Anti-drug Antibodies Titers Research Articles

Anti-drug antibodies related to CTLA-4, PD-1, or PD-L1 inhibitors across tumour types: A systematic review.

e14600 Background: Treatment-emergent anti-drug antibodies (ADAs) are postulated to reduce the efficacy of immune checkpoint inhibitors. A systematic review (SR) was conducted to evaluate the incidence of treatment-emergent ADAs with programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1), or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors and their impact on treatment outcomes in patients with cancer. Methods: Electronic databases MEDLINE, EMBASE and Cochrane Library were searched in February 2022 for studies reporting incidence of ADAs and the impact of immunogenicity on treatment efficacy in oncology patients treated with PD-1, PD-L1, or CTLA-4 checkpoint inhibitors. Results: Of the 4,612 articles identified, 34 publications reporting on 68 trials were included. An additional 41 and 32 records were identified from clinicaltrials.gov and packaging inserts respectively. In total, 141 trials of 15 checkpoint inhibitors and 16 tumour types were included. There was considerable variability in the reporting of ADAs, and comparisons between trials were challenging due to intra-study heterogeneity. The incidence of ADAs ranged from 0 to 74%. Across trials, in analyses with the largest sample sizes, atezolizumab was associated with the highest incidence of ADAs (29.6%), then nivolumab (12.2%), followed by the remaining treatments (0-4.4%). The incidence of neutralising antibodies (nAbs) mirrored ADA distribution, being highest for atezolizumab (4.3–27.5%) vs other treatments. Only 17 trials reported on ADA impact on treatment outcomes. Of 11 trials examining efficacy, two reported a negative effect of ADAs, eight reported no measurable effect and another had insufficient patient numbers. The impact of ADAs on treatment safety, and pharmacokinetics was also inconclusive. Conclusions: Treatment-emerging ADAs are inconsistently reported across trials and documented in up to 30% of subjects treated with checkpoint inhibitors across indications. Emergence of nAbs follows but does not perfectly mirror ADA titers, raising questions around the functional meaning of different ADAs. Standardised reporting of ADAs and nAbs should be advocated to facilitate more conclusive immunologic and clinical insight as to the relationship with ADAs and response. [Table: see text]

Presence and impact of antidrug antibodies (ADAs) to tremelimumab (T) or durvalumab (D) in the phase 3 HIMALAYA study of unresectable hepatocellular carcinoma (uHCC).

551 Background: ADAs to immune checkpoint inhibitors may decrease antitumor activity in HCC. Reported rates of treatment-emergent ADAs (TE-ADAs) vary from 1.5% for pembrolizumab and 8.6% for nivolumab to 54.1% for atezolizumab across indications (Enrico et al. Clin Cancer Res 2020). In the global, Phase 3 HIMALAYA study (NCT03298451) in uHCC, the STRIDE regimen (Single T Regular Interval D) significantly improved overall survival vs sorafenib (S); D monotherapy was noninferior to S (Abou-Alfa et al. NEJM Evid 2022). Here, we analyzed ADAs to T and D in HIMALAYA. Methods: Prespecified secondary analyses assessed the presence of ADAs to D and T before the first study dose (baseline), once during treatment and once after treatment discontinuation. For participants (pts) who were ADA-positive at any visit (ADA+), presence of neutralizing antibodies (nAbs) was also assessed. TE-ADA+ was defined as pts with a positive post-baseline sample only or pts with an ADA titer that increased ≥4-fold following treatment. ADA negative (ADA-) was defined as pts with no positive sample at any visit, at baseline or post-baseline. Objective response rate (ORR; RECIST v1.1, inc. unconfirmed), overall survival (OS) and treatment-related adverse events (TRAEs) were evaluated in ADA subgroups. Results: The frequency of ADAs to D was similar in the STRIDE (T+D) and D arms: 8.2% (24/294) and 7.1% (20/282) of pts, respectively, were ADA+ to D; 3.1% (9/294) and 2.8% (8/282) of pts, respectively, were TE-ADA+ to D; and 1.7% (5/294) and 0.7% (2/282) of pts, respectively, had nAbs to D. In the STRIDE arm, 15.9% (29/182) of pts were ADA+ to T, 11.0% (20/182) of pts were TE-ADA+ to T, and 4.4% (8/182) of pts had nAbs to T. Although the number of pts was small, in the STRIDE arm, ORR was 11.1% (1/9) in pts TE-ADA+ to D, 35.0% (7/20) in pts TE-ADA+ to T and 23.9% (94/393) in the full analysis set (FAS). In the D arm, ORR was 25.0% (2/8) in pts TE-ADA+ to D and 18.5% (72/389) in the FAS. OS for pts TE-ADA+/nAb+ to D or T in the D and STRIDE arms was consistent with the FAS. In both arms, TRAE and Grade 3/4 TRAE rates were not increased in the ADA+ vs ADA- groups (Table) and were generally consistent with the overall population. Conclusions: In HIMALAYA, the rates of TE-ADAs and nAbs to D and T were low (≤11%). The presence of ADAs did not appear to impact clinical efficacy or safety of STRIDE or D monotherapy in the small number of ADA+ pts. These results support a low risk of ADAs for STRIDE or D in uHCC. Clinical trial information: NCT03298451 . [Table: see text]

Anti-brolucizumab immune response as one prerequisite for rare retinal vasculitis/retinal vascular occlusion adverse events.

In October 2019, Novartis launched brolucizumab, a single-chain variable fragment molecule targeting vascular endothelial growth factor A, for the treatment of neovascular age-related macular degeneration. In 2020, rare cases of retinal vasculitis and/or retinal vascular occlusion (RV/RO) were reported, often during the first few months after treatment initiation, consistent with a possible immunologic pathobiology. This finding was inconsistent with preclinical studies in cynomolgus monkeys that demonstrated no drug-related intraocular inflammation, or RV/RO, despite the presence of preexisting and treatment-emergent antidrug antibodies (ADAs) in some animals. In this study, the immune response against brolucizumab in humans was assessed using samples from clinical trials and clinical practice. In the brolucizumab-naïve population, anti-brolucizumab ADA responses were detected before any treatment, which was supported by the finding that healthy donors can harbor brolucizumab-specific B cells. This suggested prior exposure of the immune system to proteins with structural similarity. Experiments on samples showed that naïve and brolucizumab-treated ADA-positive patients developed a class-switched, high-affinity immune response, with several linear epitopes being recognized by ADAs. Only patients with RV/RO showed a meaningful T cell response upon recall with brolucizumab. Further studies in cynomolgus monkeys preimmunized against brolucizumab with adjuvant followed by intravitreal brolucizumab challenge demonstrated that high ADA titers were required to generate ocular inflammation and vasculitis/vascular thrombosis, comparable to RV/RO in humans. Immunogenicity therefore seems to be a prerequisite to develop RV/RO. However, because only 2.1% of patients with ADA develop RV/RO, additional factors must play a role in the development of RV/RO.

P672 Switching out of class or to another anti-TNF agent is the most effective strategy in IBD patients with immunogenicity against anti-TNF antibodies

Abstract Background Immunogenicity to anti-TNF agents is associated with loss of response in inflammatory bowel disease (IBD). However, the efficacy of different strategies to restore favourable pharmacokinetics and/or clinical response upon the detection of anti-drug antibodies (ADA) has not been widely studied. We evaluated the success of different strategies leading to clinical remission with ADA disappearance (in patients continuing the same anti-TNF), in patients with IBD. Methods IBD patients with ADA to infliximab or adalimumab were identified through an electronic database search at a single tertiary centre between 2004 and 2021. ADA were measured using a drug-sensitive assay at Sanquin laboratories. Data concerning clinical, biochemical and endoscopic activity, medication and surgery were retrospectively and systematically collected by reviewing clinical records. Criteria for success of a strategy were clinical remission 1 year after ADA detection without further change in strategy combined with disappearance of ADA (in patients continuing the same anti-TNF). Results Two-hundred-and-fifty-five IBD patients (206 Crohn’s disease, 46 ulcerative colitis, 3 IBD-unclassified, 149 female) were included, 129 patients were diagnosed to have ADA against infliximab and 126 against adalimumab. At baseline, median ADA titer was 77 AU/ml (IQR 25-350), 50.2% of patients were in clinical remission. Groups were as follows: 1) 81/255 (32%) conservative management, 2) 102/255 (40%) optimization of the same anti-TNF, 3) 72/255 (28%) switch to another anti-TNF or biological class. Switch to another anti-TNF or out of class was the most successful strategy in terms of improvement of clinical remission (from 19.4% at ADA detection to 69.4% at 1 year, p<0.001). Patients that continued with the same dose anti-TNF or discontinued all biological therapy after ADA detection were often in clinical remission at baseline, but deteriorated significantly in the following year (22.7%, P=0.004). Anti-TNF dose intensification with concomitant addition/optimisation of immunomodulators was the fastest (median 3 months (IQR 2-4.5), p=0.004) and most effective (in 73% of these patients, p=0.007) strategy to suppress ADA to undetectable levels compared to anti-TNF dose intensification or immunomodulator optimization alone. Conclusion Switching to another anti-TNF or out of class switch is the most successful strategy to regain and maintain clinical remission upon detection of ADA. Intensification of anti-TNF dosing with concomitant optimisation of immunomodulatory therapy is the fastest strategy to suppress ADA.

Assessment and impact of dose escalation on anti-drug antibodies in Fabry disease.

Enzyme replacement therapy (ERT) with recombinant α-galactosidase A (AGAL) can lead to the formation of neutralizing anti-drug antibodies (ADA), which significantly limit treatment efficacy in patients with Fabry disease (FD). The effects of dose escalation on ADA titer and plasma globotriaosylsphingosine (lyso-Gb3) level are unknown. We screened 250 FD patients (200 males, 50 females) under ERT for ADAs and assessed the impact of an approved dose escalation in affected patients, focusing on ADA titers and plasma lyso-Gb3. ADA-positive patients were identified by serum-mediated inhibition assays, followed by titration assays to determine the individual inhibitory capacities of ADAs against agalsidase-alfa and agalsidase-beta. 70 (35%) of the male patients were ADA-positive, with a mean inhibitory capacity of 83.5 ± 113.7mg AGAL. Although patients receiving agalsidase-beta showed higher inhibitory capacities (84.7 ± 34.7mg) than patients under agalsidase-alfa (60.3 ± 126.7mg, p<0.001), the "theoretical deficit" to the infused dose was lower in patients receiving agalsidase-beta. In seven patients receiving agalsidase-alfa (0.2 mg/kg) ADAs were saturable by switching patients to agalsidase-beta (1.0 mg/kg). The switch resulted in increasing ADA titers within the first months. In 2 out of 7 (28.6%) therapy switchers, dose escalation could lead to durable ADA saturation. Independent of an increase in ADA titers, lyso-Gb3 levels decrease and cardiac and renal parameters remained stable after dose escalation. Dose escalation results in a heterogeneous, unpredictable ADA response, with more than a quarter of all treatment switchers succeeding in ADA saturation. Longitudinal ADA measurements are required to assess the individual risk of affected patients.

Augmenting the Persistence and Efficacy of Engineered Regulatory T Cells to Suppress Anti-Drug Antibody Formation

Background Adoptive cell therapy (ACT) using engineered antigen specific regulatory T cells (Tregs) is a powerful tool for delivering immune tolerance in autoimmune disease, transplantation and in suppressing undesirable anti-drug antibody (ADA) responses against therapeutic proteins. An important example of the latter is hemophilia A (HA), a genetic disorder characterized by deficiency of the blood clotting protein, factor VIII (FVIII). Replacement therapy with recombinant FVIII can be neutralized by ADA development in up to 30% of severe HA patients. We previously showed that ACT with Tregs expressing a chimeric CD3ε based T cell receptor fusion construct (TRuC), encoding extracellular antibody fragments with specificity to human FVIII, suppressed ADA formation to FVIII in a preclinical HA model [Mol Ther. 2021 29(9):2660-2676]. Ensuring adequate in vivo persistence and a suppressive phenotype without risk of plasticity are major concerns that impede translation of ACT with engineered Tregs. Here we evaluate a synthetic single chain antibody fusion IL2 cytokine product (IL2-IC) to selectively expand adoptively transferred FVIII-TRuC Tregs in vivo. We then combine IL2-IC delivery with FVIII-TRuC Tregs expressing the co-inhibitory receptor PD-L1 to test improved suppression to ADA formation. Methods IL2-IC was generated by fusing IL-2 cytokine to the anti-IL-2 monoclonal antibody F5111 via a flexible linker. This complex specifically delivers IL2 to cells that express high levels of IL2 receptor α (IL2Rα) (i.e., Tregs) while avoiding interaction with cells that express low levels (i.e., Tconv, NK and CD8+ T cells). To assess whether IL2-IC could expand TRuC Tregs in vivo, 2x106 FVIII TRuC Tregs were injected intravenously (IV) into HAmice followed 5 hrs later with low dose IL2-IC or IL2 fused to an irrelevant Ab (FITC-IC) as control. 24 hrs later, mice received 2 international units (IU) of FVIII, and spleens were assayed on days 3 and 6. Murine PD-L1 was co-expressed in FVIII TRuC Tregs and in vitro assessed by stimulating TRuC PDL1 Tregs with 2IU FVIII alone or in combination with 2 ug/ml of PD1-Fc to understand the impact of PDL1 signaling on the Treg phenotype. In vivo, 0.5x106 FVIII TRuC PD-L1 Tregs were IV injected in HAmice followed 5 hrs later by mock, IL2-IC or FITC-IC IV injections. 24 hrs later, mice received weekly IV injections of 1IU FVIII. Results IL2-IC treated FVIII TRuC Tregs were preferentially expanded over endogenous Tregs (fold expansion 7.47 vs 4.56 respectively) in spleens on day 3 post ACT. Whereas both IL2-IC and FITC-IC treated FVIII TRuC Tregs had higher division indices over mock treatment (4.047 ± 0.03 and 5.070 ± 0.07 over 2.00 ± 0.00), only IL2-IC treated FVIII TRuC Tregs showed increased frequencies (1.72% ± 0.376% of CD4+ T cells) as compared to FITC-IC (0.28% ± 0.005% of CD4+ T cells) or mock treatment (0.23% ± 0.023% of CD4+ T cells). FITC-IC treatment nonspecifically expanded CD8+ Tconv cells as well as NK cells, whereas IL2-IC selectively expanded Tregs. PD1-Fc triggered PD-L1 signals in FVIII stimulated TRuC Tregs resulted in significant upregulation of Treg associated activation markers FoxP3, CD69, LAP, CTLA4, PD1, ICOS and BCL2 in vitro. In vivo, IL2-IC administration combined with FVIII TRuC PD-L1 ACT led to complete suppression of ADA formation in HA mice. At 4 weeks, mice that only received FVIII infusions developed high functional ADA titers (29.53 ± 19.58 BU/mL), while IL2-IC, TRuC PDL1 Treg and TRuC PDL1 Treg + IL2-IC groups had significantly lower titers of 1.117 ± 0.952 BU/mL, 1.805 ± 0.702 BU/mL and 0.423 ± 0.243 BU/mL, respectively. FITC-IC combined with PDL1 TRuC Tregs resulted in high ADAs of average 109 ± 21.31 BU/mL, confirming the requirement for the IL2Rα targeting antibody to selectively expand Tregs. Conclusion We show that the PD-L1/PD1 axis is an important pathway that can be exploited to improve the suppressive capacity of engineered Tregs. We also demonstrate that exogenous administration of the novel IL2-IC can robustly expand FVIII TRuC Tregs. These 2 strategies can be readily combined to selectively expand and enhance the suppressive capacity of engineered Tregs. The concepts defined here can be extended for improving the persistence and suppressive potential of engineered Tregs for various autoimmune disorders and to prevent transplant rejection. We are currently evaluating long term suppression of ADA responses using this approach.

Chemically modified recombinant human sulfamidase (SOBI003) in mucopolysaccharidosis IIIA patients: Results from an open, non-controlled, multicenter study.

Mucopolysaccharidosis IIIA (MPS IIIA) is an inherited lysosomal storage disorder caused by mutations in the N-sulfoglucosamine sulfohydrolase gene that result in deficient enzymatic degradation of heparan sulfate (HS), resulting in progressive neurodegeneration in early childhood and premature death. A chemically modified variant of recombinant human sulfamidase, SOBI003, has shown to cross the blood-brain barrier (BBB) in mice and achieve pharmacologically relevant levels in cerebrospinal fluid (CSF). We report on a phase 1/2, open-label, first-in-human (FIH) study (NCT03423186) and its extension study (NCT03811028) to evaluate the long-term safety, tolerability, pharmacokinetics/pharmacodynamics (PK/PD) and clinical efficacy of SOBI003 in patients with MPS IIIA for up to 104 weeks. Six patients aged 1-6 years with confirmed MPS IIIA with developmental age ≥ 12 months received weekly intravenous injections of SOBI003 at 3 mg/kg (Cohort 1, n = 3) or 10 mg/kg (Cohort 2, n = 3). During the extension study, the individual dose of SOBI003 could be adjusted up to 20 mg/kg at the discretion of the investigator. SOBI003 was generally well tolerated. Serum concentrations of SOBI003 increased in proportion to dose, and presence in CSF confirmed that SOBI003 crosses the BBB. Anti-drug antibodies (ADA) were detected in serum and CSF in all patients, with subsequent reductions in serum SOBI003 exposure at high ADA titers. SOBI003 exerted a clear PD effect: a mean reduction in HS levels in CSF of 79% was recorded at the last assessment, together with reductions in HS levels in serum and urine. Neurocognitive development age-equivalent scores showed a stabilization of cognition for all patients, whereas no clear overall clinical effect was observed on adaptive behavior, sleep pattern or quality of life. SOBI003 was well tolerated when administered as weekly intravenous infusions at doses of up to 20 mg/kg for up to 104 weeks. ADA development was common and likely affected both PK and PD parameters. SOBI003 crossed the BBB and showed pharmacological activity on HS in CSF.

Pre-existing anti-drug antibodies in Fabry disease show less affinity for pegunigalsidase alfa

We analyzed the cross-reactivity of anti-drug antibodies (ADAs) against agalsidase-alfa and -beta from 49 patients with Fabry disease (FD) against the novel PEGylated enzyme pegunigalsidase-alfa (PRX-102). The affinity of purified anti-AGAL antibodies from pooled patient sera was significantly lower for PRX-102 compared to agalsidase-alfa and -beta (both p < 0.05). Pull-down experiments revealed the presence of masked epitopes on PRX-102, possibly due to PEGylation. ADA titers in serum (μg/mL) and corresponding inhibitory capacities against agalsidase-alfa and -beta were measured in male patients with FD, showing strong correlations (r2 = 0.9978 and 0.4930, both p < 0.001). Affinities of ADAs of individual patients against PRX-102 (Kd: 3.55 ± 2.72 μmol) were significantly lower compared to agalsidase alfa (Kd: 1.99 ± 1.26 μmol) and -beta (Kd: 2.18 ± 1.51 μmol) (both p < 0.0001). Cross-ELISAs supported the presence of masked epitopes on PRX-102. Importantly, inhibition measurements also revealed a 30% reduction in inhibitory capacity of pre-existing ADAs towards PRX-102. Enzyme-uptake experiments in AGAL-deficient EA.hy926 cells demonstrated less effects of ADAs on cellular PRX-102 uptake compared with agalsidase beta. We conclude that due to the reduced affinity of pre-existing ADAs against agalsidase-alfa or -beta, ADA-affected patients might benefit from a therapy switch to PRX-102, which is currently evaluated in clinical trials.

742-P: Antidrug Antibodies Do Not Impact Pharmacokinetics, Efficacy, and Safety of Tirzepatide: Analysis of Data from 7 Phase 3 Studies

Tirzepatide (TZP) is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon like peptide (GLP) -1 receptor agonist developed for the treatment of type 2 diabetes. Patients receiving TZP may develop an immune response to the 39 amino acid synthetic peptide. This study aimed to evaluate treatment emergent (TE) anti-drug antibodies (ADA) in TZP-treated participants across 7 Phase 3 trials and its potential effect on pharmacokinetics (PK) , efficacy, and safety. A multi-tiered immunogenicity testing strategy was used to detect and characterize ADA. ADA were characterized for their ability to cross react to native GIP (nGIP) and GLP-1 (nGLP-1) , neutralize TZP activity on GIP and GLP-1 receptors, and neutralize nGIP and nGLP-1. ADA were assessed at baseline and throughout the course of the study up to week 40 (SURPASS 1, 2, and 5) or week 52 (SURPASS 3, 4, Japan-mono, and Japan-combo) . Among all ADA-evaluable patients across the Phase 3 trials (N=5025) , TE ADA developed in 51.1% of patients treated with TZP, and the proportions were similar across the 3 TZP dose groups (5, 10, and 15 mg) . At baseline, 7.0% of patients had pre-existing ADA. Maximum ADA titers ranged from 1:20 to 1: 81920 (median 1:160) 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 the TE ADA+ patients, respectively. Less than 1.0% of TZP-treated TE ADA+ patients had cross-reactive NAb against nGIP or nGLP-1. TE ADA status, ADA titer, and NAb had no discernible impact on PK profile nor HbA1c effects of TZP. The percentage of TE ADA+ and TE ADA- patients with hypersensitivity reactions was similar. A higher proportion of TE ADA+ patients reported injection site reactions, of which all were nonserious and non-severe, and the vast majority occurred and/or resolved irrespective of TE ADA status or titer level.Overall, immunogenicity was not associated with any impact on TZP PK, efficacy, or safety. Disclosure B. Calderon: Employee; Eli Lilly and Company. G.R. Mullins: Employee; Eli Lilly and Company. M. Hodsdon: Employee; Eli Lilly and Company. Stock/Shareholder; Eli Lilly and Company. G. Li: Employee; Eli Lilly and Company. G. Anglin: Employee; Eli Lilly and Company. Stock/Shareholder; Eli Lilly and Company. S. Urva: Employee; Eli Lilly and Company. K. Schneck: Employee; Eli Lilly and Company. J.N. Bardos: Employee; Eli Lilly and Company. Stock/Shareholder; Eli Lilly and Company. R.F. Martins: Employee; Eli Lilly and Company. Stock/Shareholder; Eli Lilly and Company. K. Brown: Employee; Eli Lilly and Company. Funding Funded by Eli Lilly and Company.

A randomized, open-label, crossover study assessing the pharmacokinetic and pharmacodynamic bioequivalence of pegfilgrastim-cbqv via on-body injector vs prefilled syringe.

e18637 Background: Pegfilgrastim-cbqv, a pegfilgrastim biosimilar, is administered 24-72 h after myelosuppressive chemotherapy to prevent febrile neutropenia. Pegfilgrastim delivery via an on-body injector (OBI) applied on the day of chemotherapy eliminates the need for a second healthcare visit. This study evaluated the pharmacokinetic (PK), pharmacodynamic (PD) bioequivalence (BE), and the safety of pegfilgrastim-cbqv administered via OBI vs prefilled syringe. Methods: In this open-label, 2-period crossover study, healthy adult male participants were randomized 1:1 to 2 treatment sequences to receive a 6-mg subcutaneous (SC) injection of pegfilgrastim-cbqv via OBI or prefilled syringe in period 1 and an injection via the other method in period 2 (after a 6- to 8-wk washout). Primary endpoints (PK) were area under the concentration-time curve from time 0 to infinity (AUC0-inf), the AUC from time 0 to the last quantifiable concentration (AUC0-last), and the maximum plasma concentration (Cmax). Secondary endpoints (PD) were area under the absolute neutrophil count (ANC)-time curve from time 0 to the last quantifiable ANC (ANC AUC0-last) and maximum ANC (ANCmax). PK/PD BE was established if the 90% CI for the geometric mean ratios (GMRs) fell within 80-125%. Safety and immunogenicity were also assessed. Results: The 90% CIs of the GMRs for PK and PD endpoints in healthy participants fell within the predetermined range (Table). Treatment-emergent adverse events (TEAEs) occurred in 87.8% (OBI) vs 75.8% (prefilled syringe) of participants. Most TEAEs were musculoskeletal effects and mild in severity. The most common injection site–related TEAE was erythema (OBI 34.1%; prefilled syringe 2.5%). The injection site erythema reactions were mild in severity and self-limiting. The incidence of treatment-emergent antidrug antibodies (ADAs) in period 1 was similar with OBI (40.0%) vs prefilled syringe (36.6%); ADA titers were low, transient, and primarily directed to the polyethylene glycol (PEG) moiety of pegfilgrastim-cbqv. The ADAs had no apparent impact on PK, PD, or safety. Neutralizing antibodies were not detected in any participant. Conclusions: This study demonstrated PK and PD BE of pegfilgrastim-cbqv administered via OBI vs prefilled syringe in healthy adult males. OBI and prefilled syringe administration had similar safety and immunogenicity profiles. No unexpected safety signals were identified.[Table: see text]

P243 Anti-rituximab antibodies demonstrate neutralising capacity, associate with lower circulating drug levels and early relapse in patients undergoing treatment for systemic lupus erythematosus

Abstract Background/Aims A major limitation of biologic therapy is formation of anti-drug antibodies (ADA). We previously demonstrated that ADA to rituximab are more prevalent in patients undergoing treatment for systemic lupus erythematosus (SLE) than rheumatoid arthritis and vasculitis, and predict subsequent infusion reactions. However, little is known regarding the long-term dynamics of ADA to rituximab. In this study we evaluated the longitudinal impact of ADA positivity in terms of drug kinetics, treatment response and neutralising capacity in SLE. Methods Patients with SLE undergoing treatment with rituximab were recruited to this study (n = 35). Serum samples were collected at the following intervals post-treatment; 1-3 months, 6 months, 12 months, 36 months (n = 114). Clinical and laboratory data was collected pre-treatment and at each time point. ADA were detected using an electrochemiluminescent immunoassay. Serum rituximab levels were measured via ELISA. A complement dependent cytotoxic assay was used to determine neutralising capability of ADA in a subgroup of positive samples (n = 38). Results ADA were found to be persistently positive over the 36-month follow-up period in 64.3% of patients. There was no significant difference in baseline disease activity (BILAG / SLEDAI-2K) between those who were subsequently ADA positive vs negative. ADA positive patients were younger at diagnosis compared with ADA negative (mean 22.50 ± 9.10 vs 37.29 ± 11.31 years, p = 0.002). Multivariate logistic regression found older age at diagnosis was associated with reduced incidence of persistent ADA with a 22% decrease in risk for each addition year after diagnosis (p = 0.03). ADA positive patients had a significantly lower C3 level at baseline (mean 0.61 ± 0.23 vs 0.87 ± 0.30, p = 0.026), which remained lower at each subsequent time point post-treatment up to 12 months. ADA titres peaked earlier and remained higher in those who had been treated with rituximab previously compared with those who were rituximab naive (median 132 AU/ml vs 7 AU/ml at 1-3 months). At 6 months post-treatment, patients with detectable ADA had a significantly lower circulating drug level than ADA negative (p = 0.0018). In terms of clinical response, ADA positive patients had an initial significant improvement in disease activity (SLEDAI-2K) by 3 months (p &amp;lt; 0.001). However, response was not maintained at 12 months. In comparison, ADA-negative patients showed a significant improvement in SLEDAI-2K at 6 months and this was maintained across the 36-month follow-up period. BILAG defined relapse within 12 months of treatment was only seen in ADA positive patients. Finally, all ADA positive samples were found to neutralise rituximab in vitro. Conclusion ADA to rituximab were common and persisted over the 36 month period of this study. ADA associated with earlier drug elimination, increased relapse rates and demonstrated neutralising capacity suggesting that ADA could be a significant limitation to sustained response to treatment. Disclosure C. Wincup: Grants/research support; Lupus UK, Versus Arthritis, British Society for Rheumatology. N. Dunn: None. C. Ruetsch-Chelli: None. A. Manouchehrinia: None. N. Kharlamova: None. M. Naja: None. B. Seitz-Polski: None. D. Isenberg: None. A. Fogdell-Hahn: None. C. Ciurtin: None. E. Jury: None.

Anti-drug antibodies of IL-23 inhibitors for psoriasis: a systematic review.

Anti-drug antibodies (ADAs) can form with certain biological medications, but their clinical significance is not fully understood. ADA formation in psoriasis patients treated with IL-23 inhibitors was evaluated, looking at the incidence of ADAs, impact on clinical outcomes and association with adverse events. A systematic search of PubMed, Cochrane and Embase databases yielded 318 articles, which were manually reviewed. A total of 19 articles met the eligibility criteria. The incidence of ADAs with the IL-23 inhibitors was as follows: 4.1-14.7% with guselkumab, 141-31% with risankizumab and 6.51-18% with tildrakizumab. The incidence of neutralizing antibodies ranged from 01-0.6% with guselkumab, 21-16% with risankizumab and 2.5 to 3.2% with tildrakizumab. There was no evidence of reduced efficacy of psoriasis treatment with ADA presence alone. However, some studies found a reduction in clinical response with high ADA titres or with the presence of neutralizing antibodies. A few studies reported that patients with ADAs to guselkumab and risankizumab had a higher incidence of injection site reactions (ISRs). There do not appear to be other adverse events associated with ADAs with IL-23 inhibitors. Testing for presence of ADAs alone in this patient group does not appear to be predictive of treatment response. Clinically, it may be more productive to test for neutralizing antibodies or ADA titre values, although further investigation is required to show a definitive correlation.

Population Pharmacokinetics of Cotadutide in Subjects with Type 2 Diabetes.

Cotadutide is a balanced dual glucagon-like peptide-1/glucagon receptor agonist under development for the treatment of nonalcoholic steatohepatitis and chronic kidney disease with type 2 diabetes. The objectives of the analysis were to characterize the population pharmacokinetics of cotadutide following daily subcutaneous injection in subjects with type 2 diabetes and to evaluate the effect of demographic and clinical variables of interest on cotadutide pharmacokinetics. This study analyzed 8834 plasma concentrations of cotadutide from 759 subjects with type 2 diabetes who received daily subcutaneous doses from 20 to 600 μg from six clinical studies. The impact of covariates on cotadutide pharmacokinetics was quantified, and body weight effect on cotadutide exposure was further evaluated using a simulation approach. The model performance was evaluated through prediction-corrected visual predictive checks. A one-compartment model with first-order absorption and elimination described cotadutide pharmacokinetic data well. The mean values for cotadutide apparent clearance, apparent distribution volume, absorption rate constant, and half-life were 1.04 L/h (interindividual variability [IIV]: 26.5%), 18.7 L (IIV: 28.7%), 0.343 h-1 (IIV: 38.6%), and 12.9 h, respectively. Higher body weight, lower albumin, and higher alanine aminotransferase were associated with an increase in cotadutide clearance, while an increase in anti-drug antibody titers was associated with a decrease in cotadutide clearance. These statistically significant effects were not considered clinically significant and did not warrant dose adjustment. Effects of other tested baseline covariates (age, sex, body mass index, hemoglobin A1c, renal function, duration of diabetes) were not found to statistically significantly affect cotadutide pharmacokinetics. Cotadutide pharmacokinetics was adequately described by a one-compartment linear model with first-order absorption and elimination. Body weight-based dosing is not necessary for cotadutide based on the simulation using the final population pharmacokinetic modeling. This model will be used to evaluate exposure-response relationships for efficacy and safety in different indications that are being studied for cotadutide.

OP016: Mini-COMET: Safety and efficacy of ≥97 weeks’ avalglucosidase alfa in infantile-onset Pompe disease participants previously treated with alglucosidase alfa

OP016: Mini-COMET: Safety and efficacy of ≥97 weeks’ avalglucosidase alfa in infantile-onset Pompe disease participants previously treated with alglucosidase alfa

Biosimilar Pegfilgrastim-cbqv Demonstrated Similar Immunogenicity to Pegfilgrastim in Healthy Subjects Across Three Randomized Clinical Studies.

IntroductionBiologic therapeutics can trigger immune responses in patients. As part of the totality of evidence that is required for regulatory approval of biosimilars, immunogenicity similarity must be assessed in the clinical programs. Pegfilgrastim-cbqv (UDENYCA®) is a pegfilgrastim biosimilar approved in the USA and European Union. This article demonstrates the similar immunogenicity of pegfilgrastim-cbqv compared with its reference product, pegfilgrastim (Neulasta®).MethodsThe immunogenicity of pegfilgrastim-cbqv was assessed in three clinical studies in healthy subjects (one specifically designed to evaluate immunogenicity similarity and two studies to assess pharmacokinetics and pharmacodynamics bioequivalence) using a tiered approach, in which plasma samples were tested for the presence of antidrug antibodies (ADAs) as well as ADA binding-specificity, titer and neutralizing activity. To assess the clinical impact of ADAs, pharmacokinetics, pharmacodynamics and safety profiles were compared between ADA-positive and -negative subjects.ResultsThese studies demonstrated similar immunogenicity of pegfilgrastim-cbqv and pegfilgrastim. The small differences in ADA incidence between treatment groups observed in the immunogenicity study were driven by non-neutralizing, low-titer, polyethylene glycol (PEG)-reactive ADAs, which are commonly present in healthy subjects. No treatment-emergent neutralizing antibodies (NAbs) were detected in either treatment group, and there was no apparent impact of ADAs on pharmacokinetics, pharmacodynamics or safety.ConclusionPegfilgrastim-cbqv has similar immunogenicity to pegfilgrastim. The presented immunogenicity, pharmacokinetics, pharmacodynamics and safety data support the overall demonstration of no clinically meaningful differences between pegfilgrastim-cbqv and pegfilgrastim.Clinical Trial RegistrationNCT02418104 (CHS-1701-04, April 2015), NCT02650973 (CHS-1701-05, February 2016) and NCT02385851 (CHS-1701-03, March 2015).Supplementary InformationThe online version contains supplementary material available at 10.1007/s12325-021-02024-x.

A multicentre, efficacy and safety study of methotrexate to increase response rates in patients with uncontrolled gout receiving pegloticase (MIRROR): 12-month efficacy, safety, immunogenicity, and pharmacokinetic findings during long-term extension of an open-label study

BackgroundPublications suggest immunomodulation co-therapy improves responder rates in uncontrolled/refractory gout patients undergoing pegloticase treatment. The MIRROR open-label trial showed a 6-month pegloticase + methotrexate co-therapy responder rate of 79%, compared to an established 42% pegloticase monotherapy responder rate. Longer-term efficacy/safety data are presented here.MethodsUncontrolled gout patients (serum urate [SU] ≥ 6 mg/dL and SU ≥ 6 mg/dL despite urate-lowering therapy [ULT], ULT intolerance, or functionally-limiting tophi) were included. Patients with immunocompromised status, G6PD deficiency, severe kidney disease, or methotrexate contraindication were excluded. Oral methotrexate (15 mg/week) and folic acid (1 mg/day) were administered 4 weeks before and during pegloticase therapy. Twelve-month responder rate (SU < 6 mg/dL for ≥ 80% during month 12), 52-week change from baseline in SU, and extended safety were examined. Efficacy analyses were performed for patients receiving ≥ 1 pegloticase infusion. Pharmacokinetics (PK)/anti-drug antibodies (ADAs) were examined and related to efficacy/safety findings.ResultsFourteen patients were included (all male, 49.3 ± 8.7 years, 13.8 ± 7.4-year gout history, pre-therapy SU 9.2 ± 2.5 mg/dL). Three patients were non-responders and discontinued study treatment before 24 weeks, one patient exited the study per protocol at 24 weeks (enrolled prior to treatment extension amendment), and 10 remained in the study through week 52. Of the 10, 8 completed 52 weeks of pegloticase + methotrexate and were 12-month responders. The remaining two discontinued pegloticase + methotrexate at week 24 (met treatment goals) and stayed in the study under observation (allopurinol prescribed at physicians’ discretion); one remained a responder at 12 months. At 52 weeks, change from baseline in SU was − 8.2 ± 4.1 mg/dL (SU 1.1 ± 2.4 mg/dL, n = 10). Gout flares were common early in treatment but progressively decreased while on therapy (weeks 1–12, 13/14 [92.9%]; weeks 36–52, 2/8 [25.0%]). One patient recovered from sepsis (serious AE). Two non-responders developed high ADA titers; fewer patients had trough concentrations (Cmin) below the quantitation limit (BQL), and the median Cmin was higher (1.03 µg/mL vs. BQL) than pegloticase monotherapy trials.ConclusionsPegloticase + methotrexate co-therapy was well-tolerated over 12 months, with sustained SU lowering, progressive gout flare reduction, and no new safety concerns. Antibody/PK findings suggest methotrexate attenuates ADA formation, coincident with higher treatment response rates.Trial registrationClinicalTrials.gov, NCT03635957. Registered on 17 August 2018.

Detailed analysis of anti‐emicizumab antibody decreasing drug efficacy, using plasma samples from a patient with hemophilia A

BackgroundEmicizumab is a humanized bispecific monoclonal antibody that bridges activated factor IX (FIXa) and factor X (FX) to mimic the function of factor VIII (FVIII). It suppresses the bleeding tendency in hemophilia A patients with or without FVIII inhibitors. A case of an adult FVIII inhibitor‐positive hemophilia A patient in whom treatment with emicizumab was discontinued owing to the repeated bleeding events and prolonged activated partial thromboplastin time. ObjectiveTo analyze the mechanisms of decreased efficacy of emicizumab. MethodsResidual plasma samples were used to measure the following: emicizumab concentration in plasma, measured by enzyme‐linked immunosorbent assay; titer of anti‐drug antibody (ADA) against emicizumab, measured by electrochemiluminescence; and neutralizing activity against emicizumab, measured by Bethesda method modified by using emicizumab‐spiked FVIII‐deficient plasma. ResultsAt week 31, emicizumab concentration was 15.0 μg/ml, and ADAs were measured as positive. Emicizumab concentration continued to decrease until emicizumab discontinuation point at week 49, and after week 50, emicizumab concentrations were below the limitation of quantification. The ADA titer increased transiently from week 31, even past the emicizumab discontinuation point at week 49. The ADA titer then gradually decreased until the last sampling point at week 93. Neutralizing activity against emicizumab was detected after emicizumab discontinuation. Epitope analysis showed that the ADAs recognize the anti‐FIXa and anti‐FX Fab arms of emicizumab, but not the Fc region. ConclusionThe appearance of ADAs with emicizumab‐neutralizing activity and potential to accelerate emicizumab clearance decreased the efficacy of emicizumab.

Evaluation of atezolizumab immunogenicity: Clinical pharmacology (part 1).

Baseline patient characteristics and prognostic factors are important considerations in oncology when evaluating the impact of immunogenicity on pharmacokinetics (PK) and efficacy. Here, we assessed the impact of anti‐drug antibodies (ADA) on the PK of the immune checkpoint inhibitor atezolizumab (an anti–PD‐L1 monoclonal antibody). We evaluated data from ≈ 4500 patients from 12 clinical trials across different tumor types, treatment settings, and dosing regimens. In our dataset, ~ 30% of patients (range, 13–54%) developed treatment‐emergent ADA, and in vitro neutralizing antibodies (NAb) were seen in ~ 50% of ADA‐positive (+) patients. Pooled time course data showed a trend toward lower atezolizumab exposure in ADA+ patients, which was more pronounced in ADA+/NAb+ patients. However, the atezolizumab concentration distributions overlapped, and drug concentrations exceeded 6 µg/ml, the target concentration required for receptor saturation, in greater than 95% of patients. Patients had sufficient exposure regardless of ADA status. The dose selected to allow for dosing over effects from ADA resulted in a flat exposure‐response relationship. Analysis of study results by ADA titer showed that exposure and overall survival were not affected in a clinically meaningful way. High tumor burden, low albumin, and high CRP at baseline showed the greatest association with ADA development but not with subsequent NAb development. These imbalanced factors at baseline can confound analysis of ADA impact. ADA increases atezolizumab clearance minimally (9%), and its impact on exposure based on the totality of the clinical pharmacology assessment does not appear to be clinically meaningful.

Immunogenicity Assessment of Tbo-Filgrastim in Cancer Patients Receiving Chemotherapy

Introduction: Neutropenia is the primary cause of chemotherapy (CT) delays, interruptions, and dose reductions, potentially compromising patient outcomes, including survival and complete response rates. Granulocyte colony-stimulating factors (G-CSFs), which support the proliferation, differentiation, and activation of hematopoietic cells, reduce the incidence, severity, and duration of febrile neutropenia in CT patients. Tbo-filgrastim (Granix®) with a non-glycosylated methionyl group is a short-acting version of G-CSF approved since 2012 under a biologic license application in the United States. Recombinant proteins may induce an immune reaction. Generation of antidrug antibodies (ADAs) may have serious consequences, including anaphylaxis resulting from hypersensitivity, neutralization of endogenous counterparts by cross-reactive neutralizing antibodies (NAbs), and reduction of drug efficacy. The objective of this analysis is to evaluate the immunogenicity of tbo-filgrastim, including the presence of the binding antibodies and neutralizing antibodies against tbo-filgrastim and its endogenous counterpart (native G-CSF), in patients receiving CT for solid and hematologic malignancies.Methods: Blood samples were collected during three independent phase 3 clinical studies that compared the efficacy and safety of tbo-filgrastim with filgrastim and/or placebo, administered 1 day after CT for 5 to 14 days. A 3-tier approach (screening, confirmation, and titer assay) was implemented to evaluate binding ADAs for tbo-filgrastim using a validated homogeneous enzyme-linked immunosorbent assay. Neutralizing activity was assessed for the confirmed-positive ADA test samples using a validated cell-based proliferation assay based on the ability of NAbs from the test samples to inhibit tbo-filgrastim or glycosylated G-CSF-stimulated proliferation of NFS-60 cells in vitro . Clinical measures were examined for all patients with confirmed-positive samples of ADAs for a possible correlation between the presence of ADAs and the potential clinical impact of immunogenicity.Results: A total of 436 patients with cancer who received the drug were assessed for immunogenicity of tbo-filgrastim, including 213 patients with breast cancer, 160 patients with lung cancer, and 63 patients with non-Hodgkin lymphoma (NHL). From breast cancer patients, only 3 patients, each having one positive sample, were confirmed positive for ADAs with low titer; none of these samples showed cross-reactivity to endogenous (glycosylated) G-CSF or neutralizing antibody activity. From lung cancer patients, only 3 patients, each having one positive sample, were confirmed positive for ADAs with low titer; none of these ADA-positive samples cross-reacted with endogenous G-CSF, and one pre-dose sample showed NAb activity in cycle 1 before tbo-filgrastim treatment. From NHL patients, only 1 patient was confirmed positive for ADAs on cycle 3. This patient had only one positive post-dose sample. The ADA titer was too low to be determined; however, no cross-reactivity or NAb activity was associated with this NHL sample. Overall, the immunogenicity incidence was 1.6% (7/436) in all cancer patients tested. None of the patients with a confirmed-positive ADA sample had evidence of hypersensitive or anaphylactic reactions or loss of efficacy.Conclusions: Incidence of immunogenicity or treatment-emergent ADAs in patients receiving CT and tbo-filgrastim was low across all three cancer populations, and all positive samples had low-titer ADAs. None of positive samples had cross-reactive ADAs to the endogenous G-CSF. Except for one pre-dose sample that showed neutralizing activity towards tbo-filgrastim, no neutralizing activities were found in other positive samples towards tbo-filgrastim or endogenous G-CSF. None of the patients with a positive ADA sample had clinically relevant immunogenicity-related symptoms during the conduct of the study. DisclosuresZou:Teva Pharmaceuticals: Employment, Equity Ownership. Buchner:Teva ratiopharm: Employment, Equity Ownership. Field:Teva Pharmaceuticals: Employment. Barash:Teva Pharmaceuticals: Employment, Equity Ownership. Liu:Teva Pharmaceuticals: Employment, Equity Ownership.

Drug-specific Treg cells are induced during desensitization procedure for rituximab and tocilizumab in patients with anaphylaxis

Biologic agents (BA) are able to induce an adaptive immune response in a proportion of exposed patients with the onset of anti-drug antibodies (ADA), which are usually responsible for hypersensitivity reactions (HR). Drug desensitization (DD) for BA allows transient clinical tolerance to the drug in reactive patients. The paper aimed to analyse the modification of drug-specific immune responses along DD in two patients with previous ADA-mediated HR (anaphylaxis) to rituximab and tocilizumab. The in vivo and in vitro assays of humoral and cellular response to drugs were carried out in a longitudinal manner throughout the DD cycles. We observed a progressive decrease of the pre-procedure ADA titer with negativization during the DD cycles in both patients. The monitoring of the drug-specific effector cell response showed the decrease in the BA-induced proliferation, while T cell response to unrelated antigens resulted unmodified along the DD cycles. Lastly, the increase of circulating drug-specific Treg cells mainly producing IL-35 were shown during the DD treatment. This study provides evidence that DD treatment to two BA inhibits humoral and cellular anti-drug response by increasing regulatory T cells and cytokines in an antigen-restricted manner. These modifications could contribute to the safety of the procedure.