Immunoglobulin G1 Monoclonal Antibody Research Articles

P069 ONTAMALIMAB, A FULLY HUMAN MONOCLONAL ANTIBODY AGAINST MUCOSAL ADDRESSIN CELL ADHESION MOLECULE-1, PROVIDES SUSTAINED EXPOSURE FOLLOWING LONG-TERM TREATMENT IN PATIENTS WITH ULCERATIVE COLITIS

Abstract Introduction Ontamalimab is a fully human immunoglobulin G2 monoclonal antibody against mucosal addressin cell adhesion molecule-1 in development for the induction and maintenance of clinical remission in patients with ulcerative colitis (UC). This study aimed to assess the long-term pharmacokinetics (PK) of ontamalimab in patients with UC, and the effects of concomitant medications on PK parameters. Methods A 12-week induction study (TURANDOT; NCT01620255) was performed to assess the PK, efficacy and safety of ontamalimab (7.5, 22.5, 75 and 225 mg subcutaneous [s.c.] every four weeks [Q4W]) in patients with UC. Individuals who completed the induction study were eligible for enrollment in an open-label extension (OLE) study (TURANDOT II; NCT01771809) to assess the long-term PK, efficacy and safety of ontamalimab (75 or 225 mg s.c. Q4W up to week 72). Population PK analyses were performed using nonlinear mixed-effects modelling. Exposure-response analyses were performed to assess the relationships between minimum concentration (Cmin,ss) of ontamalimab and clinical response, clinical remission and mucosal healing. The effect of concomitant treatments (used for ≥20% of treatment duration) on PK parameters was also evaluated. Results The PK population included 130 (39.8%) women and 197 (60.2%) men, of median age of 40 years. A 1-compartment model with linear elimination adequately described the PK of ontamalimab. Population estimates of apparent clearance (CL/F) and volume of distribution (V/F) were 0.00917 L/h (0.22 L/day) and 7.44 L, respectively. Albumin had a significant effect on the variability of CL/F. Individuals with albumin levels of 30 g/L and 47 g/L are expected to have CL/F values 44% higher and 23% lower, respectively, than a typical patient with an albumin level of 39 g/L. Anti-inflammatory agents affected CL/F, such that CL/F is expected to be 14% higher in patients receiving than not receiving these agents. Other medications including immunosuppressants, steroids and treatments for peptic ulcers and gastroesophageal reflux disease had no effect on CL/F. Weight was the only covariate that significantly affected V/F. The half-life of ontamalimab was 23.4 days. Concentrations of ontamalimab over 72 weeks in the OLE study were consistent with those observed in the 12-week induction study. Ontamalimab Cmin,ss was related to efficacy, such that at week 16 (week 28 in total including induction), patients with higher Cmin,ss values were more likely to have clinical response, clinical remission and mucosal healing than those with lower Cmin,ss. Conclusion The exposure to ontamalimab was sustained following prolonged treatment in patients with UC for up to 72 weeks. Higher ontamalimab exposure was associated with a higher probability of clinical response.

Pharmacokinetics and pharmacodynamic effect of crenezumab on plasma and cerebrospinal fluid beta-amyloid in patients with mild-to-moderate Alzheimer\u2019s disease

BackgroundCrenezumab, a fully humanized anti-beta-amyloid (Aβ) immunoglobulin G4 (IgG4) monoclonal antibody, binds to both monomeric and aggregated forms of Aβ. We assessed the pharmacokinetics (PK)/pharmacodynamics (PD) of crenezumab and its interaction with monomeric Aβ(1–40) and Aβ(1–42) peptides in serum/plasma and cerebrospinal fluid (CSF) samples from the phase II ABBY and BLAZE studies and the phase Ib GN29632 study.MethodsIn ABBY, BLAZE, and GN29632 studies, patients with mild-to-moderate AD were treated with either placebo or crenezumab (300 mg subcutaneously every 2 weeks [q2w], or 15 mg/kg, 30 mg/kg, 45 mg/kg, 60 mg/kg, or 120 mg/kg intravenously q4w). Serum/plasma PK/PD analyses included samples from 131 patients who received crenezumab in all three studies. CSF PK/PD analyses included samples from 76 patients who received crenezumab in ABBY or BLAZE. The impact of baseline patient factors on Aβ profiles was also evaluated.ResultsThe serum concentration of crenezumab increased in a dose-proportional manner between 15 and 120 mg/kg q4w. Total monomeric plasma Aβ(1–40) and Aβ(1–42) levels significantly increased after crenezumab administration. The mean crenezumab CSF to serum ratio was ~ 0.3% and was similar across dosing cohorts/routes of administration. No clear correlation was observed between crenezumab concentration and Aβ(1–42) increase in CSF at week 69. The target-mediated drug disposition (TMDD) model described the observed plasma concentration–time profiles of crenezumab and Aβ well. Elimination clearance (CLel) and central volume of distribution (Vcent) of crenezumab were estimated at 0.159 L/day and 2.89 L, respectively, corresponding to a half-life of ~ 20 days. Subcutaneous bioavailability was estimated at 66.2%.ConclusionsCrenezumab PK was dose proportional up to 120 mg/kg, with a half-life consistent with IgG monoclonal antibodies. Our findings provide evidence for peripheral target engagement in patients with mild-to-moderate AD. The study also showed that a model-based approach is useful in making inference on PK/PD relationship with unmeasured species such as free plasma Aβ levels.Trial registrationsABBY: ClinicalTrials.gov, NCT01343966. Registered April 28, 2011. BLAZE: ClinicalTrials.gov, NCT01397578. Registered July 19, 2011. GN29632: ClinicalTrials.gov, NCT02353598. Registered February 3, 2015.

Characterization of IgG1 Fc Deamidation at Asparagine 325 and Its Impact on Antibody-dependent Cell-mediated Cytotoxicity and Fc\u03b3RIIIa Binding

Antibody-dependent cell-mediated cytotoxicity (ADCC) is an important mechanism of action for many therapeutic antibodies. A therapeutic immunoglobulin (Ig) G1 monoclonal antibody lost more than half of its ADCC activity after heat stress at 40 °C for 4 months. Size-exclusion and ion-exchange chromatography were used to fractionate various size and charge variants from the stressed IgG1. Physicochemical characterization of these fractions revealed that a rarely seen crystallizable fragment (Fc) modification, N325 deamidation, exhibited a positive correlation with the loss of ADCC activity. A further surface plasmon resonance study showed that this modification disrupted the binding between the IgG1 Fc and Fcγ receptor IIIa, resulting in decreased ADCC activity of the IgG1 antibody. Mutants of N325/D and N325/Q were made to confirm the effect of N325 deamidation on ADCC. We hypothesize that N325 deamidation altered the local three-dimensional structure, which might interfere with the binding and interaction with the effector cell. Because of its impact on biological activity, N325 deamidation is a critical quality attribute for products whose mechanism of action includes ADCC. A thorough understanding of the criticality of N325 deamidation and appropriate monitoring can help ensure the safety and efficacy of IgG1 or Fc-fusion products.

P446 Transcriptional and microbial biomarkers of response to anti-TL1A therapy in ulcerative colitis: the Phase 2a TUSCANY study

Abstract Background Tumour necrosis factor α-like ligand 1A (TL1A) acts as a synergistic cytokine that amplifies pro-inflammatory signals to increase T-cell, natural killer (NK) cell, and innate lymphoid cell production of cytokines, which are thought to be key drivers of inflammatory bowel disease (IBD) and intestinal fibrosis. The recent Phase 2a TUSCANY study demonstrated the efficacy of PF-06480605, a fully human immunoglobulin G1 monoclonal antibody targeting TL1A, in the treatment of participants with moderate to severe active Ulcerative Colitis (UC). Here, we present transcriptomic analysis of intestinal tissue biopsies and metagenomic analysis of the faecal microbiome to further evaluate the treatment effect of PF-06480605. Methods The Phase 2a, open-label, multicentre, single-arm TUSCANY study (NCT02840721) evaluated the safety, tolerability and efficacy of PF-06480605 in participants with moderate to severe UC. Participants received 500 mg intravenous (IV) PF-06480605 every 2 weeks (Q2W) for a total of 7 doses, with a 14-week follow-up period. We performed RNA sequencing of colonic biopsies and metagenomic sequencing (>40 million reads per sample) of faecal samples taken prior to and after 12 weeks of therapy. Differential expression and cell subset deconvolution by CytoReason were used to identify genes and immune cells involved in response to therapy. Differential abundance analyses based on taxonomic profiling was performed using the GOTTCHA metagenome mapping algorithm to discover whether microbial taxa changed in response to treatment. Results Tissue transcriptomic analysis identified a robust inhibition of adaptive (Th1, Th2 and Th17) and innate (macrophage) inflammatory pathways known to be associated with UC pathogenesis and a significant reduction in fibrosis-associated pathways (MMP3, MMP7 and MMP10). Transcriptomic responses were most pronounced in participants achieving endoscopic improvement (Mayo endoscopic subscore of ≤1). A candidate baseline gene signature was predictive of endoscopic improvement (area under the curve [AUC] 0.75; p-value = 0.03). Metagenomic analysis revealed a significant reduction in inflammatory pathobiont species (S. salivarius, S. parasanguinis, and H. parainfluenzae) following treatment. Conclusion These results provide insight into the molecular and microbial mechanisms underlying the efficacy of anti-TL1A therapy for UC. We defined a baseline transcriptomic signature to predict response and a pathobiont treatment signature. These findings may enable the development of precision medicine strategies for anti-TL1A therapy in the treatment of intestinal inflammation.

DOP72 Safety, tolerability and efficacy of anti-TL1A antibody PF-06480605 in treatment of ulcerative colitis: The open-label, multicentre, Phase 2a TUSCANY study

Abstract Background Widespread disruption of the mucosal immune system is central to the pathogenesis of ulcerative colitis (UC). One component, tumour necrosis factor (TNF) α-like ligand 1A (TL1A), is upregulated at the site of active disease in UC. Treatment of preclinical rodent models with anti-TL1A antibodies decreases disease activity, highlighting their therapeutic potential for UC. PF-06480605 is a first-in-class fully human immunoglobulin G1 monoclonal antibody targeting TL1A. Methods The Phase 2a, open-label, multicentre, single-arm TUSCANY study (NCT02840721) evaluated the safety, tolerability and efficacy of PF-06480605 in treatment of moderate to severe UC. Participants received 500 mg intravenous (IV) PF-06480605 every 2 weeks (Q2W) for a total of 7 doses, with a 14-week follow-up period. Primary safety and efficacy endpoints were incidence of treatment-emergent adverse events (TEAEs) and endoscopic improvement (EI) (Mayo endoscopic subscore [centrally read] of ≤1 without friability) at Week 14, respectively. Secondary efficacy endpoints included remission (total Mayo score ≤2, with no individual subscore >1) and endoscopic remission (Mayo endoscopic subscore = 0) at Week 14. Transcriptomic profiling on intestinal biopsies was performed. Results Of the 50 participants who received PF-06480605, 42 completed the study. The majority were male (56.0%) and white (96.0%), with a mean age of 40.0 years and prior experience of anti-TNF inhibitors (72.0%). Pancolitis (48.0%) and left-sided colitis (32.0%) were the most common forms of UC at baseline. There were 109 TEAEs, of which 18 were treatment-related. Aside from worsening UC, the most common TEAE by system organ class was arthralgia, which occurred in 6 participants, and 1 was treatment-related. Treatment-emergent serious adverse events were reported in 3 participants, and considered treatment-related in 1 participant (Table 1). No malignancies or deaths were reported. At Week 14, statistically significant EI was observed in 38.2% of participants (Table 2). The proportions of participants achieving remission and endoscopic remission at Week 14 were 24.0% and 10.0%, respectively. Transcriptomic analyses demonstrated normalisation towards a non-inflamed transcriptome in participants with EI. Conclusion PF-06480605 exhibited an acceptable safety and tolerability profile and statistically significant EI in participants with moderate to severe UC. These results warrant further evaluation in subsequent studies.

Reovirus Enhances Cytotoxicity of Natural Killer Cells Against Colorectal Cancer via TLR3 Pathway

Colorectal cancer (CRC) is currently the fourth most common cause of cancer-associated deaths. Treatment with cetuximab, a chimeric immunoglobulin G1 (IgG1) monoclonal antibody targeting epidermal growth factor receptor (EGFR), has shown limited efficacy as a CRC monotherapy. In addition, natural killer (NK) cell function is known to be severely attenuated in cancer patients. Here, w e describe a viable combination strategy to enhance NK cell cytotoxicity while also improving the effects of cetuxim ab -mediated antibody-dependent cell-mediated cytotoxicity (ADCC). Reovirus can directly activate NK cells in vitro, and NK cells can transport reovirus to tumors, where it preferentially replicates and lyses tumor cells. We first confirmed that exposure of NK cells to reovirus enhanced their cytotoxicity in a dose-dependent manner in vitro. We then investigated whether reovirus-activated NK cells exposed to cetuximab-bound CRC cells exhibited greater anti-tumor efficacy than either monotherapy. Co-culture of three separate CRC cell lines with reovirus-activated NK cells indicated that NK cytotoxicity was significantly higher in combination with cetuximab, regardless of KRAS mutation status or EGFR expression level. We also found that reovirus activation of NK cells, in conjunction with cetuximab, resulted in significantly stronger anti-tumor effects in colorectal tumor xenograft models.Finally, T oll-like receptor 3 ( TLR3) knockdown in NK cells, combined with chemical blockade of TLR3/dsRNA complex, and inhibition of the TLR3 downstream signaling pathway, demonstrated that activation of NK cells by reovirus is dependent on TLR3 and its downstream signaling pathway. This study demonstrates that combination treatment of reovirus-activated NK cells with cetuximab synergistically enhances their anti-tumor cytotoxicity, suggesting a strong candidate strategy for clinical treatment of CRC. Funding Statement: This work was supported by the National Natural Science Foundation of China (No.81860542), the Guizhou Provincial Natural Science Foundation [grant no. (2019)5663], the Program for Top Scientific and Technological Talents in Guizhou Province [grant no. KY (2018)049];Non-Profit Central Research Institute Fund of Chinese Academy of Medical Sciences(No. 2018PT31048、2019PT310013). Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. All procedures performed in studies involving animals were approved by the Ethics Committee of Guizhou Medical University (Ref: 2000803).

Grade 3 infusion-related reaction because of cetuximab administered with 5-fluorouracil and cisplatin chemotherapy for a recurrent and metastatic head and neck cancer patient who received chlorpheniramine 5 mg, dexamethasone 13.2 mg, and aprepitant 125 mg premedication

Abstract Cetuximab (Cmab), an Immunoglobulin G1 monoclonal antibody targeting the epidermal growth factor receptor, is associated with Epidermal Growth Factor Receptor inhibitor-specific adverse drug reactions, such as skin toxicities and infusion-related reactions (IRRs). IRRs have been reported in 6–18% of patients receiving Cmab, with grade 3 and 4 reactions in 1–5% in head and neck cancer patients. Premedication with corticosteroids may prevent or dampen non-Immunoglobulin E (IgE) mediated infusion reactions. We encountered a case in which a grade 3 IRR occurred secondary to Cmab that was combined with 5-fluorouracil and cisplatin (5-fluorouracil and Cisplatin + Cmab) chemotherapy for a recurrent and metastatic head and neck cancer patient who had received premedication consisting of chlorpheniramine 5 mg, dexamethasone 13.2 mg, and aprepitant 125 mg. Non-IgE-mediated reaction and cytokine release syndrome can be prevented by premedication. The patient had grade 3 IRRs because of Cmab, even though we used a higher dose of corticosteroid, dexamethasone 13.2 mg, and aprepitant. Severe IRRs because of Cmab occurred despite administration of a higher dose of dexamethasone, compared with the ordinary dose that ranges from 3.3 to 6.6 mg. Furthermore, his rapid symptom after Cmab intravenous administration confirmed to typical IgE-mediated reaction even though he received high dose of dexamethasone and chlorpheniramine. To prevent a critical situation due to severe Cmab IRRs is early first aid treatment when a patient has hypertensive reactions. Monitoring for symptoms of Cmab-induced IRRs requires not only the supervision of oncologists, nurses, and pharmacists but also patient awareness of the condition.

Fulminant Fournier’s gangrene in a patient with gastric cancer treated with ramucirumab and paclitaxel

Fournier’s gangrene (FG) is an uncommon form of necrotizing fasciitis, localized on the external genital organs, perianal region, and abdominal wall, accompanied by thrombosis of the feeding arteries, leading to gangrene of the skin and subcutaneous tissue, with manifestations of rapid clinical progression and multiple organ failure. Ramucirumab is a recombinant human immunoglobulin G1 monoclonal antibody that binds to the extracellular binding domain of vascular endothelial growth factor receptor-2 (VEGFR-2) and prevents the binding of all VEGFR ligands. The literature describes bevacizumab, aflibercept, and regorafenib associated with FG in patients with colorectal cancer. According to our knowledge this is the first report of FG possibly related to ramucirumab in a patient with gastric cancer. If not recognized in time, it can lead to fatal complications.

Immune Checkpoint Inhibitors for the Treatment of Unresectable Stage III Non-Small Cell Lung Cancer: Emerging Mechanisms and Perspectives.

There has been no improvement in outcome for patients with unresectable locally advanced (stage III) non–small cell lung cancer (NSCLC) for more than 10 years. The standard treatment for these patients is definitive concurrent chemotherapy and radiation (CCRT). Although the goal of treatment in this setting is to achieve a cure, most patients progress and their prognosis is poor, with a 5-year survival rate of 15–30%. There is thus an urgent need for the development of novel anticancer treatments in this patient population. Recent advances in cancer immunotherapy have led to a marked improvement in clinical outcome for advanced NSCLC. Such immunotherapy mainly consists of the administration of immune checkpoint inhibitors (ICIs) such as antibodies to cytotoxic T lymphocyte–associated protein–4 (CTLA-4) or to either programmed cell death–1 (PD-1) or its ligand PD-L1. Durvalumab (MEDI4736) is a high-affinity human immunoglobulin G1 monoclonal antibody that blocks the binding of PD-L1 on tumor cells or antigen-presenting cells to PD-1 on T cells. The PACIFIC study recently evaluated consolidation immunotherapy with durvalumab versus placebo administered after concurrent chemoradiotherapy (CCRT) in patients with unresectable stage III NSCLC. It revealed a significant improvement in both progression-free and overall survival with durvalumab, and this improvement was associated with a favorable safety profile. This achievement has made durvalumab a standard of care for consolidation after CCRT in patients with unresectable stage III NSCLC, and it has now been approved in this setting by regulatory agencies in the United States, Canada, Japan, Australia, Switzerland, Malaysia, Singapore, India, and the United Arab Emirates. In this review, we briefly summarize the results of the PACIFIC trial, including those of post hoc analysis, and we address possible molecular mechanisms, perspectives, and remaining questions related to combined treatment with CCRT and ICIs in this patient population.

Evaluation of Iminodiacetic Acid (IDA) as an Ionogenic Group for Adsorption of IgG1 Monoclonal Antibodies by Membrane Chromatography.

Iminodiacetic acid (IDA) is one of the chelating ligands most frequently employed in immobilized metal-ion affinity chromatography (IMAC) due to its ability to act as electron-pair donor, forming stable complexes with intermediate and borderline Lewis metal ions (electron acceptor). Thus, IDA can also be employed in ion exchange chromatography to purify positively charged proteins at neutral pH values. This study aimed to evaluate IDA as an ionogenic group (ion exchanger) immobilized on poly (ethylene vinyl alcohol) (PEVA) hollow fiber membranes for immunoglobulin G1 (IgG1) monoclonal antibody (MAb) purification. IDA-PEVA membranes showed considerable promise for MAb purification, since IgG1 was recovered in eluted fractions with traces of contaminants as confirmed by Western blotting and ELISA analysis. Quantification of IgG1 showed that a purity of 94.2% was reached in the elution step. Breakthrough curve and batch adsorption experiments showed that the MAb dynamic binding capacity (DBC) of 3.10mgg-1 and the maximum adsorption capacity of 70mgg-1 were of the same order of magnitude as those found in the literature. The results obtained showed that the IDA-PEVA hollow fiber membrane could be a powerful adsorbent for integrating large-scale processes for purification of MAb from cell culture supernatant.

Characterization of the selective in vitro and in vivo binding properties of crenezumab to oligomeric A\u03b2

BackgroundAccumulation of amyloid β (Aβ) in the brain is proposed as a cause of Alzheimer’s disease (AD), with Aβ oligomers hypothesized to be the primary mediators of neurotoxicity. Crenezumab is a humanized immunoglobulin G4 monoclonal antibody that has been shown to bind to synthetic monomeric and aggregated Aβ in vitro; however, less is known about the binding characteristic in vivo. In this study, we evaluated the binding patterns of crenezumab to synthetic and native forms of Aβ both in vitro and in vivo.MethodsCrenezumab was used to immunoprecipitate Aβ from synthetic Aβ preparations or brain homogenates from a PS2APP mouse model of AD to determine the forms of Aβ that crenezumab interacts with. Following systemic dosing in PS2APP or nontransgenic control mice, immunohistochemistry was used to localize crenezumab and assess its relative distribution in the brain, compared with amyloid plaques and markers of neuritic dystrophies (BACE1; LAMP1). Pharmacodynamic correlations were performed to investigate the relationship between peripheral and central target engagement.ResultsIn vitro, crenezumab immunoprecipitated Aβ oligomers from both synthetic Aβ preparations and endogenous brain homogenates from PS2APP mice. In vivo studies in the PS2APP mouse showed that crenezumab localizes to regions surrounding the periphery of amyloid plaques in addition to the hippocampal mossy fibers. These regions around the plaques are reported to be enriched in oligomeric Aβ, actively incorporate soluble Aβ, and contribute to Aβ-induced neurotoxicity and axonal dystrophy. In addition, crenezumab did not appear to bind to the dense core region of plaques or vascular amyloid.ConclusionsCrenezumab binds to multiple forms of amyloid β (Aβ), particularly oligomeric forms, and localizes to brain areas rich in Aβ oligomers, including the halo around plaques and hippocampal mossy fibers, but not to vascular Aβ. These insights highlight a unique mechanism of action for crenezumab of engaging Aβ oligomers.

Clinical Pharmacokinetics and Pharmacodynamics of Risankizumab in Psoriasis Patients.

Risankizumab is a humanized immunoglobulin (Ig) G1 monoclonal antibody developed and approved for the treatment of moderate-to-severe plaque psoriasis at a dose of 150 mg administered subcutaneously at weeks 0 and 4, and every 12 weeks thereafter. Ongoing trials are investigating the use of risankizumab in other inflammatory autoimmune diseases. Risankizumab exhibits linear pharmacokinetics when administered intravenously (0.01 mg/kg–1200 mg) or subcutaneously (0.25 mg/kg–300 mg), with a long terminal half-life of approximately 28 days. Following subcutaneous administration, peak plasma concentration was reached approximately 3–14 days after dosing, with an estimated bioavailability of 89%. Population pharmacokinetic analyses identified bodyweight, high titers of antidrug antibodies occurring in < 2% of evaluated subjects, baseline serum albumin, baseline high-sensitivity C-reactive protein, and baseline serum creatinine to be statistically correlated with risankizumab clearance, but none of them had a clinically meaningful impact on risankizumab efficacy in psoriasis patients following the clinical dosing regimen. Exposure–response analyses in psoriasis patients demonstrated that the maximum efficacy was achieved with the clinically approved regimen and there was no apparent correlation between risankizumab exposure and safety. A dedicated drug interaction cocktail study in patients with psoriasis demonstrated a lack of therapeutic protein–drug interaction potentials for risankizumab and various cytochrome P450 substrates. In this article, we review the clinical pharmacology data available to date for risankizumab, which supported the clinical development program and ultimately regulatory approvals for risankizumab in the treatment of patients with moderate-to-severe plaque psoriasis.

Lanadelumab for the treatment of hereditary angioedema

ABSTRACTIntroduction: Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare yet still probably underdiagnosed clinical condition. Recurrent episodes of subcutaneous and sub-mucosal swelling may involve the skin, the gastrointestinal tract or even the upper airways, exposing the patients to the risk of death. With the aim of improving patients’ quality of life, the therapeutic scenario has expanded over the years.Areas covered: The focus of the present review is lanadelumab, a fully human, κ-light-chain, monoclonal immunoglobulin G1 against plasma kallikrein, currently approved for long-term prophylaxis of C1-INH-HAE attacks in the USA and Canada and designated as an orphan drug by the European Medicines Agency.Expert opinion: Lanadelumab is able to inhibit plasma kallikrein with high selectivity and affinity. The subsequent phases of drug development and the ongoing open-label trial have proven its safety and efficacy. It overcomes some of the limitations of other drugs available for long-term prophylaxis, given the easy route of administration, the simple administration schedule and the possibility to tailor the treatment to each patient. Further studies are needed to test its efficacy also in other types of angioedema for which a central role of plasma kallikrein is envisaged.

717 The Vedolizumab Pregnancy Exposure Registry: An OTIS Pregnancy Study Update

INTRODUCTION: Vedolizumab is a gut-selective immunoglobulin (Ig) G1 monoclonal antibody that binds to α4β7 integrin; it is approved for the treatment of moderately to severely active Crohn's disease (CD) and ulcerative colitis (UC) in the U.S. and elsewhere. Published studies on the effect of vedolizumab during human pregnancy are limited. Data from the ongoing Vedolizumab Pregnancy Exposure Registry (NCT02678052) in the U.S. and Canada have been collected by the MotherToBaby Pregnancy Studies conducted by the Organization of Teratology Information Specialists (OTIS). This prospective observational cohort study intends to enroll and analyze the outcomes of 100 vedolizumab-exposed participants compared to 100 disease-matched (DM) comparison and 100 healthy comparison (HC) participants. This abstract describes progress of the study through March 1, 2019. METHODS: Pregnant women treated with vedolizumab for UC or CD for at least some part of the first trimester were enrolled in the vedolizumab-exposed group. Pregnant women with no exposure to vedolizumab were enrolled in a DM comparison group. Pregnant women with no exposure to any biologic during pregnancy and not diagnosed with an autoimmune disease or any other disease as defined by the OTIS Research Center were enrolled in a HC group. Pregnancy exposure and outcome data were collected from telephone interviews and medical records. The Short Quality of Life in Inflammatory Bowel Disease Questionnaire (SIBDQ) was administered to women with CD or UC at enrollment and 32 weeks' gestation. Follow-up of live born children included a dysmorphological exam, pediatric records review and developmental screening at one year of age. RESULTS: Between December 2015 and March 2019, outcomes were collected for 223 women, 53 in the vedolizumab group, 88 in the DM group, and 82 in the HC group. Preliminary descriptive data are shown in Table 1. No major structural birth defects were reported in the vedolizumab group, compared to 5 (5.7%) in the DM group, and 4 (5.3%) in the HC group. There was no evidence of a pattern of minor structural defects in the vedolizumab group. CONCLUSION: Updated data indicate pregnant women treated with vedolizumab in at least the 1st trimester have similar birth outcomes to disease-matched and healthy comparison women. The Vedolizumab Pregnancy Exposure Registry is ongoing with formal statistical analysis to be performed when the study is completed.

2389 Nivolumab-Induced Hepatitis: A Rare Side Effect of Programmed Cell Death-1 (PD-1) Inhibitor

INTRODUCTION: Nivolumab is a human immunoglobulin G4 (IgG4) monoclonal antibody that blocks the function of programmed cell death (PD-1) activity by binding to the PD-1 receptor. This prevents suppression of T-cell activity, which can lead to T-cells targeting cancer cells. Unfortunately, these medications induce various types of immune related adverse events including colitis, pneumonitis, endocrinopathies and hepatitis. We report rare case of of nivolumab-induced hepatitis. CASE DESCRIPTION/METHODS: An 86-year-old female with history of metastatic melanoma and was started on nivolumab 3 mg/kg every 3 weeks. Patient noted to have abnormal liver chemistries, nausea and yellowing of skin after 6 months of nivolumab. On presentation she was found to have a total bilirubin of 7.79 mg/dL, INR 1.3, AST 885 IU/L and ALT 999 IU/L. Physical examination was significant for mild scleral icterus only. An ultrasound of liver was notable prominent left lobe of liver but no focal hepatic masses and s/p cholecystectomy with no bile duct dilation. Infectious etiologies were unrevealing for viral hepatitis and acute EBV. Her autoimmune serologies were negative for anti-smooth muscle antibody and anti-mitochondrial antibody. Work up was negative for herbal supplements, illicit substance or other medications. The most likely culprit for her hepatitis was due to nivolumab. Patient was started on prednisone at 1 mg/kg daily for a total of 100 mg prednisone daily and her nivolumab dose was held. On discharge her total bilirubin was 2.45, INR 1.2, AST 62, ALT 249 and Alk Phos 252. Patient continued prednisone taper over 30-day period and by end of the month her liver chemistries had normalized and patient was asymptomatic. DISCUSSION: Nivolumab-induced hepatoxicity is rare and accounts for 3-6% of all immune-related adverse effects. The median time of onset was 3.3 months (range: 6 days to 9 months). In addition to systemic corticosteroid, alternative immunosuppressive therapies may be employed if symptoms continue after 3-5 days. Etiologies of liver dysfunction such as viral infection, obstruction and other forms of autoimmune hepatitis must be excluded. In such an event, oral mycophenolate mofetil 500 mg every 12 hours can be used for treatment. Our patient showed rapid improvement in liver chemistries and had minimal physical side effects. Healthcare provides managing patients with liver injury should be able to recognize and treat prior to development of fulminant hepatitis.

Impacts of intentional mycoplasma contamination on CHO cell bioreactor cultures.

Mycoplasma contamination events in biomanufacturing facilities can result in loss of production and costly cleanups. Mycoplasma may survive in mammalian cell cultures with only subtle changes to the culture and may penetrate the 0.2 µm filters often used in the primary clarification of harvested cell culture fluid. Culture cell‐based and indicator cell‐based assays that are used to detect mycoplasma are highly sensitive but can take up to 28 days to complete and cannot be used for real‐time decision making during the biomanufacturing process. To support real‐time measurements of mycoplasma contamination, there is a push to explore nucleic acid testing. However, cell‐based methods measure growth or colony forming units and nucleic acid testing measures genome copy number; this has led to ambiguity regarding how to compare the sensitivity of the methods. In addition, the high risk of conducting experiments wherein one deliberately spikes mycoplasma into bioreactors has dissuaded commercial groups from performing studies to explore the multiple variables associated with the upstream effects of a mycoplasma contamination in a manufacturing setting. Here we studied the ability of Mycoplasma arginini to persist in a single‐use, perfusion rocking bioreactor system containing a Chinese hamster ovary (CHO) DG44 cell line expressing a model monoclonal immunoglobulin G1 (IgG1) antibody. We examined M. arginini growth and detection by culture methods, as well as the effects of M. arginini on mammalian cell health, metabolism, and productivity. We compared process parameters and controls normally measured in bioreactors including dissolved oxygen, gas mix, and base addition to maintain pH, to examine parameter changes as potential indicators of contamination. Our work showed that M. arginini affects CHO cell growth profile, viability, nutrient consumption, oxygen use, and waste production at varying timepoints after M. arginini introduction to the culture. Importantly, how the M. arginini contamination impacts the CHO cells is influenced by the concentration of CHO cells and rate of perfusion at the time of M. arginini spike. Careful evaluation of dissolved oxygen, pH control parameters, ammonia, and arginine over time may be used to indicate mycoplasma contamination in CHO cell cultures in a bioreactor before a read‐out from a traditional method.

Use of the PCSK9 inhibitor, evolocumab, in patients with heterozygous familial hypercholesterolemia

Evolocumab is a monoclonal immunoglobulin G2 that acts against human proprotein convertase subtilisin/kexin type 9 (PCK9) used against Homozygous familial hypercholesterolemia and Heterozygous familial hypercholesterolemia in high cardiovascular disease risk patients with increased level of triglycerides. Evolocumab is administered subcutaneously 420mg every month and 140 mg twice a week in patients with HeFH as evaluated by RUTHERFORD and RUTHERFORD 2 trials. This paper reviews the six clinical trials of evolocumab that evaluated the efficacy of the drug for heterogenous familial hypercholesterolemia.

Evaluation of the potential for QTc prolongation with avelumab

PurposeTo report integrated electrocardiogram (ECG) summary and exposure–QTc analyses for avelumab, a human immunoglobulin G1 monoclonal antibody that binds programmed cell death 1 ligand 1, to assess potential effects on cardiac repolarization.MethodsData were pooled from three-phase 1/2 studies of patients with advanced solid tumors who received avelumab monotherapy (22,000 ECGs from 1818 patients). All analyses used 12-lead singlet ECGs taken using local ECG machines before and approximately 2 h after avelumab infusion on prespecified days. The exposure–QTc and outlier analyses used locally read ECGs; since larger variability is known to be associated with local reading, outlier ECGs were subsequently reevaluated by central read. QTc derived from Fridericia’s formula (QTcF) and a project-specific formula (QTcP) were analyzed. Multivariable linear mixed-effects models were used to describe the relationship between serum concentration of avelumab and QTc absolute value or change from baseline (ΔQTc).ResultsExposure–QTc models showed that the effect of avelumab on QTc or ΔQTc was minimal and not statistically significant for both QTcP and QTcF. In addition, models including avelumab concentration and diphenhydramine premedication use did not show a clinically meaningful effect on the QT interval. The frequency of QTc outliers in both short and long ranges was overestimated by local reads. Six patients (0.3%) were QTc outliers; all had either received concomitant medication known to cause QT prolongation or had a preexisting cardiac condition.ConclusionAvelumab does not have any clinically relevant effect on cardiac repolarization.

Pseudomyogenic hemangioendothelioma of bone treated with denosumab: a case report

BackgroundPseudomyogenic hemangioendothelioma (PMHE) is a rare endothelial neoplasm that involves the bones in only 14% of all cases. The optimal treatment strategy has not been established. We herein report a case of primary PMHE in which denosumab treatment showed activity in both imaging studies and the clinical outcome.Case presentationA 20-year-old woman presented with worsening pain in her left ankle. Imaging studies showed multifocal fluorodeoxyglucose (FDG)-avid [maximum standardized uptake value (SUVmax), 15.95] osteolytic lesions in the bones of her left lower extremity. While waiting for the definitive pathologic diagnosis of PMHE, denosumab, a human immunoglobulin G2 monoclonal antibody against RANKL, was initiated to treat progressive bone absorption after curettage of one of the lesions. Denosumab induced osteosclerosis around the lesions and pain relief and was discontinued 4 years after its initiation. Although all of the multifocal lesions remained, they all became less FDG-avid (SUVmax, 2.6), and the patient developed no signs of new lesions or distant metastasis.ConclusionDenosumab plays a certain role in prevention of bone destruction by PMHE through suppression of osteoclast-like giant cells and would be an excellent treatment for bone absorption by PMHE of bone.

Therapeutic drug monitoring of infliximab in spondyloarthritis. A review of the literature

Available evidence indicates that a therapeutic drug monitoring strategy leads to major cost savings related to the anti-tumour necrosis factor-α therapy in both inflammatory bowel disease and rheumatoid arthritis (RA) patients, with no negative impact on efficacy. However, although the systematic use of therapeutic drug monitoring could potentially be beneficial and economically acceptable to drug dose optimization, it is not justifiable for all drugs. Infliximab (IFX) is a chimeric monoclonal immunoglobulin G1 targeting tumour necrosis factor. It has been approved for the treatment of immuno-inflammatory diseases, including RA, ankylosing spondylitis, psoriatic arthritis, Crohn's disease and ulcerative colitis. IFX's pharmacokinetics is highly variable and influences clinical response in chronic inflammatory diseases. Clinical response increases with IFX trough concentrations in RA, ankylosing spondylitis, inflammatory bowel disease and psoriatic patients. Target concentrations predictive of good clinical response were proposed in RA, Crohn's disease and ulcerative colitis. The purpose of this article is to review the current literature surrounding IFX serum concentrations and their related parameters with disease activity in patients with spondyloarthritis. Gathering information about the efficacy of IFX in patients with spondyloarthritis and relating IFX serum concentrations to disease activity were the main goals of this study.