the least squares geometric mean ratio for C(max) was 54 % (95 % CI 42-70) and for AUC was 74 % (95 % CI 60-90). Mean apparent total body clearance from plasma after oral administration increased from 237 to 330 L/h, and the median time to reach Cmax increased from 5 to 6 h, although this change may be related to decreased bosutinib absorption when combined with lansoprazole. When co-administered with lansoprazole, bosutinib maintained an acceptable safety profile, which was primarily characterized by diarrhea (33 %), headache (21 %), and nausea (13 %). One subject experienced serious adverse events of diverticulitis, gastritis, and duodenitis after co-administration; however, no participant withdrew because of toxicity. CONCLUSIONS: This study demonstrated that bosutinib absorption may be reduced when co-administered with lansoprazole or other proton pump inhibitors. Caution should be used with such drug combinations, as subtherapeutic exposure of bosutinib may limit its clinical antitumor activity; short-acting antacids are recommended instead.

Effects of food on the pharmacokinetics of ponatinib in healthy subjects.

WHAT IS KNOWN AND OBJECTIVE: Ponatinib is a potent oral tyrosine kinase inhibitor with activity against BCR-ABL, the primary driver of chronic myeloid leukaemia and Philadelphia chromosome-positive acute lymphoblastic leukaemia. This single-centre, single-dose, randomized, open-label, three-period crossover study evaluated the pharmacokinetics and bioavailability of a single oral dose of ponatinib (45-mg tablet) under fasting conditions and following consumption of high- and low-fat meals by healthy subjects. METHODS: Subjects were randomly assigned to one of the six possible treatment sequences, each evaluating three ponatinib 45-mg treatments: administered under fasting conditions; administered after a high-fat meal; or administered after a standardized low-fat meal. The high-fat meal derived approximately 50% of its total caloric content from fat, with approximately 150, 250 and 500-600 calories derived from protein, carbohydrates and fat, respectively (total of approximately 900-1000 calories). The standardized low-fat meal derived no more than 20% of total caloric content from fat, with approximately 56, 428 and 63 calories derived from protein, carbohydrates and fat, respectively (total of approximately 547 calories). During each of the three treatment periods, blood samples were collected predose and at 13 time points over the 96-h post-dose interval. Plasma concentrations of ponatinib were measured by liquid chromatography/tandem mass spectrometry. Mixed-model analyses of variance (anova) were performed on natural log-transformed PK parameters Cmax and AUC0-∞. RESULTS AND DISCUSSION: Geometric mean maximum plasma concentration (Cmax) values for the fasted, low-fat and high-fat regimens were 54·7, 51·6 and 51·5 ng/mL, respectively. Geometric mean area under the concentration-time curve from time zero to infinity (AUC0-∞) values for the fasted, low-fat and high-fat regimens were 1273, 1244 and 1392 h × ng/mL, respectively. All limits of the 90% CIs of the estimated geometric mean ratios for Cmax and all AUC comparisons fell within the 80%-125% margins. These results indicate that consumption of a high- or low-fat meal within 30 min prior to administration of ponatinib had no effect on the single-dose pharmacokinetics of ponatinib. WHAT IS NEW AND CONCLUSION: Food does not affect the single-dose pharmacokinetics of ponatinib. These data demonstrate that ponatinib may be administered with or without food.

Effects of ketoconazole on the pharmacokinetics of ponatinib in healthy subjects.

Ponatinib is a BCR-ABL tyrosine kinase inhibitor (TKI) approved for the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia in patients resistant or intolerant to prior TKIs. In vitro studies suggested that metabolism of ponatinib is partially mediated by CYP3A4. The effects of CYP3A4 inhibition on the pharmacokinetics of ponatinib and its CYP3A4-mediated metabolite, AP24567, were evaluated in a single-center, randomized, two-period, two-sequence crossover study in healthy volunteers. Subjects (N = 22) received two single doses (orally) of ponatinib 15 mg, once given alone and once coadministered with daily (5 days) ketoconazole 400 mg, a CYP3A4 inhibitor. Ponatinib plus ketoconazole increased ponatinib maximum plasma concentration (C(max)) and area under the concentration-time curve (AUC) compared with ponatinib alone. The estimated mean ratios for AUC0-∞, AUC0-t, and C(max) indicated increased exposures to ponatinib of 78%, 70%, and 47%, respectively; exposure to AP24567 decreased by 71%. Exposure to AP24567 was marginal after ponatinib alone (no more than 4% of the exposure to ponatinib). These results suggest that caution should be exercised with the concurrent use of ponatinib and strong CYP3A4 inhibitors and that a ponatinib dose decrease to 30 mg daily, from the 45 mg daily starting dose, could be considered.

Analysis of the potential effect of ponatinib on the QTc interval in patients with refractory hematological malignancies.

PURPOSE: Cardiac dysfunction, particularly QT interval prolongation, has been observed with tyrosine kinase inhibitors approved to treat chronic myeloid leukemia. This study examines the effects of ponatinib on cardiac repolarization in patients with refractory hematological malignancies enrolled in a phase 1 trial. METHODS: Electrocardiograms (ECGs) were collected at 3 dose levels (30, 45, and 60 mg) at 6 time points. Electrocardiographic parameters, including QTc interval, were measured, and 11 morphological analyses were conducted. Central tendency analyses of ECG parameters were performed using time-point and time-averaged approaches. All patients with at least 2 baseline ECGs and 1 on-treatment ECG were included in the analyses. Patients with paired ECGs and plasma samples were included in the pharmacokinetic/pharmacodynamic analysis to examine the relationship between ponatinib plasma concentration and change from baseline in QT intervals. RESULTS: Thirty-nine patients at the 30-, 45-, and 60-mg dose levels were included in the central tendency and morphological analyses. There was no significant effect on cardiac repolarization, as evidenced by non-clinically significant mean QTcF changes from baseline of -10.9, -3.6, and -5.0 ms for the 30-, 45-, and 60-mg dose levels, respectively. The morphological analysis revealed 2 patients with atrial fibrillation and 2 with T wave inversion. Seventy-five patients were included in the pharmacokinetic/pharmacodynamic analysis across all dose levels. The slope of the relationship for QTcF versus plasma ponatinib concentration was not positive (-0.0171), indicating no exposure-effect relationship. CONCLUSIONS: Ponatinib is associated with a low risk of QTc prolongation in patients with refractory hematological malignancies.

Evaluation of the pharmacokinetics and safety of bosutinib in patients with chronic hepatic impairment and matched healthy subjects.

PURPOSE: Bosutinib, a dual Src/Abl kinase inhibitor in development for treatment of chronic myeloid leukemia, is primarily metabolized by the CYP3A4 hepatic enzyme. This study evaluated the pharmacokinetics and safety of bosutinib in patients with chronic hepatic impairment and matched healthy subjects. METHODS: Hepatically impaired patients were aged 18-65 years and of Child-Pugh classes A, B, or C; healthy subjects were matched by age, sex, body mass index, and smoking habits. A single oral dose of bosutinib 200 mg was administered on day 1 within 5 min after completion of breakfast. RESULTS: Compared with healthy subjects (n = 9), maximal plasma concentration (C(max)) and area under the curve increased 2.42-fold and 2.25-fold in Child-Pugh A (n = 6), 1.99-fold and 2.0-fold in Child-Pugh B (n = 6), and 1.52-fold and 1.91-fold in Child-Pugh C patients (n = 6). Time to C(max) decreased from 4 h in healthy subjects to 2.5, 2.0, and 1.5 h in Child-Pugh A, B, and C patients, respectively; the elimination half-life increased from 55 h in healthy subjects to 86, 113, and 111 h in Child-Pugh A, B, and C patients. Bosutinib oral clearance was lower in hepatically impaired patients compared with healthy subjects. Frequently reported adverse events included prolonged QTc interval (37.0%, n = 10), nausea (11.1%, n = 3), and vomiting (7.4%, n = 2). CONCLUSIONS: A single oral dose of bosutinib 200 mg showed acceptable tolerability in healthy subjects and in patients with mild, moderate, or severe chronic hepatic impairment.

Ascending single-dose study of the safety profile, tolerability, and pharmacokinetics of bosutinib coadministered with ketoconazole to healthy adult subjects.

BACKGROUND: Bosutinib (SKI-606) is an orally bioavailable, competitive tyrosine kinase inhibitor that selectively targets both Src and Abl tyrosine kinases. Bosutinib is metabolized primarily through the cytochrome P450 3A4 pathway. Inhibition of bosutinib metabolism by coadministration with the potent cytochrome P450 3A4 inhibitor ketoconazole could potentially increase plasma concentrations of bosutinib, allowing for the study of bosutinib tolerability at supratherapeutic concentrations in a healthy subject population. OBJECTIVE: This study assessed the safety profile, tolerability, and pharmacokinetics of different dose combinations of bosutinib coadministered with ketoconazole in healthy adults, and determined whether supratherapeutic concentrations of bosutinib can be achieved with ketoconazole. METHODS: This was a randomized, Phase I, double-blind, placebo-controlled, sequential-group study conducted in healthy adults. Single oral doses of bosutinib 100, 200, 300, 400, 500, and 600 mg or placebo were administered with ketoconazole and food on day 1; daily single oral doses of ketoconazole 400 mg were administered on days -1 and 1 through 4. RESULTS: Forty-eight subjects were enrolled. Their mean (SD) age was 32.0 (10.7) years (range, 18-50 years). The majority of the subjects (n = 44 [92%]) were white, 2 (4%) were black or African American, and 2 (4%) were of other races. Bosutinib was associated with acceptable tolerability at doses from 100 to 600 mg, with adverse events either mild (n = 30 [63%]) or moderate (n = 12 [25%]) in severity; no subject discontinued treatment due to adverse events, and no serious events were reported. Mean (SD) values for bosutinib 100 to 600 mg ranged from 58.4 (13.3) to 426 (100) ng/mL for C(max) and 2980 (802) to 23,000 (4020) ng·h/mL for AUC(0-∞); mean AUC(0-24) and AUC(0-last) ranged from 876 (234) to 7080 (1640) ng· h/mL and from 2740 (854) to 22,200 (3630) ng · h/mL, respectively. C(max) and AUC were linear and dose proportional. Mean C(max) at 600 mg was 2.1-fold higher than the steady-state C(max) previously observed for patients with chronic myelogenous leukemia who received bosutinib 500 mg once daily with food. CONCLUSIONS: Single doses of bosutinib up to 600 mg coadministered with multiple doses of ketoconazole were acceptably well tolerated in this small, selected group of healthy male volunteers. In addition, supratherapeutic exposure was achieved within this range for bosutinib when coadministered with ketoconazole. ClinicalTrials.gov identifier: NCT00777530.

A double-blind, randomized, multiple-dose, parallel-group study to characterize the occurrence of diarrhea following two different dosing regimens of neratinib, an irreversible pan-ErbB receptor tyrosine kinase inhibitor.

PURPOSE: Neratinib, a potent, low-molecular-weight, orally administered, irreversible, pan-ErbB receptor tyrosine kinase inhibitor has antitumor activity in ErbB2 + breast cancer. The objective of this study was to characterize the onset, severity, and duration of diarrhea after administration of neratinib 240 mg once daily (QD) and 120 mg twice daily (BID) for ≤14 days in healthy subjects. METHODS: A randomized, double-blind, parallel-group, inpatient study was conducted in 50 subjects given oral neratinib either 240 mg QD or 120 mg BID with food for ≤14 days. The primary endpoint was the proportion of subjects with diarrhea of at least moderate severity (grade 2; 5-7 loose stools/day). In subjects with grade 2 diarrhea, fecal analytes were determined. Pharmacokinetic profiles were characterized for neratinib on Days 1 and 7. RESULTS: No severe (grade 3) diarrhea was reported. By Day 4, all subjects had grade 1 diarrhea. Grade 2 diarrhea occurred in 11/22 evaluable subjects (50 % [90 % confidence interval (CI): 28-72 %]) in the QD group and 17/23 evaluable subjects (74 % [90 % CI: 52-90 %]) in the BID group (P = 0.130). In fecal analyses, 18 % tested positive for hemoglobin and 46 % revealed fecal lactoferrin. Specimen pH was neutral to slightly alkaline. In pharmacokinetic analyses, Day 1 peak plasma concentration and Day 7 steady-state exposure were higher with the QD regimen than the BID regimen. In an exploratory analysis, ABCG2 genotype showed no correlation with severity or onset of diarrhea. CONCLUSIONS: Incidences and onsets of at least grade 1 and at least grade 2 diarrhea were not improved on BID dosing compared with QD dosing.

A single-dose placebo- and moxifloxacin-controlled study of the effects of temsirolimus on cardiac repolarization in healthy adults.

PURPOSE: Temsirolimus, a selective inhibitor of mammalian target of rapamycin, is an approved treatment for patients with advanced renal cell carcinoma (RCC). This study assessed the effect of intravenous (i.v.) temsirolimus 25 mg, the recommended dose for patients with RCC, on the corrected QT (QTc) interval. METHODS: This 3-period crossover study enrolled healthy subjects. In periods 1 and 2, subjects received i.v. placebo either alone or with open-label oral moxifloxacin. In period 3, subjects received a single dose of temsirolimus 25 mg. The primary statistical objective was to estimate the effect of temsirolimus compared with placebo on change from time-matched baseline QTc at the end of infusion (0.5 h). Assay sensitivity was evaluated by the effect of moxifloxacin on change from time-matched baseline QTc compared with placebo. RESULTS: In total, 58 subjects were enrolled. Temsirolimus had no effect on QTc interval in the primary analysis. At 11 of 12 secondary time points, the upper bound for the temsirolimus QTc 90% confidence intervals for the time-matched change from baseline difference from placebo was <10 ms, with no evidence of QTc trends or relationship to concentrations of temsirolimus or its major metabolite, sirolimus. Moxifloxacin, the positive control, produced a significant increase in the QTc interval compared with placebo 0.5-4 h post-dose (P < 0.0001). No subject had a QTc interval exceeding 450 ms or a change from baseline of >30 ms. CONCLUSIONS: Therapeutic exposure to temsirolimus is not associated with clinically significant changes in QTc intervals in healthy adults.

A randomized, crossover, placebo- and moxifloxacin-controlled study to evaluate the effects of bosutinib (SKI-606), a dual Src/Abl tyrosine kinase inhibitor, on cardiac repolarization in healthy adult subjects.

Effects of therapeutic and supratherapeutic concentrations of bosutinib, a dual Src/Abl tyrosine kinase inhibitor, on the corrected QT interval (QTc) in 60 healthy adults were assessed, according to ICH-E14 guidelines, in this 2-part, randomized, single-dose, double-blind, crossover, placebo- and open-label moxifloxacin-controlled study. Subjects received placebo, moxifloxacin and bosutinib 500 mg with food (therapeutic) in Part 1. In Part 2, subjects received placebo and bosutinib 500 mg plus ketoconazole (supratherapeutic). ANOVA compared baseline-adjusted QTc for bosutinib with placebo; and bosutinib plus ketoconazole with placebo plus ketoconazole. Primary endpoint was population-specific QT correction (QTcN). Secondary endpoints were Bazett QT correction (QTcB), Fridericia's formula QT correction (QTcF) and individual QT correction (QTcI). Upper bounds for 90% confidence intervals were <10 msec for the mean change in QTcN from placebo at all postdose time points, suggesting that mean therapeutic exposures (C(max) , 114 ng/mL; AUC, 2,330 ng · h/mL) and mean supratherapeutic exposures (C(max) , 326 ng/mL; AUC, 15,200 ng · h/mL) were not associated with QTc changes. Similar results were obtained for QTcB, QTcF and QTcI. No clinically relevant pharmacokinetic/pharmacodynamic relationship was observed between bosutinib concentrations and QTc. No subjects had QTcB, QTcF, QTcI or QTcN >450 msec or change from baseline >30 msec. In summary, therapeutic and supratherapeutic bosutinib exposures are not associated with QTc prolongation in healthy adults.

A phase I ascending single-dose study of the safety, tolerability, and pharmacokinetics of bosutinib (SKI-606) in healthy adult subjects.

PURPOSE: Bosutinib (SKI-606), a dual Src/Abl tyrosine kinase inhibitor, is in clinical development for the treatment of patients with chronic myelogenous leukemia (CML). To support clinical development, we conducted a dose-escalation and food-effect evaluation of safety, tolerability, and pharmacokinetics (PK) of bosutinib in healthy adults. METHODS: This was a randomized, double-blind, placebo-controlled, single-ascending dose, sequential-group study of oral bosutinib. Subjects randomly received bosutinib 200, 400, 600, and 800 mg with food; 200 and 400 mg without food; or placebo. Plasma concentrations were determined by a liquid chromatography-tandem mass spectrometry assay. Non-compartmental PK analyses were performed, and power models assessed dose linearity. RESULTS: Of 55 enrolled subjects, 33 (81%) subjects had adverse events (AEs) after receiving bosutinib. Common AEs included diarrhea (39%), nausea (29%), and headache (22%). Bosutinib 200-600 mg with food was safe and well tolerated. Bosutinib exposures (C (max) and AUC) were linear and dose proportional from 200 to 800 mg with food. Absorption was relatively slow; median time to C (max) was 6 h. Apparent volume of distribution (V (z)/F) was 131-214 L/kg, mean apparent clearance (CL/F) was 2.25-3.81 L/h/kg, and mean terminal elimination half-life (t (1/2)) was 32-39 h. Preliminary food effect assessment showed that exposure to bosutinib increased by ~2.52-fold (P = 0.002) for C (max) and ~2.28-fold (P = 0.002) for AUC when 200 mg bosutinib was administered with food compared with administration under fasting conditions; administration of 400 mg bosutinib with food increased AUC by ~1.5-fold (P = 0.037). Approximately 1% of administered dose was excreted in urine. CONCLUSIONS: Bosutinib 200-600 mg with food was safe and well tolerated. Under fed conditions, bosutinib exposures were linear and dose proportional, and C (max) increased by ~1.5-fold. The t (1/2) supported a once-daily dosing regimen.

Effect of ketoconazole on the pharmacokinetics of oral bosutinib in healthy subjects.

Bosutinib (SKI-606), a dual inhibitor of Src and Abl tyrosine kinases, is being developed for the treatment of chronic myelogenous leukemia. The effect of coadministration of ketoconazole on the pharmacokinetic (PK) profile of bosutinib was evaluated in an open-label, randomized, 2-period, crossover study. Healthy subjects (fasting) received a single dose of oral bosutinib 100 mg alone and with multiple once-daily doses of oral ketoconazole 400 mg. PK sampling occurred through 96 hours. The least square geometric mean treatment ratios (90% confidence interval [CI]) of C(max(bosutinib+ketoconazole))/C(max(bosutinib alone)), AUC(T(bosutinib+ketoconazole))/AUC(T(bosutinib alone)), and AUC((bosutinib+ketoconazole))/AUC((bosutinib alone)) were assessed. Compared with bosutinib administered alone, coadministration with ketoconazole increased bosutinib C(max) 5.2-fold, AUC(T) 7.6-fold, and AUC 8.6-fold. Ketoconazole coadministration decreased the mean apparent clearance of bosutinib approximately 9-fold and increased the mean (SD) terminal half-life from 46.2 (16.4) hours to 69.0 (29.1) hours. The incidence of adverse events (AEs) was comparable between the 2 treatments. The most common AEs were headache, nausea, and increased blood creatinine. No safety-related discontinuations or serious AEs occurred. These PK results indicate that bosutinib is susceptible to interaction with potent CYP3A4 inhibitors.

A single-dose, crossover, placebo- and moxifloxacin-controlled study to assess the effects of neratinib (HKI-272) on cardiac repolarization in healthy adult subjects.

PURPOSE: Neratinib is an orally administered, small-molecule, irreversible pan-ErbB inhibitor in development for the treatment of ErbB2-positive breast cancer. This study assessed the effects of therapeutic and supratherapeutic neratinib concentrations on cardiac repolarization, in accordance with current regulatory guidance. EXPERIMENTAL DESIGN: This was a two-part study in healthy subjects. In part 1, subjects were randomized to receive placebo, 400 mg moxifloxacin, or 240 mg neratinib (therapeutic dose) following a high-fat meal. In part 2, after a washout period, subjects received placebo plus 400 mg ketoconazole or 240 mg neratinib plus ketoconazole (supratherapeutic dose). ANOVA was used to compare the baseline-adjusted QTc interval for neratinib with that of placebo (reference), and for neratinib plus ketoconazole with that of placebo plus ketoconazole (reference). Pharmacokinetic/pharmacodynamic analyses and categorical summaries of interval data were done. Assay sensitivity was evaluated by the effect of moxifloxacin on QTc compared with placebo. RESULTS: Sixty healthy subjects were enrolled in this study. The upper bounds of the 90% confidence interval for baseline-adjusted QTcN (population-specific corrected QT) were 450 milliseconds or change from baseline >30 milliseconds. Moxifloxacin produced a significant increase in QTcN compared with placebo (P < 0.05). CONCLUSIONS: Therapeutic and supratherapeutic plasma concentrations of neratinib do not prolong the QTc interval in healthy subjects.