Exposure-Response Modeling and Simulation of Progression-Free Survival and Adverse Events of Sorafenib Treatment in Patients With Advanced Thyroid Cancer.

Sorafenib is an oral multikinase inhibitor approved for the treatment of differentiated thyroid carcinoma (DTC), renal cell carcinoma, and hepatocellular carcinoma. In the phase III DECISION trial in patients with DTC, sorafenib exposure and the incidence of some adverse events (AEs) were higher than in previous trials; therefore, we analyzed exposure-response relationships, including progression-free survival (PFS) and selected AEs in patients with DTC. A novel, stratified prediction-corrected visual predictive check (pc-VPC) was developed to show robustness of the exposure-response relationships. Time-to-event simulations confirmed the benefit of the recommended dosing schedule of 800 mg/day: initial doses of 800 mg/day were associated with the highest PFS, whereas lower doses (600 or 400 mg/day) were associated with improved tolerability but reduced PFS. A simulated dose-reduction strategy of 800 mg/day for an initial two cycles followed by dose reductions seemed likely to maintain efficacy while possibly mitigating selected AEs (e.g., diarrhea and hand-foot skin reactions).

Pharmacokinetics, Safety, and Tolerability of Single-Dose Intravenous Moxifloxacin in Pediatric Patients: Dose Optimization in a Phase 1 Study.

The pharmacokinetics, safety, and tolerability of a single dose of moxifloxacin were characterized in 31 pediatric patients already receiving antibiotics for a suspected or proven infection in an open-label phase 1 study. A dosing strategy for each age cohort (Cohort 1: ≥6 years to ≤14 years; Cohort 2: ≥2 years to <6 years; Cohort 3: >3 month to <2 years) was developed using physiology-based pharmacokinetic modeling combined with a stepwise dosing scheme to obtain a similar exposure to adults receiving 400 mg of moxifloxacin. Doses, adjusted to body weight and age, were gradually escalated from 5 mg/kg in Cohort 1 to 10 mg/kg in Cohort 3 based on interim analysis of the pharmacokinetic and safety data. Plasma and urine samples before and after the 60-minute infusion were collected for the analysis of moxifloxacin and its metabolites using a validated high-pressure liquid chromatography assay with tandem mass spectrometry. Moxifloxacin and metabolite concentrations in plasma were within the ranges observed in adults; however, clearance of all analytes was lower in pediatric patients compared with adults. Population pharmacokinetic analyses using the achieved exposure levels in the 3 age cohorts (with known body weight and clearance) predicted similar efficacy and safety profiles to adults. Moxifloxacin was well tolerated in all pediatric age cohorts. Adverse events related to moxifloxacin were mild or moderate in intensity and showed no correlation with increased weight-adjusted doses. Our findings guided the selection of age-appropriate clinical doses for a subsequent phase 3 clinical trial in pediatric patients with complicated intra-abdominal infections.

Phase 1, open-label, dose-escalation study of sorafenib in combination with eribulin in patients with advanced, metastatic, or refractory solid tumors.

Combining sorafenib and eribulin mesylate may provide synergistic antitumor activities with limited overlapping toxicities. This phase 1b, open-label, dose-escalation study evaluated safety, pharmacokinetics, maximum tolerated dose/recommended phase 2 dose (MTD/RP2D), and preliminary efficacy of sorafenib plus standard-dose eribulin mesylate in patients with advanced, metastatic, or refractory tumors. Patients received sorafenib 200 mg twice daily (BID; n = 5), 600 mg/day (n = 8), and 400 mg BID (MTD; n = 27). Dose-limiting toxicities were increased alanine aminotransferase and acute coronary syndrome (both grade 3) in the 400-mg BID dose-escalation and expansion cohorts, respectively. No significant increase in mean QTcF duration was observed with eribulin plus sorafenib versus eribulin alone; there were no drug-drug interactions. Five patients achieved partial response; 16 achieved stable disease. The combination of sorafenib and eribulin mesylate presented no unexpected safety concerns and no significant impact on QT/QTc intervals or drug-drug interactions. Sorafenib 400 mg BID plus standard-dose eribulin is the RP2D.

Mass balance, metabolic disposition, and pharmacokinetics of a single oral dose of regorafenib in healthy human subjects.

PURPOSE: To evaluate the mass balance, metabolic disposition, and pharmacokinetics of a single dose of regorafenib in healthy volunteers. In addition, in vitro metabolism of regorafenib in human hepatocytes was investigated. METHODS: Four healthy male subjects received one 120 mg oral dose of regorafenib containing approximately 100 µCi (3.7 MBq) [14C]regorafenib. Plasma concentrations of parent drug were derived from HPLC-MS/MS analysis and total radioactivity from liquid scintillation counting (LSC). Radiocarbon analyses used HPLC with fraction collection followed by LSC for all urine samples, plasma, and fecal homogenate extracts. For the in vitro study, [14C]regorafenib was incubated with human hepatocytes and analyzed using HPLC-LSC and HPLC-HRMS/MS. RESULTS: Regorafenib was the major component in plasma, while metabolite M-2 (pyridine N-oxide) was the most prominent metabolite. Metabolites M-5 (demethylated pyridine N-oxide) and M-7 (N-glucuronide) were identified as minor plasma components. The mean concentration of total radioactivity in plasma/whole blood appeared to plateau at 1-4 h and again at 6-24 h post-dose. In total, 90.5% of administered radioactivity was recovered in the excreta within a collection interval of 12 days, most of which (71.2%) was eliminated in feces, while excretion via urine accounted for 19.3%. Regorafenib (47.2%) was the most prominent component in feces and was not excreted into urine. Excreted metabolites resulted from oxidative metabolism and glucuronidation. CONCLUSIONS: Regorafenib was eliminated predominantly in feces as well as by hepatic biotransformation. The multiple biotransformation pathways of regorafenib decrease the risk of pharmacokinetic drug-drug interactions.

No Effect of Levothyroxine and Levothyroxine-Induced Subclinical Thyrotoxicosis on the Pharmacokinetics of Sorafenib in Healthy Male Subjects.

BACKGROUND: Patients receiving the multikinase inhibitor sorafenib for locally recurrent or metastatic, progressive, differentiated thyroid carcinoma (DTC) refractory to radioactive iodine often receive concomitant levothyroxine for thyrotropin (TSH) suppression. In the Phase 3 DTC trial (DECISION), sorafenib exposure was approximately twofold higher than that observed in other cancers. This study assessed sorafenib pharmacokinetics without and with concomitant levothyroxine to examine whether a levothyroxine interaction or levothyroxine-induced subclinical thyrotoxicosis results in increased sorafenib exposure in patients with DTC. METHODS: This was an open-label, two-period sequential treatment study in healthy male subjects. In period 1, day 1, subjects received a single oral dose of sorafenib 400 mg, followed by a minimal 10-day washout. In period 2, day 1, levothyroxine 300 µg was administered orally once daily (q.d.) for 14 days. After 10 days, a single oral concomitant dose of sorafenib 400 mg was given. Blood samples for sorafenib pharmacokinetic analyses were obtained pre-dose and at time points up to 96 hours after sorafenib dosing. Samples for thyroid tests were collected before and after levothyroxine dosing. RESULTS: Twenty-five subjects completed the study and were evaluable for pharmacokinetic analysis. Levothyroxine 300 µg q.d. was well tolerated and induced subclinical thyrotoxicosis, producing full suppression of TSH (M ± SD = 0.032 ± 0.027 mIU/L) and increased free thyroxine (from 0.94 ± 0.09 to 1.77 ± 0.33 ng/dL) and free triiodothyronine (from 2.87 ± 0.28 to 4.24 ± 0.66 pg/mL) levels by day 11 of period 2. The geometric mean (%CV) sorafenib maximum concentration (Cmax) without and with levothyroxine was 2.09 (68.1) and 1.78 (63.9) mg/L, respectively, with a corresponding geometric mean area under the curve of 68.1 (68.2) and 64.3 (66.3) mg·h/L. Median (range) time to Cmax was 4.00 (2.98-16.0) and 4.02 (1.98-36.0) hours, respectively. Mean (%CV) half-life was 24.0 (25.3) and 25.7 (21.0) hours. All study drug-related adverse events were mild and included headache and fatigue for sorafenib, and headache, increased alanine aminotransferase and glutamate dehydrogenase, fatigue, and nervousness for levothyroxine. CONCLUSIONS: Levothyroxine 300 µg q.d. for 14 days was well tolerated, induced subclinical thyrotoxicosis, and did not affect sorafenib pharmacokinetics. The findings suggest that concomitant use of levothyroxine with sorafenib is not likely responsible for the previously reported increase in sorafenib exposure in patients with DTC. However, the possible effects of long-term levothyroxine dosing were not assessed.

A phase I open-label trial evaluating the cardiovascular safety of regorafenib in patients with advanced cancer.

PURPOSE: To characterize the cardiovascular safety profile of regorafenib in patients with advanced cancer. METHODS: Patients received regorafenib 160 mg/day for 21 days followed by a 7-day break. The primary endpoint was the change from baseline in QTcF at the regorafenib t(max) (Day 21, Cycle 1 or 2) and changes in left ventricular ejection fraction (LVEF) from baseline on Cycle 2, Day 21. Secondary objectives were pharmacokinetics, safety, anti-tumor activity and effects on electrocardiogram intervals. QT intervals were corrected using the methods of Fridericia (QTcF) and Bazett (QTcB). LVEF was assessed by multigated acquisition scanning. RESULTS: Fifty-three patients were enrolled, and all received at least one dose of regorafenib 160 mg. Twenty-five patients received regorafenib for 21 days without dose reduction. The mean change from baseline in QTcF at t(max) was (-)2 ms (90 % CI -8, 3). No patient experienced a change from baseline in QTcF > 60 ms, and two had QTcF changes between 30 and 60 ms. No patient had a QTcF or QTcB > 480 ms. In 27 patients who received at least 80 mg of regorafenib, the mean change from baseline in LVEF% ± SD was 1.7 ± 7.8. In 14 patients without a dose reduction, the mean change from baseline in LVEF% was (-)0.1 ± 8.6 at Cycle 2, Day 21. Four patients experienced a LVEF decrease between 10 and 20 %. CONCLUSION: The effects of regorafenib on the QT/QTc interval and LVEF were modest and unlikely to be of clinical significance in the setting of advanced cancer therapy.

Preliminary Safety, Pharmacokinetics, and Efficacy of Regorafenib, Cisplatin, and Pemetrexed in Patients With Advanced Nonsquamous Non-Small-Cell Lung Cancers.

UNLABELLED: Regorafenib is an oral multitargeted kinase inhibitor with potent antiangiogenic activity. In this phase I trial we evaluated the safety, pharmacokinetics, and efficacy of regorafenib with cisplatin and pemetrexed for patients with advanced nonsquamous non-small-cell lung cancers (nsNSCLCs). Nine patients enrolled before premature termination of the study. Five of 9 (56%) patients had a partial response and the median progression-free survival was 7 months (range, 1.5-15.1 months). Regorafenib had acceptable tolerability and minor pharmacokinetic interactions in combination with standard doses of cisplatin and pemetrexed in patients with advanced nsNSCLCs. BACKGROUND: The combination of bevacizumab, an antiangiogenesis agent, with cytotoxic chemotherapy improves survival in patients with advanced nonsquamous non-small-cell lung cancers (nsNSCLCs). Regorafenib is an oral multitargeted kinase inhibitor with potent antiangiogenic activity that is approved for patients with advanced colorectal cancer and gastrointestinal stromal tumors. In this phase I trial we evaluated the safety, pharmacokinetics (PK), and efficacy of regorafenib with cisplatin and pemetrexed for patients with advanced nsNSCLCs. PATIENTS AND METHODS: Chemotherapy-naive patients with advanced nsNSCLCs were treated with regorafenib 60 mg/d continuously and cisplatin 75 mg/m(2) with pemetrexed 500 mg/m(2) once every 21 days for up to 6 cycles. Thereafter, regorafenib with or without pemetrexed could be continued as maintenance. RESULTS: Nine patients enrolled before premature termination of the study because of slow recruitment and a change in the development strategy of regorafenib by the study sponsor. Five patients experienced at least 1 treatment-related Grade 3 adverse event. No Grade 4 or 5 toxicity occurred. Five of 9 (56%) patients had a partial response and the median progression-free survival was 7 months (range, 1.5-15.1 months). Minor PK interactions between regorafenib and chemotherapy were observed. CONCLUSION: Regorafenib had acceptable tolerability and minor PK interactions in combination with standard doses of cisplatin and pemetrexed in patients with advanced nsNSCLCs. Encouraging activity was appreciated in chemotherapy-naive patients with advanced nsNSCLCs. However, the small number of patients treated limits conclusions that can be drawn from these results.

Assessment of the effects of renal impairment on the pharmacokinetics of the soluble guanylate cyclase activator cinaciguat after a single intravenous dose.

This open-label, parallel-group, single-dose study assessed the safety and pharmacokinetics of cinaciguat, a novel soluble guanylate cyclase activator in clinical development for the treatment of acute decompensated heart failure, in individuals with mild, moderate, or severe renal impairment compared with individuals with normal renal function. Cinaciguat was administered as a 100 µg/h continuous infusion over 4 hours. Plasma concentrations were determined by high-performance liquid chromatography coupled with mass spectrometry. Renal function had only minor effects on the pharmacokinetics of cinaciguat. The apparent volume of distribution at steady state was slightly increased in individuals with renal impairment. The total body clearance from plasma showed a slight tendency to increase with progression of renal impairment, which can be explained by an increased hematocrit in individuals with renal impairment. No relevant influence was found on the terminal half-life. The fraction of cinaciguat unbound in plasma was very low (<1%) in all groups. Pharmacokinetic variability tended to be somewhat increased in individuals with renal impairment. Adverse events were mostly mild, and their incidence was similar in all groups. In conclusion, cinaciguat, a promising drug candidate for the treatment of acute decompensated heart failure, will not require dose adjustment based on renal function.

Lack of effect of ketoconazole-mediated CYP3A inhibition on sorafenib clinical pharmacokinetics.

Sorafenib is a novel, small-molecule anticancer compound that inhibits tumor cell proliferation by targeting Raf in the Raf/MEK/ERK signalling pathway, and inhibits angiogenesis by targeting tyrosine kinases such as vascular-endothelial growth factor receptor (VEGFR-2 and VEGFR-3) and platelet-derived growth factor receptor (PDGFR). In vitro microsomal data indicate that sorafenib is metabolized by two pathways: phase I oxidation mediated by cytochrome P450 (CYP) 3A4; and phase II conjugation mediated by UGT1A9. Approximately 50% of an orally administered dose is recovered as unchanged drug in the feces, due to either biliary excretion or lack of absorption. The aim of this study was to evaluate the effect of CYP3A inhibition by ketoconazole on sorafenib pharmacokinetics. This was an open-label, non-randomized, 2-period, one-way crossover study in sixteen healthy male subjects. A single 50 mg dose of sorafenib was administered alone (period 1) and in combination with ketoconazole 400 mg once daily (period 2) (ketoconazole was given for 7 days, and a single 50 mg sorafenib dose was administered concomitantly on day 4). No clinically relevant change in pharmacokinetics of sorafenib and no clinically relevant adverse events or laboratory abnormalities were observed in this study upon co-administration of the two drugs. Plasma concentrations of the main CYP3A4 generated metabolite, sorafenib N-oxide, decreased considerably upon ketoconazole co-administration. This effect is in accordance with the in vitro finding that CYP3A4 is the primary enzyme for sorafenib N-oxide formation. Further, these data indicate that blocking sorafenib metabolism by the CYP3A4 pathway will not lead to an increase in sorafenib exposure. This is consistent with data from a clinical mass-balance study that showed 15% of the administered dose was eliminated by glucuronidation, compared to less than 5% eliminated as oxidative metabolites. Since there was no increase in sorafenib exposure following concomitant administration of the highly potent CYP3A4 inhibitor ketoconazole with low dose sorafenib, it is postulated that higher therapeutic doses of sorafenib may be safely co-administered with ketoconazole, as well as with other inhibitors of CYP3A.

Optimizing wound healing in the face after laser abrasion.

BACKGROUND: Laser resurfacing is a popular procedure to improve the physical signs of photoaging. In addition to improvements in treatment modalities, optimizing posttreatment regimens will enhance patient care. OBJECTIVE: Our purpose was to evaluate the efficacy of two forms of wound care for the face after laser abrasion. METHODS: Forty-two patients received full-face laser resurfacing at two clinics by using either the UltraPulse carbon dioxide (CO(2)) laser (Coherent Laser Corp, Palo Alto, Calif) alone or followed by an erbium:YAG laser (Derma-20, ESC Sharplan, Inc, Needham, Mass) and/or a blended CO(2)/Er:YAG laser (Derma-K, ESC Sharplan) or a variable pulse erbium:YAG laser (Contour, Sciton Laser Corp, Palo Alto). Twenty-one patients were randomly assigned to a postoperative regimen including Silon-TSR (Bio Med Sciences, Inc, Allentown, Pa) for the first 2 to 3 days after laser resurfacing, followed by Aquaphor ointment (Beiersdorf, Charlotte, NC) to complete the first 2 weeks. The other 21 patients received the resurfacing recovery system (RRS, Neutrogena, Los Angeles, Calif) following a specific regimen. The system includes Fibracol wound dressing (Johnson & Johnson, Skillman, NJ) for 2 days, followed by a hydrogel dressing for 1 to 2 days, followed by an ointment to complete the first 2 weeks. Patients were evaluated for wound healing on days 2, 3, 6-10, 14-16, and 28-30. The skin was swabbed for colonization at every visit to determine the quantity of bacteria throughout the healing process. RESULTS: Ninety percent of patients in both groups experienced either "no pain" or "minimal pain" during the first 3 days. Total bacterial counts peaked on days 3 and 6 in the patients managed with the RRS and the Silon-TSR/Aquaphor regimen, respectively. The average day at which patients did not require a dressing was 3.0 days in the group managed with the RRS and 3.7 days in the group managed with the Silon-TSR/Aquaphor dressing regimen (P < or =.05). The average day of complete epithelial regeneration was significantly shorter at 6.3 days using the RRS compared with 7.4 days for patients using the Silon-TSR/Aquaphor regimen (P < or =.02). There was no difference in infection, adverse sequelae, exudate management, or pain in either group. CONCLUSION: Healing was optimized in patients using the RRS after laser resurfacing.

Pharmacokinetics of Nisoldipine Coat--Core Formulation in Subjects with Liver Cirrhosis.

The pharmacokinetics of a controlled-release formulation (coat--core) of the calcium channel blocker nisoldipine was investigated in eight subjects with biopsy-proved liver cirrhosis and eight healthy subjects. In Stage I, subjects received a single 10-mg dose to determine if this dose would be safely tolerated in the subjects with cirrhosis. Because all subjects in both groups tolerated the dose without difficulty, all were continued to Stage II. In Stage II, subjects received a once-daily dose of 10-mg coat-core tablets for 7 days. Serial plasma samples were assayed for nisoldipine in both stages. The C(max) and AUC of nisoldipine were approximately fourfold to fivefold higher (p < 0.01) in subjects with cirrhosis as compared to healthy subjects; however, there was overlap in the range of pharmacokinetic parameters between the two groups. The accumulation factor following multiple dosing was similar in both groups. Results suggest that nisoldipine dose should be optimized by monitoring of a pharmacodynamic end point, such as effect on blood pressure. It is likely that dose requirements for patients with liver disease will be lower.