Long-acting Antibody Research Articles

Long-Acting Strategies for Antibody Drugs: Structural Modification, Controlling Release, and Changing the Administration Route.

Because of their high specificity, high affinity, and targeting, antibody drugs have been widely used in the treatment of many diseases and have become the most favored new drugs for research in the world. However, some antibody drugs (such as small-molecule antibody fragments) have a short half-life and need to be administered frequently, and are often associated with injection-site reactions and local toxicities during use. Increasing attention has been paid to the development of antibody drugs that are long-acting and have fewer side effects. This paper reviews existing strategies to achieve long-acting antibody drugs, including modification of the drug structure, the application of drug delivery systems, and changing their administration route. Among these, microspheres have been studied extensively regarding their excellent tolerance at the injection site, controllable loading and release of drugs, and good material safety. Subcutaneous injection is favored by most patients because it can be quickly self-administered. Subcutaneous injection of microspheres is expected to become the focus of developing long-lasting antibody drug strategies in the near future.

Accelerating therapeutics development during a pandemic: population pharmacokinetics of the long-acting antibody combination AZD7442 (tixagevimab/cilgavimab) in the prophylaxis and treatment of COVID-19.

AZD7442 is a combination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-neutralizing antibodies, tixagevimab and cilgavimab, developed for pre-exposure prophylaxis (PrEP) and treatment of coronavirus disease 2019 (COVID-19). Using data from eight clinical trials, we describe a population pharmacokinetic (popPK) model of AZD7442 and show how modeling of "interim" data accelerated decision-making during the COVID-19 pandemic. The final model was a two-compartmental distribution model with first-order absorption and elimination, including standard allometric exponents for the effect of body weight on clearance and volume. Other covariates included were as follows: sex, age >65 years, body mass index ≥30 kg/m2, and diabetes on absorption rate; diabetes on clearance; Black race on central volume; and intramuscular (IM) injection site on bioavailability. Simulations indicated that IM injection site and body weight had > 20% effects on AZD7442 exposure, but no covariates were considered to have a clinically relevant impact requiring dose adjustment. The pharmacokinetics of AZD7442, cilgavimab, and tixagevimab were comparable and followed linear kinetics with extended half-lives (median 78.6 days for AZD7442), affording prolonged protection against susceptible SARS-CoV-2 variants. Comparison of popPK simulations based on "interim data" with a target concentration based on 80% viral inhibition and assuming 1.81% partitioning into the nasal lining fluid supported a decision to double the PrEP dosage from 300 mg to 600 mg to prolong protection against Omicron variants. Serum AZD7442 concentrations in adolescents weighing 40-95 kg were predicted to be only marginally different from those observed in adults, supporting authorization for use in adolescents before clinical data were available. In these cases, popPK modeling enabled accelerated clinical decision-making.

Direct long-acting antibodies: updating the language of RSV prevention to reflect the evolution of mAbs.

The language of medicine is constantly evolving, typically to better describe a new understanding of disease, adjust to changing social sensibilities, or simply to reflect a new drug class or category. We address the need for an updated language around monoclonal antibodies, or "mAbs" - a widely used medical term, but one which is now too general to accurately reflect the range of mAb pharmaceuticals, their effects, and the intended patients. The question of "what should we call a monoclonal antibody immunisation against respiratory syncytial virus (RSV) to ensure accurate understanding of the product?" was the basis for a virtual advisory panel in May 2022. The panel was convened by Sanofi with the intention of reviewing appropriate language in terminology in the context of mAb-based prophylaxis for RSV. The panel comprised several global experts on RSV and vaccination, a trained linguist specialising in doctor-patient interactions and medical language, and several experts in marketing and communications. We suggest the term "Direct Long-acting Antibody" (DLA) for a specific sub-class of mAbs for use in prevention of RSV disease in infants. This terminology should differentiate from other mAbs, which are generally not used as therapies in infants. This change will more accurately convey the specific mode of action of a mAb in infants, and how it could impact the prevention of communicable diseases: this class of mAbs is not an active treatment, but rather will offer direct and rapid protection lasting at least 5 months.

Tixagevimab/Cilgavimab in SARS-CoV-2 Prophylaxis and Therapy: A Comprehensive Review of Clinical Experience.

Effective treatments and vaccines against COVID-19 used in clinical practice have made a positive impact on controlling the spread of the pandemic, where they are available. Nevertheless, even if fully vaccinated, immunocompromised patients still remain at high risk of adverse outcomes. This has driven the largely expanding field of monoclonal antibodies, with variable results. Tixagevimab/Cilgavimab (AZD7442), a long-acting antibody combination that inhibits the attachment of the SARS-CoV-2 spike protein to the surface of cells, has proved promising in reducing the incidence of symptomatic COVID-19 or death in high-risk individuals without major adverse events when given as prophylaxis, as well as early treatment. Real-world data confirm the antibody combination's prophylaxis efficacy in lowering the incidence, hospitalization, and mortality associated with COVID-19 in solid organ transplant recipients, patients with immune-mediated inflammatory diseases and hematological malignancies, and patients in B-cell-depleting therapies. Data suggest a difference in neutralization efficiency between the SARS-CoV-2 subtypes in favor of the BA.2 over the BA.1. In treating COVID-19, AZD7442 showed a significant reduction in severe COVID-19 cases and mortality when given early in the course of disease, and within 5 days of symptom onset, without being associated with severe adverse events, even when it is used in addition to standard care. The possibility of the development of spike-protein mutations that resist monoclonal antibodies has been reported; therefore, increased vigilance is required in view of the evolving variants. AZD7442 may be a powerful ally in preventing COVID-19 and the mortality associated with it in high-risk individuals. Further research is required to include more high-risk groups and assess the concerns limiting its use, along the SARS-CoV-2 evolutionary trajectory.

A Critical Analysis of the Use of Cilgavimab plus Tixagevimab Monoclonal Antibody Cocktail (Evusheld™) for COVID-19 Prophylaxis and Treatment.

Evusheld® (tixagevimab + cilgavimab; AZD7442) was the first anti-Spike monoclonal antibody (mAb) cocktail designed not only for treatment but also with pre-exposure prophylaxis in mind. The immunoglobulins were engineered for prolonged half-life by modifying the Fc fragment, thus creating a long-acting antibody (LAAB). We review here preclinical development, baseline and treatment-emergent resistance, clinical efficacy from registration trials, and real-world post-marketing evidence. The combination was initially approved for pre-exposure prophylaxis at the time of the SARS-CoV-2 Delta VOC wave based on a trial conducted in unvaccinated subjects when the Alpha VOC was dominant. Another trial also conducted at the time of the Alpha VOC wave proved efficacy as early treatment in unvaccinated patients and led to authorization at the time of the BA.4/5 VOC wave. Tixagevimab was ineffective against any Omicron sublineage, so cilgavimab has so far been the ingredient which has made a difference. Antibody monotherapy has a high risk of selecting for immune escape variants in immunocompromised patients with high viral loads, which nowadays represent the main therapeutic indication for antibody therapies. Among Omicron sublineages, cilgavimab was ineffective against BA.1, recovered efficacy against BA.2 and BA.2.12.1, but lost efficacy again against BA.4/BA.5 and BA.2.75. Our analysis indicated that Evusheld® has been used during the Omicron VOC phase without robust clinical data of efficacy against this variant and suggested that several regulatory decisions regarding its use lacked consistency. There is an urgent need for new randomized controlled trials in vaccinated, immunocompromised subjects, using COVID-19 convalescent plasma as a control arm.

Optimization of Anti-SARS-CoV-2 Neutralizing Antibody Therapies: Roadmap to Improve Clinical Effectiveness and Implementation.

One of the major breakthroughs to combat the current Coronavirus Disease 2019 (COVID-19) pandemic has been the development of highly effective vaccines against the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Still, alternatives are needed for individuals who are at high risk of developing severe COVID-19 and are not protected by vaccination. Monoclonal antibodies against the spike protein of SARS-CoV-2 have been shown to be effective as prophylaxis and treatment against COVID-19. However, the emergence of variants of concern (VOCs) challenges the efficacy of antibody therapies. This review describes the neutralization resistance of the clinically-approved monoclonal antibody therapies against the Alpha (B.1.1.7), Beta (B.1.351), Gamma (P1), Delta (B.1.617.2), and the Omicron (B.1.1.529) variants. To guide the development of monoclonal antibody therapies and to anticipate on the continuous evolution of SARS-CoV-2, we highlight different strategies to broaden the antibody activity by targeting more conserved epitopes and/or simultaneously targeting multiple sites of vulnerability of the virus. This review further describes the contribution of antibody Fc effector functions to optimize the antibody efficacy. In addition, the main route of SARS-CoV-2 antibody administration is currently intravenously and dictates a monthly injection when used as prophylactic. Therefore, we discusses the concept of long-acting antibodies (LAABs) and non-intravenously routes of antibody administration in order to broaden the clinical applicability of antibody therapies.

Kidney Transplantation during the COVID-19 Pandemic: From Past through Present Time of Emerging Vaccine

The novel coronavirus disease 2019 (COVID-19) pandemic has significantly impacted kidney transplantation worldwide. The rate of kidney transplantation decreased during the peak of the COVID-19 pandemic, especially living donor kidney transplantation. Kidney transplant recipients are at high risk of developing severe complications from COVID-19 due to underlying comorbidities and immunosuppressed status. Management of immunosuppression, including the induction therapy and maintenance immunosuppressive regimen, has been modified at many transplant centers during the pandemic. In severe acute respiratory virus syndrome coronavirus 2 (SARS-CoV-2) infected kidney transplant recipients, the immunosuppression is usually reduced. The acute rejection treatment is usually individualized based on the risks and benefits. Several COVID-19 therapies have received emergency use authorization to prevent the progression of COVID-19 severity. Use of oral antiviral therapies is faced with challenges in terms of drug-drug interaction, drug efficacy, and lack of data in the transplant population. For COVID-19 prophylaxis in kidney transplant recipients, the effectiveness of COVID-19 vaccines is lower compared to the general population. Pre-exposure prophylaxis with a long-acting antibody combination may be an adjunct strategy for vaccination in kidney transplant recipients or those for whom COVID-19 vaccination is not contraindicated. Post-exposure prophylaxis remains to be studied. Further studies are necessary to establish standard guidelines of immunosuppressive management in kidney transplant recipients diagnosed with COVID-19 and to better understand the outcomes and adverse drug reactions of the therapeutic and prophylactic modalities including vaccination in this high-risk population.

AstraZeneca says its antibody drug prevents COVID-19 infection for six months in high-risk patients

A single injection of the long-acting antibody (LAAB) drug Evusheld (AZD7442) significantly reduced the risk of symptomatic COVID-19 infection for six months in immunocompromised patients, the drug’s manufacturer AstraZeneca has said. Evusheld is a combination of two LAABs: tixagevimab (AZD8895) and cilgavimab (AZD1061), both of which are derived from white blood cells donated by patients […]

AstraZeneca picks Lonza for COVID drug

AstraZeneca has contracted with Lonza to manufacture its antibody to prevent and treat COVID-19 A combination of two long-acting antibodies, AZD7442 is in Phase 1 clinical trials, and AstraZeneca anticipates starting Phase 3 trials by year’s end Under the contract, Lonza, a Swiss pharmaceutical services firm, will produce the antibodies in a new facility at its Portsmouth, New Hampshire, biologics complex in the first half of 2021 [ ]

Long-acting antibody ligand mimetics for HER4-selective agonism

Neuregulin protein 1 (NRG1) is a large (> 60–amino-acid) natural peptide ligand for the ErbB protein family members HER3 and HER4. We developed an agonistic antibody modality, termed antibody ligand mimetics (ALM), by incorporating complex ligand agonists such as NRG1 into an antibody scaffold. We optimized the linker and ligand length to achieve native ligand activity in HEK293 cells and cardiomyocytes derived from induced pluripotent stem cells (iPSCs) and used a monomeric Fc-ligand fusion platform to steer the ligand specificity toward HER4-dominant agonism. With the help of selectivity engineering, these enhanced ALM molecules can provide an antibody scaffold with increased receptor specificity and the potential to greatly improve the pharmacokinetics, stability, and downstream developability profiles from the natural ligand approach. This ligand mimetic design and optimization approach can be expanded to apply to other cardiovascular disease targets and emerging therapeutic areas, providing differentiated drug molecules with increased specificity and extended half-life.

Non-invasive molecular tracking method that measures ocular drug distribution in non-human primates

Intravitreal (IVT) injection has become the standard route for drug administration in retinal diseases. However, the ability to measure biodistribution of ocular therapeutics in large species remains limited, due to the invasive nature of some techniques or their lack of spatial information. The aim of this study was to develop in cynomolgus monkeys a non-invasive fluorescence imaging technology that enables tracking of IVT-dosed drugs and could be easily translated into humans. Here, we show a proof-of-concept for labeled ranibizumab with observed half-lives of 3.34 and 4.52 days at the retina and in the vitreous, respectively. We further investigate a long acting anti-VEGF antibody, which remains as an agglomerate with some material leaking out until the end of the study at Day 35. Overall, we were able to visualize and measure differences in the in vivo behavior between short and long-acting antibodies, demonstrating the power of the technology for ocular pharmacokinetics.

Calcitonin Gene-Related Peptide Targeted Immunotherapy for Migraine: Progress and Challenges in Treating Headache

A role for calcitonin gene-related peptide (CGRP) in the pathophysiology of migraine has been established over the past 25years. There have now been at least five different small-molecule CGRP antagonists that have demonstrated statistical proof of efficacy in the acute treatment of migraine. At present, multiple clinical trials are underway that are assessing the ability of long-acting antibodies against CGRP to prevent frequent migraine attacks. This review summarizes the existing data concerning the role of CGRP in migraine and attempts to highlight some possible outcomes from the ongoing anti-CGRP antibody trials.

Peri-operative Alemtuzumab (Campath-1H) and Plasmapheresis for High-PRA Positive Lymphocyte Crossmatch Heart Transplant: A Strategy to Shorten Left Ventricular Assist Device Support

Patients on a left ventricular assist device (LVAD) often have a high level of panel-reactive antibodies (PRA). Conventional therapy is to await a heart from a negative prospective-crossmatch donor. We transplanted three high-PRA patients with non-crossmatched hearts, using intra- and post-operative plasmapheresis and long-term T-/B-/plasma-cell therapy with alemtuzumab. Three highly sensitized patients (70%, 94% and 96% T-PRA; 63%, 24% and 73% B-PRA) were transplanted after 29, 187 and 94 days LVAD support. The first patient (Case 1) had an erroneous prospective negative crossmatch (due to an outside laboratory's use of the wrong patient's serum) with immediate allograft dysfunction. The correct serum showed a strongly positive crossmatch; plasmapheresis followed by alemtuzumab (20 mg intravenously) shortly after arrival in the ICU resulted in rapid hemodynamic improvement. Encouraged by this success, the next two patients (Cases 2 and 3) underwent LVAD explant and heart transplant with the next available ABO-identical, non-crossmatched donors, using plasmapheresis on bypass immediately before heart implant and alemtuzumab 20 mg intravenously upon ICU arrival, with uneventful courses. All three patients had positive retrospective T- and B-cell crossmatches. Maintenance immunosuppression consisted of cyclosporine and routine prednisone taper, with plasmapheresis as needed (Patient 1, x10; Patient 2, x5) based on diastolic dysfunction. Mycophenolate mofetil was started as a third agent several months post-transplant. Patients are presently New York Heart Association (NYHA) Class I at 26, 16 and 13 months post-transplant. In this small series with follow-up, immediate antibody removal with plasmapheresis, combined with alemtuzumab, a long-acting antibody to CD52 (expressed on T, B and some plasma cells), appears effective in allowing transplantation in sensitized, positive crossmatch recipients. Expanded use of this strategy could shorten LVAD support in many sensitized patients.

Medication Noncompliance and its Implications in Transplant Recipients

The transplant patient's therapeutic regimen consists of a lifelong drug therapy, including immunosuppressive drugs, prophylactic antimicrobials and often medications for the treatment of hypertension, diabetes mellitus and other comorbid diseases. Regular clinic appointments are required to monitor for signs and symptoms of immunological injury, recurrent disease and adverse drug effects. Patients are instructed to avoid risk factors for cardiovascular disease and cancer (e.g. diet, exercise, sun protection and not smoking). Noncompliance with all aspects of this regimen is substantial. Medication noncompliance leads to an increased incidence of acute rejection, chronic rejection and graft loss. Undoubtedly, many practitioners fail to appreciate the extent of noncompliance as the signs are often subtle and most patients are unwilling to disclose deliberate or widespread disregard for medication use. Newer immunosuppressive agents, particularly once-daily medications and long-acting antibody preparations offer convenience and monitoring that may improve compliance. This review focuses on the prevalence, correlates and consequences of medication nonadherence after organ transplantation. Current recommendations to enhance adherence are discussed.