mAb Therapy Research Articles

Recent Advancements in AAV-Vectored Immunoprophylaxis in the Nonhuman Primate Model.

Monoclonal antibodies (mAbs) are important treatment modalities for preventing and treating infectious diseases, especially for those lacking prophylactic vaccines or effective therapies. Recent advances in mAb gene cloning from naturally infected or immunized individuals has led to the development of highly potent human mAbs against a wide range of human and animal pathogens. While effective, the serum half-lives of mAbs are quite variable, with single administrations usually resulting in short-term protection, requiring repeated doses to maintain therapeutic concentrations for extended periods of time. Moreover, due to their limited time in circulation, mAb therapies are rarely given prophylactically; instead, they are generally administered therapeutically after the onset of symptoms, thus preventing mortality, but not morbidity. Adeno-associated virus (AAV) vectors have an established record of high-efficiency in vivo gene transfer in a variety of animal models and humans. When delivered to post-mitotic tissues such as skeletal muscle, brain, and heart, or to organs in which cells turn over slowly, such as the liver and lungs, AAV vector genomes assume the form of episomal concatemers that direct transgene expression, often for the lifetime of the cell. Based on these attributes, many research groups have explored AAV-vectored delivery of highly potent mAb genes as a strategy to enable long-term expression of therapeutic mAbs directly in vivo following intramuscular or intranasal administration. However, clinical trials in humans and studies in nonhuman primates (NHPs) indicate that while AAVs are a powerful and promising platform for vectored immunoprophylaxis (VIP), further optimization is needed to decrease anti-drug antibody (ADA) and anti-capsid antibody responses, ultimately leading to increased serum transgene expression levels and improved therapeutic efficacy. The following review will summarize the current landscape of AAV VIP in NHP models, with an emphasis on vector and transgene design as well as general delivery system optimization. In addition, major obstacles to AAV VIP, along with implications for clinical translation, will be discussed.

Recovery of Breakthrough Asthma Attacks Treated With Oral Steroids While on Monoclonal Antibody Therapy: Protocol for a Prospective Observational Study (BOOST).

Asthma attacks are a common and important problem. Someone experiences an asthma attack in the United Kingdom every 10 seconds. Asthma attacks cause coughing, wheezing, breathlessness, and chest tightness and are highly stressful for patients. They result in reduced quality of life, with days lost from work or school. Asthma attacks are treated with oral corticosteroids (OCSs), but these have many short- and long-term side effects. Asthma monoclonal antibodies (mAbs) have revolutionized the treatment of severe asthma by reducing asthma attacks and OCS burden by over 50%, but some people still experience attacks while on mAbs. The MEX study showed that residual asthma attacks are broadly eosinophilic (high fractional exhaled nitric oxide [FeNO]) or noneosinophilic (low FeNO), but it did not measure response to OCS treatment. There is an evidence gap in understanding the clinical and inflammatory responses that occur when using OCSs to treat residual asthma attacks in patients taking asthma mAbs. The primary objective is to compare the clinical recovery between high-FeNO and low-FeNO attacks after acute treatment with oral prednisolone among people established on long-term asthma mAb treatment. The exploratory objective is to compare the inflammatory response to acute treatment with oral prednisolone between high-FeNO and low-FeNO attacks. BOOST (Breakthrough Asthma Attacks Treated With Oral Steroids) is a single-center, prospective observational study of 60 adults established on long-term asthma mAb treatment who receive acute treatment with oral prednisolone (usual care) for an asthma attack. The primary outcome will be the proportion of treatment failure (the need to start oral prednisolone or antibiotics or an unscheduled health care visit for asthma, following an attack) at day 28. The secondary outcomes will be the change in forced expiratory volume in 1 second and the change in visual analogue scale symptom score between the stable state, attack, day 7, and day 28 visits. The exploratory outcomes include the changes in sputum, nasal, and blood inflammometry between the stable state, attack, day 7, and day 28 visits. The last asthma attack visit is anticipated to occur in December 2023. Data analysis and publication will take place in 2024. We will test the hypothesis that there is a difference in the rate of recovery of clinical and inflammatory measures between high-FeNO and low-FeNO asthma attacks that occur in patients on mAb therapy. The study data will help power a future randomized placebo-controlled trial of prednisolone treatment for nonsevere attacks in patients treated with asthma mAbs and will provide important information on whether corticosteroid treatment should be FeNO-directed. DERR1-10.2196/46741.

Managing Migraine: Medication Overuse Headache and Treatment with Eptinezumab.

Medication overuse headache (MOH) places both a physical and emotional burden on patients. MOH may occur as a consequence of a negative spiral of events comprising an increasing number of headache days while taking frequent or excessive amounts of medications for acute treatment of headaches or migraine. Despite acute and prophylactic treatment options, there remains a complex subset of patients who fail first-line oral prophylactic therapies due to insufficient response or failure to tolerate, and require access to new prophylactic treatment options, including calcitonin gene-related peptide (CGRP) inhibitors such as eptinezumab. In this article I present a series of clinical scenarios in which the use of eptinezumab may be beneficial, based on the extensive experience I have gained using the treatment, in more than 25 patients, (and over 40 infusions), over a 2-year period. Eptinezumab provides an additional therapeutic modality for patients who are refractory to other migraine medications, including other CGRP pathway monoclonal antibody (mAb) therapies. I discuss within this article the potential role for eptinezumab in various clinical scenarios such as refractory migraine, including MOH, in which the rapid bioavailability of the preparation may be of particular utility. It is important to tailor treatment plans to the individual patient needs and provide other lifestyle and non-drug-based recommendations when treating patients with MOH, who may be appropriate for treatment with eptinezumab.

EMab-300 Detects Mouse Epidermal Growth Factor Receptor-Expressing Cancer Cell Lines in Flow Cytometry.

Epidermal Growth Factor Receptor (EGFR) overexpression or its mutation mediates the sustaining proliferative signaling, which is an important hallmark of cancer. Human EGFR-targeting monoclonal antibody (mAb) therapy such as cetuximab has been approved for clinical use in patients with colorectal cancers and head and neck squamous cell carcinomas. A reliable preclinical mouse model is essential to further develop the mAb therapy against EGFR. Therefore, sensitive mAbs against mouse EGFR (mEGFR) should be established. In this study, we developed a specific and sensitive mAb for mEGFR using the Cell-Based Immunization and Screening (CBIS) method. The established anti-mEGFR mAb, EMab-300 (rat IgG1, kappa), reacted with mEGFR-overexpressed Chinese hamster ovary-K1 (CHO/mEGFR) and endogenously mEGFR-expressed cell lines, including NMuMG (a mouse mammary gland epithelial cell) and Lewis lung carcinoma cells, using flow cytometry. The kinetic analysis using flow cytometry indicated that the KD of EMab-300 for CHO/mEGFR and NMuMG was 4.3 × 10-8 M and 1.9 × 10-8 M, respectively. These results indicated that EMab-300 applies to the detection of mEGFR using flow cytometry and may be useful to obtain the proof of concept in preclinical studies.

Mechanism of Action for an All-in-One Monoclonal Antibody Against Staphylococcus aureus Infection.

Staphylococcus aureus is a major human pathogen associated with high mortality rates. The extensive use of antibiotics is associated with the rise of drug resistance, and exotoxins are not targeted by antibiotics. Therefore, monoclonal antibody (mAb) therapy has emerged as a promising solution to solve the clinical problems caused by refractory S aureus. Recent research suggests that the synergistic effects of several cytotoxins, including bicomponent toxins, are critical to the pathogenesis of S aureus. By comparing the amino acid sequences, researchers found that α-toxin and bicomponent toxins have high homology. Therefore, we aimed to screen an antibody, designated an all-in-one mAb, that could neutralize α-toxin and bicomponent toxins through hybridoma fusion. We found that this mAb has a significant pharmacodynamic effect within in vivo mouse models and in vitro experiments.

Treatment outcome comparisons of first-line targeted therapy in patients with KRAS wild-type metastatic colorectal cancer: A nationwide database study.

The first-line systemic therapy for metastatic colorectal cancer (mCRC) is a combination of one targeted therapy agent and a chemotherapy doublet. Whether bevacizumab or anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibody (mAb) is the more effective addition to a chemotherapy doublet as the first-line treatment for inoperable KRAS wild-type mCRC remains controversial in prior clinical trials. Moreover, the association between the sidedness of primary tumors and the efficacy of anti-EGFR mAb needs to be addressed. We established a cohort of patients with KRAS wild-type mCRC who were treated with first-line targeted therapy plus doublet chemotherapy between 2013 and 2018 using Taiwan's National Health Insurance Research Database. Secondary surgery was defined as either resection of primary tumors, liver metastases, lung metastases, or radiofrequency ablation. A total of 6482 patients were included; bevacizumab and anti-EGFR mAb were the first-line targeted therapies in 3334 (51.4%) and 3148 (48.6%) patients, respectively. Compared with those who received bevacizumab, patients who received anti-EGFR mAb exhibited significantly longer overall survival (OS; median, 23.1 vs. 20.2 months, p = 0.012) and time to treatment failure (TTF; median, 11.3 vs. 10 months, p < 0.001). Among left-sided primary tumors, the OS and TTF benefits of anti-EGFR mAb remained. Among right-sided primary tumors, the OS and TTF were similar regardless of the type of targeted therapy. In multivariate analyses, first-line anti-EGFR mAb therapy remained an independent predictor of longer OS and TTF for left-sided primary tumors. Patients who received anti-EGFR mAb were more likely to receive secondary surgery (29.6% vs. 22.6%, p < 0.0001) than patients who received bevacizumab. For patients who received first-line doublet chemotherapy for KRAS wild-type mCRC, adding anti-EGFR mAb was associated with significantly longer OS and TTF, especially for left-sided primary tumors.

Pharmacogenomic Analyses Implicate B Cell Developmental Status and MKL1 as Determinants of Sensitivity toward Anti-CD20 Monoclonal Antibody Therapy.

Monoclonal antibody (mAb) therapy directed against CD20 is an important tool in the treatment of B cell disorders. However, variable patient response and acquired resistance remain important clinical challenges. To identify genetic factors that may influence sensitivity to treatment, the cytotoxic activity of three CD20 mAbs: rituximab; ofatumumab; and obinutuzumab, were screened in high-throughput assays using 680 ethnically diverse lymphoblastoid cell lines (LCLs) followed by a pharmacogenomic assessment. GWAS analysis identified several novel gene candidates. The most significant SNP, rs58600101, in the gene MKL1 displayed ethnic stratification, with the variant being significantly more prevalent in the African cohort and resulting in reduced transcript levels as measured by qPCR. Functional validation of MKL1 by shRNA-mediated knockdown of MKL1 resulted in a more resistant phenotype. Gene expression analysis identified the developmentally associated TGFB1I1 as the most significant gene associated with sensitivity. qPCR among a panel of sensitive and resistant LCLs revealed immunoglobulin class-switching as well as differences in the expression of B cell activation markers. Flow cytometry showed heterogeneity within some cell lines relative to surface Ig isotype with a shift to more IgG+ cells among the resistant lines. Pretreatment with prednisolone could partly reverse the resistant phenotype. Results suggest that the efficacy of anti-CD20 mAb therapy may be influenced by B cell developmental status as well as polymorphism in the MKL1 gene. A clinical benefit may be achieved by pretreatment with corticosteroids such as prednisolone followed by mAb therapy.

Selinexor-Based Triplet Regimens in Patients With Multiple Myeloma Previously Treated With Anti-CD38 Monoclonal Antibodies

BackgroundThe increasing use of anti-CD38 monoclonal antibodies (αCD38 mAbs) for newly diagnosed or early relapsed multiple myeloma (MM), especially in non-transplant eligible patients, may lead to more patients developing αCD38 mAb-refractory disease earlier in the treatment course with fewer treatment options. Patients and methodsWe analyzed the efficacy and safety of selinexor-based triplets (selinexor+dexamethasone [Sd] plus pomalidomide [SPd, n = 23], bortezomib [SVd, n = 16] or carfilzomib (SKd, n = 23]) in a subset of STOMP (NCT02343042) and BOSTON (NCT03110562) study patients treated previously with αCD38 mAbs. ResultsSixty-two patients (median 4 prior therapies, range 1 to 11, 90.3% refractory to αCD38 mAb) were included. Overall response rates (ORR) in the SPd, SVd and SKd cohorts were 52.2%, 56.3%, and 65.2%, respectively. Overall response rate was 47.4% among patients who had MM refractory to the third drug reintroduced in the Sd-based triplet. Median progression-free survival in the SPd, SVd, and SKd cohorts was 8.7, 6.7, and 15.0 months, respectively, and median overall survival was 9.6, 16.9, and 33.0 months, respectively. Median time to discontinuation in the SPd, SVd, and SKd cohorts was 4.4, 5.9, and 10.6 months, respectively. The most common hematological adverse events were thrombocytopenia, anemia, and neutropenia. Nausea, fatigue, and diarrhea were primarily grade 1/2. Adverse events were generally manageable with standard supportive care and dose modifications. ConclusionSelinexor-based regimens may offer effective and well-tolerated therapy to patients with relapsed and/or refractory MM who had disease previously exposed or refractory to αCD38 mAb therapy and could help address the unmet clinical need in these high-risk patients.

Comparative efficacy of therapies for relapsing multiple sclerosis: a systematic review and network meta-analysis.

Aim: To assess the relative efficacy of disease-modifying therapies (DMTs) for relapsing multiple sclerosis (RMS) including newer therapies (ozanimod, ponesimod, ublituximab) using network meta-analysis (NMA). Materials & methods: Bayesian NMAs for annualised relapse rate (ARR) and time to 3-month and 6-month confirmed disability progression (3mCDP and 6mCDP) were conducted. Results: For each outcome, the three most efficacious treatments versus placebo were monoclonal antibody (mAb) therapies: alemtuzumab, ofatumumab, and ublituximab for ARR; alemtuzumab, ocrelizumab, and ofatumumab for 3mCDP; and alemtuzumab, natalizumab, and either ocrelizumab or ofatumumab (depending on the CDP definition used for included ofatumumab trials) for 6mCDP. Conclusion: The most efficacious DMTs for RMS were mAb therapies. Of the newer therapies, only ublituximab ranked among the three most efficacious treatments (for ARR).

HSD97 Treatment Utilization and Key Characteristics of COVID-19 Patients Treated with Monoclonal Antibody Therapy in the Outpatient Setting

COVID-19 treatment guidelines, particularly for monoclonal antibody (mAb) therapies, have changed over time, as new variants have emerged and new treatments have been authorized. However, limited research exists on mAb utilization and the characteristics of patients who receive this treatment. Commissioned by the FDA, this study aims to describe mAb utilization and the characteristics of patients who utilized mAb therapy in the outpatient setting. This retrospective cohort study was conducted using closed claims from Komodo’s Healthcare Map from January 1, 2019 to March 31, 2022 (study period). The sample included patients ≥18 years of age with ≥1 COVID-19 diagnosis and their first mAb therapy in the outpatient setting between January 1, 2020 and March 1, 2022 (index date). Patient characteristics were assessed during the 365 days before or on the index date, and mAb utilization was assessed on or after the index date through the end of continuous enrollment or the study period. 397,818 patients (mean age 50.5; 56.1% female) were identified. Of the patients with race and ethnicity information (46.0% and 40.4%, respectively), 82.6% were white and 90.8% were non-Hispanic or Latino. Most patients (78.9%) had at least one pre-existing condition; the most common pre-existing conditions were heart and mental health conditions. The most common mAb index therapy overall was casirivimab+imdevimab; however, the most common mAb therapy was bamlanivimab before the Delta variant vs. casirivimab+imdevimab after the Delta variant. Most patients (98.5%) received only one mAb therapy. mAb utilization varied over time possibly due to changes in the most prevalent variant, supply chain issues, and current recommendations and regulations. Most patients who received mAb therapy had pre-existing conditions or were white or non-Hispanic or Latino. Additional research is needed to better understand a potential disparity in access and clinical outcomes associated with outpatient mAb utilization.

Evaluation of small extracellular vesicles as biomarkers of efficacy with anti-PD-1 mAb therapy in patients with recurrent/metastatic HNSCC.

6042 Background: The development of biomarkers that reliably predict response to anti-PD-1 mAb therapy (IO) is a critical need. Small (30-150 nm) extracellular vesicles (sEV), aka exosomes, are “molecular mimics” of their parent cells. In cancer, plasma sEV are mixtures of tumor-derived exosomes (TEX) and vesicles produced by non-malignant cells. We conducted a retrospective study of R/M HNSCC patients treated with IO to evaluate sEV as predictive biomarkers. Methods: We evaluated sEV in plasma of R/M HNSCC patients (n = 24) obtained just prior to initiation of IO. Precleared ultrafiltered plasma was used to isolate total plasma sEV by size exclusion chromatography. Total plasma sEV were separated into two subsets, T cell-derived CD3(+) sEV and TEX-enriched CD3(-) sEV by immunocapture with anti-CD3 mAb. On-bead flow cytometry was used to estimate relative levels of proteins carried on the sEV surface. Specifically, the CD3(-) fraction was evaluated for stimulatory (stim; CD40, CD40L, OX40, OX40L, CD80) and suppressive (supp; TGFb, CTLA4, FasL, PD-L1, PD-1) proteins. Differences between responders (CR/PR/SD) and non-responders (PD) were assessed using Wilcoxon-Mann-Whitney test. Multivariate Cox proportional hazards regression was used to evaluate the relationship between the pre-treatment sEV characteristics and outcome. Results: Mean age was 62, 46% had oropharynx (82% HPV+), 17% oral cavity and 29% had larynx/hypopharynx primary. Treatment indication for IO was 46% platinum failure, remainder first line. Best response: 17% PR, 29% SD, and 54% PD. Median PFS and OS were 5.3 and 16.2 months, respectively. Total sEV protein level was not associated with efficacy. Total CD3(+) sEV level was low overall and did not correlate with lymphocyte count or neutrophil/lymphocyte ratio. High CD3(+) sEV level was associated with better OS [HR: 0.16 (95% CI 0.04-0.59), P = 0.007] and PFS [HR: 0.16 (95% CI 0.04-0.58), P = 0.005] but not response. While total TEX and levels of individual stim and supp proteins carried by TEX were not predictive of response, an increased supp/stim ratio was (P = 0.02). Importantly, high TEX supp score and stim score were both associated with better OS [HR: 0.19 (95% CI 0.05-0.77), P = 0.02, and HR: 0.26 (95% CI 0.07-0.95), P = 0.04, resp.]. High PD-L1, but not PD-1 on TEX, was associated with better OS [HR: 0.15 (95% CI 0.04-0.56), P = 0.005]; and PFS: HR: 0.33 (95% CI 0.11-0.94), P = 0.04]. Conclusions: Evaluation of two sEV subsets, T cell-derived-CD3(+) sEV and TEX-enriched CD3(-) sEV, indicated their potential utility as predictive biomarkers with IO. High T cell-derived sEV, TEX supp/stim ratio, and TEX PD-L1 expression levels were independently associated with significantly increased efficacy with IO. Our study uniquely analyzed the predictive value of plasma sEv subsets in IO treated R/M HNSCC patients, and evaluation in a larger cohort is warranted.

AB-101, an allogeneic, non–genetically modified, natural killer (NK) cell therapy, evaluated as monotherapy or in combination with rituximab in R/R non-Hodgkin lymphoma.

7529 Background: AB-101 is a non-genetically modified, cord blood-derived, allogeneic, cryopreserved, NK cell therapy for use in combination with monoclonal antibody (mAb) or innate cell engager therapies. AB-101 is being developed to enhance response to mAb therapy through the antibody-dependent cellular cytotoxicity (ADCC) mechanism. Many cancer patients (pts) are unable to mount a robust ADCC response, rendering mAb therapy less effective for these pts. AB-101 has attributes that enhance NK cell activity: Consistent phenotype for tumor engagement and cytotoxicity; Selected killer immunoglobulin-like receptor B (KIR B) haplotype; V/V CD16 polymorphism at F158 for enhanced ADCC. AB-101 outpatient administration provides optimized NK cells to pts, potentially enhancing their anti-tumor activity in combination with mAb that utilize the ADCC mechanism. We have initiated a Ph 1/2 clinical trial evaluating the combination of AB-101 with rituximab (RTX) in pts with R/R NHL of B-cell origin. Methods: Two AB-101 dose levels, 1 or 4e9 cells, will be evaluated as monotherapy or combination with RTX. All enrolled pts will receive at least 1 cycle of 4 weekly AB-101 doses, with cyclophosphamide/fludarabine lymphodepletion (LD). Pts receiving the combination may receive up to 4 treatment cycles. Results: Dose escalation is ongoing with 17 pts enrolled. Pts were elderly (median of 68 yrs) and heavily pretreated (median of 4 prior lines) with 64% having had prior CD19 CAR-T. Pts had DLBCL (9), FL (5), MCL (2), and LPL/WM (1). 11 monotherapy pts and 6 RTX combination pts were treated at time of abstract. 16 pts received AB-101 at 1e9 cells/dose; 1 pt received 4e9 cells/dose. 4 of 6 combination pts have received &gt; 1 cycle. AB-101 was generally well tolerated. The most common G3+ AEs were LD-related neutropenia and lymphopenia. All AB-101 related AEs were G1/2. ICANs and GVHD, events associated with allogeneic cell therapy, were not reported; Gr 1 CRS occurred in 2 pts and resolved within 24h. SAEs were reported in 9 pts. The most common SAEs were associated with either infections (n = 3) or PD (n = 3) and one related SAE of Gr 1 fever was reported. No pts discontinued treatment due to an AB-101-related AE. ORR for the RTX cohort was 67% (4/6) with a CR rate of 50% (3/6). 3 of 4 responses were observed in pts who failed prior CAR-T therapy. ORR for the monotherapy cohorts was 27% (3/11). Conclusions: 4 weekly doses of AB-101 given alone or with RTX appeared to be safe and well tolerated without the serious/severe toxicities associated with CAR-T therapies. Preliminary efficacy of the combination treatment is encouraging. The study is ongoing and continues to enroll the combination cohorts and the 4e9 cells/dose level. Updated safety, efficacy, and exploratory PK/PD/immunogenicity results will be provided during the presentation. Clinical trial information: NCT04673617 .

SARS-CoV-2 spike codon mutations and risk of hospitalization after antispike monoclonal antibody therapy in solid organ transplant recipients.

Neutralizing antispike monoclonal antibody (mAb) therapies were highly efficacious in preventing coronavirus disease 2019 (COVID-19)hospitalization. While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)variants may harbor spike protein mutations conferring reduced in vitro susceptibility to these antibodies, the effect of these mutations on clinical outcomes is not well characterized. We conducted a case-control study of solid organ transplant recipients who received an antispike mAb for treatment of mild-to-moderate COVID-19 and had an available sample from initial COVID-19 diagnosis for genotypic sequencing. Patients whose SARS-CoV-2 isolate had at least one spike codon mutation conferring at least fivefold decreased in vitro susceptibility were classified as resistant. Overall, 9 of 41 patients (22%) had at least one spike codon mutation that confers reduced susceptibility to the antispike mAb used for treatment. Specifically, 9 of 12 patients who received sotrovimab had S371L mutation that was predicted to confer a 9.7-fold reduced susceptibility. However, among 22 patients who required hospitalization, 5had virus with resistance mutation. In contrast, among 19 control patients who did not require hospitalization, 4 also had virus-containing resistance mutations (p > 0.99). In conclusion, spike codon mutations were common, though mutations that conferred a 9.7-fold reduced susceptibility did not predict subsequent hospitalization after treatment with antispike mAb.

Effects of PCSK9 inhibition on glucose metabolism and β-cell function in humans: a pilot study.

Anti-PCSK9 monoclonal antibodies are effective in reducing LDL-C and cardiovascular events by neutralizing circulating PCSK9. PCSK9, however, is also expressed in tissues, including the pancreas, and studies on PCSK9 KO mice have shown impaired insulin secretion. Statin treatment is already known to affect insulin secretion. Our aim was to conduct a pilot study to evaluate the effect of anti-PCSK9 mAb on glucose metabolism and β-cell function in humans. Fifteen non-diabetic subjects, candidates for anti-PCSK9 mAb therapy, were enrolled. All underwent OGTT at baseline and after 6 months of therapy. During OGTT, insulin secretion parameters were derived from C-peptide by deconvolution (β cell glucose sensitivity). Surrogate insulin sensitivity indices were also obtained from OGTT (Matsuda). Glucose levels during OGTT were unchanged after 6 months of anti-PCSK9 mAb treatment, as well as insulin and C-peptide levels. The Matsuda index remained unchanged, while β-cell glucose sensitivity improved post-therapy (before: 85.3 ± 65.4; after: 118.6 ± 70.9 pmol min-1m-2mM-1; p<0.05). Using linear regression, we found a significant correlation between βCGS changes and BMI (p=0.004). Thus, we compared subjects with values above and below the median (27.6 kg/m2) and found that those with higher BMI had a greater increase in βCGS after therapy (before: 85.37 ± 24.73; after: 118.62 ± 26.83 pmol min-1m-2mM-1; p=0.007). There was also a significant correlation between βCGS change and Matsuda index through linear regression (p=0.04), so we analyzed subjects who had values above and below the median (3.8). This subgroup analysis showed a slight though not significant improvement in βCGS in more insulin resistant patients, (before: 131.4 ± 69.8; after: 170.8 ± 92.7 pmol min-1m-2mM-1; p=0.066). Our pilot study demonstrates that six-month treatment with anti-PCSK9 mAb improves β-cell function, and does not alter glucose tolerance. This improvement is more evident in patients with greater insulin-resistance (low Matsuda) and higher BMI.

Status and Developing Strategies for Neutralizing Monoclonal Antibody Therapy in the Omicron Era of COVID-19.

The monoclonal antibody (mAb)-based treatment is a highly valued therapy against COVID-19, especially for individuals who may not have strong immune responses to the vaccine. However, with the arrival of the Omicron variant and its evolving subvariants, along with the occurrence of remarkable resistance of these SARS-CoV-2 variants to the neutralizing antibodies, mAbs are facing tough challenges. Future strategies for developing mAbs with improved resistance to viral evasion will involve optimizing the targeting epitopes on SARS-CoV-2, enhancing the affinity and potency of mAbs, exploring the use of non-neutralizing antibodies that bind to conserved epitopes on the S protein, as well as optimizing immunization regimens. These approaches can improve the viability of mAb therapy in the fight against the evolving threat of the coronavirus.

Efficacy of a Dual-Epitope Dendritic Cell Vaccine as Part of Combined Immunotherapy for HER2-Expressing Breast Tumors.

Previous work from our group and others has shown that patients with breast cancer can generate a T cell response against specific human epidermal growth factor 2 (HER2) epitopes. In addition, preclinical work has shown that this T cell response can be augmented by Ag-directed mAb therapy. This study evaluated the activity and safety of a combination of dendritic cell (DC) vaccination given with mAb and cytotoxic therapy. We performed a phase I/II study using autologous DCs pulsed with two different HER2 peptides given with trastuzumab and vinorelbine to a study cohort of patients with HER2-overexpressing and a second with HER2 nonoverexpressing metastatic breast cancer. Seventeen patients with HER2-overexpressing and seven with nonoverexpressing disease were treated. Treatment was well tolerated, with one patient removed from therapy because of toxicity and no deaths. Forty-six percent of patients had stable disease after therapy, with 4% achieving a partial response and no complete responses. Immune responses were generated in the majority of patients but did not correlate with clinical response. However, in one patient, who has survived >14 y since treatment in the trial, a robust immune response was demonstrated, with 25% of her T cells specific to one of the peptides in the vaccine at the peak of her response. These data suggest that autologous DC vaccination when given with anti-HER2-directed mAb therapy and vinorelbine is safe and can induce immune responses, including significant T cell clonal expansion, in a subset of patients.

Improved control of SARS-CoV-2 infection with nucleocapsid-specific antibodies

Abstract The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is the main antigen in all approved COVID-19 vaccines and is also the only target for monoclonal antibody (mAb) therapies. Immune responses to other viral antigens are generated after SARS-CoV-2 infection, but their contribution to the antiviral response remains unclear. Here, we interrogated whether nucleocapsid-specific antibodies can improve protection against SARS-CoV-2. We first immunized mice with a nucleocapsid-based vaccine and then transferred sera from these mice into naive mice, followed by challenge with SARS-CoV-2. We show that mice that received nucleocapsid-specific sera or a nucleocapsid-specific mAb exhibited enhanced control of SARS-CoV-2. Nucleocapsid-specific antibodies elicited NK-mediated, antibody-dependent cellular cytotoxicity (ADCC) against infected cells. To our knowledge, these findings provide the first demonstration in the coronavirus literature that antibody responses specific to the nucleocapsid protein can improve viral clearance, providing a rationale for the clinical evaluation of nucleocapsid-based mAb therapies to treat COVID-19. NIH (DP2DA051912)

First dose infusion reaction during anti-CD20 monoclonal antibody therapy in chronic lymphocytic leukemia associates with high IP-10 levels amid cytokine release syndrome

Abstract Intravenous (IV) anti-CD20 monoclonal antibody (mAb) therapy for chronic lymphocytic leukemia (CLL) patients often produces a first dose infusion reaction (FDIR) within the first 2 h that requires careful monitoring to avoid serious complications and fatalities. To better understand FDIR, we studied blood samples collected from 37 treatment-naïve CLL patients in our clinical trial NCT03788291 undergoing IV treatment with 50 mg of anti-CD20 mAb (rituximab). We analyzed four time points: baseline (prior to infusion), 1 h later (during infusion), at the end of infusion (~2.5 h) and at 48 h. Infusion reactions (CTCAE (v5) grade ≥2 events) were managed by interrupting the infusion and with symptomatic treatment. 24 (65%) patients had a FDIR and all patients completed the infusion. Patient and CLL characteristics including measures of disease severity (Rai stage, IGHV mutation status, cytogenetic defects) did not correlate with FDIR. High levels of CLL cells and/or CD20 and their subsequent depletion resulting in decreased serum mAb and/or complement are thought to be risks for FDIR. However, measurements of these parameters did not correlate. Induction of cytokine release syndrome (CRS) may correlate with FDIR. However, CRS was observed in all samples after mAb infusion. The only significant associations with FDIR were higher levels of IP-10, IL-6, and IL-8, with IP-10 most significant. Anti-CD20 mAb activated cytotoxic effector cells, such as tissue-resident macrophages that ingest CLL cells via antibody-dependent cellular phagocytosis (ADCP), may be responsible for these events leading to FDIR. A mouse model of anti-CD20 mAb FDIR and in vitro ADCP cell systems will be useful to further understand the biology of FDIR. Supported by funding from Acerta/AstraZeneca, the Cadregari Foundation, a generous donation by Elizabeth Aaron, and the NIH NCI grant number R21CA267040.

Monoclonal anti-toxin therapy supports the protective innate immune response following Clostridioides difficileinfection

Abstract Clostridioides difficile causes over 200,000 hospitalizations and 13,000 deaths annually in the United States. C. difficile infects the large intestine following perturbation of the microbiome to cause pathology that ranges in severity from diarrhea to pseudomembranous colitis. Virulence factors Toxin A and Toxin B are the primarily drivers of disease. These toxins damage the epithelial barrier leading to pathologic inflammation and bacterial translocation. Monoclonal antibodies (mAbs) that neutralize Toxin A and Toxin B, actoxumab and bezlotoxumab, respectively, significantly reduce disease severity in a murine model of C. difficile infection, however the impact of toxin neutralization on the induction of the innate immune response following infection is unknown. The goal of this study was to define the quality of the host innate immune response in the context of anti-toxin mAb therapy. At day 2 post-infection, C. difficile infected, mAb-treated mice had significantly less disease despite no differences in C. difficile burden compared to isotype-treated mice. Further, no difference in neutrophil infiltration or production of IFNg or IL-17 from innate lymphoid cells (ILCs) was observed within the intestinal lamina propria following infection. However, C. difficile-infected, mAb-treated mice had increased IL-22-producing ILCs and increased eosinophil infiltration in the intestine compared to iso-treated mice. Both IL-22 +ILCs and eosinophils promote protective host response following C. difficile infection. These findings indicate that activation of natural host protective mechanisms remain intact in the context of treatment that neutralizes toxin but does not alter C. difficile burden in the intestine. Merck Sharp &amp; Dohme LLC, a subsidiary of Merck &amp; Co., Inc., Rahway, NJ, USA

Anti-HVEM mAb therapy improves antitumoral immunity both in vitro and in vivo, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors

BackgroundTumor necrosis factor superfamily member 14 (TNFRSF14)/herpes virus entry mediator (HVEM) is the ligand for B and T lymphocyte attenuator (BTLA) and CD160-negative immune co-signaling molecules as well as viral...