Pharmacokinetics and Pharmacodynamics of Bimagrumab (BYM338).

BACKGROUND: Bimagrumab is a human monoclonal antibody binding to the activin type II receptor with therapeutic potential in conditions of muscle wasting and obesity. This phase I study evaluated the pharmacokinetics (PK), pharmacodynamics (PD), and safety of various dose regimens of bimagrumab and routes of administration in healthy older adults. METHODS: This was a randomized, double-blind, placebo-controlled, parallel-arm, multiple-dose study in older adult men and women (aged ≥ 70 years, body mass index [BMI] 18-34 kg/m2) with stable health and diet. The study comprised seven treatment groups (Cohorts 1-7). Participants received bimagrumab or placebo treatment every 4 weeks for three doses (Cohorts 1 [700 mg] and 2 [210 mg] intravenous infusion; Cohorts 3 [1500 mg] and 4 [525 mg] subcutaneous infusion), or every week for 12 doses (Cohorts 5 [300 mg], 6 [150 mg], and 7 [52.5 mg] subcutaneous bolus injection) and were followed up until week 20. Blood samples were collected for bimagrumab PK analysis. PD were assessed by dual energy X-ray absorptiometry to quantify the change from baseline in lean body mass (LBM) and fat body mass (FBM) compared with placebo. Safety was assessed throughout the study. RESULTS: Eighty-four of 91 (92.3%) randomized participants (mean age 74.5 years; BMI 28.0 kg/m2) completed the study. Demographic characteristics were generally balanced across the groups. A target-mediated drug disposition profile was observed following both intravenous and subcutaneous administration. The absolute subcutaneous bioavailability was estimated at approximately 40%. LBM increased by 4-6% (1.5-2 kg) from baseline throughout the treatment period for intravenous and subcutaneous regimens, except for the 52.5 mg subcutaneous dose, which did not differ from placebo. Concurrently, there was a decrease in FBM (approximately 2-3 kg) for all intravenous and subcutaneous regimens. Bimagrumab was generally safe and well tolerated; adverse events were mostly mild to moderate in severity. CONCLUSIONS: Dose levels of bimagrumab administered weekly subcutaneously resulted in PK profiles and PD effects comparable with monthly intravenous dosing, which supports the feasibility of the subcutaneous route of administration for bimagrumab for future clinical development.

Population Pharmacokinetic-B Cell Modeling for Ofatumumab in Patients with Relapsing Multiple Sclerosis.

BACKGROUND: Ofatumumab, a fully human anti-CD20 monoclonal antibody indicated for the treatment of relapsing forms of multiple sclerosis (RMS), binds to a unique conformational epitope, thereby depleting B cells very efficiently and allowing subcutaneous administration at lower doses. OBJECTIVES: The aims were to characterize the relationship between ofatumumab concentration and B cell levels, including the effect of covariates such as body weight, age, or baseline B cell count, and use simulations to confirm the chosen therapeutic dose. METHODS: Graphical and regression analyses previously performed based on data from a dose-range finding study provided the B cell depletion target used in the present work. All available adult phase 2/3 data for ofatumumab in RMS patients were pooled to develop a population pharmacokinetics (PK)-B cell count model, using nonlinear mixed-effects modeling. The population PK-B cell model was used to simulate B cell depletion and repletion times and the effect of covariates on PK and B cell metrics, as well as the dose response across a range of subcutaneous ofatumumab monthly doses. RESULTS: The final PK-B cell model was developed using data from 1486 patients. The predetermined B cell target was best achieved and sustained with the 20-mg dose regimen, with median B cell count reaching 8 cells/µL in 11 days and negligible repletion between doses. Only weight had a significant effect on PK, which did not translate into any clinically relevant effect on B cell levels. CONCLUSION: The PK-B cell modeling confirms the dose chosen for the licensed ofatumumab regimen and demonstrates no requirement for dose adjustment based on adult patient characteristics.

The BACE-1 inhibitor CNP520 for prevention trials in Alzheimer's disease.

The beta-site amyloid precursor protein cleaving enzyme-1 (BACE-1) initiates the generation of amyloid-ß (Aß), and the amyloid cascade leading to amyloid plaque deposition, neurodegeneration, and dementia in Alzheimer's disease (AD). Clinical failures of anti-Aß therapies in dementia stages suggest that treatment has to start in the early, asymptomatic disease states. The BACE-1 inhibitor CNP520 has a selectivity, pharmacodynamics, and distribution profile suitable for AD prevention studies. CNP520 reduced brain and cerebrospinal fluid (CSF) Aß in rats and dogs, and Aß plaque deposition in APP-transgenic mice. Animal toxicology studies of CNP520 demonstrated sufficient safety margins, with no signs of hair depigmentation, retina degeneration, liver toxicity, or cardiovascular effects. In healthy adults ≥ 60 years old, treatment with CNP520 was safe and well tolerated and resulted in robust and dose-dependent Aß reduction in the cerebrospinal fluid. Thus, long-term, pivotal studies with CNP520 have been initiated in the Generation Program.

Pharmacokinetic Interaction Between Fingolimod and Carbamazepine in Healthy Subjects.

This open-label, single-sequence study in healthy subjects investigated the effects of steady-state carbamazepine on the pharmacokinetic (PK) profile of a single 2-mg dose of fingolimod. In period 1, a single oral dose of fingolimod 2 mg (day 1) was followed by PK and safety assessments up to 36 days. In period 2, carbamazepine was administered in flexible, up-titrated doses (600 mg twice daily maximum) for 49 days. Fingolimod was administered on day 35, followed by a study completion evaluation (day 71). The PK analysis included 23 of 26 of the enrolled subjects (88.5%). Coadministration of fingolimod at steady-state carbamazepine concentrations resulted in increased fingolimod CL/F by 67% through the induction of CYP3A4, a cytochrome with negligible involvement in fingolimod clearance in an uninduced state. Fingolimod Cmax was reduced by 18% and AUCinf by 40%, as was T1/2 (106 vs 163 hours). A similar trend was observed for fingolimod-P. Models linking fingolimod-P blood concentrations to lymphocyte count or annual relapse rate suggest that such a decrease would have a low impact on the treatment effect. However, in the absence of efficacy data of fingolimod at doses lower than the therapeutic dose, their coadministration should be used with caution.

Determination of Seminal Concentration of Fingolimod and Fingolimod-Phosphate in Multiple Sclerosis Patients Receiving Chronic Treatment With Fingolimod.

The safety profile of fingolimod 0.5 mg, approved therapy for relapsing multiple sclerosis, is well established in clinical and real-world studies. As fingolimod is teratogenic in rats, it was considered important to assess the concentrations of fingolimod and its active metabolite, fingolimod-phosphate, in the semen of male patients on treatment and the risk of harming a fetus in a pregnant partner. In this multicenter open-label study, 13 male patients receiving fingolimod for at least 6 months provided 1 semen and 1 blood sample for analyte concentration measurements. The steady-state seminal concentrations of fingolimod and fingolimod-phosphate were close to those simultaneously observed in blood. The amount of fingolimod-related material in 10 mL of ejaculate was estimated to be 47.5 ng. The estimated fingolimod and fingolimod-phosphate blood Cmax values in a woman having regular sexual intercourse with a male patient treated with fingolimod 0.5 mg were approximately 400 and 2400 times smaller than the estimated values in the embryo-fetal development study in rats at the no-observed-adverse-event level. Consequently, the risk of harming a fetus in a pregnant woman is considered extremely unlikely.

Pharmacokinetics of fingolimod and metabolites in subjects with severe renal impairment: An open-label, single-dose, parallel-group study.

OBJECTIVE: This study assessed the pharmacokinetics and tolerability of fingolimod and its metabolites in severe renal impairment and healthy subjects. METHODS: In this single-dose, open-label study, 9 severe renal impairment subjects and 9 demographically matched healthy subjects were included. Each subject received a single oral dose of fingolimod 1.25 mg, and their blood and urine samples were assessed. The pharmacokinetics of fingolimod and its metabolites, fingolimod-phosphate (active metabolite, fingolimod-P), M2, and M3, were compared in both groups. Safety and tolerability were also assessed. RESULTS: In severe renal impairment subjects, mean±standard deviation values of Cmax (ng/mL) of fingolimod and fingolimod-P were 0.878±0.256 and 1.13±0.293 vs. 0.653±0.138 and 0.904±0.229 in healthy subjects, respectively. The overall drug exposures (AUCinf (ngxh/mL)) for fingolimod and fingolimod-P were 131±90.7 and 75.5±33.6 in severe renal impairment subjects vs. 82.3±36.9 and 65.9±30.6 in healthy subjects, respectively. t1/2 (hours) for fingolimod and fingolimod-P was comparable in severe renal impairment subjects (94±53 and 95±50) and healthy subjects (85±25 and 101±46). All adverse events were as expected for fingolimod 1.25 mg. CONCLUSIONS: The exposure to fingolimod and fingolimod-P was moderately increased (90% CI, 0.94-2.18) in severe renal impairment subjects, while half-lives and protein binding were similar to those in healthy subjects. Given that these changes are not clinically meaningful, fingolimod dose adjustment is considered unnecessary in patients with mild, moderate, or severe renal impairment.

Effect of fingolimod (FTY720) on cerebral blood flow, platelet function and macular thickness in healthy volunteers.

AIM: Fingolimod, a sphingosine 1-phosphate receptor modulator, is the first oral disease modifying therapy approved for the treatment of relapsing multiple sclerosis. The aim of this double-blind, placebo-controlled study was to evaluate the effect of fingolimod on cerebral blood flow, platelet function and macular thickness in healthy volunteers. METHODS: The study included 88 healthy volunteers who received fingolimod 0.5 mg or 1.25 mg or matched placebo over a period of 4 weeks. Transcranial colour coded sonography was performed to measure mean blood flow velocities, the platelet function was measured by the PFA-100® assay using a collagen/epinephrine cartridge and macular thickness was measured using optical coherence tomography. An assessment of non-inferiority of fingolimod vs. placebo was performed against a reference value (20% of the overall baseline value). RESULTS: All 88 randomized participants completed the study. At day 28 compared with baseline value, for 0.5 mg, 1.25 mg and placebo treatments, the mean middle cerebral artery blood flow velocity decreased by 4, 1 and 3.7 cm s(-1), respectively. The platelet function analyzer closure time increase was not significant (7.8, 7.5 and 10.4 s, respectively). The mean percentage change in the central foveal thickness from baseline for both eyes was below 3% for all groups. The safety profile of fingolimod in this study was found consistent with the previous reports. CONCLUSIONS: In healthy volunteers, the changes seen with both fingolimod doses were found to be within normal variability, non-inferior and comparable with those observed with placebo for all the pharmacodynamic parameters assessed.

Tolerability and Pulmonary Pharmacodynamic Effects During Treatment Initiation of Once-Daily Oral Fingolimod in Subjects With Moderate Asthma.

Fingolimod, a first-in-class sphingosine 1-phosphate receptor modulator, is the first approved oral therapy for relapsing multiple sclerosis (MS). While treatment initiation of clinical dose of fingolimod (0.5 mg) does not affect pulmonary function, supra-therapeutic doses (≥5.0 mg) increased airway resistance. The aim of this double-blind, placebo-controlled, parallel group, 10-day study was to measure the effect of fingolimod on pulmonary function in otherwise healthy patients with moderate asthma. Subjects (n = 36) were randomized into four cohorts that received either fingolimod 0.5, 1.25, 2.5 mg, or placebo once daily for 10 days. Subjects in placebo and fingolimod 0.5 mg groups did not differ in FEV1 AUEC0-6 h , FEF25-75% AUEC0-6 h , or in short-acting beta (ß) 2 agonists (SABA, rescue bronchodilator) use. Subjects on higher doses of fingolimod showed a mild reduction in FEV1 AUEC0-6 h and FEF25-75% AUEC0-6 h and a significant sixfold increase in SABA use versus placebo. One subject had moderately severe, acute exacerbation of asthma after receiving the first dose of fingolimod 1.25 mg that quickly responded to inhaled SABA. The observed safety profile was consistent with previous reports. These results provide reassurance that moderately asthmatic MS individuals can start on fingolimod 0.5 mg therapy with minimal effects on pulmonary function and SABA use.

Pharmacokinetics of fingolimod (FTY720) and a combined oral contraceptive coadministered in healthy women: drug-drug interaction study results.

BACKGROUND: Fingolimod has a novel mechanism of action in multiple sclerosis, being a first-in-class sphingosine 1-phosphate receptor modulator. Because of a potential risk of fetal toxicity based on animal studies, women of childbearing potential are advised to take effective contraceptive measures during and for 2 months after stopping fingolimod therapy. To assess whether the efficacy of a combined oral contraceptive (OC) could be compromised during fingolimod therapy, a steady-state, drug-drug interaction study of fingolimod with ethinylestradiol/levonorgestrel was performed in healthy female volunteers. OBJECTIVE: To assess the interaction between fingolimod 0.5 mg once daily and ethinylestradiol 30 µg/ levonorgestrel 150 µg once daily at a steady state. METHODS: 31 healthy women received the combined OC only on Days 1 - 14, followed by OC plus fingolimod on Days 15 - 28. RESULTS: In the presence of fingolimod, ethinylestradiol pharmacokinetics were unchanged, and levonorgestrel maximum plasma concentration at steady state and area under the concentration-time curve during a dosing interval increased by factors of 1.10 (90% CI 1.05 - 1.16) and 1.22 (90% CI 1.18 - 1.27), respectively. CONCLUSIONS: Fingolimod therapy does not alter the pharmacokinetics of the combined OC ethinylestradiol/ levonorgestrel to a clinically significant degree. Ethinylestradiol/levonorgestrel does not alter the pharmacokinetics of fingolimod. Women receiving fingolimod therapy are able to use a combined OC as a means of effective birth control.

Pharmacodynamic effects of steady-state fingolimod on antibody response in healthy volunteers: a 4-week, randomized, placebo-controlled, parallel-group, multiple-dose study.

Fingolimod, a first-in-class oral sphingosine 1-phosphate receptor (S1PR) modulator, is approved in many countries for relapsing-remitting multiple sclerosis, at a once-daily 0.5-mg dose. A reduction in peripheral lymphocyte count is an expected consequence of the fingolimod mechanism of S1PR modulation. The authors investigated if this pharmacodynamic effect impacts humoral and cellular immunogenicity. In this double-blind, parallel-group, 4-week study, 72 healthy volunteers were randomized to steady state, fingolimod 0.5 mg, 1.25 mg, or to placebo. The authors compared T-cell dependent and independent responses to the neoantigens, keyhole limpet hemocyanin (KLH), and pneumococcal polysaccharides vaccine (PPV-23), respectively, and additionally recall antigen response (tetanus toxoid [TT]) and delayed-type hypersensitivity (DTH) to KLH, TT, and Candida albicans. Fingolimod caused mild to moderate decreases in anti-KLH and anti-PPV-23 IgG and IgM levels versus placebo. Responder rates were identical between placebo and 0.5-mg groups for anti-KLH IgG (both > 90%) and comparable for anti-PPV-23 IgG (55% and 41%, respectively). Fingolimod did not affect anti-TT immunogenicity, and DTH response did not differ between placebo and fingolimod 0.5-mg groups. Expectedly, lymphocyte count reduced substantially in the fingolimod groups versus placebo but reversed by study end. Fingolimod was well tolerated, and the observed safety profile was consistent with previous reports.

Population pharmacokinetics of fingolimod phosphate in healthy participants.

Fingolimod (FTY720) is a sphingosine 1-phosphate receptor (S1PR) modulator currently being evaluated for the treatment of multiple sclerosis. Fingolimod undergoes phosphorylation in vivo to yield fingolimod phosphate (fingolimod-P), which modulates S1PRs expressed on lymphocytes and cells in the central nervous system. The authors developed a population model, using pooled data from 7 phase 1 studies, to enable characterization of fingolimod-P pharmacokinetics following oral administration of fingolimod and to evaluate the impact of key demographic variables on exposure. The fingolimod-P concentration-time course after either single or multiple doses of fingolimod was described by a 2-compartment model with first-order apparent formation and elimination, lag time in the apparent formation, and dose-dependent relative bioavailability and apparent central volume of distribution. Body weight and ethnicity were identified as demographic covariates correlated with the disposition of fingolimod-P. Model predictions indicated no need for dose adjustment of fingolimod based on body weight; the effect of ethnicity on the disposition of fingolimod requires further investigation. The accurate prediction of the pharmacokinetic profile of fingolimod-P determined empirically in 2 large phase 3 trials provides external validation of the model.

Placebo-controlled study of the effects of fingolimod on cardiac rate and rhythm and pulmonary function in healthy volunteers.

PURPOSE: Fingolimod (FTY720) is a sphingosine-1 phosphate-receptor (S1PR) modulator recently approved as a once-daily oral therapy for relapsing multiple sclerosis (MS) in many countries. As S1PRs are widely expressed, including in heart and lung tissues, this study investigated the possible effects of fingolimod on heart-rate circadian rhythm and pulmonary function. METHODS: Healthy volunteers (n = 39) were randomized to receive fingolimod 0.5 mg, 1.25 mg, or placebo for 14 days. Heart rate and measures of cardiac and pulmonary function were assessed during the study. RESULTS: Mean heart rate for the first 12 h postdose was lower for both fingolimod than for placebo groups (p < 0.001) and remained 10-15 bpm lower than placebo until day 14 (p < 0.05). Heart rate circadian rhythm, cardiac output, stroke volume, and systemic vascular resistance were similar among treatment groups throughout the study. There was no evidence of an effect of fingolimod on pulmonary function. Absolute lymphocyte counts decreased by approximately 70% from baseline in both fingolimod groups (day 14) and began to increase within 14 days of stopping treatment. CONCLUSIONS: In healthy volunteers treated for 14 days, once-daily fingolimod doses of 0.5 mg and 1.25 mg had no effect on cardiac or pulmonary function beyond a transient decrease in heart rate at treatment initiation.

Clinical pharmacokinetics of fingolimod.

Fingolimod (FTY720), a sphingosine 1-phosphate receptor modulator, is the first in a new class of therapeutic compounds and is the first oral therapy approved for the treatment of relapsing forms of multiple sclerosis (MS). Fingolimod is a structural analogue of endogenous sphingosine and undergoes phosphorylation to produce fingolimod phosphate, the active moiety. Fingolimod targets MS via effects on the immune system, and evidence from animal models indicates that it may also have actions in the central nervous system. In phase III studies in patients with relapsing-remitting MS, fingolimod has demonstrated efficacy superior to that of an approved first-line therapy, intramuscular interferon-ß-1a, as well as placebo, with benefits extending across clinical and magnetic resonance imaging measures. The pharmacokinetic profiles of fingolimod and fingolimod phosphate have been extensively investigated in studies in healthy volunteers, renal transplant recipients (the indication for which fingolimod was initially under clinical development, but the development was subsequently discontinued) and MS patients. Results from these studies have demonstrated that fingolimod is efficiently absorbed, with an oral bioavailability of >90%, and its absorption is unaffected by dietary intake, therefore it can be taken without regard to meals. Fingolimod and fingolimod phosphate have a half-life of 6-9 days, and steady-state pharmacokinetics are reached after 1-2 months of daily dosing. The long half-life of fingolimod, together with its slow absorption, means that fingolimod has a flat concentration profile over time with once-daily dosing. Fingolimod and fingolimod phosphate show dose-proportional exposure in single- and multiple-dose studies over a range of 0.125-5 mg; hence, there is a predictable relationship between dose and systemic exposure. Furthermore, fingolimod and fingolimod phosphate exhibit low to moderate intersubject pharmacokinetic variability. Fingolimod is extensively metabolized, with biotransformation occurring via three main pathways: (i) reversible phosphorylation to fingolimod phosphate; (ii) hydroxylation and oxidation to yield a series of inactive carboxylic acid metabolites; and (iii) formation of non-polar ceramides. Fingolimod is largely cleared through metabolism by cytochrome P450 (CYP) 4F2. Since few drugs are metabolized by CYP4F2, fingolimod would be expected to have a relatively low potential for drug-drug interactions. This is supported by data from in vitro studies indicating that fingolimod and fingolimod phosphate have little or no capacity to inhibit and no capacity to induce other major drug-metabolizing CYP enzymes at therapeutically relevant steady-state blood concentrations. Population pharmacokinetic evaluations indicate that CYP3A inhibitors and CYP3A inducers have no effect or only a weak effect on the pharmacokinetics of fingolimod and fingolimod phosphate. However, blood concentrations of fingolimod and fingolimod phosphate are increased moderately when fingolimod is coadministered with ketoconazole, an inhibitor of CYP4F2. The pharmacokinetics of fingolimod are unaffected by renal impairment or mild-to-moderate hepatic impairment. However, exposure to fingolimod is increased in patients with severe hepatic impairment. No clinically relevant effects of age, sex or ethnicity on the pharmacokinetics of fingolimod have been observed. Fingolimod is thus a promising new therapy for eligible patients with MS, with a predictable pharmacokinetic profile that allows effective once-daily oral dosing.

Topical treatment of Basal cell carcinomas in nevoid Basal cell carcinoma syndrome with a smoothened inhibitor.

Basal cell carcinoma (BCC) is a distinctive manifestation in nevoid basal cell carcinoma syndrome (NBCCS) patients. Both inherited and acquired mutations of patched 1 (PTCH1), a tumor-suppressor gene controlling the activity of Smoothened (SMO), are the primary cause of the constitutive activation of the Hedgehog (HH) pathway, leading to the emergence of BCCs in NBCCS. LDE225, a distinct, selective antagonist of SMO, showed potent inhibition of basaloid tumor nest formation and mediated regression of preformed basaloid tumors in organ cultures of skin derived from Ptch1 heterozygous knockout mice. In a double-blind, randomized, vehicle-controlled, intraindividual study, a total of 8 NBCCS patients presenting 27 BCCs were treated twice daily with 0.75% LDE225 cream or vehicle for 4 weeks. Application of 0.75% LDE225 cream was well tolerated and showed no skin irritation. Of 13 LDE225-treated BCCs, 3 showed a complete, 9 a partial, and only 1 no clinical response. Except for one partial response, the vehicle produced no clinical response in any of the 14 treated BCCs. Treatment with 0.75% LDE225 cream in NBCCS patients was very well tolerated and caused BCC regression, thus potentially offering an attractive therapeutic alternative to currently available therapies for this indication.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclub.

Pharmacokinetics of oral cyclosporine (Neoral) in heart transplant recipients during the immediate period after surgery.

Neoral cyclosporine has better absorption characteristics than the original Sandimmun formulation. This has allowed Neoral to be administered orally in circumstances where Sandimmun had been ineffective, including the postoperative phase of liver transplantation. Sampling strategies, such as the measurement of drug concentration 2 h after oral administration, have been used in a variety of settings to estimate systemic exposure to Neoral (measured as the area under the blood concentration curve (AUC) of the drug) in blood. We conducted a pilot study to determine whether Neoral could be administered orally immediately after heart transplantation and to determine which pharmacokinetic parameters reflect systemic drug exposure in this setting. Eight male patients (mean age 50 years) undergoing a first heart transplant were studied. Neoral was administered orally before surgery and at 12-h intervals via a nasogastric tube after surgery. Twelve-hour pharmacokinetic profiles were obtained on postoperative days 1, 3 and 5. Cyclosporine concentrations were measured with the Dade Behring Emit assay, which is specific for the parent drug. Drug concentrations were dose-normalised and drug exposure was measured by the AUC. Drug exposure following administration (AUC(0-12)) was low on day 1 but increased by 99% between postoperative day 1 and day 5 ( P<0.05), indicating more complete absorption of cyclosporine; exposure in the first 4 h post-dose (AUC(0-4)) increased by 126% ( P<0.01), reflecting more rapid cyclosporine absorption, and the maximum blood concentration observed increased by 137% ( P<0.05) during the same period. The correlation between the cyclosporine trough concentration and AUC(0-12) was low on all days. Due to the changing pattern of cyclosporine absorption, concentration measurements at a single time point could not accurately predict 12-h exposure to the drug on all study days. However, the drug concentration at 2 h post-dose had a high correlation with drug exposure during the first 4 h (correlation of C(2) to AUC(0-4): r(2)>0.93 on all days). Absorption of Neoral was low immediately after heart transplantation but improved substantially during the first 5 days after surgery. No single timed measurement of drug concentration reflected cyclosporine exposure; however, the 2-h concentration did provide an accurate measure of the early phase of drug absorption (AUC(0-4)). Oral administration of Neoral may result in inadequate immunosuppression immediately after heart transplantation unless it is supplemented either by intravenous cyclosporine or by the use of an induction agent.