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Antibody engineering technologies face increasing demands for speed, reliability and scale. We develop CeVICA, a cell-free nanobody engineering platform that uses ribosome display for in vitro selection of nanobodies from a library of 10 11 randomized sequences. We apply CeVICA to engineer nanobodies against the Receptor Binding Domain (RBD) of SARS-CoV-2 spike protein and identify >800 binder families using a computational pipeline based on CDR-directed clustering. Among 38 experimentally-tested families, 30 are true RBD binders and 11 inhibit SARS-CoV-2 pseudotyped virus infection. Affinity maturation and multivalency engineering increase nanobody binding affinity and yield a virus neutralizer with picomolar IC50. Furthermore, the capability of CeVICA for comprehensive binder prediction allows us to validate the fitness of our nanobody library. CeVICA offers an integrated solution for rapid generation of divergent synthetic nanobodies with tunable affinities in vitro and may serve as the basis for automated and highly parallel nanobody engineering. Faster, higher throughput antibody engineering methods are needed. Here the authors present CeVICA, a cell-free nanobody engineering platform using ribosome display and computational clustering analysis for in vitro selection; they use this to develop nanobodies against the RBD of SARS-CoV-2 spike protein.

Among patients with thrombotic thrombocytopenic purpura, the addition of caplacizumab, an anti–von Willebrand factor humanized, bivalent variable-domain-only immunoglobulin fragment, to daily plasma exchange resulted in faster platelet recovery, fewer TTP-related deaths, and fewer recurrences and thromboembolic events.

Thrombotic thrombocytopenic purpura is often caused by an autoantibody to ADAMTS13, resulting in ultralarge von Willebrand factor, which induces platelet aggregation. Caplacizumab blocks platelet aggregation and speeds recovery when combined with plasma exchange. Acquired thrombotic thrombocytopenic purpura (TTP) is a potentially life-threatening thrombotic microangiopathy resulting from systemic microvascular thrombosis and leading to profound thrombocytopenia, hemolytic anemia, and organ failure of varying severity. 1 Acquired TTP is caused by a severe deficiency of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) due to the presence of inhibitory autoantibodies. 2 Decreased ADAMTS13 activity leads to an accumulation of ultralarge von Willebrand factor multimers, which bind to platelets and induce aggregation. 3 These microthrombi cause tissue ischemia and organ dysfunction (commonly involving the brain, heart, and kidneys), resulting in early death 4 , 5 or in . . .

Lunsekimig is a novel, bispecific NANOBODY® molecule that inhibits both thymic stromal lymphopoietin (TSLP) and interleukin (IL)‐13, two key mediators of asthma pathophysiology. In this first‐in‐human study, we evaluated the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of lunsekimig in healthy adult participants. Participants received single ascending doses (SAD) of lunsekimig (10–400 mg intravenous [IV] or 400 mg subcutaneous [SC]) (SAD part) or multiple ascending doses (MAD part) of lunsekimig (100 or 200 mg, every 2 weeks [Q2W] for three SC doses), or placebo. Overall, 48 participants were randomized 3:1 in the SAD part and 4:1 in the MAD part for lunsekimig or placebo. The primary endpoint was safety and tolerability. The secondary endpoints included PK, antidrug antibodies (ADAs) and total target measurement. Lunsekimig was well tolerated and common treatment‐emergent adverse events were COVID‐19, nasopharyngitis, injection site reactions, and headache. Lunsekimig showed dose‐proportional increases in exposure and linear elimination. Mean t1/2z of lunsekimig was around 10 days across all IV and SC doses of the SAD and MAD parts of the study. Increases in the serum concentration of total TSLP and IL‐13 for lunsekimig versus placebo indicated target engagement. ADA of low titers were detected in four (11.1%) participants who received lunsekimig in the SAD, and seven (43.8%) in the MAD. In conclusion, lunsekimig was well tolerated in healthy participants with a linear PK profile up to single 400 mg IV and SC dose and multiple doses of 100 and 200 mg SC Q2W, with low immunogenicity.

Since the start of the COVID-19 pandemic, SARS-CoV-2 has caused millions of deaths worldwide. Although a number of vaccines have been deployed, the continual evolution of the receptor-binding domain (RBD) of the virus has challenged their efficacy. In particular, the emerging variants B.1.1.7, B.1.351 and P.1 (first detected in the UK, South Africa and Brazil, respectively) have compromised the efficacy of sera from patients who have recovered from COVID-19 and immunotherapies that have received emergency use authorization 1 – 3 . One potential alternative to avert viral escape is the use of camelid VHHs (variable heavy chain domains of heavy chain antibody (also known as nanobodies)), which can recognize epitopes that are often inaccessible to conventional antibodies 4 . Here, we isolate anti-RBD nanobodies from llamas and from mice that we engineered to produce VHHs cloned from alpacas, dromedaries and Bactrian camels. We identified two groups of highly neutralizing nanobodies. Group 1 circumvents antigenic drift by recognizing an RBD region that is highly conserved in coronaviruses but rarely targeted by human antibodies. Group 2 is almost exclusively focused to the RBD–ACE2 interface and does not neutralize SARS-CoV-2 variants that carry E484K or N501Y substitutions. However, nanobodies in group 2 retain full neutralization activity against these variants when expressed as homotrimers, and—to our knowledge—rival the most potent antibodies against SARS-CoV-2 that have been produced to date. These findings suggest that multivalent nanobodies overcome SARS-CoV-2 mutations through two separate mechanisms: enhanced avidity for the ACE2-binding domain and recognition of conserved epitopes that are largely inaccessible to human antibodies. Therefore, although new SARS-CoV-2 mutants will continue to emerge, nanobodies represent promising tools to prevent COVID-19 mortality when vaccines are compromised. Multivalent nanobodies against SARS-CoV-2 from mice engineered to produce camelid nanobodies recognize conserved epitopes that are inaccessible to human antibodies and show promise as a strategy for dealing with viral escape mutations.

SARS-CoV-2 remains a global threat to human health particularly as escape mutants emerge. There is an unmet need for effective treatments against COVID-19 for which neutralizing single domain antibodies (nanobodies) have significant potential. Their small size and stability mean that nanobodies are compatible with respiratory administration. We report four nanobodies (C5, H3, C1, F2) engineered as homotrimers with pmolar affinity for the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Crystal structures show C5 and H3 overlap the ACE2 epitope, whilst C1 and F2 bind to a different epitope. Cryo Electron Microscopy shows C5 binding results in an all down arrangement of the Spike protein. C1, H3 and C5 all neutralize the Victoria strain, and the highly transmissible Alpha (B.1.1.7 first identified in Kent, UK) strain and C1 also neutralizes the Beta (B.1.35, first identified in South Africa). Administration of C5-trimer via the respiratory route showed potent therapeutic efficacy in the Syrian hamster model of COVID-19 and separately, effective prophylaxis. The molecule was similarly potent by intraperitoneal injection. Neutralizing nanobodies (Nb) are of considerable interest as therapeutic agents for COVID-19 treatment. Here, the authors functionally and structurally characterize Nbs that bind with high affinity to the receptor binding domain of the SARS-CoV-2 spike protein and show that an engineered homotrimeric Nb prevents disease progression in a Syrian hamster model of COVID-19 when administered intranasally.

Sonelokimab (also known as M1095) is a novel trivalent nanobody comprised of monovalent camelid-derived (ie, from the Camelidae family of mammals, such as camels, llamas, and alpacas) nanobodies specific to human interleukin (IL)-17A, IL-17F, and human serum albumin. Nanobodies are a novel class of proprietary therapeutic proteins based on single-domain, camelid, heavy-chain-only antibodies. We assessed the efficacy, safety, and tolerability of sonelokimab across four dosage regimens compared with placebo in patients with plaque-type psoriasis. Secukinumab served as an active control. This multicentre, randomised, placebo-controlled, phase 2b trial was done at 41 clinics and research sites in Bulgaria, Canada, Czech Republic, Germany, Hungary, Poland, and the USA. Participants (aged 18–75 years) with stable moderate to severe plaque-type psoriasis (defined as an Investigator's Global Assessment [IGA] score of ≥3, a body surface area involvement of ≥10%, and a Psoriasis Area and Severity Index score of ≥12) for more than 6 months before randomisation, who were candidates for systemic biological therapy were included. Participants previously treated with more than two biologics or any therapy targeting IL-17 were excluded. Randomisation was stratified by weight (≤90 kg or >90 kg) and previous use of biologics. Investigators, participants, and vendors remained masked for the duration of the study, with the exception of each site's study drug administrator (who did not complete any other assessments in the study) and a study monitor who only assessed drug preparation, administration, and accountability. The study sponsor remained masked until all week 24 data were clean and locked. Participants were randomly assigned (1:1:1:1:1:1) using a centralised interactive response technology system to one of six parallel treatment groups: placebo group, sonelokimab 30 mg group, sonelokimab 60 mg group, sonelokimab 120 mg normal load group, sonelokimab 120 mg augmented load group, or secukinumab 300 mg group. All participants underwent a 4-week screening period, a 12-week placebo-controlled induction period, a 12-week dose maintenance or escalation period, and a 24-week response assessment or dose-holding period. During the placebo-controlled induction period (weeks 0–12), participants received either placebo (at weeks 0, 1, 2, 3, 4, 6, 8, and 10), sonelokimab 30 mg, 60 mg, or 120 mg normal load (at weeks 0, 2, 4, and 8), sonelokimab 120 mg augmented load (at weeks 0, 2, 4, 6, 8, and 10), or secukinumab 300 mg (at weeks 0, 1, 2, 3, 4, and 8), with placebo given at weeks 1, 3, 6, and 10 in the sonelokimab 30 mg, 60 mg, and 120 mg normal load groups, at weeks 1 and 3 in the sonelokimab 120 mg augmented load group, and at weeks 6 and 10 in the secukinumab 300 mg group. During the dose maintenance or escalation period (weeks 12–24), participants assigned to the placebo group received sonelokimab 120 mg (at weeks 12, 14, 16, and then every 4 weeks); those assigned to sonelokimab 30 mg or 60 mg groups with an IGA score of more than 1 were escalated to 120 mg and then every 4 weeks, and those with an IGA score of 1 or less stayed on the assigned dose at week 12 and then every 4 weeks; those assigned to the sonelokimab 120 mg groups received sonelokimab 120 mg at week 12 and then every 8 weeks (normal load group) or every 4 weeks (augmented load); and those assigned to the secukinumab 300 mg group received secukinumab 300 mg at week 12 and then every 4 weeks. During this period, placebo was given at week 14 in all groups, except in participants who initially received placebo, and at week 16 in the sonelokimab 120 mg normal load group. In the response assessment with dose-holding period (weeks 24–48), participants in the sonelokimab 30 mg or 60 mg groups who had dose escalation to 120 mg remained on the same regimen regardless of the IGA score at week 24. Participants in the secukinumab 300 mg group also remained on the same regimen regardless of IGA score at week 24. Participants in the sonelokimab 30 mg and 60 mg groups without dose escalation, and all participants in the two sonelokimab 120 mg groups (including placebo rollover patients) were eligible to stop the study drug at week 24. Those participants with an IGA score of 0 at week 24 received placebo; these participants resumed the previous dose of sonelokimab every 4 weeks when they had an IGA score of 1 or more (assessed every 4 weeks). Participants in these groups with an IGA score of 1 or more at week 24 continued on the same dosage. All study treatments were administered as subcutaneous injections. The final dose in all groups was given at week 44. The primary outcome was the proportion of participants in the sonelokimab groups with an IGA of clear or almost clear (score 0 or 1) at week 12 compared with the placebo group. The primary outcome and safety outcomes were assessed on an intention-to-treat basis. The study was not powered for formal comparisons between sonelokimab and secukinumab groups. This trial is registered with ClinicalTrials.gov, NCT03384745. Between Aug 15, 2018, and March 27, 2019, 383 patients were assessed for eligibility, 313 of whom were enrolled and randomly assigned to the placebo group (n=52), the sonelokimab 30 mg group (n=52), the sonelokimab 60 mg group (n=52), the sonelokimab 120 mg normal load group (n=53), the sonelokimab 120 mg augmented load group (n=51), or the secukinumab 300 mg group (n=53). Baseline characteristics of participants were similar among the groups. At week 12, none (0·0% [95% CI 0·0–6·8]) of the 52 participants in the placebo group had an IGA score of 0 or 1 versus 25 (48·1% [34·0–62·4], p<0·0001) of 52 participants in the sonelokimab 30 mg group, 44 (84·6% [71·9–93·1], p<0·0001) of 52 participants in the sonelokimab 60 mg group, 41 (77·4% [63·8–87·7], p<0·0001) of 53 participants in the sonelokimab 120 mg normal load group, 45 (88·2% [76·1–95·6], p<0·0001) of 51 participants in the sonelokimab 120 mg augmented load group, and 41 (77·4% [63·8–87·7], p<0·0001) of 53 participants in the secukinumab 300 mg group. During the placebo-controlled induction period, 155 (49·5%) of 313 participants had one or more mostly mild to moderate adverse event; the most frequent adverse events in all participants on sonelokimab during weeks 0–12 were nasopharyngitis (28 [13·5%] of 208 participants), pruritus (14 [6·7%] participants), and upper respiratory tract infection (nine [4·3%] participants). One patient from all sonelokimab-containing groups had Crohn's disease that developed during weeks 12–52. Over 52 weeks, sonelokimab safety was similar to secukinumab, with the possible exception of manageable Candida infections (one [1·9%] of 53 participants in the secukinumab group had a Candida infection vs 19 [7·4%] of 257 participants in all sonelokimab-containing groups). Treatment with sonelokimab doses of 120 mg or less showed significant clinical benefit over placebo, with rapid onset of treatment effect, durable improvements, and an acceptable safety profile. Avillion.

The SARS-CoV-2 virus is more transmissible than previous coronaviruses and causes a more serious illness than influenza. The SARS-CoV-2 receptor binding domain (RBD) of the spike protein binds to the human angiotensin-converting enzyme 2 (ACE2) receptor as a prelude to viral entry into the cell. Using a naive llama single-domain antibody library and PCR-based maturation, we have produced two closely related nanobodies, H11-D4 and H11-H4, that bind RBD (KD of 39 and 12 nM, respectively) and block its interaction with ACE2. Single-particle cryo-EM revealed that both nanobodies bind to all three RBDs in the spike trimer. Crystal structures of each nanobody–RBD complex revealed how both nanobodies recognize the same epitope, which partly overlaps with the ACE2 binding surface, explaining the blocking of the RBD–ACE2 interaction. Nanobody-Fc fusions showed neutralizing activity against SARS-CoV-2 (4–6 nM for H11-H4, 18 nM for H11-D4) and additive neutralization with the SARS-CoV-1/2 antibody CR3022.Two nanobodies that bind SARS-CoV-2 spike RBD are shown to block interaction with receptor ACE2 and thus neutralize the virus, and have an additive effect with antibody CR3022.

Interventions against variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Stable and potent nanobodies (Nbs) that target the receptor binding domain (RBD) of SARS-CoV-2 spike are promising therapeutics. However, it is unknown if Nbs broadly neutralize circulating variants. We found that RBD Nbs are highly resistant to variants of concern (VOCs). High-resolution cryoelectron microscopy determination of eight Nb-bound structures reveals multiple potent neutralizing epitopes clustered into three classes: Class I targets ACE2-binding sites and disrupts host receptor binding. Class II binds highly conserved epitopes and retains activity against VOCs and RBD SARS-CoV . Cass III recognizes unique epitopes that are likely inaccessible to antibodies. Systematic comparisons of neutralizing antibodies and Nbs provided insights into how Nbs target the spike to achieve high-affinity and broadly neutralizing activity. Structure-function analysis of Nbs indicates a variety of antiviral mechanisms. Our study may guide the rational design of pan-coronavirus vaccines and therapeutics. Highly potent neutralizing nanobodies (Nbs) are of great interest as potential COVID-19 therapeutics. Here, the authors show that potent neutralizing Nbs targeting the receptor binding domain (RBD) of the SARS-CoV-2 spike protein are also effective against convergent variants of concern of the virus. They determine eight Nb-bound spike protein cryo-EM structures, classify the binding epitopes of the Nbs and discuss their neutralization mechanisms.

Almost all the neutralizing antibodies targeting the receptor-binding domain (RBD) of spike (S) protein show weakened or lost efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged or emerging variants, such as Omicron and its sub-variants. This suggests that highly conserved epitopes are crucial for the development of neutralizing antibodies. Here, we present one nanobody, N235, displaying broad neutralization against the SARS-CoV-2 prototype and multiple variants, including the newly emerged Omicron and its sub-variants. Cryo-electron microscopy demonstrates N235 binds a novel, conserved, cryptic epitope in the N-terminal domain (NTD) of the S protein, which interferes with the RBD in the neighboring S protein. The neutralization mechanism interpreted via flow cytometry and Western blot shows that N235 appears to induce the S1 subunit shedding from the trimeric S complex. Furthermore, a nano-IgM construct (MN235), engineered by fusing N235 with the human IgM Fc region, displays prevention via inducing S1 shedding and cross-linking virus particles. Compared to N235, MN235 exhibits varied enhancement in neutralization against pseudotyped and authentic viruses in vitro. The intranasal administration of MN235 in low doses can effectively prevent the infection of Omicron sub-variant BA.1 and XBB in vivo, suggesting that it can be developed as a promising prophylactic antibody to cope with the ongoing and future infection.