Midostaurin drug interaction profile: a comprehensive assessment of CYP3A, CYP2B6, and CYP2C8 drug substrates, and oral contraceptives in healthy participants.

PURPOSE: Midostaurin, approved for treating FLT-3-mutated acute myeloid leukemia and advanced systemic mastocytosis, is metabolized by cytochrome P450 (CYP) 3A4 to two major metabolites, and may inhibit and/or induce CYP3A, CYP2B6, and CYP2C8. Two studies investigated the impact of midostaurin on CYP substrate drugs and oral contraceptives in healthy participants. METHODS: Using sentinel dosing for participants' safety, the effects of midostaurin at steady state following 25-day (Study 1) or 24-day (Study 2) dosing with 50 mg twice daily were evaluated on CYP substrates, midazolam (CYP3A4), bupropion (CYP2B6), and pioglitazone (CYP2C8) in Study 1; and monophasic oral contraceptives (containing ethinylestradiol [EES] and levonorgestrel [LVG]) in Study 2. RESULTS: In Study 1, midostaurin resulted in a 10% increase in midazolam peak plasma concentrations (Cmax), and 3-4% decrease in total exposures (AUC). Bupropion showed a 55% decrease in Cmax and 48-49% decrease in AUCs. Pioglitazone showed a 10% decrease in Cmax and 6% decrease in AUC. In Study 2, midostaurin resulted in a 26% increase in Cmax and 7-10% increase in AUC of EES; and a 19% increase in Cmax and 29-42% increase in AUC of LVG. Midostaurin 50 mg twice daily for 28 days ensured that steady-state concentrations of midostaurin and the active metabolites were achieved by the time of CYP substrate drugs or oral contraceptive dosing. No safety concerns were reported. CONCLUSION: Midostaurin neither inhibits nor induces CYP3A4 and CYP2C8, and weakly induces CYP2B6. Midostaurin at steady state has no clinically relevant PK interaction on hormonal contraceptives. All treatments were well tolerated.

Comparative Bioavailability of a Single Dose of Trametinib (TMT212) Containing 9% vs 11% Dimethyl Sulfoxide in Randomized Healthy Volunteers to Assess Long-Term Storage at Room Temperature.

Storage of trametinib tablets outside of 2-8°C protected from moisture may lead to loss of dimethyl sulfoxide (DMSO) and adversely impact trametinib bioavailability. In this open-label, phase 1, single-dose, randomized, 2-treatment, 2-period crossover study in healthy volunteers, bioavailability of a single 2-mg tablet of trametinib containing 9% DMSO (test formulation), corresponding to the lowest DMSO content in the tablet after storage at 25°C for 36 months, was evaluated vs bioavailability of a 2-mg tablet containing 11% DMSO (reference formulation). Sixty-five percent of subjects (n = 39/65) were men, and mean (standard deviation) age was 45.6 (11.17) years. Time to reach maximum plasma concentration occurred at 1.5 hours after dosing. The geometric mean ratio (90%CI) comparing 2-mg trametinib containing 9% DMSO with 2-mg trametinib containing 11% DMSO for area under the concentration-time curve from time 0 to the last measurable plasma concentration sampling time was 0.890 (0.848-0.935), suggesting the 2 formulations have similar bioavailability. The majority of adverse events were mild, with 1 subject experiencing 1 grade 3 headache. These results indicated that storage of trametinib at room temperatures ≤25°C during the overall shelf life of 36 months would not negatively impact trametinib bioavailability.

Population pharmacokinetics of sonidegib (LDE225), an oral inhibitor of hedgehog pathway signaling, in healthy subjects and in patients with advanced solid tumors.

PURPOSE: Sonidegib (Odomzo) selectively inhibits smoothened and suppresses the growth of hedgehog pathway-dependent tumors. A population pharmacokinetic (PK) analysis of sonidegib in healthy subjects and patients with advanced solid tumors was conducted to characterize PK, determine variability, and estimate covariate effects. METHODS: PK data from five phase 1 or 2 studies (N = 436) in the dose range from 100 to 3000 mg were analyzed using NONMEM. A two-compartment base model with first-order absorption, lag time, linear elimination, and bioavailability that decreased with dose was updated to describe the PK of sonidegib. Covariate analyses were performed and were incorporated into the population PK full model. RESULTS: The base and full models were robust with a good fit to the study data. Population-predicted geometric means (inter-individual variability, CV%) of apparent oral clearance, apparent volume of distribution at steady state, accumulation ratio, and elimination half-life were 9.5 L/h (71.4 %), 9163 L (74.9 %), 21 (131 %) and 29.6 days (109 %). Clinically relevant covariate effects were: A high-fat meal increased sonidegib bioavailability fivefold, healthy volunteers had threefold higher clearance, sonidegib bioavailability decreased with increasing dose levels, and PPI coadministration reduced sonidegib bioavailability by 30 %. Sonidegib PK was not significantly impacted by baseline age, weight, total bilirubin, alanine aminotransferase, albumin, creatinine clearance, gender, and ethnicity (Western countries versus Japanese). CONCLUSION: No dose adjustment is needed for mild hepatic impairment, mild and moderate renal impairment, age, weight, gender, or ethnicity. This population PK model adequately characterizes sonidegib PK characteristics and can be used for various simulations and applications.

Dynamic tumor modeling of the dose-response relationship for everolimus in metastatic renal cell carcinoma using data from the phase 3 RECORD-1 trial.

BACKGROUND: The phase 3 RECORD-1 trial (NCT00410124) established the efficacy and safety of everolimus in patients with metastatic renal cell carcinoma (mRCC) who progress on sunitinib or sorafenib. In RECORD-1, patients received 10 mg everolimus daily, with dose reduction to 5 mg daily allowed for toxicity. We have developed a model of tumor growth dynamics utilizing serial measurements of the sum of the longest tumor diameters (SLD) from individual RECORD-1 patients to define the dose-response relationship of everolimus. RESULTS: The model predicts that after 1 year of continuous dosing, the change in SLD of target lesions will be +142.1% ± 98.3%, +22.4% ± 17.2%, and -15.7% ± 11.5% in the average patient treated with placebo, 5 mg everolimus, and 10 mg everolimus, respectively. This nonlinear, mixed-effects modeling approach can be used to describe the dynamics of each individual patient, as well as the overall population. This allows evaluation of how an actual dosing history and individual covariates impact on the observed drug effect, and offers the possibility of predicting clinical observations as a function of time. CONCLUSIONS: In this pharmacodynamic model of tumor response, everolimus more effectively shrinks target lesions in mRCC when dosed 10 mg daily versus 5 mg daily, although a 5-mg dose still shows an antitumor effect. These data support earlier studies that established 10 mg daily as the preferred clinical dose of everolimus, and improve our understanding of the everolimus dose-response relationship.

Concurrent use of proton pump inhibitors or H2 blockers did not adversely affect nilotinib efficacy in patients with chronic myeloid leukemia.

PURPOSE: The impact of proton pump inhibitors (PPIs) and histamine H2 receptor antagonists (H2 blockers) on the efficacy of nilotinib was evaluated. METHODS: Retrospective analyses were performed in patients with newly diagnosed Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia in chronic phase (CML-CP; N = 492) and in patients with imatinib-resistant or imatinib-intolerant Ph+ CML-CP (N = 256) treated with nilotinib. RESULTS: In the newly diagnosed population, 87 (17.7 %) and 49 (10.0 %) patients received PPIs and H2 blockers, respectively. Major molecular response at 12 months was achieved by 59 (49.6 %) patients who received at least one PPI or H2 blocker (n = 119) and 153 (41.0 %) patients who did not receive any comedication (n = 373; P = 0.13). PPIs and H2 blockers were used by 77 (30.1 %) and 17 (6.6 %) patients with imatinib-resistant or imatinib-intolerant CML-CP, respectively. Major cytogenetic response by 12 months was achieved by 55 (64.0 %) patients who received at least one PPI or H2 blocker (n = 86) versus 98 (57.6 %) patients who did not receive any comedication (n = 170; P = 0.40); 39 (45.3 %) versus 65 (38.2 %), respectively, achieved complete cytogenetic response by 12 months (P = 0.34). Similar findings were observed in patients who received comedication for >50 % of the time on nilotinib therapy. Nilotinib steady-state trough concentration was not affected by the presence of PPIs or H2 blockers. CONCLUSIONS: Concurrent use of PPIs or H2 blockers did not affect the pharmacokinetics and efficacy of nilotinib in patients with Ph+ CML-CP.

An image method to evaluate bagasse fiber dimensions.

In the last 25 years the amount of textile nonwovens used for industrial and commercial applications increased more than 10 times. Bagasse fiber, a by-product from sugar cane industry, provides a natural resource for nonwoven industries. Even though underrated as a potential fiber, bagasse comes more and more into attention because of the increasing concern for disposal of agricultural residuals and the need for enhancing the sugar cane industry's profitability. However, there is a lack of an instrumental method to evaluate bagasse fiber length and fineness. This paper presents a study on measuring the bagasse fineness using image analysis method. Cross-sections images of bagasse fibers were visualized using Scanning Electronic Microscopy (SEM). The computing software Scion Image was used to measure bagasse fiber length and cross-sectional area. Relationship between fiber fineness and cross-sectional area was analyzed using the statistical method of regression.