Evidence map›Paper›PMID 42509201›Full record

ArticleImmunology2026

Mapping of C5-Blocking Monoclonal Antibodies Reveals New C5 Inhibitory Epitopes and Novel Modes of C5 Inhibition.

Rebekah Sian Cooke, Kok Yung Lee, Georgina Elizabeth Menzies, Masashi Mizuno, Bryan Paul Morgan, Wioleta Milena Zelek

Abstract read
In one paragraph

Article in Immunology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Rebekah Sian CookeUK Dementia Research Institute Cardiff, School of Medicine, Cardiff University, Cardiff, UK.ORCID https://orcid.org/0009-0008-0890-9565
Kok Yung LeeUK Dementia Research Institute Cardiff, School of Medicine, Cardiff University, Cardiff, UK.ORCID https://orcid.org/0000-0003-1014-0827
Georgina Elizabeth MenziesMolecular Biosciences Division, School of Biosciences, Cardiff University, Cardiff, UK.ORCID https://orcid.org/0000-0002-6600-6507
Masashi MizunoDepartment of Renal Replacement Therapy, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Bryan Paul MorganUK Dementia Research Institute Cardiff, School of Medicine, Cardiff University, Cardiff, UK.ORCID https://orcid.org/0000-0003-4075-7676
Wioleta Milena ZelekUK Dementia Research Institute Cardiff, School of Medicine, Cardiff University, Cardiff, UK.ORCID https://orcid.org/0000-0002-2230-3550

Funding

Alzheimers Society 565CSP VA 565UK Dementia Research Institute UK DRI-3002UK Research and Innovation 526567
6 · The paper itself

Abstract

C5 inhibition is a proven therapeutic target with several monoclonal antibody (mAb) and small molecule drugs in the clinic. To explore alternative modes of inhibition, novel C5-blocking mAbs were generated and compared to therapeutic mAbs eculizumab and crovalimab. Blocking mAbs were selected using complement inhibition in haemolysis assays. C5 binding and competition between mAbs were tested by ELISA and surface plasmon resonance. Impact on C5 cleavage by CVF and native convertases was tested by western blotting of C5 fragments and ELISA for C5a release. Four novel C5-blocking mAbs were identified and shown to inhibit haemolysis with comparable efficacy to crovalimab and eculizumab. Competition assays identified four distinct function-blocking epitopes; mAb 7D4 and eculizumab competed for an α-chain epitope (epitope 1), while 10B6 and crovalimab competed for a β-chain epitope (epitope 2). mAbs 2B11 and 4G2 were not competitive with epitope 1/2 binders or each other, marking two distinct blocking α-chain epitopes (epitopes 3 and 4). Epitope 1 and epitope 2 binders blocked C5 convertase-mediated C5 cleavage and C5a release, while epitope 3 and epitope 4 binders permitted C5 cleavage, demonstrating distinct modes of inhibition. We identified four distinct C5 blocking epitopes; epitope 1 targeted by eculizumab and 7D4, epitope 2 targeted by crovalimab and 10B6 and epitopes 3 and 4 targeted by 2B11 and 4G2 respectively. Although all efficiently blocked haemolysis, epitope 3 and 4 binders permitted C5a release. We reveal (at least) four blocking epitopes on C5 and (at least) two distinct mechanisms of inhibition.

Indexed as

Antibodies, BlockingAntibodies, MonoclonalComplement C5Epitope MappingEpitopesAnimalsAntibodies, Monoclonal, HumanizedHemolysisHumansProtein BindingAntibodies, BlockingAntibodies, MonoclonalAntibodies, Monoclonal, HumanizedComplement C5eculizumabEpitopesC5complement systemcrovalimabeculizumabmechanismmembrane attack complextherapeutic antibodies

Identifiers

PMID42509201
PMCPMC13636134

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.