One-year follow-up of the immunogenicity and safety of a primary series of the NVX-CoV2373 (TAK-019) vaccine in healthy Japanese adults: Final report of a phase I/II randomized controlled trial.

BACKGROUND: In the interim report of this phase I/II randomized, placebo-controlled trial in Japanese adults, a two-dose primary series of NVX-CoV2373 (5 µg SARS-CoV-2 recombinant nanoparticle spike protein [rS]; 50 µg Matrix-M) administered 21 days apart induced robust anti-SARS-CoV-2 immune responses up to day 50 and had an acceptable safety profile. METHODS: Following the double-blind phase of this study (day 1-50), participants were informed about their assignment to NVX-CoV2373 or placebo, and their reconsent was required for continuation in the open-label phase (day 51-387). This final report evaluated immunogenicity on days 202 and 387, and safety findings from the 1-year follow-up. RESULTS: In total, 131/150 participants in the NVX-CoV2373 arm and 4/50 in the placebo arm completed the study. The most common reason for discontinuation was because the participant requested a publicly available COVID-19 vaccine. At 6 months and 1 year after the second vaccine dose, both the geometric mean titres of anti-SARS-CoV-2 rS serum immunoglobulin G and serum neutralizing antibodies against the SARS-CoV-2 ancestral strain were numerically higher than before the second dose. There were no deaths, adverse events (AEs) leading to participant withdrawal, or AEs of special interest throughout the trial. During follow-up, 2.0 % (1/50) of participants in the placebo arm reported COVID-19 approximately 1 month after the second vaccine dose (serious AE requiring hospitalisation, already presented in the interim report) and 2.7 % (4/150) in the NVX-CoV2373 arm after approximately 10 months (mild [2/4] or moderate [2/4] in severity). DISCUSSION: A primary series of NVX-CoV2373 induced persistent immune responses up to 1 year after the second dose. The vaccine was well tolerated and had an acceptable safety profile. We believe our findings offer important insights for determining dosing intervals between primary and booster vaccinations.

Total Synthesis of (-)-Enigmazole A by the Macrocyclization/Transannular Pyran Cyclization Strategy.

An 18-step synthesis of (-)-enigmazole A is herein disclosed. The present synthesis is based on a modular assembly of three building blocks of similar complexity, a macrocyclic ring-closing metathesis to forge the 18-membered macrocyclic skeleton, and a desilylative transannular oxa-Michael addition for stereoselective construction of the 2,6-cis-substituted tetrahydropyran ring.

Immunogenicity and safety of a single booster dose of NVX-CoV2373 (TAK-019) in healthy Japanese adults who had previously received a primary series of COVID-19 mRNA vaccine: Primary analysis report of a phase 3 open-label trial.

BACKGROUND: We evaluated the immunogenicity and safety of a booster dose of NVX-CoV2373 in Japanese adults who had completed a primary series of COVID-19 mRNA vaccine 6-12 months previously. METHODS: This single-arm, open-label, phase 3 study, conducted at two Japanese centres, enrolled healthy adults ≥ 20 years old. Participants received a booster dose of NVX-CoV2373. The primary immunogenicity endpoint was non-inferiority (lower limit of the 95 % confidence interval [CI] ≥ 0.67) of the geometric mean titre (GMT) ratio of titres of serum neutralizing antibodies (nAbs) against the SARS-CoV-2 ancestral strain 14 days after booster vaccination (day 15) in this study, compared with those 14 days after the second primary NVX-CoV2373 vaccination (day 36) in the TAK-019-1501 study (NCT04712110). Primary safety endpoints included local and systemic solicited adverse events (AEs) up to day 7 and unsolicited AEs up to day 28. RESULTS: Between 15 April 2022 and 10 May 2022, 155 participants were screened and 150, stratified by age (20-64 years old [n = 135] or ≥ 65 years old [n = 15]), received an NVX-CoV2373 booster dose. The GMT ratio between titres of serum nAbs against the SARS-CoV-2 ancestral strain on day 15 in this study and those on day 36 in the TAK-019-1501 study was 1.18 (95 % CI, 0.95-1.47), meeting the non-inferiority criterion. Following vaccination, the proportion of participants who reported local and systemic solicited AEs up to day 7 was 74.0 % and 48.0 %, respectively. The most common local and systemic solicited AEs were tenderness (102 participants [68.0 %]) and malaise (39 participants [26.0 %]), respectively. Seven participants (4.7 %) reported unsolicited AEs between vaccination and day 28; all were severity grade ≤ 2. DISCUSSION: A single heterologous NVX-CoV2373 booster induced rapid and robust anti-SARS-CoV-2 immune responses, addressing waning immunity in healthy Japanese adults, and had an acceptable safety profile. CLINICALTRIALS: gov identifier: NCT05299359.

Immunogenicity and tolerability of a bivalent virus-like particle norovirus vaccine candidate in children from 6 months up to 4 years of age: A phase 2 randomized, double-blind trial.

We conducted a dose-finding phase 2 study of the HilleVax bivalent virus-like particle (VLP) vaccine candidate (HIL-214) in two cohorts of children, 6-≤12 months and 1-≤4 years of age (N = 120 per cohort), in Panama and Colombia (ClinicalTrials.gov, identifier NCT02153112). On Day 1, children randomized to one of the four equal groups received intramuscular injections of four different HIL-214 formulations containing 15/15, 15/50, 50/50, or 50/150 µg of GI.1/GII.4c genotype VLPs and 0.5 mg Al(OH)3. On Day 29, half the children in each group received a second vaccination (N = 60), while the other half received saline placebo injections to maintain the blind. VLP-specific ELISA Pan-Ig and histo-blood group binding antigen-blocking antibodies (HBGA) were measured on Days 1, 29, 57 and 210. On Day 29, after one dose, there were large Pan-Ig and HBGA responses in both age cohorts with some indication of dose-dependence, and higher geometric mean titers (GMT) in the older children. A further increase in titers was observed 28 days after a second dose in the 6-≤12-month-old groups, but less so in the 1-≤4-year-old groups; GMTs at Day 57 were broadly similar across doses and in both age groups. GMTs of Pan-Ig and HBGA persisted above baseline up to Day 210. All formulations were well tolerated with mostly mild-to-moderate transient solicited adverse events reported by parents/guardians, and no vaccine-related serious adverse events occurred. Further development of HIL-214 is warranted to protect the most susceptible young children against norovirus.

Immunogenicity of a bivalent virus-like particle norovirus vaccine in children from 1 to 8 years of age: A phase 2 randomized, double-blind study.

BACKGROUND: Young children can suffer severe consequences of norovirus gastroenteritis. We performed a dose-finding study of a bivalent virus-like particle (VLP) vaccine candidate (TAK-214) in healthy 1-8-year-old children. METHODS: In this phase 2 study two age cohorts (1-3 and 4-8 years of age inclusive, N = 120 per cohort) of children enrolled from Finland, Panama and Colombia were initially randomized 1:1:1:1 to four groups which were further split into two equal subgroups, to receive one or two intramuscular doses of four TAK-214 formulations containing 15/15, 15/50, 50/50 or 50/150 µg of GI.1/GII.4c genotype VLPs and 0.5 mg Al(OH)3 at 28 days interval. ELISA Pan-Ig and histoblood group antigen-blocking (HBGA) antibodies against each VLP were measured on days 1, 29, 57 and 210. Parents/guardians recorded solicited local and systemic adverse events (AE) and any unsolicited or serious AEs (SAE). RESULTS: All formulations were well-tolerated across both age cohorts and dosage groups with no vaccine-related SAEs reported. Solicited AEs were mostly mild-to-moderate, resolved quickly, and did not increase after the second dose. Pan-Ig and HBGA responses induced after one dose were only slightly increased by the second dose. Across dose groups at Day 29 after one dose GI.1 Pan Ig seroresponse rates (SRR) were 82-97% and 81-96% and GII.4c SRR were 79-97% and 80-91% in 1-3 and 4-8 year-olds, respectively. Respective rates were to 92-93% and 73-92% for GI.1, and 77-100% and 62-83% for GII.4c at Day 57 following two doses. HBGA responses had similar profiles. Both Pan Ig and HBGA geometric mean titers persisted above baseline up to Day 210. CONCLUSIONS: All dosages of TAK-214 displayed acceptable reactogenicity in 1-8-year-old children and induced robust, durable immune responses after one dose which are further increased after two doses.

Safety and immunogenicity of NVX-CoV2373 (TAK-019) vaccine in healthy Japanese adults: Interim report of a phase I/II randomized controlled trial.

BACKGROUND: We evaluated the safety and immunogenicity of NVX-CoV2373, a recombinant SARS-CoV-2 nanoparticle vaccine, in healthy Japanese participants. METHODS: This phase 1/2, randomized, observer-blind, placebo-controlled trial conducted in Japan (two sites), enrolled healthy Japanese adults aged ≥ 20 years with no history/risk of SARS-CoV-2 infection and no prior exposure to other approved/investigational SARS-CoV-2 vaccines or treatments. Participants were stratified by age (< 65 or ≥ 65 years) and randomized to receive two doses of either NVX-CoV2373 (5 µg SARS-CoV-2 rS; 50 µg Matrix-M1) or placebo, 21 days apart. Primary outcomes were safety and immunogenicity assessed by serum IgG antibody levels against SARS-CoV-2 rS protein on day 36. Herein, we report the primary data analysis at 4 weeks after the second dose, ahead of 12-month follow-up completion (data cut-off: 8 May 2021). RESULTS: Between 12 February 2021 and 17 March 2021, 326 subjects were screened, and 200 participants enrolled and randomized: NVX-CoV2373, n = 150; placebo, n = 50. Solicited adverse events (AEs) through 7 days after each injection occurred in 121/150 (80.7%) and 11/50 (22.0%) participants in the NVX-CoV2373 and placebo arms, respectively. In the NVX-CoV2373 arm, tenderness and injection site pain were the most frequently reported solicited AEs after each vaccination, irrespective of age. Robust immune responses occurred with NVX-CoV2373 (n = 150) by day 36: IgG geometric mean fold rise (95% confidence interval) 259 (219, 306); seroconversion rate 100% (97.6, 100). No such response occurred with placebo (n = 49). CONCLUSION: Two doses of NVX-CoV2373 given with a 21-day interval demonstrated acceptable safety and induced robust anti-SARS-CoV-2 immune responses in healthy Japanese adults. FUNDING: Takeda Pharmaceutical Company Limited and Japan Agency for Medical Research and Development (AMED). CLINICALTRIALS: gov identifier: NCT04712110.

A phase 1/2 randomised placebo-controlled study of the COVID-19 vaccine mRNA-1273 in healthy Japanese adults: An interim report.

INTRODUCTION: The mRNA vaccine, mRNA-1273/TAK-919, encodes the prefusion-stabilised spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report interim results of the first study evaluating safety and immunogenicity of mRNA-1273 in healthy Japanese participants. METHODS: This phase 1/2, randomised, observer-blind, placebo-controlled trial, conducted in Japan (two sites), enrolled healthy adults aged ≥ 20 years with no prior exposure to investigational coronavirus vaccines/treatments, and no known history/risk of SARS-CoV-2 infection. Participants were stratified by age (< 65/≥ 65 years) and randomised to receive two doses of 100 µg mRNA-1273 or placebo administered as intramuscular injections 28 days apart. Primary outcomes were safety and immunogenicity assessed by anti-SARS-CoV-2-spike protein-binding antibody level (bAb). A secondary outcome was SARS-CoV-2 neutralising antibody (nAb) response. RESULTS: Participants were enrolled between 21 January and 3 February 2021, and 200 were randomised: mRNA-1273, n = 150 (< 65 years, n = 100; ≥ 65 years, n = 50); placebo, n = 50 (< 65 years, n = 40; ≥ 65 years, n = 10). Solicited adverse events (AEs) through 7 days after each vaccination occurred in 144/150 (96%) and 19/50 (38%) participants in the mRNA-1273 and placebo arms, respectively. In the mRNA-1273 arm, injection-site pain, myalgia and fatigue were the most frequently reported solicited AEs after each vaccination, irrespective of age. Robust immune responses occurred with mRNA-1273 (n = 147) with a bAb geometric mean fold rise (95% confidence interval [CI]) from baseline of 1009 (865, 1177) and a nAb of 21.7 (19.8, 23.8) at day 57. Seroconversion rates (95% CI) for bAb and nAb were both 100% (97.5, 100) at day 57. No such response occurred with placebo (n = 49). CONCLUSION: Two doses of 100 µg mRNA-1273 given 28 days apart demonstrated an acceptable safety profile and induced significant anti-SARS-CoV-2 immune responses in a Japanese population aged ≥ 20 years. FUNDING: Takeda Pharmaceutical Company Limited and Japan Agency for Medical Research and Development (AMED). CLINICALTRIALS: gov: NCT04677660.

Calibrated comparison of SARS-CoV-2 neutralizing antibody levels in response to protein-, mRNA-, and vector-based COVID-19 vaccines.

SARS-CoV-2 neutralizing antibodies have been suggested to reflect the efficacy of COVID-19 vaccines. This study reports the direct comparison of the SARS-CoV-2 neutralizing antibody response elicited by a protein- (NVX-CoV2373), an mRNA- (Comirnaty), and a vector-based (Vaxzevria) COVID-19 vaccine, calibrated against the WHO international SARS-CoV-2 antibody standard, and further supports the use of neutralizing antibody levels as a correlate of protection.

Nationwide epidemiologic study of norovirus-related hospitalization among Japanese older adults.

BACKGROUND: Older adults are vulnerable to hospitalization or death from norovirus infection, but the actual disease burden remains unknown. Therefore, we conducted a nationwide survey to estimate the number of inpatients with norovirus gastroenteritis and associated deaths among Japanese older adults. METHODS: We performed a nationwide two-step query targeting 4184 hospital departments selected from 17,575 departments using stratified random sampling according to the number of beds. We asked each department to complete a mail-back questionnaire on the annual numbers of inpatients with infectious gastroenteritis and associated deaths between administrative years 2012 and 2014, and the implementation status of norovirus infection testing. In a second query, we investigated the annual number of inpatients with norovirus gastroenteritis and associated deaths in departments that had reported infectious gastroenteritis inpatients in the first query. Clinical information was collected for inpatients with norovirus gastroenteritis in administrative year 2014. RESULTS: Norovirus testing for patients hospitalized for acute gastroenteritis was routinely conducted in 16% of the responding departments. Although half the departments responded that some acute gastroenteritis inpatients received such testing but others did not. In this situation, numbers of inpatients with norovirus gastroenteritis in Japan were estimated as 31,800 (95% CI: 25,700-37,900) in administrative year 2012, 21,600 (95% CI: 17,700-25,500) in administrative year 2013, and 15,700 (95% CI: 12,900-18,500) in administrative year 2014. The estimated number of associated deaths was approximately 600 in each administrative year. Factors associated with death included higher age, living in long-term care facilities, underlying illnesses such as chronic respiratory diseases, and complications such as aspiration pneumonia. CONCLUSIONS: The actual number of norovirus inpatient would be higher than the estimated here due to the low rate of routinely implemented norovirus testing. Considering Japan's rapidly aging society and the disease burden of norovirus infection among Japanese older adults, it is important to protect this high-risk population from norovirus infection.

Minodronic acid (ONO-5920/YM529) prevents decrease in bone mineral density and bone strength, and improves bone microarchitecture in ovariectomized cynomolgus monkeys.

This study examined the effect of the highly potent nitrogen-containing bisphosphonate, minodronic acid (ONO-5920/YM529), on bone mineral density (BMD), bone turnover, bone microarchitecture and bone strength in ovariectomized (OVX) cynomolgus monkeys. Skeletally mature female cynomolgus monkeys, aged 9-17 years, were ovariectomized or sham-operated. Minodronic acid was administered orally once a day in doses of 0, 0.015, and 0.15 mg/kg from the day after surgery for 17 months. Bone resorption markers (urinary N-terminal cross-linking telopeptide of type I collagen and deoxypyridinoline), bone formation markers (serum osteocalcin and bone alkaline phosphatase) and lumbar vertebral BMD were measured at baseline and at 4, 8, 12 and 16 months after surgery. Treatment with minodronic acid dose-dependently inhibited OVX-induced increase in bone turnover markers and decrease in lumbar vertebral BMD, and minodronic acid at 0.15 mg/kg completely prevented these changes. At 17 months after surgery, minodronic acid also suppressed bone resorption (Oc.S/BS and N.Oc/BS) and bone formation (OS/BS, MS/BS, MAR, BFR/BS, and BFR/BV) in the lumbar vertebral bodies and tibia. In the mechanical tests, ultimate load on lumbar vertebral bodies and femoral neck of the OVX-control animals were significantly reduced compared to the sham animals. Minodronic acid prevented these reductions in bone strength at 0.15 mg/kg. There was significant correlation between BMD and bone strength, suggesting that the increase in bone strength was associated with the increase in BMD produced by minodronic acid. In micro-CT analysis of the lumbar vertebral bodies, minodronic acid improved trabecular architecture, converting rod structures into plate structures, and preventing the increase in trabecular disconnectivity at 0.15 mg/kg. In conclusion, similar to patients with postmenopausal osteoporosis, reduction in bone strength of lumbar vertebral bodies and femoral neck was clearly demonstrated in OVX cynomolgus monkeys. Minodronic acid prevented these reductions at a once-daily oral administration. Also, minodronic acid prevented OVX-induced changes in bone turnover, bone mass and bone microarchitecture. Long-term minodronic acid treatment was well tolerated and no adverse effects could be detected. These results suggest that minodronic acid may be a clinically useful drug for osteoporosis.

Effect of MX-68 on airway inflammation and hyperresponsiveness in mice and guinea-pigs.

MX-68 is a newly synthesized antifolate, which is a derivative of methotrexate (MTX). In this paper, the effect of MX-68 on allergic airway responses in mice and guinea-pigs was studied. In the first experiment, antigen-induced airway inflammation and airway hyperresponsiveness (AHR) to acetylcholine in mice were examined and compared with the effects of classical antifolate methotrexate and prednisolone. Mice were sensitized with ovalbumin as an antigen and challenged with ovalbumin inhalation three times. After the last inhalation, AHR and airway inflammation were observed. An increase in Th2 cytokines (IL-4 and IL-5) and a decrease in a Th1 cytokine (IFN-gamma) in the bronchoalveolar lavage fluid (BALF), as well as an elevation of the immunoglobulin level in serum, were observed in sensitized mice. Oral administration of MX-68 had no effect on changes of body weight, but prednisolone reduced body weight during the experiment. The antigen-induced AHR and increases in the number of eosinophils and lymphocytes in BALF were significantly inhibited by MX-68. MX-68 interfered with the elevation of IL-4 and IL-5 levels in BALF, but had no effect on the decrease in IFN-gamma. Moreover, MX-68 significantly inhibited the elevation of serum IgE and IgG levels. In the guinea-pig model for bronchial asthma, biphasic increases in airway resistance (immediate asthmatic response, IAR, and late asthmatic response, LAR), as well as accumulated inflammatory cells in BALF, were observed after repeated antigen challenge. These asthmatic responses and inflammatory signs were significantly decreased by administration of MX-68. These results suggest that MX-68 obviously has an anti-inflammatory effect in an animal model of asthma and would be useful clinically for the treatment of bronchial asthma.

Role of prostaglandin I2 in airway remodeling induced by repeated allergen challenge in mice.

Recently, we demonstrated that prostaglandin (PG)I2 has a regulatory role in allergic responses through the receptor, IP; however, the role of PGI2 in airway remodeling associated with chronic airway inflammation has not been elucidated. In the present study, we examined the role of PGI2 in allergen-induced airway remodeling using IP gene-deficient mice. Mice were sensitized to ovalbumin (OVA) with alum, and exposed daily for 3 wk to aerosolized OVA. Twenty-four hours after the final antigen inhalation, bronchoalveolar lavage, biochemical, and histopathologic examinations were performed. In wild-type mice, prolonged allergen exposure in sensitized animals induced the increases in the numbers of inflammatory leukocytes (including eosinophils and lymphocytes), levels of T helper type 2 (Th2) cytokines (interleukin [IL]-4, IL-5, and IL-13), levels of OVA-specific immunoglobulin (Ig)E and IgG1 in serum, and amount of hydroxyproline in the right lungs associated with transforming growth factor-beta1 levels in bronchoalveolar lavage fluid. Moreover, goblet cell hyperplasia and subepithelial fibrosis were also appreciated after repeated allergen challenge. In contrast, the disruption of IP gene significantly augmented all these parameters. These findings suggest that PGI2 has a regulatory role in allergen-induced airway remodeling as well as airway eosinophilic inflammation, Th2 cytokine production and IgE production, and that a PGI2 agonist is a therapeutic approach for the treatment of airway remodeling in allergic asthma.

Role of Th2 responses in the development of allergen-induced airway remodelling in a murine model of allergic asthma.

(1) To clarify the involvement of Th2 responses in the development of allergen-induced airway remodelling, we investigated the effect of anti-CD4 monoclonal antibody (mAb) and anti-CD8 mAb, and the responses of IL-4 gene-knockout (KO) mice in a murine model of allergic asthma. (2) Mice were immunized twice by intraperitoneal injections of ovalbumin (OA), and exposed to aeroallergen (OA, 1% w v(-1)) for 3 weeks. Twenty-four hours after the final challenge, airway responsiveness to acetylcholine was measured, and bronchoalveolar lavage (BAL) and histological examinations were carried out. (3) Anti-CD4 mAb (1 mg kg(-1)) clearly inhibited allergen-induced increases in airway responsiveness to acetylcholine, the number of eosinophils in BAL fluid, serum OA-specific IgE levels, IL-13 and transforming growth factor-beta1 levels in BAL fluid, and amount of hydroxyproline in the lung by 100, 99, 100, 100, 84, and 60%, respectively. Furthermore, the antibody (1 mg kg(-1)) also attenuated allergen-induced goblet cell hyperplasia in the epithelium and subepithelial fibrosis by 72 and 83%, respectively. In contrast, anti-CD8 mAb (1 mg kg(-1)) showed no effect on each parameter. Furthermore, all these parameters were attenuated in IL-4KO mice by 57, 93, 100, 45, 84 and 60%, and also 72 and 83%, respectively. (4) These findings suggest that Th2 responses play a critical role for the development of allergen-induced airway remodelling, and that the inhibition of Th2 responses, e.g. using anti-CD4 mAb, is a therapeutic approach for the treatment of airway remodelling in asthma.

Augmentation of allergic inflammation in prostanoid IP receptor deficient mice.

1 To evaluate the role of prostaglandin I(2) (PGI(2)) in allergic inflammation, allergic responses in the airway, skin and T cells were studied in mice lacking the receptor for PGI(2) (the prostanoid IP receptor) through gene disruption. 2 Three inhalations of antigen caused an increase in plasma extravasation, leukocyte accumulation and cytokine (interleukin (IL)-4 and IL-5) production in the airway of sensitized mice. These airway inflammatory responses were significantly greater in IP receptor deficient mice than in wild-type mice. 3 The vascular leakage caused by passive cutaneous anaphylaxis, substance P and 5-hydroxytryptamine was markedly increased in the skin of IP receptor deficient mice, compared with comparably treated wild-type mice. 4 The inhalation of antigen in sensitized mice resulted in increased serum antigen specific IgE, total IgE and IgG levels. The magnitude of the elevations of each immunoglobulin level in IP receptor deficient mice is notably higher than that in wild-type mice. To elucidate the mechanism of an enhancement of immunoglobulin production, the activity of T cells in sensitized and non-sensitized mice was studied by means of the production of cytokines. The antigen-induced IL-4 production by spleen cells from sensitized IP receptor deficient mice was almost three times greater than that in wild-type mice. On the contrary, the anti-CD3 antibody-induced interferon-gamma production by CD4(+) T cells from non-sensitized IP receptor deficient mice was significantly lower than that in wild-type mice. 5 The present data indicate that IP receptor deficiency reinforced an allergic airway and skin inflammation by augmentation of vascular permeability increase and the T helper 2 cell function. These findings suggest a regulatory role of PGI(2) in allergic inflammation.