Immunogenicity Assessment Research Articles

Simultaneous isotyping and semi-quantitation of anti-drug antibodies to an IgG1 biotherapeutic using hybrid LBA-LC-MS/MS.

Commonly, ligand-binding platforms are being used for immunogenicity assessment, but with the recent advent of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for protein quantification, this technology has become an alternative for the measurement of anti-drug antibodies (ADAs), when combined with an immunocapture step to extract them out of the biological sample. The monoclonal antibody adalimumab was immobilized on magnetic beads to isolate ADAs against this drug from serum samples. Multiple repetitions of immunopurification were used to minimize nonspecific binding and improve drug tolerance while maintaining sufficient recovery. A subsequent tryptic digestion released peptides, from which unique peptide sequences, originating from the constant region of seven ADA subclasses, were selected. These were then analyzed by LC-MS/MS against (unextracted) subclass-specific reference standards for semi-quantification. With two immunocapture and two immunopurification steps, the method simultaneously measures the ADA subclasses IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA within their relevant ranges, with good repeatability and drug tolerance, and limited interference of endogenous immunoglobulins. The method was successfully applied for the analysis of serum samples of subjects dosed with adalimumab. Hybrid LBA-LC-MS/MS is a viable platform for measuring ADAs and adds value, especially when ADA isotyping is needed.

Assessment of immunogenicity and protective efficiency of multi-epitope antigen-loaded in mannan decorated PLGA nanoparticles against tuberculosis

The antigen-targeting to dendritic cells (DCs) has gained increasing attention as the potential approach for immunotherapy in recent years due to the ability of DCs to regulate innate and adaptive immunity. In the present study, the immunogenicity and protective efficiency of mannan-decorated PLGA nanoparticles (NPs) loaded with multi-epitopes mycobacterium tuberculosis antigen (HspX-Ppe44-EsxV) were evaluated as a targeted delivery system to DCs. For this purpose, PLGA nanoparticle formulations were prepared and subsequently decorated by mannan. The physicochemical properties and level of mannan incorporation, as well as encapsulation efficiency and antigen release, were assessed. The potential of formulated NPs for antigen targeting to DCs, and immunogenicity against tuberculosis (TB) were investigated using immunofluorescence assay and in-vivo experiments. Mannan incorporation enhanced the uptake of fusion-loaded PLGA by DCs. The cytokine and antibody assays demonstrated that mannosylation of NPs and BCG-primed mice boosted by mannan-PLGA could significantly elevate Th1-biased immune responses relative to the BCG and non-modified PLGA NPs. Our findings also proved that the mannosylated vaccine in the presence of CpG could evoke Th1 and Th17 responses with appropriate protective efficiency against TB in mice. This result illustrated that the active targeting of DCs by mannan-PLGA NPs could induce a proper anti-tuberculosis response, which is essential for protection against tuberculosis.

A three-arm clinical study to compare pharmacokinetic and pharmacodynamic similarity of the denosumab biosimilar LY06006 with reference denosumab in healthy male subjects

ABSTRACT Background This study aimed to evaluate the pharmacokinetic (PK), pharmacodynamic (PD) similarity, comparable safety, and immunogenicity between LY06006, European Union-sourced denosumab (EU-DEN), and United States-sourced denosumab (US-DEN). Research design and methods In this double-blind, parallel-group, and single-dose study, 300 healthy male subjects were randomized 1:1:1 to receive a 60 mg dose of either LY06006, EU-DEN, or US-DEN subcutaneously. This study lasted for 253 days. Primary PK endpoints included maximum serum concentration (Cmax), area under the concentration-time curve (AUC) from time zero to last quantifiable concentration (AUC0-t), and AUC from time zero to infinity (AUC0-inf). Pharmacokinetic equivalence was concluded if the two-sided 90% confidence interval (CI) for the geometric least squares mean ratio (GLSMR) of primary endpoints were within 80%-125%. Other PK parameters, PD parameters, safety, and immunogenicity assessments were also conducted during the study. Results The 90% CIs for ratios of GLSMR were within the predefined equivalence margin for AUC0-inf (89.0%–111.1%), AUC0-t (89.7%–111.3%), and Cmax (92.3%–106.7%). The PD parameters, safety, and immunogenicity of LY06006 were also comparable to US-DEN and EU-DEN. Conclusion LY06006 was highly similar to US-DEN and EU-DEN in terms of PK, PD, safety and immunogenicity in healthy male subjects. Clinical trial registration www.clinicaltrials.gov identifier is NCT06095427

Polyfunctional T cells and unique cytokine clusters imprint the anti rAAV2/rAAV9 vector immune response.

Polyfunctional T cells programmed to perform activities such as degranulation of lytic enzymes and simultaneous production of multiple cytokines are associated with more effective control of viral infections. Immune responses to recombinant adeno-associated virus (rAAV) vector delivery systems can critically influence therapeutic efficacy and safety of gene therapy. However, knowledge of polyfunctional T cells in anti-AAV immune responses is scarce. To bridge this knowledge gap, we have investigated the polyfunctionality of primary human CD4 T cells from healthy donors after in-vitro exposure to rAAV2 or rAAV9 vectors. By performing proliferation assays of co-cultured T cells and rAAV pulsed monocyte-derived dendritic cells from healthy donors we demonstrate T cell reactivity of 43% and 50% to rAAV2 and rAAV9 vectors, respectively. We validated this frequency in a second screen using another set of healthy donors measuring CD25 and CD71 T cell activation. Single T cell secretome analysis of reactive donors uncovered a Th1 pro-inflammatory, cytolytic and chemoattractive cytokine release profile after stimulation with rAAV2 or rAAV9 vectors. 12.4% and 9.6% of the stimulated T cells displayed a polyfunctional cytokine response, respectively, including elevated polyfunctional inflammatory indices. These responses were characterized by cytokine clusters such as Granzyme B, MIP1-α and TNF-α released in combination by single T cells. Overall, our results provide insights into adaptive immunity with rAAV vector serotypes which will be important in advancing gene therapy safety, vector selection, immunogenicity assessment and better patient selection for AAV gene therapy.

Possibilities and Limitations in Substituting anti-Drug Antibody Titers with Signal-to-Noise Ratios: A Comprehensive Comparison Using Two Clinical Trial Datasets of Adalimumab.

Immunogenicity assessment is vital in clinical trials and is measured through a multi-tiered approach (screening, confirmatory and titer assays). However, recent studies have suggested that titer results could be reported from ADA signal-to-noise ratios (S/N ratios=sample mean signal/negative control mean signal). More data analysis using two clinical trials of adalimumab: SB5-1003 (single-dose, healthy participants) and SB5-4001 (multiple-dose, interchangeability study, patients with plaque psoriasis), therefore, is indispensable whether substituting ADA S/N ratio as an alternative way of reporting titer results has no impact on interpretation on clinical outcome. In this study, we demonstrated that there is a strong correlation between S/N ratios and titers and no impact on overall PK results. Nonetheless, sub-analyses with time or adalimumab level showed a change in the regression between S/N ratios and titers, leading to different titer values from the same S/N ratio. These data demonstrate that S/N ratios may fully replace titers in limited circumstances such as a biosimilar study which goal is to prove equivalence between the originator and candidate product, but need a caution in other cases.

First-in-Human Phase I Trial to Assess the Safety and Immunogenicity of an Orf Virus-Based COVID-19 Vaccine Booster.

The emergence of SARS-CoV-2 has necessitated the development of versatile vaccines capable of addressing evolving variants. Prime-2-CoV_Beta, a novel Orf virus-based COVID-19 vaccine, was developed to express the SARS-CoV-2 spike and nucleocapsid antigens. This first-in-human, phase I, dose-finding clinical trial was conducted to assess the safety, reactogenicity, and immunogenicity of Prime-2-CoV_Beta as a booster in healthy adults. From June 2022 to June 2023, 60 participants in Germany received varying doses of Prime-2-CoV_Beta. The study demonstrated a favorable safety profile, with no serious adverse events (AEs) reported. All AEs were mild (107) or moderate (10), with the most common symptoms being pain at the injection site, fatigue, and headache. Immunogenicity assessments revealed robust vaccine-induced antigen-specific immune responses. High doses notably elicited significant increases in antibodies against the spike and nucleocapsid proteins as well as neutralizing antibodies against SARS-CoV-2 and its variants. Additionally, the vaccine did not induce ORFV-neutralizing antibodies, indicating the potential for repeated administration. In conclusion, Prime-2-CoV_Beta was safe, well tolerated, and immunogenic, demonstrating potential as a broadly protective vaccine against SARS-CoV-2 and its variants. These promising results support further evaluation of higher doses and additional studies to confirm efficacy and long-term protection. This trial was registered at ClinicalTrials, NCT05389319.

Identification of potential antigenic proteins and epitopes for the development of a monkeypox virus vaccine: an in silico approach.

Virus assembly, budding, or surface proteins play important roles such as viral attachment to cells, fusion, and entry into cells. The present study aimed to identify potential antigenic proteins and epitopes that could be used to develop a vaccine or diagnostic assay against the Monkeypox virus (MPXV) which may cause a potential epidemic. To do this, 39 MPXV proteins (including assembly, budding, and surface proteins) were analyzed using an in silico approach. Of these 39 proteins, the F5L virus protein was found to be the best vaccine candidate due to its signal peptide properties, negative GRAVY value, low transmembrane helix content, moderate aliphatic index, large molecular weight, long-estimated half-life, beta wrap motifs, and being stable, soluble, and containing non-allergic features. Moreover, the F5L protein exhibited alpha-helical secondary structures, making it a potential "structural antigen" recognized by antibodies. The other viral protein candidates were A9 and A43, but A9 lacked beta wrap motifs, while A43 had a positive GRAVY value and was insoluble. These two proteins were not as suitable candidates as the F5L protein. The KRVNISLTCL epitope from the F5L protein demonstrated the highest antigen score (2.4684) for MHC-I, while the GRFGYVPYVGYKCI epitope from the A9 protein exhibited the highest antigenicity (1.754) for MHC-II. Both epitopes met the criteria for high antigenicity, non-toxicity, solubility, non-allergenicity, and the presence of cleavage sites. Molecular docking and dynamics (MD) simulations further validated their potential, revealing stable and energetically favorable interactions with MHC molecules. The immunogenicity assessment showed that GRFGYVPYVGYKCI could strongly induce immune responses through both IFN-γ and IL-4 pathways, suggesting its capacity to provoke a balanced Th1 and Th2 response. In contrast, KRVNISLTCL exhibited limited immunostimulatory potential. Overall, these findings lay the groundwork for future vaccine development, indicating that F5L, particularly the GRFGYVPYVGYKCI epitope, may serve as an effective candidate for peptide-based vaccine design against MPXV.

Immunogenicity assessment strategy for a chemically modified therapeutic protein in clinical development.

The clinical immunogenicity assessment for complex multidomain biological drugs is challenging due to multiple factors that must be taken into consideration. Here, we describe a strategy to overcome multiple bioanalytical challenges in order to assess anti-drug antibodies (ADA) for a novel and unique chemically modified protein therapeutic. A risk-centered approach was adopted to evaluate the immunogenic response to a modified version of human growth differentiation factor 15 (GDF15) connected to an albumin-binding fatty acid via a polyethylene glycol (PEG) linker. Key steps include monitoring anti-drug antibodies (ADAs), using a standard tiered approach of screening and confirmation. To deepen our understanding of ADA response, as a third tier of immunogenicity assessment, novel extensive characterization using a set of assays was developed, validated, and used routinely in clinical sample analysis. This characterization step included performance of titration, mapping of ADA response including anti-GDF15 and anti-PEG-fatty-acid antibody characterization, and assessment of the neutralizing anti-drug antibodies (NAbs) using cell-based assays for immunogenicity in parallel. The analytical methods were applied during two clinical trials involving both healthy volunteers and overweight or obese patients. We observed low incident rates for ADA and no ADAs against the PEG linker with fatty acid conjugation. In one of the clinical studies, we identified neutralizing ADAs. The proposed novel strategy of extensive characterization proved effective for monitoring the presence of ADAs and NAbs and can be used to support clinical development of a broad range of chemically modified proteins and multidomain biotherapeutics.

Immunogenicity Assessment of a 14-Valent Human Papillomavirus Vaccine Candidate in Mice.

Cervical cancer ranks as the fourth most common cancer affecting women globally, with HPV as the primary etiology agent. Prophylactic HPV vaccines have substantially reduced the incidence of cervical cancer. This study assessed the immunogenicity of SCT1000, a 14-valent recombinant virus-like particle (VLP) vaccine developed by Sinocelltech, Ltd. using pseudovirion-based neutralization assays (PBNAs) and total IgG Luminex immunoassays (LIAs). Currently in phase III clinical trials in China, SCT1000 targets the same HPV types as Gardasil 9®, plus five additional high-risk types, thereby covering twelve high-risk HPV types implicated in 96.4% of cervical cancer cases. In murine models, a dose of 1.85 μg per mouse was identified as optimal for evaluating SCT1000's immunogenicity in a three-dose regimen, as measured by PBNA and total IgG LIA across all 14 HPV types. SCT1000 induced high levels of protective antibodies, which were sustained for at least four months following the third dose. The vaccine also demonstrated stable and consistent immunogenicity in mouse potency assays under both long-term and accelerated conditions. Additionally, our studies revealed a strong correlation between the two serological tests used. SCT1000 elicited robust, durable, and consistent humoral immune responses across all 14 HPV types, indicating its potential as a broad-spectrum vaccine candidate against HPV types 6/11/16/18/31/33/35/39/45/51/52/56/58/59. The significant correlations observed between PBNA and total IgG LIA support the use of the Luminex-based total IgG method as a reliable and effective alternative for immunogenicity assessment in preclinical and future clinical vaccine development.

Measles-Rubella Microarray Patches Phase III Clinical Trial Framework: Proposal and Considerations.

Background: The Measles-Rubella Microarray Patch (MR-MAP) is an important technology that is expected to reduce coverage and equity gaps for measles-containing vaccines (MCVs), reach zero-dose children, and contribute to elimination of measles and rubella. MR-MAPs are anticipated to be easier to deploy programmatically and could be delivered by lesser-trained health workers, thereby increasing immunization coverage. The most advanced MR-MAP has reached clinical proof-of-concept through a Phase I/II trial in the target population of infants and young children. The World Health Organization (WHO) and partners have developed the Phase III clinical trial framework for MR-MAPs presented in this article. Objectives and Methods: The purpose of such framework is to inform the considerations, design and approach for the pivotal clinical trial design, while considering the anticipated data requirements to inform regulatory approval, WHO prequalification, and policy decision. Results: The proposed Phase III trial would compare the immunogenicity and safety of an MR-MAP with MR vaccine delivered subcutaneously in 9- to 10-month-old infants. An analysis of non-inferiority (NI) of immunogenicity would occur six weeks after the first dose. Should regulatory agencies or policy makers require, a proportion of infants could receive a second dose of either the same or alternate MR vaccine presentation six months after the first dose, with those children returning six weeks after the second dose for a descriptive assessment of immunogenicity, and then followed up six months after the second dose for evaluation of safety and immunogenicity. It is anticipated that this proposed pivotal Phase III trial framework would generate the required clinical data for regulatory licensure and WHO prequalification (PQ) of MR-MAPs. However, the trial design would need to be reviewed and confirmed by a national regulatory authority (NRA) that will assess the product for regulatory licensure and the WHO PQ team. Additional research will likely be required to generate data on concomitant vaccine delivery, the safety and immunogenicity of MR-MAPs in other age groups such as children 1-5 years and infants younger than 9 months of age, and the impact of MR-MAPs on coverage and equity. Such studies could be conducted during or after clinical MR-MAP development.

Complex immunogenicity assessment in caplacizumab-treated patients with immune-mediated thrombotic thrombocytopenic purpura who have received plasma exchange

BackgroundISTH guidelines for immune-mediated thrombotic thrombocytopenic purpura (iTTP) treatment recommend concurrent therapeutic plasma exchange (TPE), immunosuppressive therapy (IST), and caplacizumab. TPE can complicate anti-drug antibody (ADA) measurements by transferring pre-existing antibodies (pre-Abs) into patients via donor plasma and/or diluting treatment-emergent (TE) ADAs. ObjectivesTo assess the presence of ADAs in patients with iTTP who received caplacizumab. MethodsImmunogenicity data from patients with iTTP receiving caplacizumab once daily plus TPE/IST in four clinical trials (TITAN, HERCULES, Post-HERCULES, and a trial conducted in Japanese patients) in the clinical development program were analyzed. ADA and modified ADA (mADA) assays differentiated pre-Abs from TE ADAs. A functional neutralizing antibody (NAb) assay and neutralizing epitope characterization assay (NECA) assessed the presence of ADAs with neutralizing potential. The impact of ADAs on efficacy, pharmacokinetics/pharmacodynamics, and safety was evaluated. ResultsAmong 228 patients in four studies, prevalence of pre-Abs ranged from 17.1% (TITAN) to 56.7% (HERCULES), while TE ADA prevalence ranged from 3.1% (HERCULES) to 14.3% (Japanese study). The TE NAb-positive rate ranged from 0% (Japanese study) to 12% (Post-HERCULES) using the functional NAb assay and from 2.7% (Post-Hercules) to 14.3% (Japanese study) using NECA. The presence of these antibodies did not impact treatment efficacy or safety. ConclusionsA complex immunogenicity assay strategy was required to define the pre-Ab/TE ADA status of patients with iTTP treated with caplacizumab in a clinical trial setting. In addition to the wide range of pre-Abs observed, few patients had detectable TE ADAs or NAbs, neither of which impacted on efficacy/safety.

Bioinformatics Analysis and Immunogenicity Assessment of the Novel Multi-Stage DNA Vaccine W541 Against Mycobacterium Tuberculosis.

Vaccination is one of the effective measures to prevent latent tuberculosis infection (LTBI) from developing into active tuberculosis (TB). Applying bioinformatics methods to pre-evaluate the biological characteristics and immunogenicity of vaccines can improve the efficiency of vaccine development. To evaluate the immunogenicity of TB vaccine W541 and to explore the application of bioinformatics technology in TB vaccine research. This study concatenated the immunodominant sequences of Ag85A, Ag85B, Rv3407, and Rv1733c to construct the W541 DNA vaccine. Then, bioinformatics methods were used to analyze the physicochemical properties, antigenicity, allergenicity, toxicity, and population coverage of the vaccine, to identify its epitopes, and to perform molecular docking with MHC alleles and Toll-like receptor 4 (TLR4) of the host. Finally, the immunogenicity of the vaccine was evaluated in animal experiments. The W541 vaccine protein is a soluble cytoplasmic protein with a half-life of 1.1 h in vivo and an instability index of 45.37. It has good antigenicity and wide population coverage without allergenicity and toxicity. It contains 138 HTL epitopes, 73 CTL epitopes, 8 linear and 14 discontinuous B cell epitopes, and has a strong affinity for TLR4. Immune simulations have shown that it can effectively stimulate innate and adaptive immune responses. Animal experiments confirmed that the W541 DNA vaccine could effectively activate Th1- and Th17-type immune responses, producing high levels of IFN-γ and IL-17A, but could not significantly increase antibody levels. The W541 DNA vaccine can induce strong cellular immune responses. However, further optimization of the vaccine design is needed to make the expressed protein more stable in vivo. Bioinformatics analysis could reveal the physicochemical and immunological information of vaccines, which is critical for guiding vaccine design and development.

Development and characterization of high-throughput serological assays to measure magnitude and functional immune response against S. Paratyphi A in human samples.

Typhoid and Paratyphoid fever cause a global health burden, especially for the children of Southern Asia. The impact of the disease is further exacerbated by the dramatic increase of antimicrobial resistance. While vaccines against Salmonella Typhi have been developed and successfully introduced, an effective vaccine targeting S. Paratyphi A is still lacking. Several efforts are currently ongoing to develop vaccines targeting both S. Typhi and S. Paratyphi A. In order to analyze the immune response induced by vaccination and in sero-epidemiological studies, easy to perform and high throughput immunoassays are needed. Here we present the setup and characterization of a customized ELISA assay and of a luminescent-based serum bactericidal assay (L-SBA) to measure the quantity of S. Paratyphi O antigen specific antibodies and their functional activity against S. Paratyphi A. Robust quality control criteria have been put in place both for ELISA and SBA and assays have been fully characterized in terms of quantitation limit, limit of blanks, specificity, linearity and precision. Assays are being employed to analyze samples from clinical trials, enabling the assessment of immunogenicity during clinical vaccine development.

Safety and immunogenicity of a modified mRNA-lipid nanoparticle vaccine candidate against COVID-19: Results from a phase 1, dose-escalation study

ABSTRACT This phase 1, open-label, dose-escalation, multi-center study (NCT05477186) assessed the safety and immunogenicity of a booster dose of an mRNA COVID-19 vaccine (CV0501) encoding the SARS-CoV-2 Omicron BA.1 spike protein. Participants aged ≥ 18 years previously vaccinated with ≥ 2 doses of an mRNA COVID-19 vaccine received CV0501 doses ranging from 12 to 200 μg. After assessment of safety and immunogenicity of the 12 μg dose in 30 adults, 30 adults ≤ 64 years were randomized to receive either a 3 or 6 μg dose. Solicited adverse events (AEs) were collected for 7 days, unsolicited AEs for 28 days, and serious AEs (SAEs), medically attended AEs (MAAEs), and AEs of special interest (AESIs) until day (D) 181 post-vaccination. Serum neutralizing titers specific to SARS-CoV-2 BA.1, wild-type, Delta, and additional Omicron subvariants were assessed at D1, D15, D29, D91, and D181. Of 180 vaccinated participants (mean age: 49.3 years; 57.8% women), 70.6% had prior SARS-CoV-2 infection. Most solicited local (98.1%) and systemic (96.7%) AEs were of mild-to-moderate severity; the most common were injection site pain (57.5%; 33.3–73.3% across groups) and myalgia (36.9%; 13.3–56.7%). Unsolicited AEs were reported by 14.4% (6.7–26.7%) of participants (mild-to-moderate severity in 88.5% of the participants). Three participants (1.7%) reported SAEs, 16.7% (6.7–30.0%) reported MAAEs, and 8.3% (0.0–13.3%) reported AESIs (15 COVID-19 cases), none related to vaccination. Geometric means of serum neutralizing titers increased from baseline to D15 and D29 (dose-dependent), and then decreased over time. The safety and immunogenicity results supported advancement to a phase 2 trial.

AML-VAC-XS15-01: protocol of a first-in-human clinical trial to evaluate the safety, tolerability and preliminary efficacy of a multi-peptide vaccine based on leukemia stem cell antigens in acute myeloid leukemia patients.

Acute myeloid leukemia (AML) has a dismal prognosis, mostly due to minimal residual disease-driven relapse, making an elimination of persisting therapy-resistant leukemia progenitor/stem cells (LPCs) the main goal for novel therapies. Peptide-based immunotherapy offers a low-side-effect approach aiming to induce T cell responses directed against human leukocyte antigen (HLA) presented tumor antigens on malignant cells by therapeutic vaccination. Mass spectrometry-based analysis of the naturally presented immunopeptidome of primary enriched LPC and AML samples enabled the selection of antigens exclusively expressed on LPC/AML cells, which showed de novo induction and spontaneous memory T cell responses in AML patients, and whose presentation and memory T cell recognition was associated with improved disease outcome. Based on these data the therapeutic vaccine AML-VAC-XS15 was designed, comprising two mutated HLA class I-restricted peptides from the common AML-specific mutation in NPM1 and seven HLA class II-restricted peptides (six non-mutated high-frequent AML/LPC-associated antigens and one mutated peptide from the AML-specific mutation R140Q in IDH2), adjuvanted with the toll like receptor 1/2 ligand XS15 and emulsified in Montanide ISA 51 VG. A phase I open label clinical trial investigating AML-VAC-XS15 was designed, recruiting AML patients in complete cytological remission (CR) or CR with incomplete blood count recovery. Patients are vaccinated twice with a six-week interval, with an optional booster vaccination four months after 2nd vaccination, and are then followed up for two years. The trial's primary objectives are the assessment of the vaccine's immunogenicity, safety and toxicity, secondary objectives include characterization of vaccine-induced T cell responses and assessment of preliminary clinical efficacy. The AML-VAC-XS15-01 study was approved by the Ethics Committee of the Bavarian State medical association and the Paul-Ehrlich Institut (P01392). Clinical trial results will be published in peer-reviewed journals.

Assessment of mirvetuximab soravtansine immunogenicity in patients with folate receptor alpha-positive ovarian cancer.

Aim: The aim of this research was to evaluate the immunogenicity of mirvetuximab soravtansine (MIRV), an antibody-drug conjugate in patients with folate receptor alpha-positive ovarian cancer across four clinical studies.Materials & methods: An assay was developed and validated for the detection of antidrug antibodies (ADAs) against MIRV. A cell-based method was also developed and validated for the detection of neutralizing anti-MIRV antibodies (NAbs). Both ADAs and NAbs were assessed across four clinical studies in 734 patients.Results: Across studies, MIRV demonstrated low immunogenicity with 7.8% of patients with treatment-emergent ADAs, 7.2% with treatment-unaffected ADAs, and 0.5% with treatment-enhanced ADAs. MIRV trough concentrations were comparable in ADA-negative and ADA-positive individuals. Limited data suggest that MIRV ADAs may be associated with decreased efficacy. Due to the very limited number of NAb-positive individuals, no conclusions could be drawn on the effect of NAb on efficacy.Conclusion: Both the validation tests and the data from the MIRV clinical studies demonstrated that these assays were suitable and reliable for the detection of MIRV ADAs and NAbs. These validated assays will continue to be used to monitor MIRV immunogenicity in future clinical trials.

Nonclinical immunogenicity assessment of E3112, a recombinant human hepatocyte growth factor, and its impact on pharmacokinetics in rats and monkeys

E3112 is a recombinant human hepatocyte growth factor currently in development for the treatment of acute liver failure. The assessment of immunogenicity is crucial in the development of biotherapeutics. Consequently, a semi-quantitative assay of anti-drug antibody (ADA) was developed in rat and monkey serum using a ligand binding assay with electrochemiluminescence detection. A standard tiered approach was employed for the immunogenicity assessment, comprising a screening assay and a subsequent confirmatory assay. In the assay validation studies, selectivity, sensitivity, prozone effects, reproducibility, drug tolerance, and stability were evaluated. These assessments were conducted using a surrogate positive control of ADA. The accuracy and precision of the surrogate ADA were within ± 20 % and 20 %, respectively. The stability of ADA was also confirmed under a variety of conditions. The developed assays were successfully employed for the assessment of immunogenicity in rats and monkeys following the administration of a repeated dose of E3112. The administration of E3112 resulted in an increase in ADA levels, with higher levels observed in rats than in monkeys. Systemic exposures of E3112 in rats with higher ADA levels were lower than those with lower ADA, confirming the utility of nonclinical immunogenicity in interpreting pharmacokinetics and its inter-individual variability.

Human papillomavirus vaccines: organisation and experience of preclinical studies

INTRODUCTION. Vaccination is the main measure for the primary prevention of human papillomavirus (HPV)-related diseases. The development of novel vaccine candidates is underway worldwide, including in the Russian Federation. At the same time, the clinical introduction of new HPV vaccines is seriously hampered by the lack of clear and unambiguous recommendations for conducting preclinical studies of these vaccines.AIM. This study aimed to analyse regulatory documents on HPV vaccines, to study the experience of conducting preclinical studies, and to summarise the preclinical approaches that could be recommended for developers and applicants seeking approval for new preventive HPV vaccines, including the vaccines being developed in the Russian Federation.DISCUSSION. The authors have analysed regulatory documents issued by the World Health Organisation (WHO), the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), and the Council of the Eurasian Economic Commission (EEC). Additionally, the authors have reviewed the experimental results of preclinical studies of HPV vaccines. The known licensed and pipeline HPV vaccines are similar in terms of their characteristics and constructive features. However, there may be some differences in the HPV serotype coverage and the methods used to produce the HPV L1 capsid protein. To date, studies have confirmed the role of the HPV L1 capsid protein in the development of specific immunity, rendering challenge tests in animal models unnecessary. Papillomatosis modelling may be required for choosing an alternative immunological target or for studying an alternative (non-parenteral) route for vaccine administration. Preclinical study programmes may be supplemented with individual stages of comprehensive assessment of adjuvants and other additives included in novel HPV vaccine compositions.CONCLUSIONS. The authors have studied the international experience and presented a systemic overview of the methods and approaches used in preclinical studies of HPV vaccines. The authors have formulated recommendations for developers for the planning and organisation of preclinical studies of HPV vaccines (including immunogenicity, toxicity, and local tolerance assessments required for licensing new vaccines).

A post-marketing study to evaluate the safety and immunogenicity of a quadrivalent influenza split-virion vaccine in elderly people aged 60 years and older

BackgroundInfluenza remains a global public health concern. Understanding the vaccination-induced response in an aging population, which is susceptible and at high risk, is essential for disease prevention and control. Here, we report findings on the safety and immunogenicity of a quadrivalent influenza split-virion vaccine (15 µg/subtype/0.5 ml/dose) (hereinafter referred to as the “quadrivalent influenza vaccine”) in a population aged ≥ 60 years.MethodsThis open-label, pragmatic post-marketing trial enrolled 1399 older adults to receive one dose of an approved commercially available quadrivalent influenza vaccine manufactured by Hualan Biological Bacterin Inc. (hereinafter referred to as “Hualan Bio”). Participants with contraindications for the vaccine were excluded, while poor health condition was acceptable. All vaccinated subjects experienced adverse events collection within 30 days and serious adverse events within 180 days post-vaccination. 25% subjects, selected randomly, underwent venous blood sampling pre-vaccination and 30 days after post-vaccination, for detecting antibody titers against each subtype of influenza virus by hemagglutination inhibition assay. The incidences of adverse events and antibody titers against each subtype of influenza virus were statistically analyzed using SAS 9.4.ResultsNo grade 3 adverse reactions occurred within 30 days post-vaccination. The incidences of overall adverse reactions, local adverse reactions and systemic adverse reactions were 3.79%, 2.86% and 1.00%, respectively. No serious adverse reactions occurred within 180 days post-vaccination. There were 350 subjects who completed venous blood sampling pre-vaccination, among whom 348 subjects completed venous blood sampling at 30 days post-vaccination for immunogenicity assessment. With respect to hemagglutination inhibition antibodies against influenza viruses H1N1, H3N2, BV and BY subtypes, at 30 days post-vaccination, the seroconversion rates were 87.64%, 75.57%, 73.28% and 78.74%, respectively; the seropositive rates were 93.97%, 98.56%, 79.31% and 95.40%, respectively; and the geometric mean increase (GMI) in post-immunization/pre-immunization antibodies was 24.80, 7.26, 10.39 and 7.39, respectively.ConclusionOne 15 µg/subtype dose of the vaccine had a good safety profile and elicited favorable immunogenicity among subjects aged ≥ 60 years. The results of this study indicate that Hualan Bio quadrivalent influenza vaccine strike balance between safety and immunogenicity, supporting unnecessity to increase dosage or inoculation frequency for further enhancing immunogenicity.Trial registrationRegistered on ClinicalTrials.gov. Registration number: NCT06334510. Registered on 28/03/2024 (retrospectively registered).

Efficacy and Safety of Biosimilar SCT510 Compared with Bevacizumab for the First-Line Treatment of Advanced Non-Squamous Non-Small Cell Lung Cancer: A Randomized, Double-Blind, Phase III Study.

SCT510 is a biosimilar to bevacizumab (Avastin) reference product (RP) that is approved for various metastatic cancers. In this study, we aimed to demonstrate the equivalence of SCT510 and bevacizumab in terms of efficacy, safety, immunogenicity and pharmacokinetics (PK) in patients with advanced non-squamous non-small cell lung cancer (NSCLC). Patients with non-squamous NSCLC were randomized equally to the SCT510 group (comprising SCT510, paclitaxel, and carboplatin) and the bevacizumab group (comprising bevacizumab, paclitaxel, and carboplatin) for 4-6 cycles, followed by maintenance monotherapy with SCT510. The primary endpoint was the objective response rate (ORR) at week 12. Secondary endpoints included 18-week ORR, disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and 1-year survival rate, as well as assessments of safety, immunogenicity, and multi-dose PK analysis. Between March 29, 2019, and April 27, 2021, 989 patients were screened and 567 eligible patients were randomly assigned to the SCT510 group (285 patients) and the bevacizumab group (282 patients). The ORR at week 12 was 52.6% [95% confidence interval (CI) 46.66-58.55%] in the SCT510 group and 52.5% (95% CI 46.47-58.47%) in the bevacizumab group. The ORR at week 18 was 55.4% (95% CI 49.46-61.30%) for SCT510 and 55.7% (95% CI 49.68-61.62%) for bevacizumab. The ORR risk ratio (RR) at weeks 12 and 18 was 0.99 (90% CI 0.873-1.133) and 0.99 (90% CI 0.872-1.114), respectively, both within the pre-specified equivalence margin of 0.75-1.33. There were no differences between the two groups in relation to other secondary endpoints, specifically DCR, DOR, PFS, OS, and 1-year survival rate. The overall safety findings were similar between the two treatment groups, and both SCT510 and bevacizumab RP exhibited low immunogenicity. SCT510 is similar to bevacizumab in clinical efficacy, safety, immunogenicity, and PK in patients with advanced non-squamous NSCLC. The totality of the evidence supports the clinical equivalence of SCT510 and bevacizumab. NCT03792074.