Clinical pharmacology of emicizumab for the treatment of hemophilia A.

INTRODUCTION: Emicizumab is a humanized bispecific antibody approved for the routine prophylaxis of bleeding episodes in patients with hemophilia A (PwHA) regardless of the presence of factor VIII (FVIII) inhibitors. It mimics the cofactor function of missing activated FVIII by bridging activated factor IX and factor X, thereby restoring hemostasis. AREAS COVERED: This review covers the clinical pharmacology of emicizumab and the translation of its pharmacokinetics (PK) and pharmacodynamics (PD) to clinical efficacy and safety. The PK of emicizumab is linear, with an approximately 1-month half-life. Once-weekly to every-4-week subcutaneous (SC) administrations maintain effective trough concentrations throughout the dosing intervals, associated with a coagulation potential analogous to that in patients with mild hemophilia A. In combination with activated prothrombin complex concentrate, and to a lesser extent with recombinant activated factor VII, emicizumab exerts a synergistic effect, whereas combination with FVIII may result in a non-additive coagulation potential at normal FVIII activity. EXPERT OPINION: The translation of emicizumab PK/PD into clinical effects was demonstrated in several phase III studies, which showed remarkable bleed control and a favorable safety profile in PwHA. These emicizumab attributes, together with the convenience of use (infrequent SC injections), offer a novel paradigm for the management of PwHA.

Development of a population pharmacokinetic model to characterize the pharmacokinetics of intrathecally administered tominersen in cerebrospinal fluid and plasma.

Tominersen is an intrathecally administered antisense oligonucleotide targeting huntingtin mRNA which leads to a dose-dependent, reversible lowering of cerebrospinal fluid (CSF) mutant huntingtin protein concentration in individuals with Huntington's disease. Nonlinear mixed-effect population pharmacokinetic (PopPK) modeling was conducted to characterize the CSF and plasma pharmacokinetics (PK) of tominersen, and to identify and quantify the covariates that affect tominersen PKs. A total of 750 participants from five clinical studies with a dose range from 10 to 120 mg contributed CSF (n = 6302) and plasma (n = 5454) PK samples. CSF PK was adequately described by a three-compartment model with first-order transfer from CSF to plasma. Plasma PK was adequately described by a three-compartment model with first-order elimination from plasma. Baseline total CSF protein, age, and antidrug antibodies (ADAs) were the significant covariates for CSF clearance. Body weight was a significant covariate for clearances and volumes in plasma. ADAs and sex were significant covariates for plasma clearance. The developed PopPK model was able to describe tominersen PK in plasma and CSF after intrathecal administration across a range of dose levels, and relevant covariate relationships were identified. This model has been applied to guide dose selection for future clinical trials of tominersen in patients with Huntington's disease.

A Phase I Study to Assess the Effect of Speed of Injection on Pain, Tolerability, and Pharmacokinetics After High-volume Subcutaneous Administration of Gantenerumab in Healthy Volunteers.

PURPOSE: Gantenerumab, a fully human anti-amyloid-ß IgG1 monoclonal antibody that binds to aggregated forms of amyloid-ß, is being investigated as a potential disease-modifying treatment for early (prodromal to mild) Alzheimer disease (AD). Our study compared the pain associated with 5- and 15-s subcutaneous injections of gantenerumab and evaluated the tolerability and pharmacokinetic properties of subcutaneous gantenerumab. METHODS: This randomized, open-label, single-active-dose, placebo-controlled crossover study was conducted in 50 healthy volunteers aged 40-80 years with no history of clinically significant disorders, drug or alcohol abuse, familial history of early-onset AD, or prior gantenerumab exposure. Eligible participants were randomized to a sequence of one 300-mg SC gantenerumab injection into the abdomen and 2 SC placebo injections (1 into the abdomen and 1 into the thigh) during 5 or 15 s. All injections were administered at least 90 min apart. Participants were assessed for local pain by visual analog scale (VAS) and verbal rating scale; safety profiles were assessed by recording adverse events (AEs), and plasma pharmacokinetic properties were also evaluated. FINDINGS: Immediately after the subcutaneous gantenerumab injection, the pain VAS score was numerically higher without reaching statistical significance in the 5-s versus 15-s injection group (VAS least-squares mean difference, 7.492 mm; 95% CI, -4.439-19.423 mm). In both injection speed groups, the mean pain VAS score was comparable after subcutaneous gantenerumab and placebo injections into the abdomen. Pain was reported after needle insertion and immediately after dosing, subsiding within 5 min after the dose. The pain VAS score was numerically higher after SC placebo injection into the thigh versus abdomen (5-s injection group: mean [SD] VAS score, 26.68 [27.83] vs 19.20 [25.60] mm; 15-s injection group: mean [SD] VAS score, 14.16 [20.62] vs 9.48 [12.04] mm). No serious AEs were reported; no participants withdrew because of an AE. All AEs were of mild intensity, were transient, and had resolved without sequelae at follow-up. The most common AEs were injection site reactions; redness was the most frequently observed skin reactivity event after subcutaneous gantenerumab administration (5-s injection group: 36%; 15-s injection group: 32%). After subcutaneous administration, gantenerumab reached a peak plasma concentration at a median time of 119 h (approximately 5 days); plasma concentrations declined in a monoexponential manner. Comparable pharmacokinetic profiles were observed between the injection speed groups. IMPLICATIONS: Subcutaneous gantenerumab injections at speeds of 5 and 15 s were well tolerated in healthy volunteers and could enable at-home administration by patients with AD or their caregivers. ClinicalTrials.gov identifier: NCT02882009.

Efficacy, safety, and pharmacokinetics of emicizumab prophylaxis given every 4 weeks in people with haemophilia A (HAVEN 4): a multicentre, open-label, non-randomised phase 3 study.

BACKGROUND: Emicizumab, a subcutaneously administered, humanised, bispecific, monoclonal antibody, is approved to treat people with haemophilia A of all ages with and without coagulation factor VIII (FVIII) inhibitors. HAVEN 4 assessed emicizumab prophylaxis administered as one dose every 4 weeks in adults and adolescents with haemophilia A, regardless of FVIII inhibitor status. METHODS: In this phase 3, multicentre, open-label, two-stage study, patients aged 12 years and older with severe congenital haemophilia A (<1% of normal FVIII activity in blood) or haemophilia A with FVIII inhibitors, undergoing treatment with either FVIII concentrates or bypassing agents were recruited from three sites in Japan and Spain for a run-in cohort, and from 17 sites in Australia, Belgium, Japan, Poland, Spain, and the USA for a subsequent expansion cohort. Participants in the run-in and expansion cohorts were given emicizumab subcutaneously 6 mg/kg every 4 weeks for 24 weeks or more; for patients in the expansion cohort this regimen was preceded by four loading doses of 3 mg/kg once weekly. In the run-in cohort, we assessed pharmacokinetics after single and multiple (every 4 weeks) subcutaneous administration of 6 mg/kg emicizumab and safety. In the expansion cohort, the efficacy endpoint was efficacy of prophylactic emicizumab in maintaining adequate bleed prevention, assessed in all patients who received at least one dose of emicizumab and reported as annualised bleed rates for treated bleeds, all bleeds (treated and untreated), treated spontaneous bleeds, treated joint bleeds, and treated target joint bleeds. Safety was assessed in all participants given emicizumab. This study is registered with ClinicalTrials.gov, number NCT03020160, and is ongoing. FINDINGS: Between Jan 30, 2017, and Feb 27, 2017, seven patients were enrolled into the initial run-in cohort, which confirmed the expected pharmacokinetic profile and safety of the regimen based on model-based simulations, providing sufficient evidence for opening of the expansion cohort (n=41), which was recruited and enrolled between May 24, 2017, and June 30, 2017. The annualised rate of treated bleeds was 2·4 (95% CI 1·4-4·3). 23 (56·1%; 95% CI 39·7-71·5) of 41 reported no treated bleeds and 37 (90%; 76·9-97·3) reported zero to three treated bleeds. The annualised bleed rate was 4·5 (95% CI 3·1-6·6) for all bleeds, 0·6 (0·3-1·5), for treated spontaneous bleeds, 1·7 (0·8-3·7) for treated joint bleeds, and 1·0 (0·3-3·3) for treated target joint bleeds. The most frequent treatment-related adverse event was injection-site reaction (nine [22%] of 41 patients). We observed no thrombotic events or development of de-novo antidrug antibodies with neutralising potential or FVIII inhibitors. INTERPRETATION: Emicizumab given once every 4 weeks showed clinically meaningful bleed control while being well tolerated. This regimen could improve patient care by decreasing treatment burden and increasing adherence to effective prophylaxis, potentially decreasing the development of secondary complications for people with haemophilia A. FUNDING: F Hoffmann-La Roche and Chugai Pharmaceutical.

Effect of Renal Impairment on the Pharmacokinetics and Pharmacodynamics of Tofogliflozin (A SELECTIVE SGLT2 Inhibitor) in Patients with Type 2 Diabetes Mellitus.

PURPOSE: Tofogliflozin is an orally available selective inhibitor of sodium-glucose co-transporter 2 for treatment of type 2 diabetes mellitus (T2DM). Two studies were conducted to evaluate the effect of renal impairment on pharmacokinetics and pharmacodynamics of tofogliflozin. METHODS: The studies were: 1) single dose study in T2DM patients with normal renal function and mild, moderate and severe renal impairment, and 2) multiple dose study for 24 weeks in T2DM patients with normal renal function and moderate renal impairment. RESULTS: Renal function did not have a clinically relevant effect on the PK of tofogliflozin. Urinary glucose excretion up to 24 h after administration of tofogliflozin (UGE24h) decreased with decreasing glomerular filtration rate. Lowering UGE24h resulted in waning glycemic control but not body weight reduction. CONCLUSIONS: Single and multiple administrations of tofogliflozin were generally well tolerated in T2DM patients with various renal functions. As far as investigated here, these studies indicate no dose adjustment is required for patients with renal impairment.

Pharmacodynamics, pharmacokinetics, safety and tolerability of the novel dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist RG7697 after single subcutaneous administration in healthy subjects.

AIMS: To evaluate the pharmacodynamics, pharmacokinetics and safety of single subcutaneous (s.c.) injection of ascending doses of RG7697, a dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist, in healthy subjects. METHODS: A total of 51 healthy volunteers were enrolled in this double-blind, placebo-controlled study investigating RG7697 doses ranging from 0.03 to 5 mg. Adverse events (AEs) were monitored and drug concentrations, fasting glycaemic variables, vital signs, ECG, antibody formation and routine laboratory variables were assessed. A meal tolerance test (MTT) was performed at the same time on day -1 (baseline) and day 1. RESULTS: RG7697 was generally well tolerated in healthy participants after s.c. injections up to 3.6 mg. Tolerability was limited by gastrointestinal AEs (nausea and vomiting) at the highest dose. There was a small dose-dependent increase in heart rate. No episodes of hypoglycaemia occurred. RG7697 concentrations peaked at 2 to 4 hours post-dose with a half-life of 19 to 25 hours. During MTT, RG7697 at doses ≥1.8 mg, reduced glucose maximum plasma concentration (Cmax ; -46%) without affecting overall glucose area under the curve (AUC). Its effect on insulin was more pronounced, with reductions in both Cmax (-64%) and AUC (-51%). Pharmacodynamic variables were well correlated to RG7697 average plasma concentration during MTT, with IC50 (average concentration required for 50% reduction) values of 49 and 24.5 ng/mL for glucose and insulin, respectively. CONCLUSION: Single s.c. injections of RG7697 up to 3.6 mg were generally well tolerated. Evidence of glycaemic effect and pharmacokinetic profiles consistent with once-daily dosing render this drug candidate suitable to be further tested in multiple-dose clinical trials in patients with type 2 diabetes.

Pharmacodynamics, pharmacokinetics and safety of multiple ascending doses of the novel dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist RG7697 in people with type 2 diabetes mellitus.

AIMS: To investigate the pharmacodynamics, pharmacokinetics and safety of multiple ascending doses of RG7697, a dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist, in patients with type 2 diabetes mellitus (T2D). METHODS: A total of 56 patients with T2D received once-daily subcutaneous (s.c.) injection of RG7697 (0.25-2.5 mg) or placebo for 14 days in a randomized, double-blind, dose-escalation study. Adverse events (AEs), vital signs, ECGs and routine laboratory variables were intensively monitored. Drug concentrations, fasting glycaemic variables, 24-hour glucose profiles, glycated haemoglobin (HbA1c) and antibody formation were measured. Several meal tolerance and gastric emptying tests were performed during the study. RESULTS: Daily s.c. injections of RG7697 were well tolerated by the majority of participants with T2D. The most frequently reported AEs with RG7697 were diarrhoea, nausea and decreased appetite. Asymptomatic events of hypoglycaemia were relatively uniformly distributed across dose groups including placebo. Pharmacokinetic steady-state was achieved within 1 week. Meaningful reductions in fasting, postprandial and 24-hour plasma glucose profile were observed at doses ≥0.75 mg, and were associated with numerical decreases in HbA1c (-0.67% [2.5-mg dose] vs -0.21% [placebo]). Decrease in postprandial insulin at doses ≥1.1 mg suggested improvement in insulin sensitivity. Minimum delay in gastric emptying and body weight reductions numerically greater than placebo (- 3.0 kg vs -0.9 kg) were seen at the highest dose of 2.5 mg. CONCLUSIONS: Daily doses of RG7697 for 2 weeks were well tolerated by the majority of patients with T2D. Pharmacokinetic data supported once-daily dosing and pharmacodynamic effect displayed dose-dependent reductions in fasting and postprandial plasma glucose, without increasing the risk of hypoglycaemia.

Oral administration of the 11ß-hydroxysteroid-dehydrogenase type 1 inhibitor RO5093151 to patients with glaucoma: an adaptive, randomised, placebo-controlled clinical study.

BACKGROUND/AIMS: Cortisol is involved in the regulation of intraocular pressure (IOP). This study aimed to assess the effect of 11ß-hydroxysteroid-dehydrogenase type 1 (11ßHSD1) inhibition by oral administration of RO5093151 on IOP. METHODS: The exposure of key ocular compartments following oral administration was assessed in rabbits. An adaptive, randomised, placebo-controlled study gated by a Bayesian decision criterion was performed in 35 patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). Following a 7-day placebo-controlled run-in period, 200 mg twice daily RO5093151 or placebo (4:1) were administered for 7 days. The extent of 11ßHSD1 inhibition was assessed by the ratio of urinary tetrahydrocortisol (5α and 5ß)/tetrahydrocortisone (THF/THE). Time-matched IOP assessments were performed. RESULTS: A high distribution of RO5093151 into the rabbit eye was observed. In humans, a high and sustained inhibition of 11ßHSD1 was shown by the decrease of THF/THE from 0.9 at baseline to 0.18 on day 7. There was no statistically significant difference in change of IOP from baseline. In the 'worse eye', the adjusted least square mean change from baseline was -2.7 mm Hg (95% CI -4.2 to -1.2) and -2.9(95% CI -5.9 to 0.1) in the RO5093151 and placebo group, respectively. CONCLUSIONS: Despite high inhibition of 11ßHSD1 and expected moderate to high tissue distribution in ocular tissues, a 7-day treatment with a high oral dose of RO5093151 did not result in a clinically meaningful effect on IOP in patients with POAG or OHT.

A novel double-tracer technique to characterize absorption, distribution, metabolism and excretion (ADME) of [14C]tofogliflozin after oral administration and concomitant intravenous microdose administration of [13C]tofogliflozin in humans.

BACKGROUND: Human mass balance studies and the assessment of absolute oral bioavailability (F) are usually assessed in separate studies. Intravenous microdose administration of an isotope tracer concomitant to an unlabeled oral dose is an emerging technique to assess F. We report a novel double-tracer approach implemented for tofogliflozin combining oral administration of a radiolabel tracer with concomitant intravenous administration of a stable isotope tracer. Tofogliflozin is a potent and selective sodium/glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus currently in clinical development. OBJECTIVES: The objectives of the present study were to assess the systemic exposure of major circulating metabolites, excretion balance, F and contribution of renal clearance (CLR) to total clearance (CL) of tofogliflozin in healthy subjects within one study applying a novel double-tracer technique. METHODS: Six healthy male subjects received 20 mg [(12)C/(14)C]tofogliflozin (3.73 MBq) orally and a concomitant microdose of 0.1 mg [(13)C]tofogliflozin intravenously. Pharmacokinetics of tofogliflozin were determined for the oral and intravenous route; the pharmacokinetics of the metabolites M1 and M5 were determined for the oral route. Quantification of [(12)C]tofogliflozin in plasma and urine and [(13)C]tofogliflozin in plasma was performed by selective LC-MS/MS methods. For the pre-selected metabolites of tofogliflozin, M1 and M5, a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to plasma and urine samples. Total radioactivity was assessed in plasma, urine and feces. Pharmacokinetic analysis was conducted by non-compartmental methods. RESULTS: The pharmacokinetics of tofogliflozin in healthy subjects were characterized by an F of 97.5 ± 12.3 %, CL of 10.0 ± 1.3 l/h and volume of distribution at steady-state (V(ss)) of 50.6 ± 6.7 l. The main route of elimination of total drug-related material was by excretion into urine (77.0 ± 4.1 % of the dose). The observed CL(R) of 25.7 ± 5.0 ml/min was higher than the product of the estimated glomerular filtration rate (eGFR) and fraction unbound in plasma (f(u)) (eGFR × f(u) 15 ml/min), indicating the presence of net active tubular secretion in the renal elimination of tofogliflozin. However, CLR contributed only 15.5 % to the CL of tofogliflozin, suggesting that reductions in CLR by renal impairment won't significantly affect systemic exposure to tofogliflozin. Tofogliflozin and its metabolite M1 were the only major circulating entities accounting for 46 ± 8.6 and 50 ± 8.2 %, respectively, of total circulating drug-related material, while the metabolite M5 was a minor circulating metabolite accounting for 3.0 ± 0.3 % of total circulating drug-related material. Both the M1 and M5 metabolites were excreted into urine and the major metabolite M1 did not exhibit active tubular secretion. CONCLUSIONS: These results demonstrate the utility of the double-tracer approach to provide essential pharmacokinetic data and excretion data for drug-related material in one study at the same dosing occasion. The data obtained allowed the characterization of absorption, distribution, metabolism and excretion of tofogliflozin. Tofogliflozin exhibited highly favorable pharmacokinetic properties as demonstrated by its high F, low CL and a low V(ss. The presence of only one major circulating metabolite of tofogliflozin was unambiguously demonstrated. As a drug targeting the kidney, luminal exposure of the kidney is achieved by renal filtration and active tubular secretion.