Positive Anti-drug Antibodies Research Articles

Assessing Immunogenicity in Drug Reviews and Prescribing Information in Japan.

Anti-drug antibodies (ADAs) generated in response to biopharmaceuticals can significantly impact pharmacokinetics (PK) and overall drug efficacy. Thus, the ICH M4 guidelines mandate summarizing immunogenicity data from clinical trials in drug approval applications. However, following the approval of the first antibody drug in Japan in 2001, no cross-sectional investigation has focused on immunogenicity during the regulatory review process. Therefore, this study aims to examine the review reports and prescribing information of antibody drugs approved in Japan to identify key points related to immunogenicity evaluation. We conducted a cross-sectional analysis of review reports for antibody drugs approved between June 2001 and July 2022 by the Japanese regulatory authority. Specifically, we evaluated the ADA positivity rate, presence of neutralizing antibodies, antibody titers, and effects of ADA on PK, efficacy, and safety. We also compared this information with that provided in the prescribing information. Our analysis revealed that the ADA positivity rate and its effects on PK, efficacy, and safety were critical aspects of the review process. The emphasis on these factors varied depending on the number of applications and disease area. The information presented in the prescribing information was largely consistent with that discussed in the review reports. Overall, this study provides the first cross-sectional evaluation of immunogenicity considerations in the regulatory review of antibody drugs in Japan. Our findings can contribute to the efficiency of clinical trial planning and preparation of approval applications, to potentially improve the overall drug development process and address the drug loss problem in Japan.

Comparison of subcutaneous and intravenous infliximab in patients with inflammatory bowel disease showed no differences in immunogenicity or treatment persistence at 1 year

BackgroundInfliximab (IFX) effectiveness in inflammatory bowel disease (IBD) can be impaired by antidrug antibodies (ADA). Subcutaneous IFX has a different pharmacokinetic profile compared with intravenous administration, potentially affecting immunogenicity.MethodsRetrospective audit...

New Ustekinumab Biosimilar Candidate FYB202: Pharmacokinetic Equivalence Demonstrated in a Randomized, Double-Blind, Parallel-Group, Single-Dose Trial in Healthy Subjects.

In the RUSTIC trial, pharmacokinetic (PK) similarity between the proposed ustekinumab biosimilar FYB202 and EU-approved (EU-Ref) and US-licensed ustekinumab (US-Ref) as well as between both reference drugs was assessed after a single 45-mg subcutaneous injection. Safety analyses comprised immunogenicity (antidrug antibodies, neutralizing antibodies), adverse events, and local tolerability. Overall, 491 healthy adults were randomized 1:1:1 and observed for up to 112days; 486 completed the trial, and 478 were included in the PK analysis. All 3 comparisons showed PK similarity, since the 90% confidence intervals of the respective geometric mean ratios for area under the concentration-time curve from time 0 to infinity and maximum serum concentration were contained within the acceptance interval of 80%-125%. No clinically meaningful differences regarding overall safety, immunogenicity, and local tolerability were observed. Notably, after FYB202 administration, in fewer subjects at least 1 positive antidrug antibody result was observed compared to the reference groups (FYB202, 20%; EU-Ref, 42%; US-Ref, 51%). In conclusion, the RUSTIC trial demonstrated equivalent PK characteristics for FYB202 when compared to both EU-Ref and US-Ref ustekinumab and between both reference drugs. It provides the basis for the marketing authorization of FYB202, together with an extensive analytical characterization and the results of a confirmatory efficacy and safety trial in patients with moderate to severe plaque psoriasis.

Neutralizing Antibody Sample Testing and Report Harmonization

Immunogenicity testing and characterization is an important part of understanding the immune response to administration of a protein therapeutic. Neutralizing antibody (NAb) assays are used to characterize a positive anti-drug antibody (ADA) response. Harmonization of reporting of NAb assay performance and results enables efficient communication and expedient review by industry and health authorities. Herein, a cross-industry group of NAb assay experts have harmonized NAb assay reporting recommendations and provided a bioanalytical report (BAR) submission editable template developed to facilitate agency filings. This document addresses key bioanalytical reporting gaps and provides a report structure for documenting clinical NAb assay performance and results. This publication focuses on the content and presentation of the NAb sample analysis report including essential elements such as the method, critical reagents and equipment, data analysis, study samples, and results. The interpretation of immunogenicity data, including the evaluation of the impact of NAb on safety, exposure, and efficacy, is out of scope of this publication.Graphical

What are the benefits of therapeutic drug monitoring in the optimization of adalimumab therapy? a systematic review and meta-analysis up to 2022.

Persistent uncertainties exist surrounding the therapeutic drug monitoring (TDM) of adalimumab in clinical settings. To address these issues, we conducted a systematic review to assess the current evidence regarding the benefits of TDM for adalimumab. PubMed, EMBASE, and Cochrane Databases were searched from inception to October 2022. The trials regarding to the list three key questions were considered: 1) Could routine proactive TDM assist in improving outcomes in patients receiving adalimumab? 2) Could reactive TDM assist in guiding subsequent treatment strategies for patients with treatment failure to adalimumab? 3) Could TDM assist in informing dose reduction or discontinuation in patients with low disease activity or in remission treated with adalimumab? Two reviewers independently selected the studies and extracted the data. Meta-analysis was performed to calculate the relative risk (RR) and 95% confidence interval (CI). A total of 9 studies was included in this review. For proactive TDM, meta-analysis indicated that proactive TDM (n = 163/257, 63.42%) showed no significant superiority over reactive TDM and/or conventional management (n = 336/606, 55.44%) in achieving and/or maintaining clinical remission by random effects model (RR: 1.24, 95% CI 0.98-1.58, I 2 = 73%). There were three studies that supporting the reactive TDM, low drug levels in the absence of anti-drug antibodies (ADA) strongly indicate the need for dose intensification, and infliximab is a feasible choice for patients with low drug levels and ADA positivity. While swapping to another class should be considered in patients with adequate drug levels. In addition, TDM can help clinicians optimize dosing schedules and prevent overtreatment in patients who have achieved low disease activity and sufficient drug concentrations, with no predictive value for successful adalimumab discontinuation. Current evidence suggests that proactive TDM is numerically but not statistically significant superiority over reactive TDM and/or conventional management. Reactive TDM can aid in understanding treatment failure and developing subsequent therapy. For patients reaching low disease activity and remission, TDM can help successful dose reduction, while it cannot inform the successful drug discontinuation. However, existing trials are limited, and more well-designed trials are necessary to clarify the role of TDM in adalimumab treatment.

Adalimumab (ADA) in Pediatric Non-infectious Uveitis: An Observational Study.

Pediatric uveitis is a rare but sight-threatening condition. Prompt and adequate treatment is crucial to preserve vision and avoid long-term complications. In cases that are resistant to corticosteroids and disease-modifying anti-rheumatic drugs (DMARDs), anti-tumor necrosis (anti-TNF) biologic agents are usually added. In this study, we report our experience with adalimumab (ADA) anti-TNF use in this group of patients. This is a retrospective observational study conducted in a tertiary pediatric uveitis clinic, in Manchester Royal Eye Hospital. All patients were pediatric patients (aged 2-18 years old) under follow-up during the period of six months. The patients' data were analyzed according to the diagnosis, age of onset of uveitis, systemic medications used before and concomitantly withADA, duration of uveitis before starting ADA, its effect, and time to notice the therapeutic effect in controlling inflammation. Finally, cases were reviewed for the development of anti-drug antibodies. Forty-two patients were included in the study. Idiopathic uveitis was diagnosed in 47.6% of patients and 40.5% of patients were associated with juvenile idiopathic arthritis (JIA). Most (97.6%) of patients were using topical steroids before starting ADA and 95.2% continued using steroids after established ADA use, but systemic steroid use was reduced from 33.3% to 14.3%. The most common non-biologic DMARD used before ADA was methotrexate (MTX) (90.5%). One-third of the patients started ADA between 6 and 12 months after the diagnosis of uveitis, while this percentage dropped to 9.5% the year after diagnosis. Seventy-eight percent of patients acquired complete clinical control of inflammation on ADA use. Almost 78.6% of patients showed a full response in less than six months. In eight patients who were not controlled or were transiently controlled on ADA, three patients had positive anti-drug antibodies. In one patient, antidrug antibodies were identified after 12 years of ADA use, and in another, after 4 years. Adalimumab is an effective, well-tolerated drug in children with uveitis refractory to non-biologic DMARD therapy. DMARDs were usually used alongside ADA in this cohort and few patients had confirmed ADA antibodies.

Antibiotics influence the risk of anti-drug antibody formation during anti-TNF therapy in Chinese inflammatory bowel disease patients.

Aims: The formation of anti-drug antibodies (ADAs) during anti-tumor necrosis factor (anti-TNF) therapy is reported to lead to reducing serum drug levels, which may bring about a loss of response to treatment. Previous research has suggested an association between specific antibiotic classes and ADA formation during anti-TNF therapy. However, there are few studies specifically examining this association in Chinese inflammatory bowel disease (IBD) patients. Therefore, our study aimed to evaluate the possible effect of antibiotic use on ADA formation to anti-TNF therapy in Chinese patients with IBD. Methods: A total of 166 patients with IBD, including 149 with Crohn's disease (CD) and 17 with ulcerative colitis (UC), were included in this retrospective analysis. These patients were initially treated with anti-TNF therapy (infliximab or adalimumab) after January 2018 and reviewed with available ADA levels before October 2023. After univariable analysis of all the variables, a multivariate Cox proportional hazards model was used to assess the association between antibiotic use and ADA development. Results: Among 166 IBD patients treated with infliximab (108/166, 65.1%) or adalimumab (58/166, 34.9%), 31 patients (18.7%) were measured as positive ADA levels. Cox proportional hazard model demonstrated an increased risk of ADA formation in IBD patients who used β-lactam-β-lactamase inhibitor combinations (BL-BLIs) (HR = 5.143, 95%CI 1.136-23.270, p = 0.033), or nitroimidazoles (HR = 4.635, 95%CI 1.641-13.089, p = 0.004) during 12months before the ADA test. On the contrary, a reduced risk was noted in patients treated with fluoroquinolones (HR = 0.258, 95% CI 0.072-0.924, p = 0.037). Moreover, the median serum infliximab or adalimumab concentration in patients with positive ADA levels was significantly lower than that in patients with negative ADA levels (infliximab: 0.30 vs. 1.85μg/mL, p < 0.0001; adalimumab: 0.45 vs. 7.55μg/mL, p = 0.0121). Conclusion: ADA development is associated with various antibiotic classes. BL-BLIs and nitroimidazoles might increase the risk of ADA formation during anti-TNF therapy in Chinese IBD patients, while the treatment with fluoroquinolones could probably reduce such risk. There were certain limitations in the retrospective analysis of the study, therefore, the results are just for reference, and other studies are needed to further confirm our findings.

Abstract 7167: Impact of patient specific factors on exposures of tarlatamab, a half-life extended DLL3-directed bispecific T-cell engager in patients with advanced small cell lung cancer

Abstract Background: Tarlatamab is a first in class, half-life extended delta-like ligand (DLL3) targeted bispecific T-cell engager (BiTE) immunotherapy that has shown antitumor activity with durable objective responses and promising survival outcomes in the ongoing studies in patients with previously treated small-cell lung cancer (NCT03319940, NCT05060016) (Ahn et al, 2023; Paz-Ares et al, 2023). Here we describe the effects of patient specific factors [age, sex, bodyweight, ethnicity, estimates of renal and hepatic function, prior lines of therapy, baseline disease status, emergence of anti-drug antibodies (ADA)] on tarlatamab exposures. Methods: Tarlatamab serum concentrations were available from 420 subjects (8509 samples) pooled across the ongoing Phase 1 DeLLphi-300 study (dose range 0.003 mg to 100 mg Q2W and 200 mg Q3W) and Phase 2 DeLLphi-301 study (10 mg and 100 mg Q2W). The data were analyzed using a nonlinear-mixed effects modeling approach implemented in NONMEM (v7.5) software. Model selection and evaluation was guided by standard statistical and graphical approaches. Impact of key baseline demographic variables on tarlatamab clearance and volume of distribution were evaluated. Results: Tarlatamab exposures increased in a dose-proportional manner and were not impacted by age, sex, ethnicity, estimates of renal and hepatic function, prior lines of therapy or baseline disease status. Asian race resulted in 14% higher peak serum concentrations relative to Caucasian subjects. Higher body weight (99 kg; 90th percentile) was associated with a 24% decrease in Day 28 pre-dose concentration (Ctrough) relative to median bodyweight (73 kg). Lower body weight (54 kg; 10th percentile) was associated with a 27% increase in Ctrough relative to median bodyweight. Positive ADA status resulted in a 24% decrease in Ctrough. However, at the recommended dose of 10 mg Q2W, neither body weight nor ADA status had a clinically relevant impact on tarlatamab efficacy or safety measures (Ahn et al, 2023). Conclusion: Overall, based on these analyses, no dose adjustment for tarlatamab is required based on age, sex, bodyweight, ethnicity, estimates of renal and hepatic function, prior lines of therapy, baseline disease status or emergence of ADA. Citation Format: Stephanie M. Kong, Mukul Minocha, Po-Wei Chen, Pablo Martinez, Erik S. Anderson, Amanda Parkes, Brett E. Houk, Chih-Wei Lin. Impact of patient specific factors on exposures of tarlatamab, a half-life extended DLL3-directed bispecific T-cell engager in patients with advanced small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7167.

Phase 1b/2 study of penpulimab (AK105), an antiprogrammed cell death-1 immunoglobulin G1 antibody, in advanced or metastatic solid tumors (AK105-204).

Penpulimab, a new-generation antiprogrammed cell death-1 immunoglobulin G1 monoclonal antibody, was engineered to optimize receptor occupancy and eliminate fragment crystallizable γ-mediated effector function. In this multicenter, phase 1b/2, multicohort study, the objective was to investigate the efficacy, safety, and immunogenicity of penpulimab in advanced solid tumors. Patients who had unresectable, advanced solid tumors were enrolled from six centers and received 200mg penpulimab on day 1 every 2weeks for up to 24months. The primary end point was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors, version criteria 1.1. Between September 2, 2019, and January 1, 2020, 65 patients were enrolled and received penpulimab. At the time of data cutoff (May 11, 2022), the median follow-up was 12.6months (range, 1.1-28.6 months). The ORR was 12.3 (95% confidence interval [CI], 5.5%-22.8%), with three (4.6%) complete responses and five (7.7%) partial responses. Twelve patients (18.5%) achieved stable disease, resulting in a disease control rate of 30.8% (95% CI, 19.9%-43.4%). The median duration of response was not reached (95% CI, 6.70 months to not estimable). In all cohorts, the median progression-free survival was 1.74months (95% CI, 1.41-2.69 months), and the median overall survival was 16.59months (95% CI, 7.82-22.18 months). Grade 3 or greater treatment-related adverse events and immune-related adverse events occurred in 9.2% and 27.7% of patients, respectively. Positive antidrug antibody responses to penpulimab were observed in one patient (1.8%). Penpulimab showed promising antitumor activity with an acceptable safety profile, offering a potential new treatment approach for solid tumors. These findings supported the evaluation of penpulimab's durable activity and safety, as monotherapy or in combination therapy, in specific malignancies.

Pharmacokinetics and pharmacodynamics of the proposed biosimilar denosumab GP2411 and reference denosumab in healthy males

ABSTRACT Background This Phase I study compared the pharmacokinetic (PK) and pharmacodynamic (PD) similarity of GP2411 proposed denosumab biosimilar to reference denosumab (a monoclonal antibody for specific pro-resorptive conditions). Research design and methods Healthy males (28–65 years, 50–90 kg) were randomized to a single sub-therapeutic subcutaneous injection of 35 mg GP2411, EU-Xgeva® or US-Xgeva®, and followed for 39 weeks. The primary endpoints were AUCinf, AUClast, and Cmax. Results Four hundred ninety-two participants completed treatment. The 90% confidence intervals (CIs) (AUCinf, AUClast, and Cmax) and 95% CI of the geometric mean ratios of AUEC of % change from baseline in serum CTX were fully contained within the prespecified equivalence margins (0.80, 1.25), demonstrating similarity. The occurrence of treatment-emergent adverse events (TEAEs) with GP2411, EU-Xgeva® and US-Xgeva® was similar (72.9%, 76.0%, and 71.0% of participants, respectively). Most were Grade 1 or 2, <30% were treatment-related, and there was only one TEAE-related study discontinuation. Rates of positive anti-drug antibodies (ADAs) were similar (57.8%, 64.9%, and 69.1% of participants respectively), but immunogenicity was only borderline detectable and of very low magnitude. Ninety-nine percent of positive ADAs were transient. Conclusion GP2411 demonstrated similarity with EU-Xgeva® and US-Xgeva® in PK, PD, safety, and immunogenicity in this population. Clinical trial registration EudraCT 2019-001651-39

P583 Infliximab Monitoring in Crohn's Disease and Development of Neural Networks Using Clinical Variables to Predict Disease Activity and Immunogenicity

Abstract Background Infliximab (IFX) is a biological drug that inhibits the action of tumor necrosis factor-alpha (TNFα), a pro-inflammatory cytokine enrolled in the pathogenesis of Crohn's disease (CD). Trough-level drug monitoring (TDM) has been increasingly used in clinical practice to optimize biological therapy and improve precision medicine. Therefore, this study aimed to analyze the serum level of IFX and antidrug antibodies (ADA) in active and in remission CD patients and develop prediction models via neural networks using a combination of clinical variables. Methods Seventy-five CD patients who underwent IFX therapy in the maintenance phase were included. Disease activity was defined by endoscopic and/or radiological criteria, comprising remission (CDR) and active (CDA) groups. Serum IFX levels were measured by ELISA (Promonitor ®) and rapid lateral flow test (Quantum-Blue®). ADA was measured using ELISA (Promonitor ®). For statistical analysis, a non-parametric test was used, with adopted p≤0.05. To create a prediction model, four sets of neural networks were constructed for the following output variables: remission/activity, presence or not of ADA, therapeutic level according to ELISA, and therapeutic level according to the lateral flow test. The neural networks and ROC curves were designed using the Keras package in Python software. The study was approved by the Research Ethics Committee. Results No differences were observed in the IFX level when comparing the CDA and CDR groups in both tests (p&amp;gt; 0.05). There was no statistical difference in IFX levels according to the use of immunosuppressants (IMS) (p&amp;gt;0.05). ADA levels &amp;gt; 5AU/mL were detected in only 11 (14.6%) patients. All patients with positive ADA had infratherapeutic IFX levels in both tests, and 72.7% were on combination therapy with IMS. Of the 4 neural networks developed, two, whose output variables were “remission/activity” and “presence or not of ADA,” showed excellent performance, with AUC ranging from 82% to 92% and 100%, respectively. Conclusion The introduction of IFX monitoring may allow more individualized and precise therapeutic management. Regarding the performance characteristics of the neural networks, an AUC &amp;gt;80% was evident in two of them. Through clinical and non-invasive laboratory variables, disease activity was determined. Furthermore, the finding of combinations of variables that determine the ADA level, and at the same time not having demonstrated good models for IFX serum level measurement, means that the latter continues to be necessary for clinical practice. Otherwise, ADA levels, which indicate immunogenicity, can be predicted by non-invasive clinical variables.

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.

P1021 Comparison of subcutaneous and intravenous infliximab in patients with inflammatory bowel disease showed no differences in immunogenicity or treatment persistence at one year

Abstract Background The effectiveness of infliximab (IFX) in inflammatory bowel disease (IBD) can be impaired by the formation of anti-drug antibodies (ADA). Subcutaneous (SC) IFX has a different pharmacokinetic profile compared to intravenous (IV) administration. These differences may affect the risk of immunogenicity and we sought to explore this in a retrospective study. Methods We performed a retrospective study in Leeds, United Kingdom. Adult patients starting IFX for the first time between January 2019 and June 2022 were identified. All received standard induction with three IV doses followed by either: 1) maintenance SC IFX 2-weekly (standard practice from 2021), or 2) maintenance IV IFX (standard practice until 2021). We compared ADA levels, IFX trough levels and treatment persistence between groups after 12-months of treatment. ADA levels above 10 AU/ml were considered positive and ADA levels above 50 AU/ml as clinically relevant. Results After excluding 41 patients (16 stopped IFX after IV induction, 24 moved to SC after &amp;gt;4 IV doses, and 1 lost to follow-up), 101 patients receiving maintenance SC IFX were compared to 108 patients continuing with maintenance IV IFX. At 12-months, prevalence of ADA positivity was similar in both groups (48.1% SC vs 50.6%; p=0.775). Clinically relevant ADA levels (&amp;gt;50 AU/ml) were also similar (21.1% SC vs 26.5% IV; p=0.481). Additionally, there were no statistically significant differences in terms of detectable IFX trough levels and treatment persistence after 12-months of treatment between the two groups. Patients receiving combination therapy with IFX and immunomodulators showed a significant reduction in ADA formation irrespective of the route of IFX administration. 34.8% of patients receiving combination therapy had detectable ADA compared to 65.2% receiving IFX monotherapy (OR 0.28 (95% CI 0.13-0.58; p=0.001)). Treatment persistence was also significantly higher in those receiving combination therapy compared with monotherapy at 12-months (73.3% vs. 51.9%; p=0.004). The proportion of patients with detectable drug levels at 12-months was also higher with combination therapy (91.3% vs. 72.7%; p=0.005). Conclusion There were no significant differences in ADA levels, IFX levels, and treatment persistence between the SC and IV routes of IFX administration after 12 months of treatment. Concurrent use of immunomodulators was associated with reduced immunogenicity and better treatment persistence regardless of the route of maintenance IFX. Clinicians should advise patients on the benefits of immunomodulator combination therapy when initiating IFX regardless of route of administration.

Thoracic Vertebral Fracture in a Female Case of Ankylosing Spondylitis Complicated with Turner Syndrome and Insufficient Response to Adalimumab

Background: Ankylosing spondylitis (AS) is a chronic disease characterized by inflammatory back pain, with osteoporosis prevalence ranging from 18.7% to 62% 1. Vertebral fractures are four times more likely to occur 2. Turner syndrome (TS) is the most common sex chromosome abnormality in females, with a 1.4- to 2.2-fold increased likelihood of osteoporosis-related fractures 3. Seven cases of AS combined with TS with HLA-B27 positivity have been reported4. Methods: We report a case of a female patient with AS and TS who exhibited an inadequate response to adalimumab (ADA) and suffered a thoracic vertebral fracture. Results: A 41-year-old woman with HLA-B27 negative was diagnosed with AS in 2012 because of low back pain, and began ADA treatment in 2018. The patient had a past history of TS (45X/47XXX) with ultrasound revealing smaller than normal ovaries and uterus. Body weight was 54kg and height was 145cm (BMI25.68). She had primary amenorrhea, a wrist fracture at a young age, and a thoracic spine fracture in 2018. Bone mineral density (BMD) values for orthotopic lumbar vertebrae L1-L4 were 0.74 g/cm2, with Z-score of -2.7, and 0.564 g/cm2 at the left femoral neck with Z-score of -2.4. The FRAX tool predicted a 10-year fracture risk of 2.4% for the occurrence of major osteoporotic fracture (MOF), and a fracture risk of 0.9% for hip fracture. She initiated hormone replacement therapy (HRT). In November 2022, she discontinued ADA due to COVID-19 infection. Laboratory tests identified slightly elevated inflammatory markers (Fig. 1), low trough drug level of 0.31ug/ml and positive anti-drug antibody. In February 2023, she slipped in a snowdrift and experienced increased back pain. Spinal MRI revealed osteoporosis with a T7 compression fracture and a new T9 fracture (Figure 2 A,B). Sacroiliac (SI) joints MRI showed significant improvement of inflammation (Fig. 2 C,D). Spine surgery consultation suspected fracture attributed to obvious kyphosis deformity and stress concentration during falls, resulting in buckling compression. Repeated test determined a BMD value of 0.920 g/cm2 for orthotopic L3-L4 with a Z-score of -1.4, and a BMD value of 0.775 g/cm2 for the left total hip with a Z-score of -1.2, the 10-year probability of MOF was 3.2%, and that of hip fracture was 0.5%. She was diagnosed with severe osteoporosis due to recurrent fracture despite of BMD improvement and anti-osteoporosis medications were postponed. Conclusion: This case further proved the dominant role of disease co-morbidity and insufficient treatment in the unfavorable outcome regardless of genetic predisposition.

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.

Quantification of anti-drug antibodies against E6011, an anti-fractalkine monoclonal antibody, in monkey and human serum, by an electrochemiluminescence assay

E6011, a humanized anti-fractalkine monoclonal antibody, is under development for the treatment of various inflammatory diseases, such as rheumatoid arthritis. Therapeutic antibodies may induce production of anti-drug antibodies (ADA) that may deteriorate efficacy and/or enhance immunogenic reaction. It is important to have an ADA assay to understand the characteristics of biotherapeutics under development. A simple and reproducible assay has thus been developed for the determination of ADA against E6011 in monkey and human serum by electrochemiluminescence (ECL) detection. An immune-complex of biotinylated E6011, ADA, and ruthenium-labeled E6011 was attached to avidin-coated wells for ECL signal detection. Screening and confirmatory cutpoints were determined to judge negative or positive ADA. Sensitivity of ADA was 1.61 and 1.34 ng/mL in monkey and human serum, respectively. Accuracy and precision of the assay were within ±20% and 20%, respectively. Drug tolerance of the assay in monkey and human sera was ensured up to 100 and 1000 μg/mL E6011 at the surrogate ADA levels of 1 and 4 μg/mL, respectively. The developed assay was successfully applied to ADA quantification in monkeys and humans in support of immunogenicity assessments.

Impact of switching between reference biologics and biosimilars of tumour necrosis factor inhibitors for rheumatoid arthritis: a systematic review and network meta-analysis

What is the impact of switching between biologics and biosimilars of adalimumab, etanercept, and infliximab on efficacy and safety for rheumatoid arthritis? A systematic review and network meta-analysis were performed to compare switching and non-switching groups of treatments. Pooled Risk Relative (RR) or standardised mean differences (SMD) with 95% credible intervals (95% CrIs) were obtained. Seventeen randomized trials with a switching phase involving 6,562 patients were included. Results showed that a single switch from biologics to biosimilars compared to continuing biologics had comparable effects for primary and co-primary outcomes, the American College of Rheumatology criteria with 20% response (ACR20) (7 trials, 1,926 patients, RR 0.98, 95% CrIs 0.93 to 1.03) and the Health Assessment Questionnaire—Disability Index (HAQ-DI) (5 trials, 1,609 patients, SMD − 0.07, 95% CrIs − 0.23 to 0.1), and within the equivalence margins: ACR20 [RR 0.94, 1.06] and HAQ-DI [SMD − 0.22, 0.22]. The risk of treatment-emergent adverse events, discontinuation, and positive anti-drug antibodies were comparable after switching. Safety results were imprecise, and the follow-up period might not be sufficient to evaluate long-term effects, especially malignancies. Overall, the practice of single switching between approved biologics and biosimilars of Tumour Necrosis Factor inhibitors is efficacious and safe for rheumatoid arthritis.

Efficacy and safety of lanadelumab in Japanese patients with hereditary angioedema: A phase 3 multicenter, open-label study.

The safety and efficacy of lanadelumab for the prevention of hereditary angioedema (HAE) attacks have not been studied in Japanese patients. We report outcomes from a phase 3, multicenter, open-label study (NCT04180163) of lanadelumab in Japanese patients with HAE. Japanese patients with HAE aged ≥12 years with ≥1 investigator-confirmed HAE attack during the 4-week run-in baseline period were enrolled into the study and received lanadelumab 300 mg every 2 weeks subcutaneously for 52 weeks. Dosing could be reduced to 300 mg every 4 weeks during the second 26-week treatment period if patients had well-controlled symptoms (e.g., attack-free) for 6 months. The primary efficacy endpoint was no investigator-confirmed HAE attacks (attack-free status) during days 0-182. Other outcomes included the rate of investigator-confirmed HAE attacks per month (28 days) and lanadelumab safety. Twelve patients (mean ± SD age 41.9 ± 12.4 years) were enrolled. During the first 26 weeks (days 0-182), five (41.7%) patients were attack-free. The mean ± SD HAE attack rate per month decreased by 74.0%, from 3.8 ± 2.4 during baseline to 1.2 ± 2.6 during the overall 52-week treatment period. There were no deaths or discontinuations due to treatment-emergent adverse events (TEAEs), no severe or serious TEAEs related to lanadelumab, and no positive anti-drug antibody results. The most frequent TEAEs were injection-site reactions (37 events in six patients). Most of the injection-site reaction adverse events were mild in severity. Results of this study support the findings from two global phase 3 studies for lanadelumab use as prophylactic therapy in Japanese patients with HAE.

Serum Concentrations of Infliximab and IL-6 for Predicting One-Year Discontinuation of Infliximab Treatment Owing to Secondary Non-response in Patients with Rheumatoid Arthritis.

Secondary non-response to infliximab (IFX) occurs in some patients with rheumatoid arthritis (RA). Although therapeutic drug monitoring (TDM) is a useful tool to optimize IFX therapy, it is unclear whether it can help to identify the risk of secondary non-response. This study aimed to explore the utility of serum levels of IFX or other biomarkers to predict IFX discontinuation owing to secondary non-response. A single-center, retrospective study was conducted using the Kyoto University Rheumatoid Arthritis Management Alliance cohort database between 2011 and 2020. Serum IFX levels were measured using liquid chromatography-tandem mass spectrometry. An electrochemiluminescence assay was used to quantify serum levels of tumor necrosis factor-α and interleukin-6 and detect anti-drug antibodies. Eighty-four out of 310 patients were eligible for this study. The cutoff levels of biomarkers were determined by receiver operating characteristic analysis. IFX persistence was similar between groups stratified using IFX levels, tumor necrosis factor-α levels, interleukin-6 levels, and anti-drug antibodies positivity. The group with lower IFX and higher interleukin-6 levels had the worst therapy persistence (p = 0.017) and the most frequent disease worsening (90.0%, p < 0.001). Evaluating both interleukin-6 and IFX levels, not just IFX alone, enabled us to identify patients at risk of discontinuing IFX treatment. These findings support the utility of measuring IFX and interleukin-6 levels for successful maintenance therapy for RA.

Response to Biologic Drugs in Patients With Rheumatoid Arthritis and Antidrug Antibodies

There are conflicting data on the association of antidrug antibodies with response to biologic disease-modifying antirheumatic drugs (bDMARDs) in rheumatoid arthritis (RA). To analyze the association of antidrug antibodies with response to treatment for RA. This cohort study analyzed data from the ABI-RA (Anti-Biopharmaceutical Immunization: Prediction and Analysis of Clinical Relevance to Minimize the Risk of Immunization in Rheumatoid Arthritis Patients) multicentric, open, prospective study of patients with RA from 27 recruiting centers in 4 European countries (France, Italy, the Netherlands, and the UK). Eligible patients were 18 years or older, had RA diagnosis, and were initiating a new bDMARD. Recruitment spanned from March 3, 2014, to June 21, 2016. The study was completed in June 2018, and data were analyzed in June 2022. Patients were treated with a new bDMARD: adalimumab, infliximab (grouped as anti-tumor necrosis factor [TNF] monoclonal antibodies [mAbs]), etanercept, tocilizumab, and rituximab according to the choice of the treating physician. The primary outcome was the association of antidrug antibody positivity with EULAR (European Alliance of Associations for Rheumatology; formerly, European League Against Rheumatism) response to treatment at month 12 assessed through univariate logistic regression. The secondary end points were the EULAR response at month 6 and at visits from month 6 to months 15 to 18 using generalized estimating equation models. Detection of antidrug antibody serum levels was performed at months 1, 3, 6, 12, and 15 to 18 using electrochemiluminescence (Meso Scale Discovery) and drug concentration for anti-TNF mAbs, and etanercept in the serum was measured using enzyme-linked immunosorbent assay. Of the 254 patients recruited, 230 (mean [SD] age, 54.3 [13.7] years; 177 females [77.0%]) were analyzed. At month 12, antidrug antibody positivity was 38.2% in patients who were treated with anti-TNF mAbs, 6.1% with etanercept, 50.0% with rituximab, and 20.0% with tocilizumab. There was an inverse association between antidrug antibody positivity (odds ratio [OR], 0.19; 95% CI, 0.09-0.38; P < .001) directed against all biologic drugs and EULAR response at month 12. Analyzing all the visits starting at month 6 using generalized estimating equation models confirmed the inverse association between antidrug antibody positivity and EULAR response (OR, 0.35; 95% CI, 0.18-0.65; P < .001). A similar association was found for tocilizumab alone (OR, 0.18; 95% CI, 0.04-0.83; P = .03). In the multivariable analysis, antidrug antibodies, body mass index, and rheumatoid factor were independently inversely associated with response to treatment. There was a significantly higher drug concentration of anti-TNF mAbs in patients with antidrug antibody-negative vs antidrug antibody-positive status (mean difference, -9.6 [95% CI, -12.4 to -6.9] mg/L; P < 001). Drug concentrations of etanercept (mean difference, 0.70 [95% CI, 0.2-1.2] mg/L; P = .005) and adalimumab (mean difference, 1.8 [95% CI, 0.4-3.2] mg/L; P = .01) were lower in nonresponders vs responders. Methotrexate comedication at baseline was inversely associated with antidrug antibodies (OR, 0.50; 95% CI, 0.25-1.00; P = .05). Results of this prospective cohort study suggest an association between antidrug antibodies and nonresponse to bDMARDs in patients with RA. Monitoring antidrug antibodies could be considered in the treatment of these patients, particularly nonresponders to biologic RA drugs.