Phase 1 safety and pharmacokinetics studies of BRII-196 and BRII-198, SARS-CoV-2 spike-targeting monoclonal antibodies

Background. BRII-196 and BRII-198 are two anti-SARS-CoV-2 monoclonal neutralizing antibodies with modified Fc region that extends half-life and are being developed as cocktail therapy for the treatment of COVID-19. Safety, tolerability, pharmacokinetics, and immunogenicity of BRII-196 and BRII-198 were investigated in healthy adults. Methods. Single ascending doses of BRII-196 and BRII-198 were evaluated in parallel in the first-in-human, placebo-controlled phase 1 studies. A total of 32 healthy adults were randomized and received a single intravenous infusion of 750, 1500, and 3000 mg of BRII-196 (n=12), BRII-198 (n=12), or placebo (n=8) and were followed for 180 days. Results. All infusions were well tolerated at infusion rates between 0.5 mL/min to 4 mL/min with no dose-limiting adverse events, deaths, serious adverse events, or any systemic or local infusion reactions. Most treatment-emergent adverse events were isolated asymptomatic laboratory abnormalities of Grade 1-2 in severity. Each mAb displayed pharmacokinetics expected of Fc-engineered human IgG1 with mean terminal half-lives of approximately 46 days and 76 days, respectively, with no evidence of significant anti-drug antibody development. Conclusions. BRII-196 and BRII-198 were well-tolerated. Clinical results support further development as therapeutic or prophylactic options for SARS-CoV-2 infection.

A Single Intravenous Infusion of Human Choriodecidual Mesenchymal Stem Cell Decreases Early Burn Mortality in a Rodent Model

Background:Systemic inflammatory responses (SIR) are the main cause of pulmonary dysfunction leading to mortality within hours of extensive burns. Based on previous studies showing that cell entrapment occurs in the lungs following the infusion of human choriodecidual mesenchymal stem cells (hcMSCs), we hypothesize that the intravenous infusion of hcMSCs, with an immunomodulatory potential, will decrease the risk of SIR induced pulmonary failure leading to mortality in burn patients. Methods:Forty adult male Sprague-Dawley rats were randomized into two groups. Group A (sham control, n = 10) received no injury or intervention; the remaining rats (n = 30) were subjected to burns covering 40 % of the total body surface area by immersion of the dorsum in 100 °C water for 15 s under general anesthesia. Injured rats were further randomized into different treatment groups: Group B (saline only control, n = 10), Group C (saline plus culture medium control, n = 10), and Group D (saline plus 2 × 106 hcMSCs, n = 10). Culture medium or hcMSCs were given in a single infusion via the tail vein immediately after burns. Mortality was evaluated on post-burn days 7 and 14. Results:The overall mortality among injured rats was 30 % (9/30). In the first week post-injury, four rats in Group C and three in Group B versus none in Group D died. In the second week, one rat in both Groups C and D died. Altogether, mortality among Group D rats was 10 %, significantly lower than that in groups B and C combined (40 %; p<0.001).Conclusions:We show that a single intravenous infusion of 2 × 106 hcMSCs decreased burn mortality in a severely burned animal model. However, clinical translation requires additional studies to exclude potential adverse effects and to determine the optimal dosage and timing of administration.

First-in-Human Gene Therapy Study of AAVhu37 Capsid Vector Technology in Severe Hemophilia A - BAY 2599023 has Broad Patient Eligibility and Stable and Sustained Long-Term Expression of FVIII

Background Gene therapy for hemophilia A has the potential to reduce the treatment burden for patients and their care providers by eliminating the need for regular factor VIII (FVIII) prophylaxis through long-term expression of endogenous FVIII at levels sufficient to provide bleed protection. Host immunity to the capsid serotype limits patients' eligibility and may impact the balance between vector dose and clinical outcome. BAY 2599023 (AAVhu37FVIII) is the first clinical-stage adeno-associated virus (AAV) gene therapy vector based on the AAVhu37 serotype. BAY 2599023 is a non-replicating AAV vector and contains a single-stranded DNA genome encoding a B-domain-deleted FVIII, under the control of a liver-specific promoter/enhancer combination optimized for transgenic expression. The AAVhu37 capsid is a member of the hepatotropic clade E family, and was selected based on preclinical studies demonstrating efficient liver-directed FVIII gene transfer, favorable biodistribution and durable FVIII expression. However, pre-existing humoral immunity against AAV capsids may limit patient eligibility. Here, we evaluate the seroprevalence and titer levels of pre-existing neutralizing antibodies (Nabs) against AAVhu37, and additional AAV capsids, using cell-based transduction inhibition assays. We also report current, preliminary, long-term safety and FVIII activity following a single intravenous infusion of BAY 2599023, in a phase 1/2 open-label, first-in-human, dose-finding study (NCT03588299). Methods Seroprevalence and titer distribution of Nabs against AAVhu37, AAV5 and AAV8 have been assessed in serum samples derived from 100 US patients with hemophilia A (African American and Caucasian male donors, 19-61 years). For AAVhu37, the clinical trial Nab assay was utilized to determine Nab titer levels according to cellular transduction inhibition. Additionally, we developed and fully validated Nab assays for AAV5 and AAV8. The ongoing BAY 2599023 phase 1/2 dose-finding study included male patients aged ≥18 years with severe hemophilia A, each receiving a single intravenous infusion of BAY 2599023. Patients were enrolled sequentially into three dose cohorts (0.5 × 1013 GC/kg, 1.0 × 1013 GC/kg and 2.0 × 1013 GC/kg), each comprising two patients. Patients had no history of FVIII inhibitors, no detectable neutralizing immunity against the AAVhu37 capsid above a Nab titer of 1:5, and ≥150 exposure days to FVIII products. Primary endpoints were adverse events (AEs), serious AEs (SAEs) and AEs/SAEs of special interest (S/AESIs). The secondary endpoint was change in FVIII activity from baseline. Informed patient consent and ethics committee approval were obtained. Results In the seroprevalence study, the lowest pre-existing Nab prevalence was found for AAVhu37, with a low maximum observed titer of 1:26. Based on our results, 86% of patients would be eligible for AAVhu37-based treatment (Table 1). To date, patients in the first (0.5 × 1013 GC/kg) and second cohort (1.0 × 1013 GC/kg) have completed ≥52 weeks of observation; patients in cohort 3 (2.0 × 1013 GC/kg) have at least 33 weeks of observation. Regardless of the level achieved and the assay used, 5 out of 6 of patients show sustained FVIII levels (all ≥5%) over time and up to 16 months. Patients in cohorts 2 and 3 have all been off prophylaxis since ~6 weeks after gene transfer. No spontaneous bleeds were reported after achieving protective FVIII levels (&gt;15 IU/dL) and discontinuation of prophylaxis in the third cohort. No SAEs have been reported to date. Mild-to-moderate elevation in alanine aminotransferase/aspartate aminotransferase were recorded for one patient in the second cohort and both patients in the third cohort. All were treated with corticosteroids (one resolved, two in resolution). The latest follow-up data for up to 22 months will be presented. Conclusions BAY 2599023 has a broad patient eligibility due to low seroprevalence and low titers of pre-existing Nabs against AAVhu37 compared with other AAVs. BAY 2599023 has a good safety profile, with the potential to achieve endogenous expression of FVIII at therapeutic levels over an extended period. Successful proof-of-concept has been achieved, with measurable and sustained expression of endogenous FVIII. Disclosures Pipe: Apcintex, Bayer, BioMarin, Catalyst Biosciences, CSL Behring, HEMA Biologics, Freeline, Novo Nordisk, Pfizer, F. Hoffmann-La Roche Ltd/Genentech, Inc., Sangamo Therapeutics, Sanofi, Takeda, Spark Therapeutics, uniQure: Consultancy; Siemens: Research Funding; Medical and Scientific Advisory Council to the National Hemophilia Foundation; Medical Advisory Board to World Federation of Hemophilia: Membership on an entity's Board of Directors or advisory committees. Ferrante:Bayer: Current Employment. Reis:Bayer: Current Employment. Wiegmann:Bayer: Current Employment. Lange:Bayer: Current Employment, Current equity holder in private company. Braun:Bayer: Current Employment, Current equity holder in private company. Michaels:Bayer: Current Employment.

Analysis of C. difficile infection–related outcomes in European participants in the bezlotoxumab MODIFY I and II trials

The MODIFY I/II trials demonstrated that bezlotoxumab, a human monoclonal antibody against Clostridioides difficile toxin B, given during antibiotic treatment for Clostridioides difficile infection (CDI) significantly reduced C. difficile recurrence (rCDI) in adults at high risk for rCDI. Efficacy of CDI-directed intervention may depend on ribotype regional epidemiology, and patient characteristics. This post hoc analysis assessed the efficacy of bezlotoxumab in the subgroup of MODIFY I/II trial participants enrolled in Europe. Data from the bezlotoxumab (10 mg/kg single intravenous infusion) and placebo (0.9% saline) groups from MODIFY I/II were compared to assess initial clinical cure (ICC), rCDI, all-cause, and CDI-associated rehospitalizations within 30 days of discharge, and mortality through 12 weeks post-infusion. Of 1554 worldwide participants, 606 were from Europe (bezlotoxumab n = 313, 51%; placebo n = 292; 48%). Baseline characteristics were generally similar across groups, although there were more immunocompromised participants in the bezlotoxumab group (27.2%) compared with placebo (20.1%). Fifty-five percent of participants were female, and 86% were hospitalized at randomization. The rate of ICC was similar between treatment groups. The rate of rCDI in the bezlotoxumab group was lower compared with placebo among European participants overall, and among those with ≥ 1 risk factor for rCDI. Bezlotoxumab reduced 30-day CDI-associated rehospitalizations compared with placebo. These results are consistent with overall results from the MODIFY trials and demonstrate that bezlotoxumab reduces rCDI and CDI-associated rehospitalizations in European patients with CDI. MODIFY I/II (NCT01241552 and NCT01513239)

Preclinical Evaluation of a Single Intravenous Infusion of hUC-MSC (BX-U001) in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory disease of the joints, which causes severe pain and excessive systemic circulation of harmful inflammatory cytokines. Current treatments are limited, with some patients not responding well, and some experiencing severe and detrimental side effects. Mesenchymal stem cells (MSC) are cell-based therapeutics being evaluated as potent immunomodulators in RA and may provide relief to patients not responding well to drug-based treatments. We evaluated the safety and efficacy of BX-U001 human umbilical cord tissue–derived mesenchymal stem cells (hUC-MSC) to treat RA, in support of a successful investigational new drug application. A collagen-induced arthritis (CIA) mouse model of RA was established in DBA/1 J mice. Mice from the treatment assessment group were given a tail vein infusion of hUC-MSC 24 days after primary RA induction, while control assessment (CA) group mice were given cell-free carrier solution. All animals were evaluated daily for RA symptoms via clinical scoring, blood was taken periodically for cytokine analysis, and mice were dissected at end point for histological analysis. A linear mixed model was used to compare the rate of change among groups. The clinical scores of TA group were significantly reduced compared with CA group ( P < 0.01), indicating therapeutic effects. The histological scores of the joints in TA group were significantly lower than those in the CA group ( P < 0.05), but had no significant difference compared with Healthy groups ( P > 0.05). The concentration of (interleukin) IL-6 in TA group was significantly reduced by 80.0% ( P < 0.0001) 2 days after treatment and by 93.4% at the experimental endpoint compared with levels prior to hUC-MSC injection. A single intravenous infusion of hUC-MSC (2 × 106 cells/mouse), to CIA-induced DBA/1 J mice, resulted in significant alleviation of RA symptoms and may provide significant therapeutic benefits in humans.

Evaluation of MEDI8852, an Anti-Influenza A Monoclonal Antibody, in Treating Acute Uncomplicated Influenza

ABSTRACT We evaluated MEDI8852, a human IgG1 monoclonal antibody that binds a highly conserved influenza A hemagglutinin stalk epitope, in outpatients with uncomplicated influenza A infection. A total of 126 subjects aged 18 to 65 years were enrolled during the 2015 to 2016 Northern and 2016 Southern Hemisphere seasons. Subjects with symptom onset ≤5 days before dosing were randomized to four cohorts: 750 mg (cohort 1) or 3,000 mg (cohort 2) MEDI8852 (single intravenous infusion) plus 75 mg oseltamivir, placebo plus 75 mg oseltamivir (cohort 3), and 3,000 mg MEDI8852 alone (cohort 4). Subjects were monitored through day 10 for solicited influenza symptoms, day 28 for adverse events (AEs), and day 101 for serious AEs and AEs of special interest. Nasopharyngeal samples were collected through day 7 for confirmation of influenza A infection, viral shedding, and oseltamivir and MEDI8852 susceptibility. Slightly more AEs were reported in subjects receiving MEDI8852 (cohorts 1, 2, and 4 combined: 39/93, 41.9%) than oseltamivir only (cohort 3: 10/32, 31.3%). Most AEs were mild or moderate. The most common AE was bronchitis (11/93, 11.8%; 1/32, 3.1%). The median (range) decrease in viral shedding (log10 virus genome copies/ml) was similar between the two groups (−3.58 [−6.2. 0.5]; −3.43 [−5.9, 0.9]). Genotypic analyses found a limited number of hemagglutinin and neuraminidase amino acid changes between viruses isolated before and after therapy; however, none appeared within a known oseltamivir-resistant site or MEDI8852-binding region. The safety profile of MEDI8852 supports its continued development for treatment of patients hospitalized with influenza A infection. (This study has been registered at ClinicalTrials.gov under identifier NCT02603952.)