Ustekinumab as Induction and Maintenance Therapy for Crohn's Disease.

BACKGROUND: Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin-12 and interleukin-23, was evaluated as an intravenous induction therapy in two populations with moderately to severely active Crohn's disease. Ustekinumab was also evaluated as subcutaneous maintenance therapy. METHODS: We randomly assigned patients to receive a single intravenous dose of ustekinumab (either 130 mg or approximately 6 mg per kilogram of body weight) or placebo in two induction trials. The UNITI-1 trial included 741 patients who met the criteria for primary or secondary nonresponse to tumor necrosis factor (TNF) antagonists or had unacceptable side effects. The UNITI-2 trial included 628 patients in whom conventional therapy failed or unacceptable side effects occurred. Patients who completed these induction trials then participated in IM-UNITI, in which the 397 patients who had a response to ustekinumab were randomly assigned to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 8 weeks or every 12 weeks) or placebo. The primary end point for the induction trials was a clinical response at week 6 (defined as a decrease from baseline in the Crohn's Disease Activity Index [CDAI] score of ≥100 points or a CDAI score <150). The primary end point for the maintenance trial was remission at week 44 (CDAI score <150). RESULTS: The rates of response at week 6 among patients receiving intravenous ustekinumab at a dose of either 130 mg or approximately 6 mg per kilogram were significantly higher than the rates among patients receiving placebo (in UNITI-1, 34.3%, 33.7%, and 21.5%, respectively, with P≤0.003 for both comparisons with placebo; in UNITI-2, 51.7%, 55.5%, and 28.7%, respectively, with P<0.001 for both doses). In the groups receiving maintenance doses of ustekinumab every 8 weeks or every 12 weeks, 53.1% and 48.8%, respectively, were in remission at week 44, as compared with 35.9% of those receiving placebo (P=0.005 and P=0.04, respectively). Within each trial, adverse-event rates were similar among treatment groups. CONCLUSIONS: Among patients with moderately to severely active Crohn's disease, those receiving intravenous ustekinumab had a significantly higher rate of response than did those receiving placebo. Subcutaneous ustekinumab maintained remission in patients who had a clinical response to induction therapy. (Funded by Janssen Research and Development; ClinicalTrials.gov numbers, NCT01369329 , NCT01369342 , and NCT01369355 .).

Pharmacokinetics and Exposure Response Relationships of Ustekinumab in Patients With Crohn's Disease.

BACKGROUND & AIMS: Ustekinumab is a monoclonal antibody that binds with high affinity to the p40 subunit of human interleukin 12 (IL12 and IL23) that has been approved for treatment of patients with moderate to severe Crohn's disease (CD). However, there are few data on its pharmacokinetic properties or the relationship between drug exposure levels and patient response. We collected data from 2 Phase 3 induction studies and 1 maintenance study to determine ustekinumab's pharmacokinetic features, relationship between exposure and response, and optimal serum concentrations for efficacy. METHODS: We collected data on serum concentrations of ustekinumab and efficacy from induction studies of patients with moderate to severe CD given ustekinumab for 8 weeks following a single intravenous dose (either 130 mg or approximately 6 mg/kg). We collected the same data from a maintenance study of patients with a response to ustekinumab in the induction study who then received subcutaneous injections (90 mg) every 8 or 12 weeks for 44 weeks. At week 44 of the maintenance study (52 weeks after treatment began), patients were evaluated for the primary endpoint of clinical remission (defined as a CD activity index score below 150 points), endoscopic markers of efficacy, and serum level of C-reactive protein. Ustekinumab concentration data were categorized into quartiles and relationships between exposure and response were assessed. Optimal concentration cutoff values were evaluated using receiver operating characteristic curve analysis. RESULTS: Serum concentrations of ustekinumab over time were proportional to dose and did not differ significantly between the induction studies. In the maintenance study, ustekinumab concentration reached the steady state by the second maintenance dose; the median trough concentration was approximately threefold higher in patients given ustekinumab at 8-week intervals compared with 12-week intervals. Ustekinumab serum concentrations associated with rates of clinical remission and endoscopic efficacy endpoints, correlated inversely with level of C-reactive protein, and did not associate with use of immunomodulators. Trough concentrations of ustekinumab of 0.8 (or even up to 1.4 µg/mL) or greater were associated with maintenance of clinical remission in a higher proportion of patients than patients with lower trough concentrations. CONCLUSIONS: In an analysis of data from Phase 3 studies of patients with moderate to severe CD, we found serum concentrations of ustekinumab to be proportional to dose and associate with treatment efficacy. Concentrations of ustekinumab did not seem to be affected by cotreatment with immunomodulators. Clinicaltrials.gov no. NCT01369329 (UNITI 1), NCT01369342 (UNITI 2), and NCT01369355 (IM-UNITI).

Efficacy of Ustekinumab for Inducing Endoscopic Healing in Patients With Crohn's Disease.

BACKGROUND & AIMS: We evaluated the ability of ustekinumab, a monoclonal antibody against the p40 subunit of interleukins 12 and 23, to induce endoscopic healing in patients with moderate to severe Crohn's disease (CD). METHODS: We performed an endoscopy substudy of 334 patients with moderate to severe CD participating in 3 randomized controlled phase 3 studies to determine the safety and efficacy of ustekinumab induction and maintenance therapy. All patients underwent colonoscopy at baseline and week 8 of the induction studies and at week 44 of the maintenance study; all colonoscopies were assessed by a blinded central reader. During the induction studies, patients were randomly assigned to groups given intravenous ustekinumab (130 mg or 6 mg/kg) or placebo. At the baseline time point of the maintenance study (week 8 of the induction studies), patients with a clinical response to ustekinumab were randomly assigned to groups given subcutaneous ustekinumab (90 mg every 12 weeks or 8 weeks) or placebo. Additional maintenance analysis populations were patients who did not respond to ustekinumab or placebo during the induction studies, and patients who responded to placebo during the induction studies; we performed a post-hoc pooled analysis of randomly assigned and non-randomly assigned patients of the maintenance study. We analyzed data from patients with an ulcer in at least 1 segment at baseline of the induction studies. The primary end point was change in the Simplified Endoscopic Activity Score for Crohn's Disease (SES-CD), from baseline, at week 8. We also assessed the efficacy of maintenance therapy. RESULTS: Patients given ustekinumab had a greater reduction in SES-CD from the induction baseline time point until week 8 than placebo (reduction of 2.8 in patients given ustekinumab vs a reduction of 0.7 points in patients given placebo; P = .012). Results were similar among patients in different induction studies and patients given different doses of ustekinumab. At week 44, reductions in the SES-CD from the induction baseline were greater in patients given ustekinumab (for combined groups, a reduction of 2.5; P = .176 and for every 8 weeks, a reduction of 3.1; P = .107) than patients given placebo (reduction of 1.9 points). Maintenance results were similar for the larger pooled post-hoc analysis. CONCLUSIONS: In an analysis of data from 3 trials of patients with moderate to severe CD, ustekinumab (intravenous induction and subcutaneous maintenance) reduces SES-CD compared with placebo. We observed significant reductions in endoscopic disease activity at week 8 of induction therapy with ustekinumab. (ClinicalTrials.gov numbers, NCT01369329, NCT01369342, and NCT01369355).

Association Between Ustekinumab Trough Concentrations and Clinical, Biomarker, and Endoscopic Outcomes in Patients With Crohn's Disease.

BACKGROUND & AIMS: Ustekinumab, an inhibitor of the p40 subunit of interleukins 12 and 23, is an effective treatment for patients with Crohn's disease (CD). Trough concentrations of tumor necrosis factor (TNF) antagonists and presence of anti-drug antibodies are associated with important clinical and endoscopic outcomes. We investigated associations between trough concentrations of ustekinumab and clinical, biomarker, and endoscopic outcomes of real-world patients with CD. METHODS: We recruited 62 patients with CD who were either refractory or intolerant to TNF antagonists, treated with ustekinumab from April 2014 to September 2015. Patients received 90 mg of ustekinumab subcutaneously at weeks 0, 1, and 2 during induction and 90 mg every 4 or 8 weeks during maintenance. Clinical, biomarker, and endoscopic outcomes, trough concentrations of ustekinumab, and anti-drug antibodies were assessed at both week 10 postinduction therapy and at week 26 or later during maintenance therapy in a prospective longitudinal patient cohort or at week 26 or later during maintenance therapy in a cross-sectional patient cohort. Analysis was performed on data combined from both maintenance cohorts, which had similar outcomes at week 26 or later. A primary analysis determined if ustekinumab drug trough concentrations were associated with clinical response (reduction in Harvey Bradshaw Index score of 3 or greater), clinical remission (Harvey Bradshaw Index score <5), steroid-free clinical remission, biomarker (serum level of C-reactive protein [CRP] or level of fecal calprotectin) reduction, biomarker normalization (serum level of CRP below 5 mg/L or level of fecal calprotectin below 200 µg/g), endoscopic response (simple endoscopic score for CD reduced by 50% or more), or endoscopic remission (simple endoscopic score for CD of 2 or less). RESULTS: At week 26 or beyond, 80.7% of patients had a clinical response, 66.1% were in clinical remission, 50.0% were in steroid-free clinical remission, 58.9% had an endoscopic response, and 19.6% were in endoscopic remission. The mean trough concentration of ustekinumab at this time point was higher in patients with an endoscopic response (4.7 µg/mL) than without (3.8 ug/mL; P = .03). An optimal ustekinumab threshold trough concentration at week 26 or later was found to be 4.5 µg/mL (area under the curve, 0.67). A greater proportion of patients with trough concentrations of ustekinumab above 4.5 µg/mL at week 26 or later had an endoscopic response (75.9%) than did patients with trough concentrations below this level (40.7%; P = .008). Patients with trough concentrations of ustekinumab above 4.5 µg/mL at week 26 or later also had a lower mean level of CRP (12.6 mg/L) than did patients with trough concentrations below this level (mean level of CRP, 23.9 mg/L; P = .04). We did not detect antibodies against ustekinumab in any patient. CONCLUSIONS: Ustekinumab therapy was effective in patients with CD who had not responded to or were intolerant to treatment with a TNF antagonist. Maintenance trough concentrations of ustekinumab above 4.5 µg/mL at 26 weeks or later were associated with biomarker reduction and endoscopic response.

A randomised phase II study evaluating the efficacy and safety of subcutaneously administered ustekinumab and guselkumab in patients with active rheumatoid arthritis despite treatment with methotrexate.

OBJECTIVE: Interleukin (IL)-12 and IL-23 have been implicated in the pathogenesis of rheumatoid arthritis (RA). The safety and efficacy of ustekinumab, a human monoclonal anti-IL-12/23 p40 antibody, and guselkumab, a human monoclonal anti-IL-23 antibody, were evaluated in adults with active RA despite methotrexate (MTX) therapy. METHODS: Patients were randomly assigned (1:1:1:1:1) to receive placebo at weeks 0, 4 and every 8 weeks (n=55), ustekinumab 90 mg at weeks 0, 4 and every 8 weeks (n=55), ustekinumab 90 mg at weeks 0, 4 and every 12 weeks (n=55), guselkumab 50 mg at weeks 0, 4 and every 8 weeks (n=55), or guselkumab 200 mg at weeks 0, 4 and every 8 weeks (n=54) through week 28; all patients continued a stable dose of MTX (10-25 mg/week). The primary end point was the proportion of patients with at least a 20% improvement in the American College of Rheumatology criteria (ACR 20) at week 28. Safety was monitored through week 48. RESULTS: At week 28, there were no statistically significant differences in the proportions of patients achieving an ACR 20 response between the combined ustekinumab group (53.6%) or the combined guselkumab group (41.3%) compared with placebo (40.0%) (p=0.101 and p=0.877, respectively). Through week 48, the proportions of patients with at least one adverse event (AE) were comparable among the treatment groups. Infections were the most common type of AE. CONCLUSIONS: Treatment with ustekinumab or guselkumab did not significantly reduce the signs and symptoms of RA. No new safety findings were observed with either treatment. TRIAL REGISTRATION NUMBER: NCT01645280.

Ustekinumab for patients with primary biliary cholangitis who have an inadequate response to ursodeoxycholic acid: A proof-of-concept study.

UNLABELLED: The interleukin (IL)-12 signaling cascade has been associated with primary biliary cholangitis (PBC). This multicenter, open-label, proof-of-concept study evaluated the anti-IL12/23 monoclonal antibody, ustekinumab (90 mg subcutaneous at weeks 0 and 4, then every 8 weeks through week 20), in adults with PBC and an inadequate response to ursodeoxycholic acid therapy (i.e., alkaline phosphatase [ALP] >1.67× upper limit of normal [ULN] after ≥6 months). ALP response was defined as a >40% decrease from baseline and ALP remission as ALP normalization (if baseline ALP 1.67×-2.8× ULN) or <1.67× ULN (if baseline ALP >2.8× ULN). Changes in Enhanced Liver Fibrosis (ELF) scores and serum bile acids were also assessed. At baseline, patients had median disease duration of 3.2 years, median ELF score of 9.8, and highly elevated total bile acid concentration (median, 43.3 µmol/L); 13 of 20 (65%) patients had baseline ALP >3× ULN. Although steady-state serum ustekinumab concentrations were reached by week 12, no patient achieved ALP response or remission. Median percent ALP reduction from baseline to week 28 was 12.1%. ELF score decreased slightly from baseline to week 28 (median reduction: 0.173), and total serum bile acid concentrations decreased from baseline to week 28 (median reduction: 8.8 µmol/L). No serious infections or discontinuations resulting from adverse events were reported through week 28. One patient had a serious upper gastrointestinal hemorrhage considered unrelated to test agent by the investigator. CONCLUSION: Open-label ustekinumab therapy, though associated with a modest decrease in ALP after 28 weeks of therapy, did not otherwise appreciably change ALP and overt proof-of-concept was not established as per prespecified primary endpoint of proposed efficacy. No new ustekinumab safety signals were observed. (Hepatology 2016;64:189-199).

Ustekinumab treatment in severe atopic dermatitis: Down-regulation of T-helper 2/22 expression.

BACKGROUND: It has recently been suggested that patients with moderate to severe atopic dermatitis (AD) may profit from anti-interleukin (IL)-12/-23 p40 therapy. OBJECTIVE: We sought to assess the immunologic effects of ustekinumab treatment on AD skin and to correlate them with the clinical efficacy of this drug. METHODS: We investigated the course of 3 patients with severe AD who were administered 45 mg of subcutaneous ustekinumab over a period of 16 weeks. Clinical scores and skin biopsy specimens, taken at baseline and at week 8, were used to assess changes in disease severity. RESULTS: All patients showed a gradual improvement of the disease, achieving a 50% reduction in the Eczema Area and Severity Index score by week 16. Immunohistology of skin biopsy specimens revealed a significant decrease in the degree of epidermal hyperplasia/proliferation and the number of infiltrating dermal T cells, dendritic cells, and mast cells after treatment. Using quantitative real-time polymerase chain reaction of lesional skin, we found a clear reduction of T-helper 2-/22-associated molecules after therapy. LIMITATIONS: The small number of patients (n = 3) limits efficacy analysis and warrants prospective placebo-controlled studies in larger patient cohorts. CONCLUSION: Blocking IL-12/-23 p40 could be beneficial for a subgroup of patients with severely infiltrated AD.

Challenges in longitudinal exposure-response modeling of data from complex study designs: a case study of modeling CDAI score for ustekinumab in patients with Crohn's disease.

Informative exposure-response modeling of clinical endpoints is important in drug development to identify optimum dose and dosing regimens. Despite much recent progress in mechanism-based longitudinal modeling of clinical data, challenges remain in clinical trials of diseases such as Crohn's disease, where a commonly used composite endpoint Crohn's Disease Activity Index (CDAI) has considerable variation in its administration and scoring between different assessors and complex study designs typically include maintenance phases with randomized withdrawal re-randomizations and other response driven dose adjustments. This manuscript illustrates the complexities of exposure-response modeling of such composite endpoint data through a latent-variable based Indirect Response model framework for CDAI scores using data from three phase III trials of ustekinumab in patients with moderate-to-severe Crohn's Disease. Visual predictive check was used to evaluate model performance. Potential impacts of the study design on model development and evaluation of the E-R relationship in the induction and maintenance phases of treatment are discussed. Certain biases appeared difficult to overcome, and an autocorrelated residual error model was found to provide improvement.

Systematic Review and Meta-analysis: The Association Between Serum Ustekinumab Trough Concentrations and Treatment Response in Inflammatory Bowel Disease.

BACKGROUND: Optimizing therapy and monitoring response are integral aspects of inflammatory bowel disease treatment. We conducted a systematic review and meta-analysis to determine whether serum ustekinumab trough concentrations during maintenance therapy were associated with ustekinumab treatment response in patients with inflammatory bowel disease. METHODS: A systematic review was performed to March 21, 2022, to identify studies using MEDLINE, EMBASE, and the Cochrane library. We included studies that reported the association between serum ustekinumab trough concentrations with clinical or endoscopic remission. Outcome measures were combined across studies using the random-effects model with an odds ratio (OR) for binary outcomes of endoscopic and clinical remission. RESULTS: We identified 14 observational studies that were included in the analysis for clinical remission (919 patients, 63% with Crohn's disease) or endoscopic remission (290 patients, all with Crohn's disease). Median ustekinumab trough concentrations were higher amongst individuals achieving clinical remission compared with those not achieving remission (mean difference, 1.6 ug/mL; 95% confidence interval [CI], 0.21-3.01 ug/mL). Furthermore, individuals with median serum trough concentration in the fourth quartile were significantly more likely to achieve clinical (OR, 3.61; 95% CI, 2.11-6.20) but not endoscopic remission (OR, 4.67; 95% CI, 0.86-25.19) compared with those with first quartile median trough concentrations. CONCLUSION: Based on the results of this meta-analysis primarily relating to patients with Crohn's disease on maintenance ustekinumab treatment, it appears that there is an association between higher ustekinumab trough concentration and clinical outcomes. Prospective studies are required to determine whether proactive dose adjustments of ustekinumab therapy provides additional clinical benefit.

This meta-analysis of 14 observational studies found an association between better clinical outcomes and higher trough ustekinumab levels for maintenance treatment in inflammatory bowel disease.

Physiologically-based pharmacokinetic modeling to predict the exposure and provide dosage regimens of Ustekinumab in pediatric patients with inflammatory bowel disease.

Ustekinumab (UST), a fully human immunoglobulin G1 κ monoclonal antibody, exhibiting high affinity for the p40 subunit shared by IL-12 and IL-23, which play key roles in the pathogenesis of inflammatory bowel disease (IBD). By scaling the physiologically-based pharmacokinetic modeling (PBPK) model of UST in adult patients with IBD, we aim to predict effective dosages for UST in pediatric patients, thereby offering a more practical dosing regimen for real-world applications. In this work, a PBPK model for UST in adult patients with IBD has been developed using PK-Sim and Mobi. Advanced ontogeny model has been incorporated to extrapolate the model to pediatric patients. The simulation results showed that the fold errors of the predicted and observed values of the area under the curve (AUC) and peak plasma concentration (Cmax) were between 0.79 and 1.73. For children aged 6-18, it is recommended to administer the drug per kilogram of body weight, at the model-recommended dose, to achieve a median AUC similar to that of the adult reference population post-administration. This comprehensive model construction enables us to comprehensively and extensively explore the pharmacokinetic characteristics of UST in pediatric patients of different age groups, providing robust support for clinical applications and personalized drug therapy.

Relationship between Ustekinumab trough concentrations and clinical, biochemical and endoscopic outcomes in Crohn's disease: A multi-center nationwide retrospective study (TARGET STUDY).

Ustekinumab has been shown to be effective in inducing and maintain clinical and endoscopic remission in Crohn disease (CD). We aim to assess whether ustekinumab trough levels are associated with improved outcomes in CD in real-life. We recruited patients with CD who were treated with ustekinumab for at least 6 months from January 2017 to June 2023. Patients received ustekinumab 6 mg/kg intravenous induction followed by 90 mg every 4-, 8-, or 12-weeks during maintenance were included. We assessed clinical, biochemical, and endoscopic outcomes. Trough concentrations of ustekinumab that were taken from week 42 to week 52 were measured. Primary outcome was to evaluate the relationship between ustekinumab trough concentrations and clinical remission, biochemical normalization, and endoscopic remission. Logistic regression was conducted to assess outcomes. A total of 137 patients with CD, median age of 32 years and 83 (60.6%) males. The median serum levels of ustekinumab measured was 7.2 mcg/mL (interquartile range [IQR] 3.1-9.6). Using Spearman correlation analysis, a strong negative correlation was observed between ustekinumab drug levels and simple endoscopic score (SES-CD) (r = -0.464, P < .001). Additionally, ustekinumab drug levels demonstrated substantial negative correlations with disease severity measured by Harvey-Bradshaw index (HBI) score (r = -0.582, P < .001), C-Reactive Protein (CRP) levels (r = -0.598, P < .001) and fecal calprotectin (FC) levels (r = -0.529, P < .001). A multivariable analysis adjusted for age, sex and body mass index (BMI) showed a significant association between ustekinumab serum drug levels and predefined outcomes. Ustekinumab serum drug level above 4.5 mcg/mL was associated with 24% increase in the likelihood of having an SES-CD score <3 (OR 1.24, confidence interval [CI] 1.12-1.37, P value < .001), 44% more likely to achieve HBI score <5 (OR 1.44, CI 1.26-1.65, P value < .001), 52% higher likelihood of CRP more than 10 (OR 1.52, CI 1.31-1.77, P < .001), and 42% increased likelihood of FC more than 250 (OR 1.42, CI 1.24-1.62, P < .001). Ustekinumab trough concentrations above 4.5 mcg/mL were associated with clinical, biochemical and endoscopic remission in CD. Prospective data is warranted to confirm these findings.

AVT04: An Ustekinumab Biosimilar.

AVT04 (Uzpruvo®) is a biosimilar of the reference anti-interleukin (IL)-12 and IL-23 monoclonal antibody ustekinumab. It is approved in the EU for plaque psoriasis, paediatric plaque psoriasis, psoriatic arthritis and Crohn's disease as per the reference product. AVT04 has similar physicochemical characteristics to those of reference ustekinumab, and the pharmacokinetic similarity of the agents has been shown in healthy volunteers and patients with moderate to severe chronic plaque psoriasis. AVT04 demonstrated clinical efficacy similar to that of reference ustekinumab in patients with moderate to severe chronic plaque psoriasis, and was generally well tolerated in this population. The tolerability, safety and immunogenicity profiles of AVT04 were similar to those of reference ustekinumab, and switching from reference ustekinumab to AVT04 had no impact on efficacy, safety or immunogenicity. The role of reference ustekinumab in the management of inflammatory diseases is well established and AVT04 provides an effective biosimilar alternative for patients requiring ustekinumab therapy.

Comparison of Pharmacokinetic Similarity, Immunogenicity, and Safety of Ustekinumab and BAT2206 in Healthy Chinese Male Subjects in a Double-Blind, Randomized, Single-Dose, Parallel-Group Phase I Trial.

OBJECTIVE: We aimed to evaluate the similarity of BAT2206 to its originator, ustekinumab, including pharmacokinetic profiles, immunogenicity, and safety in healthy Chinese male subjects. METHODS: This was a double-blinded, randomized, single-dose, parallel-group clinical trial, in which 270 healthy male subjects were enrolled to receive a single subcutaneous injection (45 mg) of either BAT2206 or ustekinumab (European Union or USA) at a 1:1:1 ratio. The pairwise pharmacokinetic similarities and the safety and immunogenicity of both drugs were evaluated and compared. RESULTS: The results showed that the 90% confidence interval of the geometric mean ratio for primary pharmacokinetic parameters (maximum plasma concentration and area under the plasma concentration-time curve from time zero to infinity) among BAT2206 and ustekinumab (USA or European Union sourced) groups were all within the predefined equivalent interval of 80-125%. Furthermore, all the groups had similar incidences of treatment-emergent adverse events, in which the majority of cases belonged to Common Terminology Criteria for the Classification of Adverse Events Grade 1 or 2. Anti-drug antibodies were detected in 54 (20.1%) subjects, namely 24 (26.7%), 13 (14.8%), and 17 (18.9%) patients in the BAT2206, ustekinumab (European Union), and ustekinumab (USA) groups, respectively. In contrast, the incidences of positive neutralizing antibodies were similar among the three groups. CONCLUSIONS: Pharmacokinetic similarity between BAT2206 and ustekinumab (USA or European Union sourced) was confirmed. The three groups had similar safety profiles, and the investigational drugs were well tolerated by subjects. CLINICAL TRIAL REGISTRATION: This study was registered with ClinicalTrials.gov (NCT04371185).

Ustekinumab pharmacokinetics after subcutaneous administration in swine model.

BACKGROUND: Due to multiple similarities in the structure and physiology of human and pig skin, the pig model is extremely useful for biological drug testing after subcutaneous administration. Knowledge of the differences between subcutaneous injection sites could have a significant impact on the absorption phase and pharmacokinetic profiles of biological drugs. OBJECTIVES: This study aimed to analyze the impact of administration site on pharmacokinetics and selected biochemical and hematological parameters after a single subcutaneous administration of ustekinumab in pigs. Drug concentrations in blood plasma were analyzed by enzyme-linked immunosorbent assay. Pharmacokinetic analyses were performed based on raw data using Phoenix WinNonlin 8.1 software and ThothPro v 4.1. METHODS: The study included 12 healthy, female, large white piglets. Each group received a single dose of ustekinumab given as a 1 mg/kg subcutaneous injection into the internal part of the inguinal fold or the external part of the inguinal fold. RESULTS: The differences in absorption rate between the internal and external parts of the inguinal fold were not significant. However, the time of maximal concentration, clearance, area under the curve calculated between zero and mean residence time and mean residence time between groups were substantially different (p > 0.05). The relative bioavailability after administration of ustekinumab into the external part of the inguinal fold was 40.36% lower than after administration of ustekinumab into the internal part of the inguinal fold. CONCLUSIONS: Healthy breeding pigs are a relevant model to study the pharmacokinetic profile of subcutaneously administered ustekinumab.

Ustekinumab in Paediatric Patients with Moderately to Severely Active Crohn's Disease: Pharmacokinetics, Safety, and Efficacy Results from UniStar, a Phase 1 Study.

BACKGROUND AND AIMS: The objective was to evaluate the pharmacokinetics, safety/tolerability, and efficacy of ustekinumab in children with moderately to severely active Crohn's disease. METHODS: In this Phase 1, multicentre, 16-week, double-blind, induction dose-ranging study [NCT02968108], patients aged 2-<18 years [body weight ≥10 kg] were randomised [1:1] to one of two weight range-based intravenous induction doses: 130 mg vs 390 mg in patients ≥40kg and 3 mg/kg vs 9 mg/kg in patients <40kg. At Week 8, all patients received a single subcutaneous ustekinumab maintenance dose of 90 mg in patients ≥40kg or 2 mg/kg in patients <40kg. RESULTS: A total of 44 patients were randomised and treated with ustekinumab [n = 23 lower dose; n = 21 higher dose]; median [interquartile range] age was 13.0 [12-16] years. Pharmacokinetics were similar to those in adults with Crohn's disease. However, serum ustekinumab concentrations were lower among those with body weight <40 kg compared with patients ≥40 kg and the reference Phase 3 adult population. Through Week 16, 73% of patients reported ≥1 adverse event [82.6% lower vs 62% higher dose]; two discontinued due to adverse events [one in each group]. Serious adverse events occurred in 16% [26% lower, 5% higher dose], with Crohn's disease exacerbation being the most frequent. At Week 16, 22%/29% [lower/higher dose] achieved clinical remission [Paediatric Crohn's Disease Activity Index ≤10]. CONCLUSIONS: The pharmacokinetics/safety profiles were generally consistent with those observed in adults with Crohn's disease. These results suggest a different dosing regimen may be required for patients <40 kg from that employed in this study; additional pharmacokinetic analyses may be needed in this population.

Population Pharmacokinetics and Exposure-Response Modeling Analyses of Ustekinumab in Adults With Moderately to Severely Active Ulcerative Colitis.

To characterize the pharmacokinetics (PK) and exposure-response (E-R) relationship of ustekinumab, an anti-interleukin-12/interleukin-23 (IL-12/IL-23) human monoclonal antibody, in the treatment of moderately to severely active ulcerative colitis (UC), population PK and E-R modeling analyses were conducted based on the data from the pivotal phase 3 induction and maintenance studies in UC patients. The observed serum concentration-time data of ustekinumab were adequately described by a 2-compartment linear PK model with first-order absorption and first-order elimination. Body weight, baseline serum albumin, sex, and antibodies to ustekinumab were the covariates to influence ustekinumab PK, but the magnitudes of the effects of these covariates were not considered clinically relevant, and dose adjustment was not warranted. Positive E-R relationships were demonstrated between ustekinumab exposure metrics and clinical endpoints (including clinical response, clinical remission, and endoscopic healing based on Mayo score) at induction week 8 and maintenance week 44, consistent with the effectiveness of ustekinumab in the induction and maintenance treatment of patients with UC. E-R modeling results suggest that ustekinumab ∼6 mg/kg intravenous induction and 90-mg subcutaneous every-8-week maintenance dose would produce greater efficacy than the 130 mg intravenous induction and the 90-mg subcutaneous every-12-week maintenance regimen, respectively. Our work provides a comprehensive evaluation of ustekinumab PK and E-R in a modeling framework to support ustekinumab dose recommendations in patients with UC.

Using Real-World Data to Guide Ustekinumab Dosing Strategies for Psoriasis: A Prospective Pharmacokinetic-Pharmacodynamic Study.

Variation in response to biologic therapy for inflammatory diseases, such as psoriasis, is partly driven by variation in drug exposure. Real-world psoriasis data were used to develop a pharmacokinetic/pharmacodynamic (PK/PD) model for the first-line therapeutic antibody ustekinumab. The impact of differing dosing strategies on response was explored. Data were collected from a UK prospective multicenter observational cohort (491 patients on ustekinumab monotherapy, drug levels, and anti-drug antibody measurements on 797 serum samples, 1,590 measurements of Psoriasis Area Severity Index (PASI)). Ustekinumab PKs were described with a linear one-compartment model. A maximum effect (Emax ) model inhibited progression of psoriatic skin lesions in the turnover PD mechanism describing PASI evolution while on treatment. A mixture model on half-maximal effective concentration identified a potential nonresponder group, with simulations suggesting that, in future, the model could be incorporated into a Bayesian therapeutic drug monitoring "dashboard" to individualize dosing and improve treatment outcomes.

Therapeutic Drug Monitoring With Ustekinumab and Vedolizumab in Inflammatory Bowel Disease.

In patients with Crohn's disease (CD) and ulcerative colitis (UC), the use of therapeutic drug monitoring (TDM) with TNF-α antagonists has led to a personalized approach to optimize treatment and has been shown to be cost-effective. The utility of this TDM-based personalized approach for novel biologic agents, which target different inflammatory pathways, is unclear. Commercial assays for ustekinumab (UST) and vedolizumab (VDZ) are available, but there is little available guidance for clinicians regarding the use of TDM with these drugs. Although there is limited evidence for definitive threshold concentrations for UST and VDZ, this review highlights the available literature on the pharmacokinetics of these medications, the association of clinical and endoscopic outcomes with drug concentrations, and the clinical utility of TDM to guide treatment decisions.