Anti-drug Antibodies Titers Research Articles

7217 Impact of INZ-701 on Bone and Mineral Metabolism Biomarkers and Clinical Outcomes in Adults with ENPP1 Deficiency - Results from 48-week Phase 1/2 Open Label Study

Abstract Disclosure: K. Gunter: Employee; Self; Inozyme Pharma. Stock Owner; Self; Inozyme Pharma. R.A. Wermers: Research Investigator; Self; Inozyme Pharma. R. Fuhr: Employee; Self; Parexel GmbH. Research Investigator; Self; Inozyme Pharma. D. Schnabel: Research Investigator; Self; Inozyme Pharma. A. Besancon: Research Investigator; Self; Inozyme Pharma. M.A. Nour: Research Investigator; Self; Inozyme Pharma. D. Wenkert: Stock Owner; Self; Inozyme Pharma. Y. Sabbagh: Employee; Self; Inozyme Pharma. Stock Owner; Self; Inozyme Pharma. Background: ENPP1 Deficiency is a rare disorder due to inactivating mutations in the ENPP1 gene that result in low levels of inorganic pyrophosphate (PPi), a critical regulator of mineralization. Subsequent pathologic soft tissue calcification results in severe vascular calcification and ∼50% infant mortality. By early adolescence the majority of survivors develop FGF-23 mediated hypophosphatemic rickets, characterized by bone deformities, short stature, joint/ligament calcification and musculoskeletal pain. No targeted therapy exists for this disease. INZ-701 is a recombinant ENPP1-Fc investigational product. Purpose: To describe the safety, tolerability, immunogenicity, and exploratory efficacy (bone and mineral metabolism biomarkers and clinical outcomes) of INZ-701 in adults with ENPP1 Deficiency through the end of the phase 2 study period (week 48). Methods: Phase 1/2, multicenter, open-label, multiple ascending dose study including three adults in each of three dose cohorts (0.2, 0.6 and 1.8 mg/kg, total N=9) with genetic variants in ENPP1 and PPi <1300 nM (NCT04686175). Participants were dosed subcutaneously on Day 1, then twice weekly from Day 8 to end of study. Data through wk 48 as of July 6, 2023 are included; topline wk 48 data will be presented. Per protocol, participants may continue to receive INZ-701 beyond wk 48. Results: Rapid increase in mean PPi from baseline of 426±407 nM was noted in all patients, reaching the healthy volunteer range within 6 hrs of the first dose with sustained elevation through wk 48. Mean PPi across the 0.2, 0.6 and 1.8 mg/kg dose cohorts from day 32 to wk 48 was 1299±131 nM, 1356±136 nM, and 1282±81 nM, respectively. There were improvements from baseline to wk 48 in mean pooled FGF-23 (-22 pg/mL) and serum phosphate (+0.18 mg/dL), with dose-dependent changes in bone specific alkaline phosphatase consistent with bone healing. DEXA revealed improvements in spine BMD and BMC. There were trends towards improvement in mean % predicted change in 6MWT from baseline to wk 48: cohort 1, 76.7% (SE 10.5) to 85.0% (SE 3.0); cohort 2, 52.2% (SE 10.9 ) to 79.0% (SE 2.9); cohort 3, wk 48 data not available. Improvements were also observed in physician and patient global impression of change score (with no patients deteriorating) and PROMIS pain intensity score. INZ-701 was well tolerated with no drug-related serious or severe (> grade 2) adverse events. Low titers of non-neutralizing anti-drug antibodies (≤160) were observed in 7/9 patients. Long half-life of approximately 126 hours suggests the potential for once-weekly dosing. Conclusions: In adults with ENPP1 Deficiency, INZ-701 was well tolerated with no related serious or severe adverse events. INZ-701 demonstrated a rapid and sustained increase in PPi levels from baseline to week 48 with corresponding improvements in bone mineral biomarkers, functional performance, and patient and physician-reported outcomes. Presentation: 6/3/2024

Reactive Immunomodulator Addition to Infliximab Monotherapy Restores Clinical Response in Inflammatory Bowel Disease: A Meta-Analysis.

Patients with inflammatory bowel disease (IBD) receiving infliximab (IFX) commonly experience immunogenic loss of response (LOR) by formation of anti-drug antibodies (ADAs). An immunomodulator (IMM) used in combination with initial IFX induction is known to reduce ADA development and improve clinical outcomes. We aimed to assess the impact of reactively adding an IMM to patients on IFX monotherapy. We conducted a retrospective cohort study and systematic review with meta-analysis of patients with IBD demonstrating immunologic LOR, with or without clinical LOR, that had an IMM (azathioprine, 6-mercaptopurine, or methotrexate) reactively added (reactive combination therapy; rCT) to combat elevated ADAs and raise IFX level. Data were extracted for pooled effect size estimation using random-effects models, and ADA and IFX trough levels were compared pre- and post-IMM initiation. We identified 6 patients who received rCT due to rising ADA titers and low IFX levels. Median ADA titer decreased from 506ng/mL (interquartile range (IQR) [416-750]) to 76.5ng/mL (IQR [25.8-232]), an 85% decrease (p = 0.031). Median IFX trough increased from 0.4µg/mL (IQR [0.4-0.48]) to 8.25µg/mL (IQR [3.7-9.6]), a 20.6-fold increase (p = 0.038). Meta-analysis pooled effect size of 7 studies with 89 patients showed an 87% ADA titer reduction [95% confidence interval (CI) = 72-94%], 6.7-fold increased IFX trough (95% CI = 2.4-18.7), and 76% clinical remission rescue rate (95% CI = 59-93%). These results suggest rCT is a valid rescue strategy in patients with immunogenic LOR to IFX to reduce ADA titers, restore therapeutic IFX levels, and recapture clinical remission of IBD.

Population PK modeling of certolizumab pegol in pregnant women with chronic inflammatory diseases.

Certolizumab pegol (CZP; CIMZIA™) is the only Fc-free tumor necrosis factor inhibitor with data from a clinical study demonstrating no to minimal placental transfer. The pharmacokinetics (PK) of certolizumab pegol during pregnancy and postpartum in women with chronic inflammatory diseases were assessed using a population PK model based on data from the CHERISH study (NCT04163016), a longitudinal, prospective, open-label PK phase IB study. Model development was performed in NONMEM using a frequentist prior approach, with prior information based on a population PK model for certolizumab pegol in non-pregnant adult patients (NCT04740814). A one-compartment model with first-order absorption (Ka = 0.236 1/day) and linear elimination (CL/F = 0.416 L/day) from the central compartment (V/F = 7.86 L) best described certolizumab pegol PK in the CHERISH study. The structural model parameters were estimated with good precision (RSE < 25%). Baseline BW was included as a covariate on CL/F and V/F. Pregnancy trimester and time-varying log-transformed anti-drug antibody (ADA) titer were identified as the only significant covariates for CL/F with a comparable influence on CL/F. Individuals with higher ADA titer (75th percentile) during pregnancy exhibited CL/F up to 1.43-fold higher relative to individuals postpartum that showed median levels of ADA titer. However, the confidence interval for the combined effect of pregnancy stage and ADA titer effects on CL/F overlapped with the CL/F range of the typical individual postpartum. In addition, simulations showed a large overlap in certolizumab pegol concentrations between pregnant and non-pregnant adults. The findings of this population PK analysis support the maintenance of established certolizumab pegol dosing regimens throughout pregnancy.

Evaluating the Performance of Two Automated Anti-drug Antibodies Assays for Infliximab and Adalimumab Without Acid Dissociation

Monitoring anti-drug antibodies (ADAs) to infliximab and adalimumab is critical to treatment management in various autoimmune disorders. The growing need for proactive therapeutic monitoring further requires the detection of ADAs in the presence of measurable concentrations of infliximab or adalimumab. To provide robust analytical assays for clinical application, we evaluated two automated immunoassays developed using ImmunoCAP™ technology and based on the bridging format to measure serum ADAs to infliximab and adalimumab respectively. Without an acid-dissociation step, these research prototype assays can detect a positive control monoclonal ADA towards infliximab and adalimumab, ranging from < 25 ng/ml to 10,000 ng/mL. Both assays exhibit imprecision less than 20% at different ADA titer levels and can distinguish ADAs towards different drug targets. In method comparison using authentic patient samples, the quantitative results of the ADA assays are not directly comparable to two existing clinical immunoassays for ADAs (correlation coefficient rs = 0.673 for infliximab ADAs; rs = 0.510 for adalimumab ADAs), presumably due to the lack of commutable ADA standards and the polyclonal nature of ADAs. Nevertheless, there is qualitative agreement between the methods when evaluating putative positive and negative patient samples (overall agreement 0.83 for infliximab ADAs; 0.76 for adalimumab ADAs). Biotin and high levels of rheumatoid factors may interfere with the performance of the automated assays due to competitive binding with the biotinylated drug and non-specific formation of bridging complexes. The two ImmunoCAP assays can provide new analytical methods for proactive therapeutic monitoring of adalimumab and infliximab.Graphical

Immune-Mediated Liver Effects Associated With Administration of a Human Anti-IL-21 Receptor Antibody (ATR-107) in Rats.

The toxicity of ATR-107, a human anti-interleukin-21 receptor (IL-21R) monoclonal antibody (mAb), was evaluated in CD-1 mice and cynomolgus monkeys after single-dose intravenous (IV) administration, and in Sprague-Dawley (SD) rats and cynomolgus monkeys after weekly IV and subcutaneous (SC) administration in 13-week toxicity studies that included recovery. Adverse liver necrosis, diffuse bridging fibrosis, and higher liver enzymes occurred in rats in the low-dose IV group (10 mg/kg), but not at 50 or 250 mg/kg IV, and not following SC administration despite overlapping systemic ATR-107 exposures. Similar findings were not seen in mice or cynomolgus monkeys. A series of investigative rat toxicity studies showed liver findings only occurred after administration of at least 3 weekly doses, only occurred in rats that developed anti-drug antibodies (ADAs), and the incidence was associated with higher ADAs titers. However, the presence of ADAs did not always result in liver injury. Liver findings did not occur in nude rats, which had high ATR-107 exposures and no ADAs. These findings suggest an adaptive immune response with formation of ADAs was necessary for development of ATR-107-related liver findings, and that liver injury can occur in rats secondary to development of ADAs following repeated administration of a human therapeutic mAb.

Relative bioavailability, immunogenicity, and safety of two adalimumab-adbm formulations in healthy volunteers: a double-blind, randomized, single-dose, parallel-arm Phase I trial (VOLTAIRE-HCLF)

ABSTRACT Objective VOLTAIRE-HCLF compared the relative bioavailability of citrate-free high-concentration and reference formulations of the biosimilar adalimumab-adbm (Cyltezo®), including pharmacokinetic (PK) profiles, immunogenicity, and safety profiles in healthy volunteers. Methods Healthy volunteers (N = 200) aged 18–55 years and with body mass index of 18.5–29.9 kg/m2 and no prior exposure to adalimumab were randomized in a 1:1 ratio to receive a single subcutaneous injection of either adalimumab-adbm 40 mg/0.4 mL (high-concentration formulation) or 40 mg/0.8 mL (reference formulation). Participants completed 13 follow-up visits over 57 days, followed by a safety follow-up period of up to 70 days. Results The main PK parameters were similar for the high-concentration and reference groups. For all primary endpoints, the geometric mean ratios and 90% confidence intervals of AUC0–1344, AUC0–∞, and Cmax for both groups were entirely within the standard 80–125% bioequivalence acceptance range at 101.88% (93.31–111.23%), 105.38% (95.06–116.81%), and 91.29% (84.38–98.76%), respectively. There were no differences in the proportion of anti-drug antibody-positive participants or in the distribution of anti-drug antibody titers between the two formulations at any time point after drug dosing. Participants who were given the high-concentration formulation of adalimumab-adbm experienced a lower incidence of adverse events and local reactions than those who were given the reference formulation. Conclusions Overall, the high-concentration and reference adalimumab-adbm formulations had highly similar PK and immunogenicity profiles and were safe and well tolerated. Clinical trial registration NCT05203289

Implications of Immunogenicity Testing for Therapeutic Monoclonal Antibodies: A Quantitative Pharmacology Framework

The interpretation of immunogenicity results for a mAb product and prediction of its clinical consequences remain difficult, despite enormous advances in methodologies and efforts toward the best practice for consistent data generation and reporting. To this end, the contribution from the clinical pharmacology discipline has been largely limited to comparing descriptively the pharmacokinetic (PK) profiles by antidrug antibodies (ADA) status or testing the significance of ADA as a covariate in a population PK setting, similar to the practice for small-molecule drugs in investigating the effect of an intrinsic/extrinsic factor on the drug disposition. There is a need for a mAb disposition framework that captures the dynamics of ADA formation and drug’s interactions with the ADA and target as parts of the drug distribution and elimination. Here we describe such a framework and examine it against the PK, ADA, and clinical response data from a phase 3 trial in patients treated with adalimumab. The proposed framework offered a generalized understanding of how the dose, target affinity, and drug/ADA analyte forms affects the manifestation of ADA response with regard to its detections and alterations of drug disposition and effectiveness. Furthermore, as an example, its utility for dose considerations was demonstrated through predicting for late-stage trials of a PCSK9 inhibitor in terms of development in ADA incidence and titers, and consequences on the drug disposition, interaction with target, and downstream lowering effect on LDL-C.Graphical

Infliximab desensitization in patients with inflammatory bowel diseases: a safe therapeutic alternative

Background Hypersensitivity reactions (HSR) to the administration of infliximab (IFX) in Inflammatory Bowel Diseases (IBD) patients are not rare and usually lead to drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR. Methods We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after desensitization were collected. Clinical outcomes, including recurrence of HSR were evaluated. Results From 2005 to 2020, 27 patients (Crohn’s Disease: 26 (96%) were included). Desensitization after HSR was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants at time of desensitization. Eight (30%) patients presented HSR at first (n = 2), second (n = 4) or third (n = 2) IFX perfusion after desensitization. None led to intensive care unit transfer or death. Thirteen (48%) had clinical response at 6 months and 8 (29%) were still under IFX treatment two years after desensitization. IFX trough levels and ADA were available for 14 patients at time of desensitization. Most patients (12 out of 14) had ADA at a high level. At 6 months, among the 7 patients with long term response to IFX, 4 presented a decrease of ADA titers and 2 had a significant trough level of IFX. Conclusion IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics. What is already known? Hypersensitivity reactions to the administration of infliximab is frequent. Occurrence of hypersensitivity reaction, either immediate or delayed, usually leads to permanent drug discontinuation. What is new here? Infliximab desensitization is well tolerated with no hypersensitivity reaction recurrence in 70% of patients. Clinical success at 6 months was of 48% and around a third of patients remained under infliximab therapy two years after desensitization. Antidrug antibodies decreased and infliximab trough levels increased in these patients showing the impact of desensitization on immunogenicity. How can this study help patient care? Infliximab desensitization represents a potential option for patients refractory to multiple biologics who presented hypersensitivity reaction to the drug.

P921 Maintenance of clinical, biochemical and transmural remission in inflammatory bowel disease patients switching from intravenous to subcutaneous infliximab

Abstract Background Subcutaneous (SC) infliximab (IFX) effectively maintains biochemical, clinical and endoscopic remission in inflammatory bowel disease (IBD) with a comparable safety profile to intravenous (IV) formulation. Transmural healing is considered a desirable long-term treatment endpoint in IBD, especially in Crohn’s disease (CD). Whether switching from intravenous to SC-IFX effectively maintains transmural remission in IBD is still unknown. Methods This is a preliminary report from a prospective multicentre cohort study on IBD patients in clinical and endoscopic remission on IV-IFX treatment switched to SC-IFX. Enrolled patients were followed-up for 12 months, with fecal calprotectin (FC), C-reactive protein (CRP), infliximab trough levels and anti-drug antibodies (ADAs) measured at baseline, at 3, 6 and 12 months. Intestinal ultrasound (IUS) was performed at baseline and every six months. At month 12 a full colonoscopy was performed for mucosal healing assessment. Remission rates and safety profile were subsequently recorded. T-Test and ANOVA for mean comparisons and Kaplan-Meier estimates were used for survival curves. Results 43 IBD patients (69% males) were enrolled, 58% with CD, of whom 52% reported a history of perianal disease. Median disease duration and IFX therapy were 6 (IQR 3-12) and 5 (IQR 2-9) years, respectively. During a median follow-up of 311 (range 122-489) days, clinical remission rate was 98% (Harvey-Bradshaw Index &amp;lt;5 and Mayo score &amp;lt;2). No reactivation of perianal disease was reported. FC and CRP remained stable at each time point (p&amp;gt; 0.05). The median baseline infliximab level was 10.02 ( range 0.1- 41.84) ug/ml. Undetectable infliximab levels (&amp;lt;1 ug/ml) and positive ADAs were found in 6 and 14 patients, respectively; at 3 months, a significant increase in infliximab levels (mean increase 27.5 ng/ml; ± 12.5 SD; p&amp;lt; 0.001) and a progressive decrease of ADAs titer were observed, despite unchanged SC-IFX dose. At baseline, all patients had normal bowel wall thickness (i.e. ileum ≤ 3mm, colon≤4 mm) and a Limberg score ≤1at IUS; reactive lymphadenopathies were reported in 5 patients and a mild abdominal effusion in 1. No significant changes were shown during follow-up. Mild endoscopic activity was found in 2 out 30 patients who performed follow-up endoscopy. Regarding safety profile 12 mild infectious events, 2 mild cutaneous injection site reaction and 1 non-IBD related hospital admission were observed. Conclusion Switching from IV to SC infliximab in a selected cohort of IBD patients confirmed to be safe and effective in maintaining clinical, biochemical, and transmural remission. IUS is a useful, non-invasive and low-cost tool for periodic disease assessment in this subset of patients.

Population Pharmacokinetic Modeling of Cotadutide: A Dual Agonist Peptide of Glucagon-Like Peptide and Glucagon Receptors Administered to Participants with Type II Diabetes Mellitus, Chronic Kidney Disease, Obesity and Non-Alcoholic Steatohepatitis.

Cotadutide is a dual glucagon-like peptide-1 (GLP-1) and glucagon (GCG) receptor agonist peptide. The objective of this analysis was to develop a population pharmacokinetic (popPK) model of cotadutide, and to identify any potential effect on the PK from intrinsic and extrinsic covariates. The popPK analysis utilized a non-linear mixed-effects modeling approach using the data from 10 clinical studies in different participant categories following once-daily subcutaneous dose administration ranging from 20 to 600μg. Additionally, the covariates affecting cotadutide exposure were quantified, and the model performance was evaluated through the prediction-corrected visual predictive checks. A one-compartment model with first-order absorption and elimination adequately described the data as confirmed via visual predictive check plots and parameter plausibility. The mean values for cotadutide apparent clearance (CL/F), apparent volume of distribution (V/F), absorption rate constant (Ka), and half-life were 1.05 L/h, 20.0 L, 0.38 h-1, and 13.3 hours, respectively. Covariate modeling identified body weight, alanine transaminase, albumin, anti-drug antibody (ADA) titer values, formulation strength and injection device, and participant categories as significant covariates on PK parameters, where ADAs have been identified to decrease cotadutide clearance. The model demonstrated that a 150-kg participant was estimated to have 30% lower for both AUC and Cmax and a 66 kg participant was estimated to have 35% higher for both AUC and Cmax relative to a reference individual with a median weight of 96 kg. A popPK model was developed for cotadutide with cotadutide clinical data, and the impact of the statistically significant covariates identified was not considered clinically meaningful. The popPK model will be used to evaluate exposure-response relationships for cotadutide clinical data.

Subcutaneous Administration of Monoclonal Antibodies: Pharmacology, Delivery, Immunogenicity, and Learnings From Applications to Clinical Development.

Subcutaneous (s.c.) administration of monoclonal antibodies (mAbs) can reduce treatment burden for patients and healthcare systems compared with intravenous (i.v.) infusion through shorter administration times, made possible by convenient, patient-centric devices. A deeper understanding of clinical pharmacology principles related to efficacy and safety of s.c.-administered mAbs over the past decade has streamlined s.c. product development. This review presents learnings from key constituents of the s.c. mAb development pathway, including pharmacology, administration variables, immunogenicity, and delivery devices. Restricted mAb transportation through the hypodermis explains their incomplete absorption at a relatively slow rate (pharmacokinetic (PK)) and may impact mAb-cellular interactions and/or onset and magnitude of physiological responses (pharmacodynamic). Injection volumes, formulation, rate and site of injection, and needle attributes may affect PKs and the occurrence/severity of adverse events like injection-site reactions or pain, with important consequences for treatment adherence. A review of immunogenicity data for numerous compounds reveals that incidence of anti-drug antibodies (ADAs) is generally comparable across i.v. and s.c. routes, and complementary factors including response magnitude (ADA titer), persistence over time, and neutralizing antibody presence are needed to assess clinical impact. Finally, four case studies showcase how s.c. biologics have been clinically developed: (i) by implementation of i.v./s.c. bridging strategies to streamline PD-1/PD-L1 inhibitor development, (ii) through co-development with i.v. presentations for anti-severe acute respiratory syndrome-coronavirus 2 antibodies to support rapid deployment of both formulations, (iii) as the lead route for bispecific T cell engagers (BTCEs) to mitigate BTCE-mediated cytokine release syndrome, and (iv) for pediatric patients in the case of dupilumab.

Safety, Pharmacokinetics and Immunogenicity of Single and Multiple Ascending Doses of the Anti‐Tau Therapeutic Antibody E2814: A Phase 1, First‐In‐Human (FIH) Study in Healthy Subjects

AbstractBackgroundE2814 is an anti‐tau therapeutic monoclonal antibody (mAb) which is being developed as a potential disease‐modifying therapy for Alzheimer’s disease (AD). E2814 inhibits the propagation of pathological tau species by binding to the microtubule binding region (MTBR). This study evaluated safety, pharmacokinetics (PK), and immunogenicity of single and multiple doses of E2814.MethodsThis randomized, placebo‐controlled study evaluated 5 single ascending doses (SAD) and 4 multiple ascending doses (MAD) in healthy subjects. Subjects (n = 8/cohort) received single or multiple (every 4 weeks) 1‐hour IV infusions of E2814 (or placebo). Safety was evaluated through a review of adverse events (AE), clinical laboratory test results, physical examination, electrocardiogram results, and vital signs. Serial blood and CSF samples for measurement of serum and CSF E2814 concentrations by a validated electrochemiluminescence (ECL) assay were obtained at prespecified time‐points. The serum PK parameters were estimated using non‐compartmental analysis. Anti‐drug antibodies (ADA) in serum were measured by a validated ECL assay.ResultsE2814 has an adequate single and multiple dose safety profile. No treatment‐emergent serious AEs, severe AEs, infusion‐related reactions, or dose limiting events were observed. There was a dose‐related increase in serum and CSF E2814 exposures. The median time to maximum E2814 concentrations in serum was 1.5 to 2 h. The half‐life of E2814 was 23 days which is typical of mAb. In SAD, serum AUC and Cmax were approximately dose proportional at lower doses and greater than dose‐proportional at higher doses. In MAD, accumulation based on Cmax and AUC was ∼1.2 and 1.3‐fold, respectively by the third dose in all dose group. The serum‐to‐CSF concentration ratio ranged between 0.1 to 0.3%. The immunogenicity to E2814 was low. In SAD, 5 subjects had transient low level ADA titers by last study day. In MAD, 1 subject had a confirmatory positive ADA at baseline prior to dose on Day 1. PK in the ADA positive subjects was comparable to that of ADA negative subjects.ConclusionE2814 presented an adequate safety and immunogenicity profile in healthy adults. E2814 PK was comparable to that with other mAbs. These results support further development of E2814 as a potential disease‐modifying therapy for AD.

Signal-to-noise ratio to assess magnitude, kinetics and impact on pharmacokinetics of the immune response to an adalimumab biosimilar.

Background: The antidrug antibody (ADA) signal-to-noise (S/N) ratio was explored as a novel immunogenicity measure to evaluate the immune response of healthy subjects to a single dose of GP2017, an adalimumab biosimilar. Methodology/results: Bioanalytical methods used for the analysis of ADA S/N ratios and ADA titers were validated for sensitivity, precision and drug interference. ADA S/N ratios strongly correlated with ADA titers. Correlations between ADA area under the curve and ADAmax and pharmacokinetics (PK) were stronger for ADA S/N ratio than for ADA titers. Conclusion: ADA S/N ratio allowed for a more sensitive evaluation of the magnitude and kinetics of the immune response, was better correlated with adalimumab PK and was superior to ADA titers in assessing the impact of the immune response on PK.

Marstacimab, an Anti-Tissue Factor Pathway Inhibitor, in Participants with Hemophilia Α or B, with and without Inhibitors: An Integrated Analysis of Safety

Background: Marstacimab (PF-06741086) targets tissue factor pathway inhibitor (TFPI) to restore hemostasis via the extrinsic pathway of blood coagulation. In phase 1/2 studies, long-term subcutaneous (SC) administration of marstacimab reduced bleeding episodes in adults with severe hemophilia A (HA) or hemophilia B (HB) (factor VIII or factor IX [FIX] ˂1%, respectively), with or without inhibitors. BASIS, the pivotal phase 3 study of marstacimab in adolescents and adults with severe HA (&amp;lt;1%) or moderately severe to severe (FIX ≤2%) HB, is ongoing. Given the potential risk for thrombotic and thromboembolic complications with novel non-factor-based agents, integrated safety analysis of studies of such agents are of interest. Wereport an integrated analysis of marstacimab safety in participants with HA or HB. Methods: Data from participants in the phase 1b/2 study (NCT02974855), its long-term follow-up (LTFU; NCT03363321), the pivotal phase 3 BASIS study (NCT03938792), and its long-term extension (LTE; NCT05145127) were included. In the phase 1b/2 study, male participants (N=26) with severe HA or HB, with or without inhibitors, were assigned to escalating weekly SC doses of marstacimab based on inhibitor status (without inhibitors: 300 mg, a single 300-mg loading dose with subsequent 150-mg doses, or 450 mg; with inhibitors: 300 mg). In the BASIS study, male participants (N=163) with severe HA or moderately severe to severe HB, with or without inhibitors, received a single SC 300-mg loading dose followed by once-weekly 150 mg in the 12-month active treatment phase (ATP). Adverse events (AEs), serious adverse events (SAEs), and AEs of special interest (AESI), including thromboembolic events and injection site reactions (ISRs), were monitored. Results: Overall, 144 unique participants received marstacimab and were included in this analysis: 28 in the phase 1b/2 study (median treatment duration, 2.8 [range, 1.2-3.0] months) and its LTFU (15.0 [1.2-16.4] months) and 116 in the BASIS study (12.1 [0.9-13.1] months) and its LTE (6.4 [1.1-16.1] months; overall BASIS + LTE, 17.3 [0.9-28.2] months). Demographics, baseline characteristics, and marstacimab treatment and dosing ( Table 1) and a summary of safety are shown in Table 2. There were no treatment-related SAEs in the phase 1b/2 study and 1 treatment-related SAE (peripheral swelling) in the BASIS study and its LTE. There were no deaths in any study. There were no AEs related to thromboembolism during treatment in participants with HA or HB across the marstacimab clinical program. Adverse drug reactions were consistent across studies. In the BASIS study and its LTE, ISRs (n=13, 11.2%) tended to be transient and mild in severity and did not lead to discontinuation from the study: other reactions were also mild: pruritus (n=4, 3.4%); rash (n=1, 0.9%) and headache (n=8, 6.9%). One participant, with a history of hemorrhoids, in the BASIS ATP had a grade 2 event of thrombosed hemorrhoids considered related to marstacimab (a local inflammation event, not related to any other thromboembolic event; dose was not interrupted or changed due to this event). No clinically important findings in laboratory values were associated with marstacimab. In the BASIS ATP, antidrug antibodies (ADAs) developed in 23/112 participants (20.5% incidence; titers were low and resolved in 22/23 participants by end of study); 6/23 were positive for neutralizing antibodies (NAbs; titers were transient and resolved by the end of study). In the LTE, ADA developed in 1/44 (2.3%) participants; the ADA titer was negative prior to marstacimab but positive at the end of the main study (titer = 2.48), positive at Day 180 in the LTE (titer = 2.41), and the participant tested negative for NAbs at both timepoints. No differences in the marstacimab safety profile, as determined by AEs, SAEs, AESIs, and discontinuations due to AEs, were reported in ADA positive or negative participants. Across the BASIS study and its LTE, 18 participants had a marstacimab dose escalation from 150 mg to 300 mg; 8/18 (44.4%) had AEs, all mild or moderate in severity and there were no AEs or SAEs leading to treatment discontinuation. Conclusion: Once-weekly SC marstacimab was well tolerated in participants with severe HA or moderately severe to severe HB, without inhibitors, with a low rate and mild severity of ISRs, transient ADAs, and no thromboembolic events with continuous treatment up to 28 months in the phase 3 program.

Quantifying the Effect of Methotrexate on Adalimumab Response in Psoriasis by Pharmacokinetic–Pharmacodynamic Modeling

Previously, we showed that the combination of methotrexate and adalimumab treatment leads to less antidrug antibody development. In this study, we quantify the pharmacokinetics/pharmacodynamics (PK/PD) of adalimumab and evaluate the influence of methotrexate cotreatment. A population PK-PD model was developed using prospective data from 59 patients with psoriasis (baseline PASI= 12.6) receiving adalimumab over 49 weeks. Typical PK and PD parameters and their corresponding interpatient variability were estimated. We performed a covariate analysis to assess whether interpatient variability could be explained by addition of methotrexate and other covariates. In total, 330 PASIs, 252 adalimumab serum concentrations, and 247 antidrug antibody titers were available. Presence of antidrug antibodies (adalimumab group= 46.7%, adalimumab+ methotrexate group= 38.7%; P= .031) was correlated with increased adalimumab apparent clearance (P < .001). In the PD model, the use of concomitant methotrexate was borderline to significantly correlated with a decreased half-maximal inhibitory concentration (adalimumab concentration for which clinical response score is reduced by half; P < .10). On the basis of our PK-PD model, concomitant use of methotrexate indirectly increases adalimumab concentration, partially through less antidrug antibodies formation, which may result in better efficacy.

A systematic examination of anti-drug antibody titer estimation: Applied recommendations

Biologic drugs (therapeutic proteins or peptides) have become one of the most important therapeutic modalities over the past few decades. Drug-induced immunogenicity is a significant concern as it may affect safety, tolerability, and efficacy. With more sensitive and drug-tolerant screening assays in use today, reliable estimation of anti-drug-antibody (ADA) titer has become more important for understanding clinically relevant ADA levels. Titer is commonly defined as the dilution factor resulting in an assay signal equal to a pre-specified cut point factor. Given its influence on the resulting titer precision, the choice of a titer cut point factor warrants careful consideration. In this paper, we discuss the theoretical dilution model, investigate how titer variability depends on the cut point factor and propose a standardized cut point factor to increase precision of titer estimates. Additionally, we demonstrate that non-linear regression-based titer estimation provides both improved precision and implementation efficiency relative to commonly used estimation approaches.

Tirzepatide Immunogenicity on Pharmacokinetics, Efficacy, and Safety: Analysis of Data From Phase 3 Studies.

Antidrug antibodies (ADA) can potentially affect drug pharmacokinetics, safety, and efficacy. This work aimed to evaluate treatment-emergent (TE) ADA in tirzepatide (TZP)-treated participants across 7 phase 3 trials and their potential effect on pharmacokinetics, efficacy, and safety. ADA were assessed at baseline and throughout the study until end point, defined as week 40 (SURPASS-1, -2, and -5) or week 52 (SURPASS-3, -4, Japan-Mono, and Japan-Combo). Samples for ADA characterization were collected at SURPASS trial sites. Participants included ADA-evaluable TZP-treated patients with type 2 diabetes (N = 5025). Interventions included TZP 5, 10, or 15 mg. ADA were detected and characterized for their ability to cross-react with native glucose-dependent insulinotropic polypeptide (nGIP) and glucagon-like peptide-1 (nGLP-1), neutralize tirzepatide activity on GIP and GLP-1 receptors, and neutralize nGIP and nGLP-1. TE ADA developed in 51.1% of tirzepatide-treated patients. Proportions were similar across dose groups. Maximum ADA titers ranged from 1:20 to 1: 81 920 among TE ADA+ patients. Neutralizing antibodies (NAb) against TZP activity on GIP and GLP-1 receptors were observed in 1.9% and 2.1% of patients, respectively. Less than 1.0% of patients had cross-reactive NAb against nGIP or nGLP-1. TE ADA status, ADA titer, and NAb status had no effect on the pharmacokinetics or efficacy of TZP. More TE ADA+ patients experienced hypersensitivity reactions or injection site reactions than TE ADA- patients. The majority of hypersensitivity and injection site reactions were nonserious and nonsevere, and most events occurred and/or resolved irrespective of TE ADA status or titer. Immunogenicity did not affect TZP pharmacokinetics or efficacy. The majority of hypersensitivity or injection site reactions experienced by TE ADA+ patients were mild to moderate in severity.

PHASE 1B OPEN‐LABEL STUDY OF LONCASTUXIMAB TESIRINE IN COMBINATION WITH OTHER ANTICANCER AGENTS IN PATIENTS WITH RELAPSED/REFRACTORY B‐CELL NON‐HODGKIN LYMPHOMA (LOTIS‐7)

Introduction: Combining agents with different mechanisms of action may enhance treatment (Tx) efficacy in patients (pts) with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL). Loncastuximab tesirine (loncastuximab tesirine-lpyl; Lonca), an FDA-approved, CD19-directed, antibody-drug conjugate indicated for R/R diffuse large B-cell lymphoma (DLBCL), showed significant efficacy and manageable toxicity in a phase 2 trial in pts with R/R DLBCL. In preclinical models, Lonca + polatuzumab vedotin (Pola) showed improved efficacy. CD20 × CD3 T-cell–engaging antibodies and Lonca target different antigens; combining these is expected to increase efficacy. The safety and activity of Lonca combined with other agents in pts with R/R B-NHL will be evaluated in LOTIS-7. Methods: LOTIS-7, a phase 1b, open-label, multicenter, multiarm study (NCT04970901), will enroll ∼200 pts with B-NHL in part 1 (dose escalation, 60 pts) and part 2 (dose expansion, 140 pts). Part 2 may include specific subpopulation(s) of B-NHL informed by part 1. Primary endpoints are frequency and severity of adverse events (AE), serious AE, dose-limiting toxicities, and frequency of AE-related dose modifications. Secondary endpoints are overall response rate; duration of response; complete response rate; progression-free, relapse-free, and overall survival; Lonca concentrations; and antidrug antibody titers. Planned arms include Lonca + Pola (arm C), glofitamab (arm E), or mosunetuzumab (arm F). Arm C enrollment is open: pts are treated with Lonca + Pola as an outpatient infusion. In part 1, arm C pts receive Lonca at escalating doses (90-150 µg/kg) and Pola (1.8 mg/kg) on day 1 of each 3-week cycle; pts in arms E and F will receive Lonca 150 µg/kg for 2 cycles, then 75 µg/kg for subsequent cycles + glofitamab (2.5 mg on cycle [C]1 day [D]8, 10 mg on C1D15, and 10 or 30 mg for C2-12 D1, arm E) or mosunetuzumab subcutaneously (5 mg on C1D1, 15 or 45 mg for C1D8, and 45 mg for C1D15 and C2-8 D1, arm F) after initial step-up dosing. Lonca Tx may continue for up to 1 year or until disease progression, unacceptable toxicity, or other discontinuation criteria. Key eligibility criteria include age ≥18 years, pathologic diagnosis of R/R B-NHL (2016 WHO classification), measurable disease (2014 Lugano classification), Tx failure/intolerance, ≥2 lines of prior therapy (LOT) for part 1 (≥1 LOT for part 2), and ECOG performance status of 0-2. Pts previously receiving a study drug could not enroll in that respective study arm. Pts who received a stem-cell transplant within 60 days (100 days for arms E/F) before study Tx; received allogeneic stem cell or solid organ transplant (arms E/F); have lymphoma with active CNS involvement, ascites, edema, or effusion; or have significant comorbidities are excluded. The study opened in December 2021; as of January 2023, 12 pts have been enrolled and 9 treated in the Lonca + Pola arm. Encore Abstract - previously submitted to ASCO 2023 The research was funded by: ADC Therapeutics SA; medical writing: CiTRUS Health Group. Keywords: aggressive B-cell non-Hodgkin lymphoma, combination therapies, ongoing trials Conflicts of interests pertinent to the abstract. B. T. Hess Consultant or advisory role ADC Therapeutics, Bristol-Myers Squibb/Celgene M. M. Solh Research funding: Partner Therapeutics Other remuneration: Bristol-Myers Squibb, Amgen, AbbVie, Seattle Genetics M. Gandhi Honoraria: GlaxoSmithKline, TG Therapeutics, Karyopharm Therapeutics, Janssen Oncology Y. Wang Employment or leadership position: ADC Therapeutics America, Inc. Stock ownership: Johnson & Johnson (immediate family member) Y. Qin Employment or leadership position: ADC Therapeutics America, Inc. Stock ownership: ADC Therapeutics America, Inc. Research funding: ADC Therapeutics America, Inc. E. Yu Employment or leadership position: ADC Therapeutics America, Inc. Stock ownership: ADC Therapeutics America, Inc., Merck, Zentalis, Karuna Therapeutics, Biomarin P. L. Zinzani Consultant or advisory role Celltrion, Gilead Sciences, Janssen-Cilag, Bristol-Myers Squibb, Servier, Sandoz, MSD Oncology, Roche, EUSA Pharma, Kyowa Kirin, Takeda, Secura Bio, TG Therapeutics, Novartis, ADC Therapeutics, Incyte, BeiGene Other remuneration: MSD Oncology, EUSA Pharma, Novartis G. P. Collins Consultant or advisory role Roche, Takeda, Incyte, Pfizer, MSD Oncology, Celgene, BeiGene, Daiichi Sankyo, Celleron Therapeutics, ADC Therapeutics Honoraria: Roche, Takeda, Gilead Sciences, Pfizer, Novartis, Daiichi Sankyo, Incyte, Celleron Therapeutics, MSD Oncology, BeiGene, ADC Therapeutics, AstraZeneca Research funding: MSD Oncology, Celgene, Bristol-Myers Squibb, Amgen, Pfizer Educational grants: Roche, Takeda Other remuneration: Roche, Takeda, Novartis, Gilead Sciences

Phase 1b open-label study of loncastuximab tesirine in combination with other anticancer agents in patients with relapsed/refractory B-cell non-Hodgkin lymphoma (LOTIS-7).

TPS7581 Background: Combining agents with different mechanisms of action may enhance treatment (Tx) efficacy in patients (pts) with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL). Loncastuximab tesirine (loncastuximab tesirine-lpyl; Lonca), an FDA-approved, CD19-directed, antibody-drug conjugate indicated for R/R diffuse large B-cell lymphoma (DLBCL), showed significant efficacy and manageable toxicity in a phase 2 trial in pts with R/R DLBCL. In preclinical models, Lonca + polatuzumab vedotin (Pola) showed improved efficacy. CD20×CD3 T-cell engaging antibodies and Lonca target different antigens; combining these is expected to increase efficacy. The safety and activity of Lonca combined with other agents in pts with R/R B-NHL will be evaluated in LOTIS-7. Methods: LOTIS-7, a phase 1b, open-label, multicenter, multiarm study (NCT04970901), will enroll ~200 pts with B-NHL in part 1 (dose escalation, 60 pts) and part 2 (dose expansion, 140 pts). Part 2 may include specific subpopulation(s) of B-NHL informed by part 1. Primary endpoints are frequency and severity of adverse events (AE), serious AE, dose-limiting toxicities, and frequency of AE-related dose modifications. Secondary endpoints are overall response rate; duration of response; complete response rate; progression-free, relapse-free, and overall survival; Lonca concentrations; and antidrug antibody titers. Planned arms include Lonca + Pola (arm C), glofitamab (arm E), or mosunetuzumab (arm F). Arm C enrollment is open: pts are treated with Lonca + Pola as an outpatient infusion. In part 1, arm C pts receive Lonca at escalating doses (90-150 µg/kg) and Pola (1.8 mg/kg) on day 1 of each 3-week cycle; pts in arms E and F will receive Lonca 150 µg/kg for 2 cycles, then 75 µg/kg for subsequent cycles + glofitamab (2.5 mg on cycle [C]1 day [D]8, 10 mg on C1D15, 10 or 30 mg for C2-12 D1, arm E) or mosunetuzumab SC (5 mg on C1D1, 15 or 45 mg for C1D8, and 45 mg for C1D15 and C2-8 D1, arm F) after initial step-up dosing. Lonca Tx may continue for up to 1 year or until disease progression, unacceptable toxicity, or other discontinuation criteria. Key eligibility criteria include age ≥18 years, pathologic diagnosis of R/R B-NHL (2016 WHO classification), measurable disease (2014 Lugano classification), Tx failure/intolerance, ≥2 lines of prior therapy (LOT) for part 1 (≥1 LOT for part 2), and ECOG performance status of 0-2. Pts previously receiving a study drug could not enroll in that respective study arm. Pts who received a stem-cell transplant within 60 days (100 days for arms E/F) before study Tx; received allogenic stem cell or solid organ transplant (arms E/F); have lymphoma with active CNS involvement, ascites, edema, or effusion; or have significant comorbidities are excluded. The study opened in December 2021; 12 pts have been enrolled and 9 treated in the Lonca + Pola arm. Clinical trial information: NCT04970901 .

Donanemab exposure‐efficacy relationship in patients with early symptomatic Alzheimer’s disease

AbstractBackgroundDonanemab is an IgG1 antibody targeting N3pG (a modified beta amyloid present solely in brain plaques). A population pharmacokinetic/amyloid positron emission tomography (PET) imaging model described donanemab’s effect on amyloid plaque measurements and associated treatment‐effect with maintaining median (95%CI) threshold concentration of 4.43 (0.96 to 10.4 mg/mL). The extent to which exposure exceeded this threshold did not influence degree of amyloid removal. The current analysis aimed to quantify treatment effect on change in clinical decline (integrated AD Rating Scale, iADRS); evaluate the relationship of donanemab‐mediated changes in amyloid plaque on iADRS; and evaluate patient factors potentially affecting response to donanemab treatment.MethodAnalyses included patients with early symptomatic Alzheimer’s disease (AD, including prodromal AD and mild AD dementia) randomized to donanemab monotherapy versus placebo in a phase 2 study (TRAILBLAZER‐ALZ; N = 256; NCT03367403). Exposure‐response modeling employed a non‐linear mixed effects modeling approach. The treatment‐efficacy model utilized a Richard’s logistic function to fit the time course of all available iADRS data and characterize clinical decline. The impact of absolute or relative change from baseline in amyloid PET measurements (centiloids) was evaluated as a predictor of clinical decline.ResultDisease progression model‐based analyses showed donanemab significantly reduced rate of clinical decline by 28% in the overall population and 42% in APOE ε4 carriers (iADRS, p&lt;.001 for both). No clear treatment‐effect was identified in the smaller APOE ε4 noncarrier population (27% of study participants). Overall, serum concentrations of donanemab were not correlated with clinical decline. Antidrug antibody titer did not affect donanemab’s efficacy. Model simulations showed patients would benefit from donanemab treatment regardless of baseline disease severity, and patients with worse iADRS score at baseline had a greater absolute drug effect (difference between donanemab and placebo at 76 weeks). APOE ε4 carriers who had a 100% decrease in amyloid level from baseline with donanemab treatment are predicted to achieve, on average, a 43.5% slowing of clinical decline rate versus placebo‐treated patients (Figure).ConclusionFindings show donanemab treatment would benefit patients regardless of baseline disease severity. Both exposure‐efficacy and amyloid plaque biomarker models showed donanemab reduces rate of clinical decline and produces better patient outcomes than placebo.