Target-Mediated Drug Disposition Population Pharmacokinetics Model of Alirocumab in Healthy Volunteers and Patients: Pooled Analysis of Randomized Phase I/II/III Studies

Target-Mediated Modeling of Alirocumab in Adolescents and Children ≥8 to <12 Years of Age Using Phase II and III Data

A population pharmacokinetic (PK) covariate analysis was conducted utilizing data from adolescents and children ≥8 to <12 years of age with heterozygous familial hypercholesterolemia. One phase II and 1 phase III study were analyzed (121 patients on active treatment). A 2-compartment target-mediated model with linear and target-mediated elimination and transit compartments describing lag time in absorption was utilized. Weight and high-dose statins were statistically significant covariate. Except for the central volume, estimated population PK parameters describing linear kinetics were similar across pediatric patients and healthy adults. Coadministration of concomitant high doses of statins was associated with an increase in the production rate of proprotein convertase subtilisin/kexin type 9. The primary covariate model adequately described alirocumab PKs in the pediatric population. The analysis supports the recommended weight-adjusted subcutaneous dosing regimens for alirocumab in children with heterozygous hypercholesterolemia aged ≥8 years.

Local depletion of large molecule drugs due to target binding in tissue interstitial space

Drug-target binding determines a drug's pharmacodynamics but can also have a profound impact on a drug's pharmacokinetics, known as target-mediated drug disposition (TMDD). TMDD models describe the influence of drug-target binding and target turnover on unbound drug concentrations and are frequently used for biologics and drugs with nonlinear plasma pharmacokinetics. For drug targets expressed in tissues, the effect of TMDD may not be detected when analyzing plasma concentration curves, but it might still affect tissue concentrations and occupancy. This review aimed to investigate the likeliness of such a scenario by reviewing the literature for a typical range of TMDD parameter values and their impact on local drug concentrations and target occupancy in a whole-body PBPK model with TMDD. Our analysis demonstrated that tissue drug concentrations are impacted and significantly depleted in many physiological scenarios. In contrast, the effect on plasma concentrations is much lower, specifically for smaller organs with lower perfusion. Moreover, in scenarios with fast internalization of the drug-target complex, the distribution of large molecules from plasma to tissue interstitial space emerges as a rate-limiting step for the drug-target interaction. These factors may lead to overpredicting local drug concentrations when considering only plasma pharmacokinetics. A sensitivity analysis revealed the high and not always intuitive impact of drug-specific parameters, including the drug molecule hydrodynamic radius, dissociation constant (Kd), drug-target complex internalization rate constant (kint), and target dissociation rate constant (koff), on the drug's pharmacokinetics. Our analysis demonstrated that tissue TMDD needs to be considered even if plasma pharmacokinetics are linear.

Population PK/PD modeling of low-density lipoprotein cholesterol response in hypercholesterolemic participants following administration of bococizumab, a potent anti-PCSK9 monoclonal antibody

We sought to characterize the population pharmacokinetic/pharmacodynamic (PK/PD) relationship of bococizumab (RN316/PF-04950615), a humanized IgG2Δa monoclonal antibody that binds to secreted human proprotein convertase subtilisin kexin type 9 (PCSK9), using data derived from 16 phase I, II, and III clinical studies (36,066 bococizumab observations, 46,790 low-density lipoprotein cholesterol [LDL-C] measurements, 3499 participants). A two-compartment disposition model with parallel linear and Michaelis-Menten elimination and an indirect response model was used to characterize the population PK and LDL-C response of bococizumab. Potential model parameters and covariate relationships were explored, and visual predictive checks were used for model assessment and validation. Key covariates included the effect of anti-drug antibodies (ADAs) on exposure through impact on clearance and bioavailability; impact of statins on bococizumab elimination (maximal rate of metabolism); and impact of statins, Asian race, and male sex on LDL-C efficacy (maximum effect). ADAs and neutralizing ADAs did not have additional effects on LDL-C beyond the influence on bococizumab exposure. In conclusion, the population PK/PD model adequately describes bococizumab concentration and LDL-C efficacy. The covariate effects are consistent with the presumed mechanism of action of PCSK9 inhibitors. With increasing availability of antibody-based therapeutics, improved understanding of the effect of ADAs and statins on bococizumab PK/PD adds to the literature and enhances our pharmacological understanding of how immunogenicity and concomitant medications may impact the PK/PD of biotherapeutics.

Pharmacokinetic/LDL-C and exposure-response analysis of tafolecimab in Chinese hypercholesterolemia patients: Results from phase I, II, and III studies

Tafolecimab, a novel fully human monoclonal antibody targeting PCSK9, has been assessed in Chinese healthy volunteers and patients with hypercholesterolemia. This analysis is to develop and qualify a population pharmacokinetics (PopPKs)/LDL-C model to characterize tafolecimab PK and LDL-C profiles, evaluate the impact of potential covariates on tafolecimab, estimate individual predicted exposure, and LDL-C decreasing, furthermore, explore exposure-response relationship to support clinical use. Data from six clinical trials in China were used to develop the PopPK/LDL-C model. A Michaelis-Menten approximation of the target-mediated drug disposition (TMDD) model was used to describe PK data and indirect response (IDR) model was developed to estimate the LDL-C profile. A stochastic approximation expectation maximization algorithm was applied to estimate PopPK/LDL-C parameters. The PK/LDL-C time course data for tafolecimab were well described by TMDD/IDR model. Baseline covariates resulting in statistically significant changes in PK/LDL-C parameters included: body weight and sex on absorption rate constant; body weight, sex, and unbound PCSK9 on central volume; body weight and sex on clearance; baseline LDL-C on first-order rate constants for the removal of an effect); and disease and sex on maximum effect. However, the magnitudes of changes associated with these covariates do not necessitate dose adjustment. Exposure-efficacy relationship indicated that the nadir of LDL-C reduction achieved with the steady-state trough plasma concentration (Ctrough ) of tafolecimab at 5 μg/mL, and no further LDL-C decreasing with the increasing Ctrough . There was no exposure dependency observed in exposure-safety exploration. The PopPK/LDL-C model was successfully developed, validated, and predicted tafolecimab/LDL-C concentrations and individual exposures.

Proprotein Convertase Subtilisin/Kexin 9 as a Modifier of Lipid Metabolism in Atherosclerosis

Despite being the most common treatment strategy in the management of atherosclerosis and subsequent cardiovascular disease, classical statin therapy has certain disadvantages, including numerous side effects. In addition, a regimen with daily administration of the drug is hard to comply with. Thus, there is a need for modern and more efficient therapeutic strategies in CVD treatment. There is extensive evidence indicating that PCSK9 promotes atherogenesis through a variety of mechanisms. Thus, new treatment methods can be developed that prevent or alleviate atherosclerotic cardiovascular disease by targeting PCSK9. Comprehensive understanding of its atherogenic properties is a necessary precondition for the establishment of new therapeutic strategies. In this review, we will summarize the available data on the role of PCSK9 in the development and progression of atherosclerosis. In the last section, we will consider existing PCSK9 inhibitors.

Combined Semi-mechanistic Target-Mediated Drug Disposition and Pharmacokinetic-Pharmacodynamic Models of Alirocumab, PCSK9, and Low-Density Lipoprotein Cholesterol in a Pooled Analysis of Randomized Phase I/II/III Studies

BACKGROUND AND OBJECTIVES

Alirocumab is a cholesterol-lowering monoclonal antibody targeting proprotein convertase subtilisin kexin type 9 (PCSK9) indicated in the prevention of cardiovascular risk and exhibiting target-mediated drug disposition (TMDD). The aim of this work was to develop an integrated pharmacokinetic-pharmacodynamic model to describe the interaction of alirocumab with PCSK9 and its impact on the evolution of low-density lipoprotein cholesterol (LDL-C) levels and explore labeling specification for subpopulations.

METHODS

Using data collected from nine phase I/II/III clinical studies (n = 527, subcutaneous or intravenous administration), a TMDD model considering the quasi-steady-state approximation was developed to characterize the interaction dynamics of alirocumab and PCSK9, combined with an indirect pharmacodynamic model describing the inhibition of LDL-C by PCSK9 in a one-step approach using nonlinear-mixed effects modeling. A "full fixed effects modeling" strategy was implemented to quantify parameter-covariate relationships.

RESULTS

The model captures the interaction between alirocumab and its target PCSK9 and how this mechanism drives LDL-C depletion, with an estimation of the associated between-subject variability of model parameters and the quantification of clinically relevant parameter-covariate relationships. Co-administration of statins was found to increase the central volume of distribution of alirocumab by 1.75-fold (5.6 L versus 3.2 L) and allow for a 14% greater maximum lipid-lowering effect (88% versus 74%), highlighting the synergy of action between anti-PCSK9 therapeutic antibodies and statins toward lowering LDL-C plasma levels. Baseline levels of PCSK9 were found to be related to the amplitude of LDL-C variations by increasing the concentration of free PCSK9 necessary to reach half its capacity of inhibition of LDL-C degradation.

CONCLUSION

The maximum effect of alirocumab is achieved when free PCSK9 concentration is close to zero, as seen mostly after 150 mg every 2 weeks (Q2W) or 300 mg every 4 weeks (Q4W), indicating that there would be no additional clinical benefit of increasing the dose higher than these recommended dosing regimens.

A quantitative systems pharmacology modeling platform for evaluating triglyceride profiles in patients with high triglycerides receiving evinacumab

A model to quantitatively characterize the effect of evinacumab, an investigational monoclonal antibody against angiopoietin‐like protein 3 (ANGPTL3) on lipid trafficking is needed. A quantitative systems pharmacology (QSP) approach was developed to predict the transient responses of different triglyceride (TG)‐rich lipoprotein particles in response to evinacumab administration. A previously published hepatic lipid model was modified to address specific queries relevant to the mechanism of evinacumab and its effect on lipid metabolism. Modifications included the addition of intermediate‐density lipoprotein and low‐density lipoprotein compartments to address the modulation of lipoprotein lipase (LPL) activity by evinacumab, ANGPTL3 biosynthesis and clearance, and a target‐mediated drug disposition model. A sensitivity analysis guided the creation of virtual patients (VPs). The drug‐free QSP model was found to agree well with clinical data published with the initial hepatic liver model over simulations ranging from 20 to 365 days in duration. The QSP model, including the interaction between LPL and ANGPTL3, was validated against clinical data for total evinacumab, total ANGPTL3, and TG concentrations as well as inhibition of apolipoprotein CIII. Free ANGPTL3 concentration and LPL activity were also modeled. In total, seven VPs were created; the lipid levels of the VPs were found to match the range of responses observed in evinacumab clinical trial data. The QSP model results agreed with clinical data for various subjects and was shown to characterize known TG physiology and drug effects in a range of patient populations with varying levels of TGs, enabling hypothesis testing of evinacumab effects on lipid metabolism.

Development of a Pharmacokinetic Model Describing Neonatal Fc Receptor-Mediated Recycling of HL2351, a Novel Hybrid Fc-Fused Interleukin-1 Receptor Antagonist, to Optimize Dosage Regimen

HL2351 (hIL‐1Ra‐hyFc) is a novel recombinant protein formed by the fusion of two human interleukin‐1 receptor antagonist components into one antibody‐derived fragment crystallizable portion. Although HL2351 has a pharmacological mechanism of action similar to that of anakinra as a commercialized biopharmaceutical drug, HL2351 has been desired to reduce the dose frequency and improve therapeutic efficacy due to its long circulation half‐life. In this study, we aimed to develop a population pharmacokinetic (PK) model for HL2351 using a neonatal Fc receptor (FcRn)–mediated recycling model based on a quasi‐steady‐state approximation of target‐mediated drug disposition (TMDD) for the description of interactions between the drug and FcRn. FcRn recycling was expected in the case of HL2351 because of PK related to the antibody portion. A TMDD model was also applied to describe interactions of IL1R with HL2351 or anakinra. PK data were collected from a phase I study conducted in six groups (1, 2, 4, 8, 12 mg/kg HL2351 and 100 mg anakinra single subcutaneous administration; n = 8 per group). In consequence, the PK of anakinra and HL2351 following administration of multiple doses at different dosages were simulated. Optimized doses were considered based on average concentrations of IL1R bound to anakinra and HL2351. HL2351 at doses of 326 mg or 4.267, 4.982, 5.288, 5.458, or 5.748 mg/kg once weekly or HL2351 at 1726 mg or 21.92, 26.86, 29.10, 30.36, or 32.53 mg/kg once biweekly would have similar therapeutic effects with anakinra at a dose of 100 mg or 1, 2, 3, 4, or 8 mg/kg administered once daily, respectively.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Alirocumab in Healthy Chinese Subjects: A Randomized, Double-Blind, Placebo-Controlled, Ascending Single-Dose Study

BACKGROUND

The addition of alirocumab (a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 [PCSK9]) to background statin therapy provides significant incremental low-density lipoprotein cholesterol (LDL-C) lowering and cardiovascular event risk reduction.

OBJECTIVES

Our objectives were to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of alirocumab in healthy Chinese subjects.

METHODS

In this double-blind, placebo-controlled, phase I study, 35 Chinese subjects (aged 21-45 years) with baseline LDL-C > 100 mg/dL (2.59 mmol/L) were randomized to receive a single 1 mL subcutaneous injection of alirocumab 75, 150, or 300 mg, or placebo, and followed up for ~ 12 weeks.

RESULTS

Treatment-emergent adverse events, most frequently nasal congestion and dry throat, were reported in three of seven or eight subjects in each alirocumab dose group (two of seven in the placebo group). One patient receiving alirocumab 300 mg had a mild local injection-site reaction. No alirocumab recipients demonstrated antidrug antibodies. Maximum alirocumab serum concentrations (6-34 mg/dL) occurred at a median of 3-7 days across the dose groups. Maximum mean LDL-C reductions from baseline were observed on days 8, 15, and 22 with alirocumab 75 (55.3%), 150 (63.7%), and 300 mg (73.7%), respectively. Mean free PCSK9 levels were reduced to below the lower limit of quantification within 4 h of dosing. Total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B were reduced with alirocumab.

CONCLUSIONS

In Chinese subjects, alirocumab 75, 150, and 300 mg was safe and well-tolerated. Pharmacokinetic/pharmacodynamic parameters, including clinically meaningful reductions in LDL-C and other lipids/lipoproteins, were consistent with data from Japanese and Western populations. Clinicaltrials.gov identifier: NCT02979015.

Influence of Antigen Mass on the Pharmacokinetics of Therapeutic Antibodies in Humans

Therapeutic antibodies are increasingly used to treat various diseases, including neoplasms and chronic inflammatory diseases. Antibodies exhibit complex pharmacokinetic properties, notably owing to the influence of antigen mass, i.e. the amount of antigenic targets to which the monoclonal antibody binds specifically. This review focuses on the influence of antigen mass on the pharmacokinetics of therapeutic antibodies quantified by pharmacokinetic modelling in humans. Out of 159 pharmacokinetic studies, 85 reported an influence of antigen mass. This influence led to non-linear elimination decay in 50 publications, which was described using target-mediated drug disposition or derived models, as quasi-steady-state, irreversible binding and Michaelis-Menten models. In 35 publications, the pharmacokinetics was apparently linear and the influence of antigen mass was described as a covariate of pharmacokinetic parameters. If some reported covariates, such as the circulating antigen level or tumour size, are likely to be correlated to antigen mass, others, such as disease activity or disease type, may contain little information on the amount of antigenic targets. In some cases, antigen targets exist in different forms, notably in the circulation and expressed at the cell surface. The influence of antigen mass should be soundly described during the early clinical phases of drug development. To maximise therapeutic efficacy, sufficient antibody doses should be administered to ensure the saturation of antigen targets by therapeutic antibodies in all patients. If necessary, antigen mass should be taken into account in routine clinical practice.

Population Pharmacokinetic/Pharmacodynamic Analysis of Alirocumab in Healthy Volunteers or Hypercholesterolemic Subjects Using an Indirect Response Model to Predict Low-Density Lipoprotein Cholesterol Lowering: Support for a Biologics License Application Submission: Part II

BACKGROUND

Alirocumab, a human monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly lowers low-density lipoprotein cholesterol levels.

OBJECTIVE

This analysis aimed to develop and qualify a population pharmacokinetic/pharmacodynamic model for alirocumab based on pooled data obtained from 13 phase I/II/III clinical trials.

METHODS

From a dataset of 2799 individuals (14,346 low-density lipoprotein-cholesterol values), individual pharmacokinetic parameters from the population pharmacokinetic model presented in Part I of this series were used to estimate alirocumab concentrations. As a second step, we then developed the current population pharmacokinetic/pharmacodynamic model using an indirect response model with a Hill coefficient, parameterized with increasing low-density lipoprotein cholesterol elimination, to relate alirocumab concentrations to low-density lipoprotein cholesterol values.

RESULTS

The population pharmacokinetic/pharmacodynamic model allowed the characterization of the pharmacokinetic/pharmacodynamic properties of alirocumab in the target population and estimation of individual low-density lipoprotein cholesterol levels and derived pharmacodynamic parameters (the maximum decrease in low-density lipoprotein cholesterol values from baseline and the difference between baseline low-density lipoprotein cholesterol and the pre-dose value before the next alirocumab dose). Significant parameter-covariate relationships were retained in the model, with a total of ten covariates (sex, age, weight, free baseline PCSK9, total time-varying PCSK9, concomitant statin administration, total baseline PCSK9, co-administration of high-dose statins, disease status) included in the final population pharmacokinetic/pharmacodynamic model to explain between-subject variability. Nevertheless, the high number of covariates included in the model did not have a clinically meaningful impact on model-derived pharmacodynamic parameters.

CONCLUSIONS

This model successfully allowed the characterization of the population pharmacokinetic/pharmacodynamic properties of alirocumab in its target population and the estimation of individual low-density lipoprotein cholesterol levels.

[Pharmacokinetic variability of therapeutic antibodies]

Therapeutic antibodies have been increasingly used for the treatment of various diseases, including cancers and chronic inflammatory diseases. The pharmacokinetic interindividual variability of mAbs is large and influences, at least in part, the clinical response to antibody treatment. This variability is explained by a number of individual sources of variability, which are reviewed here. Some of them are major because they are frequently reported to greatly influence the interindividual variability; notably, increased body size, the presence of anti-drug antibodies, and high antigen mass are associated with decreased antibody concentrations. Other individual sources of variability are of less critical importance. They include sex, age, co-treatments, or genetic polymorphisms of IgG Fc receptors (FcgRs). The interindividual variability of antibody pharmacokinetics should be soundly described in order to design optimal dosing strategy.

Tumor necrosis factor-mediated disposition of infliximab in ulcerative colitis patients

Ulcerative Colitis (UC) is an inflammatory bowel disease typically affecting the colon. Patients with active UC have elevated tumor necrosis factor (TNF) concentrations in serum and colonic tissue. Infliximab is a monoclonal antibody directed against TNF and binds with high affinity. Target-mediated drug disposition (TMDD) is reported for monoclonal antibodies meaning that their pharmacokinetics are affected by high target affinity. Here, a TMDD model is proposed to describe the interaction between infliximab and TNF in UC patients. Data from 20 patients with moderate to severe UC was used. Patients received standard infliximab induction therapy (5 mg kg⁻¹) at week 0, followed by infusions at week 2 and 6. IFX, anti-drug antibodies and TNF serum concentrations were measured at day 0 (1 h after infusion), 1, 4, 7, 11, 14, 18, 21, 28 and 42. A binding model, TMDD model, and a quasi-steady state (QSS) approximation were evaluated using nonlinear mixed effects modeling (NONMEM). A two-compartment model best described the concentration–time profiles of infliximab. Typical clearance of infliximab was 0.404 L day⁻¹ and increased with the presence of anti-drug antibodies and with lower albumin concentrations. The TMDD-QSS model best described the pharmacokinetic and pharmacodynamics data. Estimate for TNF baseline (B_max was 19.8 pg mL⁻¹ and the dissociation constant (K_ss) was 13.6 nM. This model could eventually be used to investigate the relationship between suppression of TNF and the response to IFX therapy.

Population Pharmacokinetic Analysis of Alirocumab in Healthy Volunteers or Hypercholesterolemic Subjects Using a Michaelis-Menten Approximation of a Target-Mediated Drug Disposition Model-Support for a Biologics License Application Submission: Part I

BACKGROUND

Alirocumab, a human monoclonal antibody, inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9) to significantly reduce low-density lipoprotein cholesterol levels; pharmacokinetics (PK) are governed by non-linear, target-mediated drug disposition (TMDD).

OBJECTIVES

We aimed to develop and qualify a population PK (PopPK) model to characterize the PK profile of alirocumab, evaluate the impact of covariates on alirocumab PK and on individual patient exposures, and estimate individual predicted concentrations for a subsequent PK/pharmacodynamic (PD) analysis.

METHODS

Data from 13 phase I-III trials of 2799 healthy volunteers or patients with hypercholesterolemia treated with intravenous or subcutaneous alirocumab (13,717 alirocumab concentrations) were included; a Michaelis-Menten approximation of the TMDD model was used to estimate PK parameters and exposures. The final model comprised two compartments with first-order absorption. Elimination from the central compartment was described by linear (CLL) and non-linear Michaelis-Menten clearance (Vm and Km). The model was validated using visual predictive check and bootstrap methods. Patient exposures to alirocumab were computed using individual PK parameters.

RESULTS

The PopPK model was well-qualified, with the majority of observed alirocumab concentrations in the 2.5th-97.5th predicted percentiles. Covariates responsible for interindividual variability were identified. Body weight and concomitant statin administration impacted CLL, whereas time-varying free PCSK9 concentrations and age affected Km and peripheral distribution volume (V3), respectively. No covariates were clinically meaningful, therefore no dose adjustments were needed.

CONCLUSIONS

The model explained the between-subject variability, quantified the impact of covariates, and, finally, predicted alirocumab concentrations (subsequently used in a PopPK/PD model, see Part II) and individual exposures.

Alirocumab for low-density lipoprotein cholesterol lowering

Ischemic heart disease and stroke are the leading causes of death in the world currently. Both of these conditions are primarily caused by atherosclerosis, the underlying pathophysiology of which is the deposition of lipid, specifically low-density lipoprotein cholesterol (LDL-C) within the arterial bed. PCSK9, is a proteolytic enzyme, which indirectly increases LDL-C levels by causing the destruction of LDL receptors, the main way that humans regulate their serum LDL-C levels. Inhibitors of PCSK9 in conjunction with statins have allowed achievement of very low LDL-C levels. This review will provide an in-depth efficacy and safety review of alirocumab, a monoclonal antibody inhibitor of PCSK9, including the ODYSSEY OUTCOMES trial.

PCSK9 in cholesterol metabolism: from bench to bedside

Dyslipidemia, and specifically elevated low-density lipoprotein (LDL) cholesterol, is one of the most important cardiovascular risk factors. Statins are considered first line therapy for the primary and secondary prevention of cardiovascular disease. However, statins may not be adequate treatment for elevated circulating LDL levels and are ineffective in certain familial hypercholesterolemias. The discovery of proprotein convertase subtilisin/kexin type 9 (PCSK9), a regulatory protein that affects LDL receptors, offers a new alternative for these patients. Moreover, gain-of-function PCSK9 mutations were discovered to be the root cause of familial autosomal dominant hypercholesterolemia. Inhibition of PSCK9 reduces plasma LDL levels, even in patients for whom statins are ineffective or not tolerated. Alirocumab and evolocumab, human monoclonal antibodies that inhibit PCSK9, have been approved to lower LDL levels. While there are drawbacks to these treatments, including adverse events, administration by subcutaneous injection, and high cost, these drugs are indicated for the treatment of atherosclerotic cardiovascular disease and familial hypercholesterolemia as adjunct to diet and maximally tolerated statin therapy. PCSK9 inhibitors may work synergistically with statins to lower LDL. Novel approaches to PCSK9 inhibition are currently in development with the aim of providing safe and effective treatment options to decrease cardiovascular event burden, ideally at lower cost and with oral bioavailability.

Pharmacokinetics and pharmacodynamics of bococizumab, a monoclonal antibody to PCSK9, after single subcutaneous injection at three sites [NCT 02043301]

AIM

To characterize the single-dose pharmacokinetics (PK) and pharmacodynamics (PD) of bococizumab, a monoclonal antibody inhibiting proprotein convertase subtilisin/kexin type 9 (PCSK9), administered subcutaneously (s.c.) to the abdomen, thigh, or upper arm (NCT02043301).

METHODS

Seventy-five adults with low-density lipoprotein cholesterol (LDL-C) ≥130 mg/dL and not on background lipid-lowering therapy were randomized (1:1:1) to a single 150-mg s.c. dose of bococizumab administered to the abdomen, thigh, or upper arm. Blood samples for bococizumab and lipids were collected for 12 weeks postdose.

RESULTS

Plasma bococizumab concentration-time profiles and PK parameters were generally similar across injection sites. Mean maximum observed concentration (C_max ) ranged from 8.14 to 11.9 μg/mL, and area under the concentration-time curve (AUC_inf ) ranged from 160.3 to 198.9 µg∙day/mL. The median time to C_max (T_max ) ranged from 4.25 to 6.93 days. Similar LDL-C concentration-time profiles were observed across injection sites, with mean (% coefficient of variation) maximum reductions in LDL-C of -57.5% (15.8), -57.0% (25.9), and -55.0% (24.1) for the abdomen, thigh, and upper arm, respectively. Adverse events (AEs) were mostly mild and generally similar across injection sites. Commonly reported AEs were upper respiratory tract infection (9.3%), headache (6.7%), and injection site reaction (6.7%). One serious AE was reported (ischemic colitis), which was not considered related to study drug.

CONCLUSIONS

Similar PK profiles and robust LDL-C reductions were observed following a single 150-mg s.c. injection of bococizumab administered to the abdomen, thigh, or upper arm in untreated subjects with LDL-C ≥130 mg/dL. Bococizumab was generally well tolerated following a single 150-mg s.c. administration in this subject population.

Comparative Pharmacokinetics and Pharmacodynamics of Bococizumab Following a Single Subcutaneous Injection Using Drug Substance Manufactured at Two Sites or Administration via Two Different Devices

The pharmacokinetics (PK) and pharmacodynamics (PD) of bococizumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, were compared following a single 150-mg subcutaneous dose administered to healthy subjects (n = 156-158/arm) via: (1) a prefilled syringe (PFS) using drug substance (DS) manufactured by Pfizer, (2) a PFS using DS manufactured by Boehringer Ingelheim Pharma, (3) a prefilled pen using DS manufactured by Pfizer (NCT02458209). Blood samples were collected for 12 weeks postdose. Safety was monitored throughout. Mean maximum plasma concentration (C_max ) ranged between 11.0 and 11.3 μg/mL, and area under the plasma concentration-time curve (AUC_inf ) ranged between 177.6 and 185.0 μg·day/mL across treatments. The 90% confidence intervals for the ratios of adjusted geometric means for C_max and AUC_inf fell within the 80%-125% range for both DS and delivery device comparisons. Comparable low-density lipoprotein cholesterol profiles were observed, with nadir values of 54.3-56.1 mg/dL across treatments. Similar PCSK9 responses were also observed. Safety profiles were similar across treatments, and the majority of adverse events (AEs) were mild. Three subjects reported serious AEs. The most frequently reported AEs were headache, injection-site reaction, and upper respiratory tract infection, with no clear differences across treatments. Comparable PK, PD, and safety were observed following a single bococizumab 150-mg subcutaneous injection regardless of site of DS manufacture or delivery device used.