Disease progression model using the integrated Alzheimer's Disease Rating Scale.

INTRODUCTION: An Alzheimer's disease (AD) dementia disease progression model was developed based on the integrated Alzheimer's Disease Rating Scale (iADRS). METHODS: Data from 3483 placebo participants in six AD trials were used to develop the disease progression model with NONMEM (version 7.4.2) and examined for mild cognitive impairment, and mild and moderate dementia due to AD. RESULTS: Baseline iADRS score was significantly influenced by AD symptomatic medication use, EXPEDITION2 enrollment (included moderate AD participants), age, and baseline Mini-Mental State Examination (MMSE) score. Rate of disease progression increased across disease stage and was significantly influenced by AD medication use, age, and baseline MMSE score. Apolipoprotein E ε4 carrier status did not influence baseline iADRS score or disease progression. DISCUSSION: These results demonstrate a disease progression model describing the time course of the iADRS across the AD severity spectrum. This model can assist future clinical trials in study design optimization and treatment effect interpretation. HIGHLIGHTS: A disease progression model described the integrated Alzheimer's Disease Rating Scale (iADRS) time course in mild cognitive impairment to moderate Alzheimer's disease. Using the linear regression model, iADRS scores can be calculated for Mini-Mental State Examination scores. Results can help optimize future clinical trial design and aid in understanding treatment effects.

Population pharmacokinetic and exposure-efficacy analysis of ixekizumab in paediatric patients with moderate-to-severe plaque psoriasis (IXORA-PEDS).

AIMS: Ixekizumab is a high-affinity monoclonal antibody that selectively targets interleukin-17A used in the treatment of adult and paediatric patients with moderate-to-severe psoriasis. This analysis evaluated the pharmacokinetics (PK) of ixekizumab and the exposure-efficacy relationship in paediatric patients aged 6 to <18 years with psoriasis. METHODS: Population PK and exposure-efficacy models were developed. The models used data from paediatric patients with psoriasis participating in the Phase 3 IXORA-PEDS trial in which patients were dosed according to weight categories. The exposure-efficacy model is a Psoriasis Area and Severity Index (PASI) time course model using data up to Week 12, a co-primary efficacy endpoint. RESULTS: A 2-compartment population PK model describes the PK of ixekizumab in paediatric patients with the effect of body weight incorporated on clearance and volume terms using an allometric relationship. The weight category-based dosing ensured that ixekizumab mean trough serum concentrations in paediatric patients with psoriasis (3.20-3.33 µg/mL) were within the range of concentrations observed in adult patients with psoriasis (mean [standard deviation]: 3.48 [2.16] µg/mL) administered an efficacious dosing regimen. The observed PASI response rates at Week 12 in paediatric patients (91.9/81.8/52.5% for PASI75/90/100) are well predicted by the final exposure-efficacy model and response rates are similar or higher than those achieved in adults (86.2/66.6/35.0% for PASI75/90/100). CONCLUSION: This analysis is the first to describe the PK and exposure-efficacy relationship of ixekizumab in paediatric patients with psoriasis. The analyses support the selection of the weight category-based ixekizumab dosing regimens approved for use in paediatric patients with psoriasis.

Duration of action of two insulin glargine products, LY2963016 insulin glargine and Lantus insulin glargine, in subjects with type 1 diabetes mellitus.

AIMS: LY2963016 (LY IGlar) and Lantus (IGlar) are insulin glargine products manufactured by distinct processes, but with identical amino acid sequences. This study compared the duration of action of LY IGlar and IGlar in subjects with type 1 diabetes mellitus (T1DM). MATERIALS AND METHODS: This was a randomized, double-blind, single-dose, two-period, crossover study. Twenty subjects underwent 42-hour euglycaemic clamps after a single subcutaneous 0.3-U/kg dose of LY IGlar or IGlar. In this study, the duration of action was defined as the time required for blood glucose levels to rise consistently above a predefined cut-off of 8.3 mmol/L (150 mg/dL) from a state of euglycaemia. Blood samples were collected to measure blood glucose for pharmacodynamic (PD) evaluations. RESULTS: End of action was reached within 42 hours in 26 of 40 clamps (13 LY IGlar and 13 IGlar). The median duration of action for all subjects was 37.1 and 40.0 hours, and the mean duration of action (calculated using only patients who reached end of action) was 23.8 and 25.5 hours for LY IGlar and IGlar, respectively. The duration of action was demonstrated to be similar between the treatments using time-to-event analysis (log-rank test of equality p = .859). Following administration of LY IGlar and IGlar, the PD parameters of maximum glucose infusion rate (R max ) and total glucose infusion during the clamp (G tot ) were comparable. CONCLUSION: LY IGlar and IGlar had similar duration of action and comparable PD parameters in subjects with T1DM.

Mirikizumab Exposure-Response Relationships in Patients with Moderately-to-Severely Active Ulcerative Colitis in Randomized Phase II and III Studies.

Mirikizumab is a humanized anti-interleukin-23p19 monoclonal antibody being developed for ulcerative colitis (UC) and Crohn's disease. We characterized the relationship of mirikizumab systemic exposure with efficacy and safety end points in patients with UC using phase II (NCT02589665) and III (NCT03518086, NCT03524092) trial data. Exposure-response models were developed for clinical remission, clinical response, endoscopic remission, and change in modified Mayo score following induction (50-1,000 mg i.v. every 4 weeks) and maintenance (200 mg s.c. every 4 or 12 weeks) treatment. These models evaluated observed and pharmacokinetic model-predicted mirikizumab exposures as the exposure measure. Key safety event rates were compared across mirikizumab exposure quartiles in the phase III trial. Mirikizumab efficacy in patients with UC showed an apparent positive association with systemic exposure following both induction and maintenance. However, further analysis found this relationship to be overstated by the presence of confounding factors that were not among the tested patient covariates. While prior biologic experience and baseline disease severity showed statistically significant influences on estimated placebo effect, no patient factors affected the mirikizumab effect parameters in any of the phase III exposure-response models. There was no apparent mirikizumab concentration relationship with any adverse event of special interest. When the phase II and III data and confounding are considered together, efficacy was unlikely to be strongly affected by variation in exposures across individual patients at the phase III dose. Together with the previously demonstrated mirikizumab exposure insensitivity to patient factors, these findings indicate that mirikizumab dose adjustment to patient characteristics is not required.

Mirikizumab Pharmacokinetics in Patients with Moderately to Severely Active Ulcerative Colitis: Results from Phase III LUCENT Studies.

BACKGROUND AND OBJECTIVE: Mirikizumab is a humanized anti-interleukin-23-p19 monoclonal antibody being developed for ulcerative colitis and Crohn's disease. This analysis characterized mirikizumab pharmacokinetics using phase II and III trial data from patients with moderately to severely active ulcerative colitis. METHODS: Serum pharmacokinetic data in patients receiving mirikizumab 50-1000 mg intravenously every 4 weeks as induction treatment and mirikizumab 200 mg subcutaneously every 4 or 12 weeks as maintenance treatment across three trials (N = 1362) were analyzed using non-linear mixed-effects modeling. Covariate effects on mirikizumab exposure were evaluated using simulation-based estimations. RESULTS: Mirikizumab pharmacokinetics was best described by a linear two-compartment model with first-order absorption. Clearance, volume of distribution for central and peripheral compartments, and half-life were estimated at approximately 0.022 L/h (linear), 3.11 L and 1.69 L, and 9.5 days, respectively. Statistically significant effects of body weight and serum albumin levels on clearance, body weight on central and peripheral volumes of distribution, and body mass index on bioavailability were observed but effects were small relative to random inter-individual variability (% coefficient of variation: 18-64%). The subcutaneous bioavailability of mirikizumab was 48%. CONCLUSIONS: Mirikizumab displayed pharmacokinetic characteristics typical of a monoclonal antibody where clearance increased with body weight and decreased with the albumin level, and bioavailability decreased with body mass index. These effects were small relative to random variability, indicating that a dose adjustment for patient factors is not required. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT02589665 (28 October, 2015), NCT03518086 (8 May, 2018), NCT03524092 (14 May, 2018).

Donanemab Population Pharmacokinetics, Amyloid Plaque Reduction, and Safety in Participants with Alzheimer's Disease.

Donanemab is an amyloid-targeting therapy that resulted in robust amyloid plaque reduction and slowed Alzheimer's disease (AD) progression compared with placebo in the phase II TRAILBLAZER-ALZ study (NCT03367403). The objectives of the current analyses are to characterize (i) the population pharmacokinetics of donanemab, (ii) the relationship between donanemab exposure and amyloid plaque reduction (response), and (iii) the relationship between donanemab exposure and amyloid-related imaging abnormalities with edema or effusions (ARIA-E). Model development included data from participants with mild cognitive impairment or mild to moderate dementia due to AD from the phase Ib study on donanemab (NCT02624778) and participants with early symptomatic AD from the TRAILBLAZER-ALZ study. The analysis showed donanemab has a terminal elimination half-life of 11.8 days. Body weight and antidrug antibody titer impact donanemab exposure but not the pharmacodynamic response. Maintaining a donanemab serum concentration above 4.43 µg/mL (95% confidence interval: 0.956, 10.4) is associated with amyloid plaque reduction. The time to achieve amyloid plaque clearance (amyloid plaque level < 24.1 Centiloids) varied depending on the baseline amyloid level, where higher baseline levels were associated with fewer participants achieving amyloid clearance. The majority of participants achieved amyloid clearance by 52 weeks on treatment. Apolipoprotein ε4 carriers, irrespective of donanemab serum exposure, were 4 times more likely than noncarriers to have an ARIA-E event by 24 weeks.

Donanemab exposure and efficacy relationship using modeling in Alzheimer's disease.

INTRODUCTION: Donanemab is an amyloid-targeting therapy that specifically targets brain amyloid plaques. The objective of these analyses was to characterize the relationship of donanemab exposure with plasma biomarkers and clinical efficacy through modeling. METHODS: Data for the analyses were from participants with Alzheimer's disease from the phase 1 and TRAILBLAZER-ALZ studies. Indirect-response models were used to fit plasma phosphorylated tau 217 (p-tau217) and plasma glial fibrillated acidic protein (GFAP) data over time. Disease-progression models were developed using pharmacokinetic/pharmacodynamic modeling. RESULTS: The plasma p-tau217 and plasma GFAP models adequately predicted the change over time, with donanemab resulting in decreased plasma p-tau217 and plasma GFAP concentrations. The disease-progression models confirmed that donanemab significantly reduced the rate of clinical decline. Simulations revealed that donanemab slowed disease progression irrespective of baseline tau positron emission tomography (PET) level within the evaluated population. DISCUSSION: The disease-progression models show a clear treatment effect of donanemab on clinical efficacy regardless of baseline disease severity.

Donanemab (LY3002813) dose-escalation study in Alzheimer's disease.

INTRODUCTION: This study explored the safety and tolerability features of donanemab (LY3002813) in patients with mild cognitive impairment due to Alzheimer's disease (AD) or mild to moderate AD dementia. METHODS: Patients with AD were enrolled into the single-ascending dose phase and were administered a single, intravenous (IV) dose of donanemab (five dosing cohorts from 0.1 to 10 mg/kg) or placebo followed by a 12-week follow-up period for each dose level. After the follow-up period, the same patients proceeded into the multiple-ascending dose (MAD) phase (five cohorts) and were administered IV doses of donanemab (0.3 to 10 mg/kg) or placebo approximately once per month for up to four doses depending on the initial doses (only cohort 1 went from 0.1 mg/kg to a higher dose of 0.3 mg/kg during the MAD phase). This phase concluded with a 12-week follow-up period. The relative exposure assessment of an unblinded, single, subcutaneous 3-mg/kg dose of donanemab in patients with AD was also performed, followed by a 12-week follow-up period. One cohort of healthy subjects received an unblinded, single, IV 1-mg/kg dose of donanemab. These two cohorts did not continue to the MAD phase. RESULTS: Donanemab was generally well tolerated up to 10 mg/kg. After single-dose administration from 0.1 to 3.0 mg/kg, the mean terminal elimination half-life was ≈4 days, increasing to ≈10 days at 10 mg/kg. Only the 10-mg/kg dose showed changes in amyloid positron emission tomography. Amyloid reduction of 40% to 50% was achieved. Approximately 90% of subjects developed anti-drug antibodies at 3 months after a single intravenous dose. DISCUSSION: Intravenous donanemab 10 mg/kg can reduce amyloid deposits in AD despite having a shorter than expected half-life.

A Euglycemic Glucose Clamp Study to Evaluate the Bioavailability of LY2963016 Relative to Insulin Glargine in Healthy Chinese Subjects.

Insulin glargine (IGlar) and LY2963016 (LY IGlar) are long-acting insulin analogs with identical primary amino acid sequences. We conducted a randomized, open-label, 2-treatment, 2-period, crossover study in healthy Chinese subjects to evaluate the relative bioavailability of LY IGlar to IGlar and pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of LY IGlar. Subjects (n = 58) were randomized to receive single subcutaneous doses (0.5 U/kg) of LY IGlar and IGlar with a ≥7-day washout period between study treatments. Serum was collected before and up to 24 hours after dosing to assess PK characteristics. PD characteristics were assessed by euglycemic clamp up to 24 hours after dosing. Linear mixed-effects models were used to fit the log-transformed primary PK (maximum observed concentration and area under the concentration-time curve from time 0 to 24 hours) and PD parameters (maximum glucose infusion rate and total amount of glucose infused during clamp period). The geometric least squares means ratios (90% confidence interval) of LY IGlar to IGlar for maximum observed concentration and area under the concentration-time curve from time 0 to 24 hours were 0.961 (0.887-1.04) and 0.941 (0.872-1.01), respectively. The geometric least squares means ratios (90% confidence interval) of LY IGlar to IGlar were 0.91 (0.85-0.98) for maximum glucose infusion rate and 0.89 (0.82-0.97) for total amount of glucose infused during clamp period. LY IGlar demonstrated similarity to IGlar in PK and PD characteristics following single-dose (0.5 U/kg) administration in healthy Chinese subjects.

Exposure-Response Modeling to Characterize the Relationship Between Ixekizumab Serum Drug Concentrations and Efficacy Responses at Week 12 in Patients With Moderate to Severe Plaque Psoriasis.

Ixekizumab, a high-affinity monoclonal antibody, selectively targets interleukin-17A and has been shown to be efficacious in the treatment of moderate to severe psoriasis. The objective was to describe the relationship between ixekizumab concentrations and efficacy response (static Physician Global Assessment [sPGA] and the Psoriasis Activity and Severity Index [PASI) scores] after 12 weeks of ixekizumab treatment in psoriasis patients from 3 phase 3 studies. Data from 2888 psoriasis patients randomized to receive placebo or 80 mg ixekizumab every 2 weeks or every 4 weeks were analyzed. Separate logistic regression models describing the relationship between ixekizumab concentrations and sPGA or PASI scores at week 12 were used to determine the probability of patients achieving a response and to investigate the impact of various patient factors other than drug concentrations on response rates. Both dosing regimens were efficacious, with higher rates of response achieved with the higher range of observed ixekizumab concentrations after every-2-week dosing. Although higher bodyweight, palmoplantar involvement, lower baseline disease state, or high baseline C-reactive protein were associated with slightly lower response rates, the magnitude of effect of these factors on sPGA(0,1) response was small, with all subgroups able to achieve high levels of response. Other factors tested had no effect including age, sex, and antidrug antibody status. Logistic regression modeling of ixekizumab concentration and efficacy data accurately identified the proportion of responders using sPGA or PASI end points. The higher concentration ranges achieved with 80 mg every 2 weeks versus every 4 weeks were associated with higher response levels.

Ixekizumab Pharmacokinetics, Anti-Drug Antibodies, and Efficacy through 60 Weeks of Treatment of Moderate to Severe Plaque Psoriasis.

Ixekizumab, a high-affinity monoclonal antibody that selectively targets IL-17A, is efficacious for moderate to severe plaque psoriasis. We examined relationships between serum ixekizumab concentrations, treatment-emergent anti-drug antibodies (TE-ADAs), and efficacy during 60 weeks of treatment in a randomized, controlled, phase 3 study. Steady-state ixekizumab serum trough concentrations were rapidly achieved and associated with high clinical responses at week 12 with a starting dose of 160 mg followed by 80 mg every 2 weeks. During the long-term extension period dosage of 80 mg every 4 weeks, stable serum trough concentrations maintained high clinical responses through week 60. Most (82.6%, 308/373) patients never developed TE-ADA. In TE-ADA-positive patients (17.4%, n = 65), variations in ADA titers, neutralizing capacity, and persistence were observed. Fifty-six patients (15%) developed low or moderate maximum titers, with serum concentrations and efficacy comparable to those of TE-ADA-negative patients. Nine patients (2.4%) developed high titers, with variable individual clinical responses; four of these nine patients achieved at least PASI 75 at week 60. Median serum concentrations in the TE-ADA-high titer group were generally comparable to the median serum concentrations in the lower titer groups. For most patients, TE-ADA had a negligible impact on ixekizumab serum concentrations and efficacy. Clinicaltrials.gov: NCT01646177.

Dose/Exposure-Response Modeling to Support Dosing Recommendation for Phase III Development of Baricitinib in Patients with Rheumatoid Arthritis.

Baricitinib is an oral inhibitor of Janus kinases (JAKs), selective for JAK1 and 2. It demonstrated dose-dependent efficacy in patients with moderate-to-severe rheumatoid arthritis (RA) in a phase IIb study up to 24 weeks. Population pharmacokinetic/pharmacodynamic (PopPK/PD) models were developed to characterize concentration-time profiles and dose/exposure-response (D/E-R) relationships for the key efficacy (proportion of patients achieving American College of Rheumatology 20%, 50%, or 70% response rate) and safety endpoints (incidence of anemia) for the phase IIb study. The modeling suggested that 4 mg q.d. was likely to offer the optimum risk/benefit balance, whereas 2 mg q.d. had the potential for adequate efficacy. In addition, at the same total daily dose, a twice-daily regimen is not expected to provide an advantage over q.d. dosing for the efficacy or safety endpoints. The model-based simulations formed the rationale for key aspects of dosing, such as dose levels and dosing frequency for phase III development.

LY2963016 Insulin Glargine and Insulin Glargine (Lantus) Produce Comparable Pharmacokinetics and Pharmacodynamics at Two Dose Levels.

LY2963016 (LY IGlar) and Lantus (IGlar) are insulin glargine products with identical amino acid sequences. This was a phase 1 single-site, randomized, subject- and investigator-blinded, 4-treatment, 4-period crossover study to compare the pharmacokinetic (PK) and pharmacodynamic (PD) properties of LY IGlar and IGlar at 2 different doses. Fasted healthy subjects were randomly assigned to receive 2 single doses of LY IGlar and IGlar (0.3 and 0.6 U/kg for each product). Blood samples were collected up to 24 hours postdose to assess PK, and a euglycemic clamp lasting up to 24 hours postdose was conducted to assess PD. Twenty-four healthy subjects aged 23 to 52 years participated in the study. The primary PK parameters (area under the concentration versus time curve from 0 to 24 hours [AUC0-24 ] and maximum observed drug concentration [Cmax ]) and PD parameters (total amount of glucose infused during the clamp [Gtot ] and maximum glucose infusion rate [Rmax ]) were not statistically different between LY IGlar and IGlar at either dose. No safety concerns were noted with either drug. The study demonstrated that the PK and PD parameters for LY IGlar and IGlar were comparable following single doses at both 0.3 and 0.6 U/kg.

Comparison of the Pharmacokinetics and Pharmacodynamics of LY2963016 Insulin Glargine and EU- and US-Approved Versions of Lantus Insulin Glargine in Healthy Subjects: Three Randomized Euglycemic Clamp Studies.

OBJECTIVE: LY2963016 (LY IGlar) and Lantus (IGlar) are insulin glargine products manufactured by distinct processes but with identical amino acid sequences. Three studies evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) similarity of LY IGlar and the European Union- and US-approved versions of IGlar. RESEARCH DESIGN AND METHODS: These were three single-site, randomized, double-blind, two-treatment, four-period, crossover, euglycemic clamp studies. In each study, fasted healthy subjects received 0.5 units/kg s.c. doses of two different insulin glargine products on two occasions each, following a randomized sequence. A ≥7-day washout period separated the doses. Blood samples were collected predose and up to 24 h postdose to assess PK; PD was assessed by a euglycemic clamp lasting up to 24 h. RESULTS: A total of 211 subjects participated in the three studies. The PK (area under the curve [AUC]; maximum observed concentration [Cmax]) and PD (maximum glucose infusion rate [Rmax]; total glucose infusion during the clamp [Gtot]) were similar between LY IGlar and IGlar, with the ratios of geometric means ranging from 0.90 to 0.95 for PK parameters and from 0.91 to 0.99 for PD parameters across studies. In all cases, the 90% CIs for the ratios of geometric means were completely contained in the prespecified acceptance limits of 0.80-1.25. Adverse events were similar between treatments. CONCLUSIONS: These studies demonstrated that the PK and PD properties of LY IGlar and IGlar were similar after single 0.5 units/kg s.c. doses in healthy subjects, contributing to the totality of evidence supporting similarity of these products.