Formation Of Anti-drug Antibodies Research Articles

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.

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

Obinutuzumab Pretreatment as a Novel Approach to Mitigate Formation of Anti-Drug Antibodies Against Cergutuzumab Amunaleukin in Patients with Solid Tumors.

The immunocytokine cergutuzumab amunaleukin (CEA-IL2v) showed manageable safety and favorable pharmacodynamics in Phase I/Ib trials in patients with advanced/metastatic carcinoembryonic antigen-positive (CEA+) solid tumors, but this was accompanied by a high incidence of anti-drug antibodies (ADAs). We examined B-cell depletion with obinutuzumab as a potential mitigation strategy. Preclinical data comparing B-cell depletion with rituximab versus obinutuzumab are summarized. Substudies of Phase I/Ib trials investigated the effect of obinutuzumab pretreatment on ADA development, safety, pharmacodynamics, and anti-tumor activity of CEA-IL2v ± atezolizumab in patients with advanced/metastatic or unresectable CEA+ solid tumors who had progressed on standard of care. Preclinical data showed superior B-cell depletion with obinutuzumab versus rituximab. In clinical studies, patients received CEA-IL2v monotherapy with (n = 16) or without (n = 6) obinutuzumab pretreatment (monotherapy study), or CEA-IL2v + atezolizumab + obinutuzumab pretreatment (n = 5; combination study). In the monotherapy study, after 4 cycles (every 2 weeks treatment), 0/15 evaluable patients administered obinutuzumab pretreatment had ADAs versus 4/6 patients without obinutuzumab. Obinutuzumab pretreatment with CEA-IL2v monotherapy showed no new safety signals and pharmacodynamic data suggested minimal impact on T cells and natural killer cells. Conversely, increased liver toxicity was observed in the combination study (CEA-IL2v + atezolizumab + obinutuzumab pretreatment). These preliminary findings suggest that obinutuzumab pretreatment before CEA-IL2v administration in patients with CEA+ solid tumors may be a feasible and potent ADA mitigation strategy, with an acceptable safety profile, supporting broader investigation of obinutuzumab pretreatment for ADA mitigation in other settings.

Development and Validation of the Cell-based Functional Method for Neutralizing Anti-adalimumab Antibodies Detection in Human Serum

Introduction. Adalimumab, a fully humanized monoclonal antibody, is a tumor necrosis factor (TNFα) inactivator that is used against a number of autoimmune diseases such as rheumatoid arthritis and other most common inflammatory arthropathies (ankylosing spondylitis, psoriatic arthritis). Despite the proven efficacy of adalimumab treatment, there is a risk of adverse events, tied up with the formation of anti-drug antibodies, including neutralizing antibodies. Currently, the evaluation and characterization of neutralizing antibodies has become an important part of clinical trials in the development of new drugs and biosimilars.Aim. The aim of this study is to develop and validate the cell-based functional method for neutralizing anti-adalimumab antibodies determination in human serum.Materials and methods. For determination of neutralizing anti-adalimumab antibodies, the cell line L-929 has been employed. L-929 is a cell line sensitive to the TNFα-mediated apoptosis; the neutralizing antibodies interact with adalimumab that leads to TNFα-mediated cytotoxicity. Cytotoxicity was measured using resazurin, an aromatic compound that is a redox indicator.Results and discussion. The developed method was validated for cut point, selectivity, sensitivity, precision, specificity and stability (short- and long-term). An important part of a method development for determining neutralizing antibodies is the selection of concentrations of TNFα (4 ng/ml) and adalimumab (250 ng/ml), as well as determining the minimum required dilution – this parameter is established as 1 : 20. Cut point was chosen as a «floating» cut point, and a correction factor (normalization factor) was determined equal to 0,86. The sensitivity of the developed method was estimated at 108,9 ng/ml of neutralizing anti-adalimumab antibodies.Conclusion. The obtained results can be applied for determining anti-adalimumab neutralizing antibodies in the assessment of the adalimumab immunogenicity, including clinical trials.

A221 AZATHIOPRINE DOSING THRESHOLD IN ANTI-TNF COMBINATION THERAPY FOR MINIMIZING IMMUNOGENICITY AND OPTIMIZING TREATMENT EFFICACY FOR PATIENTS WITH INFLAMMATORY BOWEL DISEASE. A RETROSPECTIVE COHORT STUDY

Abstract Background Reported rates of anti-drug antibody (ADA) formation to tumor necrosis factor-a antagonists (anti-TNF) range from 20-75%. One way to reduce the risk of ADA formation is to combine a second immune-suppressing agent such as azathioprine (AZA) with the anti-TNF agent, known as combination therapy. However, it is unknown if the risk of combination therapy, including the additive risk of AZA and anti-TNF side effects, could be reduced by exposing individuals with inflammatory bowel disease (IBD) to the lowest dose of azathioprine while still maintaining the beneficial effect of ADA prevention. Aims To identify the minimum dose of AZA needed to prevent ADA formation to anti-TNF agents in individuals with IBD receiving combination therapy. We also assessed the occurrence of adverse drug events, treatment loss of response, treatment discontinuation and the need for treatment dose escalation. Methods A retrospective cohort study is ongoing in adult participants with IBDreceiving either infliximab or adalimumab in combination with AZA. Patients are divided based on their AZA dosage (low dose group, AZA ampersand:003C2mg/kg/day versus standard dose group, AZA 2mg/kg/day). All participants will be followed for 1 year and observed for the occurrence of ADA formation, adverse drug events, treatment loss of response, treatment discontinuation and the need for treatment dose escalation. Results To date, 48 participants are currently included (low dose, n=29; standard dose, n=19). 42 are on Infliximab and 6 are on Adalimumab. The occurrence of ADA was 17.4% in the low dose group and 20% in the standard dose group (pampersand:003E0.99). More participants lost response to treatment and discontinued anti-TNF therapy in the standard dose group (n=7/19, 36.8%) versus the low-dose group (n=8/29, 27.6%, p=0.54). More participants in the low-dose group received anti-TNF dose escalation (n= 20/29,68.9%) compared to the standard dose group (n=6/19, 31.6%, p=0.017). Adverse events, to Anti-TNF was seen in (n=3/19, 15.7%) in the standard dose group, in comparison to (n=4/29, 13.79%, pampersand:003E0.99) in the low dose group. Adverse events to AZA were surprisingly higher in the low dose group (n=14/29, 48.3%) while in the standard dose, it was (n=5/19, 26.3%, p=0.14). Conclusions The preliminary result of the study suggests that there is no significant difference in anti-drug antibody formation between standard and low doses of azathioprine in combination with anti-TNF therapy, in addition, data showed significant lower rates of Anti-TNF discontinuation and loss of response to treatment in low Azathioprine dose group. Completion of the study will help further define if low-dose AZA can be used for ADA prevention in anti-TNF combination therapy without compromising important clinical outcomes. Funding Agencies None

Strategy and validation of a nonclinical generic plug-and-play antidrug antibody method for human monoclonal antibody biotherapeutics.

The measurement of antidrug antibodies (ADA) in nonclinical studies provides limited value becausethe formation and incidence of nonclinical ADA does not translate to clinical experience. The formation and presence of ADA in nonclinical species can, however, correlate to reduced drug exposure and safety observations including vasculitis and immune complex disease. Generic ADA methods for humanized monoclonal antibody biotherapeutics mitigate the need to develop bespoke ADA methods during nonclinical drug development. A drug-tolerant, sensitive, generic ADA immunoassay has been developed and validated for measuring ADA in cynomolgus monkey serum samples, allowing for immediate qualification of future monoclonal antibody biotherapeutics. This approach allows us to differentiate complexed and free ADA in a rapidly deployable manner when needed.

Pharmacokinetics, pharmacodynamics, and toxicity of a PD-1-targeted IL-15 in cynomolgus monkeys.

PF-07209960 is a novel bispecific fusion protein composed of an anti-PD-1 antibody and engineered IL-15 cytokine mutein with reduced binding affinity to its receptors. The pharmacokinetics (PK), pharmacodynamics (PD), and toxicity of PF-07209960 were evaluated following once every other week subcutaneous (SC) or intravenous (IV) administration to cynomolgus monkeys in a repeat-dose PKPD (0.01-0.3 mg/kg/dose) and GLP toxicity study (0.1-3 mg/kg/dose). PF-07209960 showed dose dependent pharmacokinetics with a terminal T1/2 of 8 and 13 hours following IV administration at 0.03 and 0.1 mg/kg, respectively. The clearance is faster than a typical IgG1 antibody. Slightly faster clearance was also observed following the second dose, likely due to increased target pool and formation of anti-drug antibodies (ADA). Despite a high incidence rate of ADA (92%) observed in GLP toxicity study, PD-1 receptor occupancy, IL-15 signaling (STAT5 phosphorylation) and T cell expansion were comparable following the first and second doses. Activation and proliferation of T cells were observed with largest increase in cell numbers found in gamma delta T cells, followed by CD4+ and CD8+ T cells, and then NK cells. Release of cytokines IL-6, IFNγ, and IL-10 were detected, which peaked at 72 hours postdose. There was PF-07209960-related mortality at ≥1 mg/kg. At scheduled necropsy, microscopic findings were generalized mononuclear infiltration in various tissues. Both the no observed adverse effect level (NOAEL) and the highest non severely toxic dose (HNSTD) were determined to be 0.3 mg/kg/dose, which corresponded to mean Cmax and AUC48 values of 1.15 μg/mL and 37.9 μg*h/mL, respectively.

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.

N31 HLA-DQA1*05 detection in saliva, an effective alternative in the monitoring and control of patients with Inflammatory Bowel Disease

Abstract Background The development of Inflammatory Bowel Disease (IBD) appears to be related to genetic susceptibility and an excessive immune response of the intestinal mucosa. Tumour necrosis factor (anti-TNF) therapies are the most widely used biologic drugs to treat immune-mediated diseases, but repeated administration may induce the formation of anti-drug antibodies. The ability to identify patients at increased risk of developing anti-TNFα antibodies would facilitate the selection of therapy and the use of preventive strategies. It has been shown that approximately 40% of the European population carries the HLA-DQA1*05 allele, and that its presence could have an important impact on treatment as it has been associated with: - Increased risk of immunogenicity of anti-TNFα therapy, regardless of concomitant treatment or anti-TNFα drug selected. - Decreased efficacy due to the formation of neutralising antibodies, leading to possible primary or secondary failures. - Occurrence of adverse events such as infusion reactions or hypersensitivity reactions. - Alterations in pharmacokinetics, so that drug clearance is accelerated regardless of whether the antibodies are neutralising. In our hospital we have the possibility to request the determination of the HLA-DQA1*05 allele through a detection kit in saliva. The main aim is to present a useful and effective tool for the detection of the HLA-DQA1*05 allele. Methods The methodology requires the inclusion of 30 newly diagnosed patients, patients naïve to biological treatment or patients on treatment with a first biological drug for no more than 24 months, by both the doctor and the nurse.The nurse will explain the previous preparation to the patient and will collect the sample using the saliva detection kit. Once the results have been received, the physician is notified. Results The detection of the HLA-DQA1*05 allele in our patients is 36.84%, a percentage similar to that detected in the European population through the detection of the HLA-DQA1*05 allele in blood. Conclusion - Having the ability to identify individuals at high risk of anti-TNF antibody formation and apply targeted combination therapy to these individuals is very valuable in clinical practice. - Saliva determination of the HLA-DQA1*05 allele is an efficient and cheaper alternative in hospitals where HLA-DQA1*05 detection in blood is not available in the laboratory. - The extraction and performance of the technique is simple, fast, obtaining the results within 5 days of submission, and convenient for both the patient and the healthcare professional.

Poor prognostic factors of pharmacokinetic origin predict outcomes in inflammatory bowel disease patients treated with anti-tumor necrosis factor-α.

We evaluated baseline Clearance of anti-tumor necrosis factors and human leukocyte antigen variant (HLA DQA1*05) in combination as poor prognostic factors (PPF) of pharmacokinetic (PK) origin impacting immune response (formation of antidrug antibodies) and disease control of inflammatory bowel disease (IBD) patients treated with infliximab or adalimumab. Baseline Clearance was estimated in IBD patients before starting treatment using weight and serum albumin concentrations. HLA DQA1*05 carrier status (rs2097432 A/G or G/G variant) was measured using real time polymerase chain reaction. The outcomes consisted of immune response, clinical and biochemical remission (C-reactive protein<3 mg/L in the absence of symptoms), and endoscopic remission (SES-CD<3). Statistical analysis consisted of logistic regression and nonlinear mixed effect models. In 415 patients enrolled from 4 different cohorts (median age 27 [IQR: 15-43] years, 46% females), Clearance>0.326 L/day and HLA DQA1*05 carrier status were 2-fold more likely to have antidrug antibodies (OR=2.3, 95%CI: 1.7-3.4; p<0.001, and OR=1.9, 95%CI: 1.4-2.8; p<0.001, respectively). Overall, each incremental PPF of PK origin resulted in a 2-fold (OR=2.16, 95%CI: 1.7-2.7; p<0.01) higher likelihood of antidrug antibody formation. The presence of both PPF of PK origin resulted in higher rates of antidrug antibodies (p<0.01) and lower clinical and biochemical remission (p<0.01). Each incremental increase in PPF of PK origin associated with lower likelihood of endoscopic remission (OR=0.4, 95%CI: 0.2-0.7; p<0.001). Prior biologic experience heightened the negative impact of PPF of PK origin on clinical and biochemical remission (p<0.01). Implementation of proactive therapeutic drug monitoring reduced it, particularly during maintenance and in the presence of higher drug concentrations (p<0.001). We conclude that PPF of PK origin, including both higher Clearance and carriage of HLA DQA1*05, impact outcomes in patients with IBD.

Tofacitinib to prevent anti-drug antibody formation against LMB-100 immunotoxin in patients with advanced mesothelin-expressing cancers.

LMB-100 is a mesothelin (MSLN)-targeting recombinant immunotoxin (iTox) carrying a Pseudomonas exotoxin A payload that has shown promise against solid tumors, however, efficacy is limited by the development of neutralizing anti-drug antibodies (ADAs). Tofacitinib is an oral Janus Kinase (JAK) inhibitor that prevented ADA formation against iTox in preclinical studies. A phase 1 trial testing LMB-100 and tofacitinib in patients with MSLN-expressing cancers (pancreatic adenocarcinoma, n=13; cholangiocarcinoma, n=1; appendiceal carcinoma, n=1; cystadenocarcinoma, n=1) was performed to assess safety and to determine if tofacitinib impacted ADA formation. Participants were treated for up to 3 cycles with LMB-100 as a 30-minute infusion on days 4, 6, and 8 at two dose levels (100 and 140 µg/kg) while oral tofacitinib was administered for the first 10 days of the cycle (10 mg BID). Peripheral blood was collected for analysis of ADA levels, serum cytokines and circulating immune subsets. The study was closed early due to occurrence of drug-induced pericarditis in 2 patients. Pericarditis with the combination was not reproducible in a transgenic murine model containing human MSLN. Two of 4 patients receiving all 3 cycles of treatment maintained effective LMB-100 levels, an unusual occurrence. Sustained increases in systemic IL-10 and TNF-α were seen, a phenomenon not observed in prior LMB-100 studies. A decrease in activated T cell subsets and an increase in circulating immunosuppressive myeloid populations occurred. No radiologic decreases in tumor volume were observed. Further testing of tofacitinib to prevent ADA formation is recommended in applicable non-malignant disease settings. https://www.clinicaltrials.gov/study/NCT04034238.

Development and characterization of NILK-2301, a novel CEACAM5xCD3 κλ bispecific antibody for immunotherapy of CEACAM5-expressing cancers

BackgroundT-cell retargeting to eliminate CEACAM5-expressing cancer cells via CEACAM5xCD3 bispecific antibodies (BsAbs) showed limited clinical activity so far, mostly due to insufficient T-cell activation, dose-limiting toxicities, and formation of anti-drug antibodies (ADA).MethodsWe present here the generation and preclinical development of NILK-2301, a BsAb composed of a common heavy chain and two different light chains, one kappa and one lambda, determining specificity (so-called κλ body format).ResultsNILK-2301 binds CD3ɛ on T-cells with its lambda light chain arm with an affinity of ≈100 nM, and the CEACAM5 A2 domain on tumor cells by its kappa light chain arm with an affinity of ≈5 nM. FcγR-binding is abrogated by the “LALAPA” mutation (Leu234Ala, Leu235Ala, Pro329Ala). NILK-2301 induced T-cell activation, proliferation, cytokine release, and T-cell dependent cellular cytotoxicity of CEACAM5-positive tumor cell lines (5/5 colorectal, 2/2 gastric, 2/2 lung), e.g., SK-CO-1 (Emax = 89%), MKN-45 (Emax = 84%), and H2122 (Emax = 97%), with EC50 ranging from 0.02 to 0.14 nM. NILK-2301 binds neither to CEACAM5-negative or primary colon epithelial cells nor to other CEACAM family members. NILK-2301 alone or in combination with checkpoint inhibition showed activity in organotypic tumor tissue slices and colorectal cancer organoid models. In vivo, NILK-2301 at 10 mg/kg significantly delayed tumor progression in colon- and a pancreatic adenocarcinoma model. Single-dose pharmacokinetics (PK) and tolerability in cynomolgus monkeys at 0.5 or 10 mg/kg intravenously or 20 mg subcutaneously showed dose-proportional PK, bioavailability ≈100%, and a projected half-life in humans of 13.1 days. NILK-2301 was well-tolerated. Data were confirmed in human FcRn TG32 mice.ConclusionsIn summary, NILK-2301 combines promising preclinical activity and safety with lower probability of ADA-generation due to its format compared to other molecules and is scheduled to enter clinical testing at the end of 2023.

Immunogenicity of Recombinant Erwinia asparaginase (JZP458) for Acute Lymphoblastic Leukemia (ALL) or Lymphoblastic Lymphoma (LBL)

Introduction: L-asparaginase is important in multi-agent treatment regimens for pediatric and adult patients (pts) with ALL/LBL. However, hypersensitivity reactions (HSRs) to E. coli-derived asparaginases (ASP) often lead to treatment delay or discontinuation. JZP458, a recombinant Erwinia ASP derived from a Pseudomonas fluorescens expression platform, is indicated as part of multi-agent chemotherapy regimens for ALL/LBL in adult and pediatric pts ≥1 month old who developed HSRs to E. coli-derived ASP. Here we report the immunogenicity profile of JZP458 based on study AALL1931. Methods: AALL1931 was an open-label, 2-part, multicenter, phase 2/3 trial conducted with the Children's Oncology Group to investigate efficacy, safety, and pharmacokinetics (PK) of JZP458 in ALL/LBL (NCT04145531). Eligible pediatric and adult pts with ALL/LBL who developed HSRs (grade ≥3 allergic reaction or silent inactivation) to E. coli-derived ASP received JZP458 as part of their multi-agent treatment regimen. Each dose of E. coli-derived pegaspargase was substituted with 6 doses of JZP458 either intramuscularly (IM, Part A) or intravenously (IV, Part B) on Mon/Wed/Fri over 2 weeks, defined as 1 course. Efficacy endpoints were the proportion of pts maintaining therapeutic nadir serum ASP activity (SAA) ≥0.1 IU/mL at the last 72-hour (primary endpoint) or 48-hour (key secondary endpoint) time point during course 1. Other endpoints included safety and tolerability, PK, and antidrug antibody (ADA) formation. Immunogenicity samples were collected prior to dose 1 in each course, prior to dose 6 in course 1, and at end-of-study safety follow-up visit (30±3 days after last dose). For pts experiencing HSRs, additional samples were tested for ADAs. A multi-tiered approach was used to measure ADAs and neutralizing antibodies (NAbs) to evaluate immunogenicity of JZP458. First, samples were screened for ADAs that bind JZP458. Samples with potentially ADA-positive (+) results were retested for binding specificity confirmation. Samples confirmed as ADA+ were tested further for NAbs. For pts with ADA+ samples obtained prior to study end, follow-up ADA samples up to approximately 6 months after the last dose of the last course were collected. The ADA assay was a validated binding assay based on an electro-chemiluminescence immunosorbent assay technique and the NAb assay was a validated enzymatic activity assay. Results: The median (range) age of pts was 10 (1-25) years. Analysis of pts receiving IM JZP458 (n=167) showed that 82 (49%) pts had confirmed ADA toward JZP458; of these, 7 (4%) were ADA+ at pre-dose 1. Twenty-two pts (15% of 146 pts with samples) remained ADA+ at the end of study. Overall, 18 (11%) pts developed treatment-related HSRs after receiving IM JZP458. Among ADA+ pts (n=82), 11 (13%) experienced treatment-related HSR and 4 (5%) developed positive NAbs. Of ADA-negative (-) pts, 7/85 (8%) experienced treatment-related HSRs. Among pts receiving IV JZP458 (n=61), 34 (56%) had confirmed ADA toward JZP458; of these, 1 (2%) was ADA+ at pre-dose 1. Seventeen pts (34% of 50 pts with samples) remained ADA+ at the end of study. Overall, 16 (26%) pts developed treatment-related HSRs after receiving IV JZP458. Among ADA+ pts (n=34), 12 (35%) experienced treatment-related HSRs and 2 (6%) developed positive NAbs. Of ADA- pts, 4/27 (15%) experienced treatment-related HSRs. Anti-JZP458 antibody status was evaluated as a potential covariate for PK of IM or IV JZP458 within the population PK analysis and it was not found to be a significant covariate. SAA levels were similar between ADA+ and ADA- pts. Overall treatment-related adverse events (TRAEs) in ADA+ and ADA- pts were similar and consistent with the most common TRAEs expected with ASP-containing chemotherapy for ALL (Table). TRAEs led to JZP458 discontinuation for 14 pts with ADA+ status in Part A (8%) and 13 in Part B (21%). Conclusions: The majority of pts who developed ADAs did not develop HSRs or NAbs. The overall rate of HSRs was similar to literature-reported rates for ASP and appeared to be higher with IV vs IM JZP458. ADA status did not appear to impact PK and other AEs for JZP458. Based on these results, no specific immunological concerns were identified with JZP458 beyond known immunogenicity risks associated with ASP and no specific clinical decisions are recommended based on immunogenicity testing.

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.

Characterization of anti-drug antibody dynamics using a bivariate mixed hidden-markov model by nonlinear-mixed effects approach

Biological therapies may act as immunogenic triggers leading to the formation of anti-drug antibodies (ADAs). Population pharmacokinetic (PK) models can be used to characterize the relationship between ADA and drug disposition but often rely on the ADA bioassay results, which may not be sufficiently sensitive to inform on this characterization.In this work, a methodology that could help to further elucidate the underlying ADA production and impact on the drug disposition was explored. A mixed hidden-Markov model (MHMM) was developed to characterize the underlying (hidden) formation of ADA against the biologic, using certolizumab pegol (CZP), as a test drug. CZP is a PEGylated Fc free TNF-inhibitor used in the treatment of rheumatoid arthritis and other chronic inflammatory diseases.The bivariate MHMM used information from plasma drug concentrations and ADA measurements, from six clinical studies (n = 845), that were correlated through a bivariate Gaussian function to infer about two hidden states; production and no-production of ADA influencing PK. Estimation of inter-individual variability was not supported in this case. Parameters associated with the observed part of the model were reasonably well estimated while parameters associated with the hidden part were less precise. Individual state sequences obtained using a Viterbi algorithm suggested that the model was able to determine the start of ADA production for each individual, being a more assay-independent methodology than traditional population PK. The model serves as a basis for identification of covariates influencing the ADA formation, and thus has the potential to identify aspects that minimize its impact on PK and/or efficacy.

Advancing Subcutaneous Dosing Regimens for Biotherapeutics: Clinical Strategies for Expedited Market Access.

In recent years, subcutaneous administration of biotherapeutics has made significant progress. The self-administration market for rheumatoid arthritis has witnessed the introduction of additional follow-on biologics, while the first subcutaneous dosing options for monoclonal antibodies have become available for multiple sclerosis. Oncology has also seen advancements with the authorization of high-volume subcutaneous formulations, facilitated by the development of high-concentration formulations and innovative delivery systems. Regulatory and Health Technology Assessment bodies increasingly consider preference data in filing dossiers, particularly in evaluating novel drug delivery methods. The adoption of a pharmacokinetic-based clinical bridging approach has become standard for transitioning from intravenous to subcutaneous administration. Non-inferiority studies with pharmacokinetics as the only primary endpoint have started deviating from traditional randomization schemes, favoring the subcutaneous route and comparing with historical intravenous data. While nonclinical and computational models made progress in predicting safety and immunogenicity for subcutaneously dosed antibodies, clinical trial evidence remains essential due to inter-individual variations and the impact of formulation parameters on anti-drug antibody formation. Ongoing technological advancements and the expanding knowledge base on pharmacokinetic-pharmacodynamic correlation across specialty areas are expected to further accelerate clinical development of subcutaneous biologics.

Two-center validation of assays for the detection of binding and neutralizing anti-factor VIII antibodies.

Patients with hemophilia A treated with coagulation Factor VIII (FVIII) products are at risk for developing anti-FVIII antibodies. The ABIRISK Consortium aimed to provide knowledge on the formation and detection of anti-drug antibodies against biopharmaceutical products, including FVIII. Accordingly, standardized and validated assays for the detection of binding (total) and neutralizing antibodies are needed. Two-center validation of an ELISA for the detection of total FVIII-binding IgG-antibodies and Nijmegen-Bethesda assays for the quantification of FVIII-neutralizing antibodies according to consensus validation guidelines. Validation of assays at both sites was done according to published recommendations and included preanalytics, the determination of key assay parameters, including cut-points, assay sensitivity, precision, and FVIII interference. The validated assays reproducibly detected FVIII-binding and -neutralizing antibodies with comparable performance in both laboratories. Floating screening cut-points were established for both assays. Determined mass-based sensitivity of both assays (all values ≤66ng/mL) complied with the minimum sensitivity for the detection of anti-drug antibodies as recommended by the FDA (<100ng/mL). Intra- and inter-assay coefficients of variation did not exceed 25%. Assay validation further revealed that pre-analytical heat treatment led to potentially false-positive ELISA results, while up to 0.15 IU/mL, residual FVIII showed no significant impact. Overall, good agreement of results was found for patient samples analyzed at both study sites. Comprehensive validation of different anti-FVIII-antibody assays in two laboratories gave novel insights into the impact of pre-analytical sample treatment as well as the comparability of test results generated by the use of methodically different assays.

Adalimumab serum levels and anti-drug antibodies: associations to treatment response and drug survival in inflammatory joint diseases.

To explore associations between serum adalimumab level, treatment response and drug survival in order to identify therapeutic drug levels for therapeutic drug monitoring of adalimumab. Also, to assess occurrence and risk factors of anti-drug antibody (ADAb) formation. Non-trough adalimumab and ADAb levels were measured by automated fluorescence assays in serum collected after 3 months of adalimumab treatment in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) or axial spondyloarthritis (axSpA) included in the observational NOR-DMARD study. Treatment response was evaluated after 3 months, and drug survival during long-term follow-up. In 340 patients (97 RA, 69 PsA, 174 axSpA), median adalimumab level was 7.3 mg/l (IQR 4.0-10.3). 33 (10%) patients developed ADAb. Findings were comparable across diagnoses. In RA and PsA, adalimumab levels ≥6.0 mg/l were associated with treatment response (Odds Ratio [OR] 2.2 [95% CI 1.0, 4.4]) and improved drug survival (Hazard Ratio [HR] 0.49 [0.27, 0.80]). In axSpA, a therapeutic level could not be identified, but higher adalimumab levels were associated with response. Factors associated with ADAb formation were previous bDMARD use, no methotrexate comedication and use of adalimumab originator compared with GP2017. Higher adalimumab levels were associated with better response and improved drug survival for all diagnoses, with a suggested lower threshold of 6.0 mg/l for RA/PsA. This finding, the large variability in drug levels among patients receiving standard adalimumab dose, and the high proportion of patients developing ADAb, encourages further investigations into the potential role of therapeutic drug monitoring of adalimumab.

Efficacy of tumor necrosis factor-α inhibitors in the treatment of various immunoinflammatory diseases: focus on immunogenicity

In clinical practice, differences in the efficacy of tumor necrosis factor-α inhibitors (iTNF-α) have been observed in different diseases.Objective: to evaluate the efficacy of iTNF-α in patients with immune-mediated diseases and its relation to the immunogenicity of these drugs.Material and methods. The study included 70 patients with rheumatic diseases (RD) and 53 with inflammatory bowel disease (IBD) treated with infliximab (IFN), adalimumab, or certolizumab pegol (CZP). Disease activity and response to therapy were evaluated, as well as measurement of the minimal residual concentration of iTNF-α and the level of anti-drug antibodies.Results and discussion. Therapy efficacy was maintained in 60 (85.7%) patients with RD and 35 (66.0%) with IBD (odds ratio, OR 1.3; p=0.01). Event-free survival of therapy was observed more frequently in RD and was longer than in IBD (p&lt;0.01). The incidence of treatment failure was 3.13 times higher in IBD than in RD (p&lt;0.01). In contrast to IBD, low TNF-α levels were more common in RD patients who did not respond to treatment than in those who did (80% and 40%, respectively; OR 6.0; p&lt;0.05). Anti-TNF-α antibodies were detected in 75% of patients with ineffective treatment with INF and CZP in the RD group and in 14.3% in the IBD group (OR 0.06; p&lt;0.05).Conclusion. In patients with RD, the effect of iTNF-α lasted more frequently and longer than in patients with IBD. In ankylosing spondylitis and rheumatoid arthritis, the ineffectiveness of iTNF-α was associated with the formation of anti-drug antibodies or their low concentration in most cases, but in IBD only in half of the cases.

The Role of Low-Dose Oral Methotrexate in Increasing Anti-TNF Drug Levels and Reducing Immunogenicity in IBD

Concomitant immunomodulation is utilised in combination with anti-TNF therapy for IBD primarily to increase drug levels and prevent anti-drug antibody formation. Whilst thiopurines have traditionally been the immunomodulator of choice in IBD populations, there are concerns regarding the long-term safety of the prolonged use of these agents: particularly an association with lymphoproliferative disorders. Given this, we have explored the existing literature on the use of low-dose oral methotrexate as an alternative immunomodulator for this indication. Although there is a lack of data directly comparing the efficacies of methotrexate and thiopurines as concomitant immunomodulators, the available literature supports the use of methotrexate in improving the pharmacokinetics of anti-TNF agents. Furthermore, low-dose oral methotrexate regimens appear to have comparable efficacies to higher-dose parenteral administration and are better tolerated. We suggest that clinicians should consider the use of low-dose oral methotrexate as an alternative to thiopurines when the primary purpose of concomitant immunomodulation is to improve anti-TNF pharmacokinetics.