Safety and immunogenicity of a serum-free purified Vero rabies vaccine in comparison with the rabies human diploid cell vaccine (HDCV; Imovax® Rabies) administered in a simulated rabies post-exposure regimen in healthy adults.

A new generation, serum-free, antibiotic-free, purified Vero rabies vaccine (PVRV-NG; Sanofi) has been developed based on the same Pitman-Moore viral strain used for the currently licensed purified Vero cell rabies vaccine (PVRV; Verorab®, Sanofi) and human diploid cell vaccine (HDCV; Imovax® Rabies, Sanofi). PVRV-NG has demonstrated a satisfactory safety profile and induces robust immune responses, with non-inferiority demonstrated versus PVRV when given as a three-dose pre-exposure prophylaxis (PrEP) regimen in healthy children and adults. Here, we evaluated the safety and immunogenic non-inferiority of PVRV-NG compared to HDCV when administered as simulated post-exposure prophylaxis (PEP), with concomitant administration of human rabies immunoglobulin (HRIG), in healthy adults in the USA. Participants were vaccinated according to the 5-dose Essen intramuscular regimen (4-week, 1-injection site regimen, with a single dose given on days 0, 3, 7, 14 and 28) for PEP, with concomitant HRIG administered on day 0. Rabies virus neutralising antibodies (RVNA) were evaluated on days 0, 14, 28 and 42. Non-inferiority of PVRV-NG compared with HDCV was shown if the lower limit of the 95 % confidence interval (CI) for the difference in seroconversion rates (RVNA titers ≥ 0.5 IU/mL on day 14) between PVRV-NG and HDCV was above the non-inferiority margin of -5 %. Safety was evaluated after each vaccination and monitored throughout the study. The difference in seroconversion rate between the PVRV-NG and HDCV groups was -2.8 % (95 % CI, -8.08 to 4.20), indicating that non-inferiority was not demonstrated. The seroconversion rate was < 99 % in both study groups on day 14. There were no major safety concerns identified, and PVRV-NG demonstrated a similar safety profile to HDCV.

Evaluation of a primary course of H9N2 vaccine with or without AS03 adjuvant in adults: A phase I/II randomized trial.

BACKGROUND: Avian influenza A H9N2 strains have pandemic potential. METHODS: In this randomized, observer-blind study (ClinicalTrials.gov: NCT01659086), 420 healthy adults, 18-64years of age, received 1 of 10 H9N2 inactivated split-virus vaccination regimens (30 participants per group), or saline placebo (120 participants). H9N2 groups received 2 doses (days 0, 21) of 15µg hemagglutinin (HA) without adjuvant, or 1.9µgHA+AS03A, 1.9µgHA+AS03B, 3.75µgHA+AS03A, or 3.75µgHA+AS03B; followed by the same H9N2 formulation or placebo (day 182). AS03 is an adjuvant system containing α-tocopherol (AS03A: 11.86mg; AS03B: 5.93mg) and squalene in an oil-in-water emulsion. Immunogenicity (hemagglutination inhibition [HI] and microneutralization assays) and safety were assessed up to day 546. RESULTS: All adjuvanted formulations exceeded regulatory immunogenicity criteria at days 21 and 42 (HI assay), with seroprotection and seroconversion rates of ≥94.9% and ≥89.8% at day 21, and 100% and ≥98.1% at day 42. Immunogenicity criteria were also met for unadjuvanted vaccine, with lower geometric mean titers. In groups administered a third vaccine dose (day 182), an anamnestic immune response was elicited with robust increases in HI and microneutralization titers. Injection site pain was reported more frequently with adjuvanted vaccines. No vaccine-related serious adverse events were observed. CONCLUSIONS: All H9N2 vaccine formulations were immunogenic with a clinically acceptable safety profile; adjuvanted formulations were 4-8 times dose-sparing (3.75-1.9vs 15µgHA). TRIAL REGISTRATION: Registered on ClinicalTrials.gov: NCT01659086.

Safety and immunogenicity of the rVSV∆G-ZEBOV-GP Ebola virus vaccine candidate in healthy adults: a phase 1b randomised, multicentre, double-blind, placebo-controlled, dose-response study.

BACKGROUND: The 2014 Zaire Ebola virus outbreak highlighted the need for a safe, effective vaccine with a rapid onset of protection. We report the safety and immunogenicity of the recombinant vesicular stomatitis virus-Zaire Ebola virus envelope glycoprotein vaccine (rVSV∆G-ZEBOV-GP) across a 6 log10 dose range in two sequential cohorts. METHODS: In this phase 1b double-blind, placebo-controlled, dose-response study we enrolled and randomly assigned healthy adults (aged 18-61 years) at eight study sites in the USA to receive a single injection of vaccine or placebo, administered by intramuscular injection. In cohort 1, participants were assigned to receive 3 × 103, 3 × 104, 3 × 105, or 3 × 106 PFU doses of rVSV∆G-ZEBOV-GP or placebo. In cohort 2, participants were assigned to receive 3 × 106, 9 × 106, 2 × 107, or 1 × 108 PFU doses of rVSV∆G-ZEBOV-GP or placebo. Participants were centrally allocated by the study statistician to vaccine groups or placebo through computer-generated randomisation lists. The primary safety outcome was incidence of adverse events within 14 days in the modified intention-to-treat population (all randomly assigned participants who received vaccine or placebo), and the primary outcome for immunogenicity was IgG ELISA antibody titres at day 28 in the per-protocol population. Surveillance was enhanced for arthritis and dermatitis through to day 56. This study is registered with ClinicalTrials.gov, number NCT02314923. FINDINGS: Between Dec 26, 2014, and June 8, 2015, 513 participants were enrolled and randomly assigned; one was not immunised because of unsuccessful phlebotomy. In cohort 1, 256 participants received vaccine (3 × 103 [n=64], 3 × 104 [n=64], 3 × 105 [n=64], or 3 × 106 PFU [n=64]) and 74 received placebo. In cohort 2, 162 participants received vaccine (3 × 106 [n=20], 9 × 106 [n=47], 2 × 107 [n=47], or 1 × 108 PFU [n=48]) and 20 received placebo. Most adverse events occurred in the first day after vaccination, and were mild to moderate in intensity, of a short duration, and more frequent at high vaccine doses (9 × 106 PFU and greater). At the 2 × 107 PFU dose (used in phase 3 trials), the most common local adverse events versus placebo within the first 14 days were arm pain (57·4% [27 of 47] vs 7·4% [seven of 94]) and local tenderness (59·6% [28 of 47] vs 8·5% [eight of 94]). The most common systemic adverse events at the 2 × 107 PFU dose versus placebo, occurring in the first 14 days, were headache (46·8% [22 of 47] vs 27·7% [26 of 94]), fatigue (38·3% [18 of 47] vs 19·1% [18 of 94]), myalgia (34·0% [16 of 47] vs 10·6% [10 of 94]), subjective fever (29·8% [14 of 47] vs 2·1% [two of 94]), shivering or chills (27·7% [13 of 47] vs 7·4% [seven of 94]), sweats (23·4% [11 of 47] vs 3·2% [three of 94]), joint aches and pain (19·1% [nine of 47] vs 7·4% [seven of 94]), objective fever (14·9% [seven of 47] vs 1·1% [one of 94]), and joint tenderness or swelling (14·9% [seven of 47] vs 2·1% [two of 94]). Self-limited, post-vaccination arthritis occurred in 4·5% (19 of 418) of vaccinees (median onset 12·0 days [IQR 10-14]; median duration 8·0 days [6-15]) versus 3·2% (three of 94) of controls (median onset 15·0 days [6-20]; median duration 47·0 days [37-339]), with no apparent dose relationship. Post-vaccination dermatitis occurred in 5·7% (24 of 418) of vaccinees (median onset 9·0 days [IQR 2-12]; median duration 7·0 days [4-9]) versus 3·2% (three of 94) of controls (median onset 5·0 days [3-53]; median duration 33·0 days [5-370]). A low-level, transient, dose-dependent viraemia occurred in concert with early reactogenicity. Antibody responses were observed in most participants by day 14. IgG and neutralising antibody titres were dose-related (p=0·0003 for IgG ELISA and p<0·0001 for the 60% plaque-reduction neutralisation test [PRNT60] by linear trend). On day 28 at the 2 × 107 PFU dose, the geometric mean IgG ELISA endpoint titre was 1624 (95% CI 1146-2302) and seroconversion was 95·7% (95% CI 85·5-98·8); the geometric mean neutralising antibody titre by PRNT60 was 250 (176-355) and seroconversion was 95·7% (85·5-98·8). These robust immunological responses were sustained for 1 year. INTERPRETATION: rVSV∆G-ZEBOV-GP was well tolerated and stimulated a rapid onset of binding and neutralising antibodies, which were maintained through to day 360. The immunogenicity results support selection of the 2 × 107 PFU dose. FUNDING: Biomedical Advanced Research and Development Authority, US Department of Health and Human Services.

Immunogenicity and safety of an AS03-adjuvanted H7N1 vaccine in healthy adults: A phase I/II, observer-blind, randomized, controlled trial.

BACKGROUND: H7 influenza strains have pandemic potential. AS03-adjuvanted H7N1 A/mallard/Netherlands/12/2000 split-virion vaccine formulations were evaluated as model H7-subtype vaccine and tested after H7N9 emerged in China, and caused severe human disease with high mortality. METHODS: In this phase I/II, observer-blind, randomized trial in US and Canada, 420 healthy adults (21-64years) were randomized to receive 1 of 4 H7N1 vaccine formulations (3.75 or 7.5µg hemagglutinin adjuvanted with either AS03A or AS03B), 15µg unadjuvanted H7N1 hemagglutinin, or saline placebo, given as 2-dose series. Immunogenicity was assessed using hemagglutination-inhibition (HI) and microneutralization (MN) assays, at day 42 (21days post-dose 2), month 6, and month 12 (HI only) for the per-protocol cohorts (398, 379 and 368 participants, respectively). Safety is reported up to month 12. RESULTS: Beneficial AS03 adjuvant effect was demonstrated. Committee for Medical Products for Human Use, and Center for Biologics Evaluation and Research (CBER) criteria were met for all adjuvanted formulations at day 42 (H7N1 HI assay); seroprotection (SPR) and seroconversion rates (SCR) were 88.5-94.8%, mean geometric increase (MGI) 19.2-34.9, and geometric mean titers (GMT) 98.3-180.7. Unadjuvanted H7N1 vaccine did not meet CBER criteria. In adjuvanted groups, antibody titers decreased over time; month 12 SPRs and GMTs were low (2.0-18.8% and 8.1-12.2). MN antibodies showed similar kinetics, with titers persisting at higher range than HI at month 6. All adjuvanted groups showed cross-reactivity against H7N9, with HI responses similar to H7N1. The most frequent solicited symptom in adjuvanted groups was injection site pain (71.2-86.7%); grade 3 solicited symptoms were infrequent. Nine participants reported 17 serious adverse events; none were considered causally related to vaccination. CONCLUSIONS: Adjuvanted H7N1 vaccine formulations had an acceptable safety profile and induced an antibody response after 2 doses with cross-reactivity to H7N9. ClinicalTrials.gov: NCT01934127.

Safety, tolerability, and immunogenicity of a 4-antigen Staphylococcus aureus vaccine (SA4Ag): Results from a first-in-human randomised, placebo-controlled phase 1/2 study.

BACKGROUND: A prophylactic Staphylococcus aureus four-antigen vaccine (SA4Ag) is under development for prevention of invasive S. aureus disease. A preliminary S. aureus three-antigen vaccine (SA3Ag) was reformulated to include a novel manganese transporter protein (MntC or rP305A). This study describes the first-in-human dose-finding, safety, and immunogenicity results for SA4Ag. METHODS: In this double-blind, sponsor-unblind, placebo-controlled, phase 1/2 study, 454 healthy adults aged 18-64years were randomised to receive a single dose of one of three formulations of SA4Ag with escalating dose levels of rP305A or placebo. Functional immune responses were measured using opsonophagocytic activity (OPA) killing and fibrinogen-binding inhibition (FBI) assays; antigen-specific immunogenicity was assessed using a four-plex competitive Luminex® immunoassay (cLIA). RESULTS: A high proportion of SA4Ag recipients met the pre-defined antibody thresholds for each antigen at Day 29. A substantial and dose-level dependent immune response was observed for rP305A, with up to 18-fold rises in cLIA titres at Day 29. Robust functional responses were demonstrated, with >80-fold and >20-fold rises in OPA assay titres at Day 29 using S. aureus strains expressing capsular polysaccharide serotypes 5 and 8, respectively. Durable antibody responses were observed through month 12, gradually waning from peak levels achieved by days 11-15. SA4Ag was well tolerated, and no vaccine-related serious adverse events were reported. CONCLUSIONS: Single-dose vaccination of SA4Ag in healthy adults aged 18-64years safely induced rapid and robust functional immune responses that were durable through month 12, supporting further development of this vaccine. TRIAL REGISTRATION NUMBER: NCT01364571.

Safety, tolerability, and immunogenicity of a single dose 4-antigen or 3-antigen Staphylococcus aureus vaccine in healthy older adults: Results of a randomised trial.

BACKGROUND: The decline in immune function with age is a challenge to vaccine development. Following an initial study in adults aged 18-64years, this study evaluated the safety and immunogenicity of Staphylococcus aureus (S. aureus) 4-antigen (SA4Ag) and 3-antigen (SA3Ag) vaccine in older adults. SA3Ag included capsular polysaccharide serotypes 5 and 8 (CP5 and CP8) conjugated to the nontoxic mutant form of diphtheria toxin (CRM197) and a recombinant version of clumping factor A (ClfA). SA4Ag included these antigens, with the addition of a recombinant manganese transporter C (rP305A or MntC). Both vaccines were unadjuvanted. METHODS: In this double-blind, sponsor-unblinded, placebo-controlled, phase 1/2 study, 284 healthy adults (aged 65-85years) were randomised to receive a single dose of one of three formulations of SA4Ag with escalating dose levels of rP305A, SA3Ag, or placebo. Functional immune responses were measured using opsonophagocytic activity (OPA) killing and fibrinogen-binding inhibition (FBI) assays; immunogenicity was also assessed using a competitive Luminex® immunoassay (cLIA). T-cell responses were measured in a small subgroup of subjects using intracellular cytokine staining (ICS) assays. RESULTS: The results demonstrated rapid and robust functional immune responses to all antigens in healthy older adults. A high proportion of active vaccine recipients met the pre-defined antibody thresholds for each antigen at Day 29. SA4Ag elicited a dose-level response to rP305A with up to a 13-fold rise in cLIA titres at Day 29. Opsonophagocytic activity (OPA) assays showed >50- and >20-fold rises in functional titres using S. aureus strains expressing CP5 and CP8, respectively, at Day 29. T-cell cytokine responses were not substantially above background levels. There were no safety concerns in this study population and no increases in adverse events with higher rP305A dose levels. CONCLUSIONS: Single-dose vaccination of SA4Ag and SA3Ag in healthy adults aged 65-85years safely induced rapid and robust functional immune responses, supporting further development of SA4Ag for the prevention of S. aureus disease in adults up to age 85years. TRIAL REGISTRATION NUMBER: NCT01643941.

Immune response and reactogenicity of intradermal administration versus subcutaneous administration of varicella-zoster virus vaccine: an exploratory, randomised, partly blinded trial.

BACKGROUND: The licensed live, attenuated varicella-zoster virus vaccine prevents herpes zoster in adults older than 50 years. We aimed to determine whether intradermal administration of zoster vaccine could enhance vaccine immunogenicity compared with conventional needle subcutaneous administration. METHODS: In this randomised, dose-ranging study, adults aged 50 years or older who had a history of varicella or who had resided in a country with endemic varicella-zoster virus infection for 30 years or more were eligible. Participants received the approved full or a 1/3 dose of zoster vaccine given subcutaneously or one of four intradermal doses (full, 1/3, 1/10, or 1/27 dose) using the MicronJet600 device. The two subcutaneous doses and the four intradermal doses were randomised (1·5:1:1:1:1:1) by computer generated sequence with randomisation stratified by age (50-59 years or 60 years or older). The primary immunogenicity endpoint was the change from baseline in IgG antibody to varicella-zoster virus-specific glycoproteins (gpELISA) measured at 6 weeks. All patients were included in the primary and safety analyses. This study is registered with ClinicalTrials.gov, number NCT01385566. FINDINGS: Between Sept 2, 2011, and Jan 13, 2012, 224 participants were enrolled from three clinics in the USA and 223 were randomly assigned: 52 to receive the full dose subcutaneous zoster vaccine, 34 to receive the 1/3 dose subcutaneous zoster vaccine, 34 to receive the full dose intradermal zoster vaccine, 35 to receive the 1/3 dose intradermal zoster vaccine, 34 to receive the 1/10 dose intradermal zoster vaccine, and 34 to receive the 1/27 dose intradermal zoster vaccine. Full dose zoster vaccine given subcutaneously resulted in a gpELISA geometric mean fold-rise (GMFR) of 1·74 (90% CI 1·48-2·04) at 6 weeks post-vaccination compared with intradermal administration which resulted in a significantly higher gpELISA GMFR of 3·25 (2·68-3·94; p<0·0001), which also remained high at 18 months. An apparent dose-response relation was observed with intradermal administration (1/3 dose subcutaneous GMFR 1·64 [90% CI 1·36-1·99], 1/3 dose intradermal 2·58 (2·13-3·13), 1/10 dose intradermal 2·22 [1·83-2·69], and 1/27 dose intradermal 1·64 [1·35-2·00]). Each partial dose of zoster vaccine given intradermaly had a gpELISA GMFR comparable to that of full dose zoster vaccine given subcutaneously. Transient erythema and induration were more common after intradermal administration (31% erythema for full subcutaneous dose and 77% for intradermal dose). INTERPRETATION: Intradermal zoster vaccine showed a greater increase in varicella-zoster virus gpELISA antibody compared with subcutaneous zoster vaccine at comparable doses. Larger and longer studies of intradermal administration of live, attenuated zoster vaccine are needed to provide convincing evidence of improved cell mediated immunity. FUNDING: Merck & Co Inc.

A phase 1a, first-in-human, randomized study of a respiratory syncytial virus F protein vaccine with and without a toll-like receptor-4 agonist and stable emulsion adjuvant.

BACKGROUND: Respiratory syncytial virus (RSV) causes significant illness in older adults resulting in substantial health and economic impact. A successful vaccine would reduce morbidity in this growing segment of the population. METHODS: In this double-blind phase 1 study, subjects 60 years of age and older were enrolled by cohort and randomized to receive vaccines containing escalating doses (20, 50, or 80µg) of soluble RSV fusion protein (sF) alone or adjuvanted with 2.5µg of glucopyranosyl lipid A, a toll-like receptor-4 agonist, in 2% stable emulsion (GLA-SE). Each cohort included 20 vaccine and 4 placebo recipients. Immune responses were evaluated using assays for RSV microneutralizing, anti-F IgG, and palivizumab competitive antibodies and for F-specific interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) responses. RESULTS: The inclusion of adjuvant increased local reactogenicity, with the majority of subjects who received sF and adjuvant reporting low-grade injection site pain or tenderness. At all doses, the safety profile was acceptable for further development. Immune responses were antigen dose-dependent, and the inclusion of adjuvant increased both humoral and cellular immune responses, with responses statistically higher than for placebo recipients in all 4 assays. At the highest dosage level with adjuvant, half of the subjects had a ≥3-fold rise from day 0 in RSV neutralizing antibody titers, and all had a ≥3-fold rise in antibody levels by anti-F IgG and palivizumab competitive antibody assays on day 29. For the day 8 IFNγ ELISPOT assay, 74% of subjects in the highest dosing cohort had a ≥3-fold rise from baseline. CONCLUSIONS: The safety and immunogenicity results from this study support inclusion of the GLA-SE adjuvant in this RSV vaccine for older adults and also support assessment of the efficacy of the vaccine in a larger clinical trial. Clinicaltrials.gov NCT02115815.

A phase 1, placebo-controlled, randomized study of the safety, tolerability, and immunogenicity of a Clostridium difficile vaccine administered with or without aluminum hydroxide in healthy adults.

INTRODUCTION: Clostridium difficile is a significant cause of morbidity and mortality in hospitals, nursing homes, and long-term care facilities. The bacteria can produce 3 toxins, of which the C. difficile toxin A and C. difficile toxin B are the principal virulence factors for C. difficile-associated disease. METHODS: A phase 1, first-in-human, placebo-controlled, dose-escalation study was performed to assess the safety and immunogenicity of an investigational vaccine candidate consisting of genetically and chemically detoxified, purified toxins A and B. The toxoids, either alone or in combination with aluminum hydroxide (Al(OH)3), were administered to healthy adults 50-85 years of age at antigen dose levels of 50, 100, or 200 µg in a 3-dose regimen administered at 0, 1, and 6 months. RESULTS: Overall, the C. difficile vaccine formulations and doses administered were generally well tolerated. Local reactions and systemic events were predominantly mild to moderate, were more common in the 50-64-year age cohort, and comprised mostly injection site pain, headache, and fatigue. In subjects who received the vaccine formulations, both the toxin A- and toxin B-specific neutralizing antibody geometric mean concentrations increased substantially at 1 month after Dose 2 and after Dose 3 compared to baseline. In the 50-64-year age cohort, geometric mean fold rises (GMFRs) in toxin A-specific neutralizing antibodies from baseline at Month 7 ranged from 59.19 to 149.23 in the vaccine groups compared to 2.47 in the control group. For toxin-B specific neutralizing antibodies, the GMFRs from baseline at Month 7 ranged from 116.67 to 2503.75 in the vaccine groups compared to 2.48 in the control group. In the 65-85-year age cohort, GMFRs in toxin A-specific neutralizing antibodies from baseline at Month 7 ranged from 42.73 to 254.77 in the vaccine groups compared to 2.03 in the control group. For toxin-B specific neutralizing antibodies, the GMFRs from baseline at Month 7 ranged from 136.12 to 4922.80 in the vaccine groups compared to 1.58 in the control group. Potent antitoxin neutralizing responses were still evident in immunized subjects in both age groups at Month 12. Although there was no clear dose-level response pattern, the data suggest that both the antitoxin A- and B-specific neutralizing responses were trending higher in the toxoid-only groups compared to the toxoid+Al(OH)3 groups. Furthermore, the magnitude of the immune response was similar in the 2 age cohorts. CONCLUSION: The vaccine formulations studied in this phase 1 study were immunogenic and well tolerated. The results presented support further development of the C. difficile vaccine candidate in a larger population of subjects to determine the optimal dose and immunization schedule. CLINICAL TRIAL REGISTRY: NCT01706367.

Randomized, double-blind, active-controlled study evaluating the safety and immunogenicity of three vaccination schedules and two dose levels of AV7909 vaccine for anthrax post-exposure prophylaxis in healthy adults.

AV7909 vaccine being developed for post-exposure prophylaxis of anthrax disease may require fewer vaccinations and reduced amount of antigen to achieve an accelerated immune response over BioThrax(®) (Anthrax Vaccine Adsorbed). A phase 2, randomized, double-blind, BioThrax vacccine-controlled study was conducted to evaluate the safety and immunogenicity of three intramuscular vaccination schedules and two dose levels of AV7909 in 168 healthy adults. Subjects were randomized at a 4:3:2:4:2 ratio to 5 groups: (1) AV7909 on Days 0/14; (2) AV7909 on Days 0/28; (3) AV7909 on Days 0/14/28; (4) half dose AV7909 on Days 0/14/28; and (5) BioThrax vaccine on Days 0/14/28. Vaccinations in all groups were well tolerated. The incidences of adverse events (AEs) were 79% for AV7909 subjects and 65% for BioThrax subjects; 92% of AV7909 subjects and 87% of BioThrax subjects having AEs reported Grade 1-2 AEs. No serious AEs were assessed as potentially vaccine-related, and no AEs of potential autoimmune etiology were reported. There was no discernible pattern indicative of a safety concern across groups in the incidence or severity of reactogenicity events. Groups 2-4 achieved success for the primary endpoint, demonstrated by a lower 95% confidence limit of the percentage of subjects with protective toxin neutralizing antibody NF50 values (≥0.56) to be ≥40% at Day 63. Group 1 marginally missed the criterion (lower bound 95% confidence limit of 39.5%). Immune responses were above this threshold for Groups 1, 3 and 4 at Day 28 and all groups at Day 42. Further study of an AV7909 two-dose schedule given 2 weeks apart is warranted in light of the favorable tolerability profile and immunogenicity response relative to three doses of BioThrax vaccine, as well as preliminary data from nonclinical studies indicating similar immune responses correlate with higher survival for AV7909 than BioThrax vaccine.

Pharmacokinetics, Pharmacodynamics, and Safety of MEDI4212, an Anti-IgE Monoclonal Antibody, in Subjects with Atopy: A Phase I Study.

INTRODUCTION: The anti-IgE therapy omalizumab is currently licensed for the treatment of moderate to severe allergic asthma and chronic idiopathic urticaria. Owing to limitations in the use of omalizumab, a need exists for optimized anti-IgE therapies to broaden clinical indications and patient populations, and to improve dosing schedules. The objective of this phase I, randomized, placebo/omalizumab-controlled, first-in-human, dose-escalation study was to evaluate the pharmacokinetics, pharmacodynamics, and safety of the high-affinity, anti-IgE therapy MEDI4212 in non-Japanese and Japanese subjects with atopy and/or diagnostic IgE ≥ 30 IU/mL. METHODS: Subjects with atopy and/or baseline IgE ≥ 30 IU/mL were randomized to a single dose of subcutaneous (5, 15, 60, 150, or 300 mg) or intravenous (300 mg) MEDI4212, subcutaneous omalizumab, or placebo. Following administration, pharmacokinetic, pharmacodynamic [IgE (free and total), and cellular FcεRI expression], and safety assessments were made. RESULTS: MEDI4212 rapidly suppressed free serum IgE to a greater extent than omalizumab; however, recovery of free IgE to baseline in MEDI4212-dosed subjects was rapid when compared with the slow and gradual recovery seen in omalizumab-dosed individuals. The loss of IgE suppression corresponded with a rapid decrease of serum MEDI4212. FcεRI expression on dendritic cells and basophils was reduced following MEDI4212 dosing. MEDI4212 was well tolerated by subjects; adverse events were generally of low severity and no subjects discontinued due to adverse events. CONCLUSIONS: The increased potency of MEDI4212 may be of clinical interest for individuals with high-diagnostic IgE levels where more extensive IgE suppression is required for clinical response. However, the modest duration of free IgE suppression below the target concentration noted with MEDI4212 in this study suggests limited potential for dosing schedule advantages over omalizumab. FUNDING: MedImmune. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01544348.

Phase 3 trial evaluating the immunogenicity and safety of a three-dose BioThrax® regimen for post-exposure prophylaxis in healthy adults.

BACKGROUND: This study was conducted to support licensure of a post-exposure prophylaxis indication for BioThrax(®) (anthrax vaccine adsorbed) concurrent with antimicrobials for individuals exposed to aerosolized anthrax spores. METHODS: The immunogenicity and safety of a three-dose regimen (0, 2, and 4 weeks) of BioThrax administered subcutaneously (SC) were evaluated in 200 healthy adults 18-65 years of age. Toxin-neutralizing antibody (TNA) was expressed as 50% neutralization factor (NF50) at predetermined time points through Day 100. Safety was assessed by physical examinations, vital signs, solicited local and systemic reactions using web-enabled subject diaries, in-clinic solicited reactions, and unsolicited adverse events (AEs). RESULTS: The prospectively defined success criteria for the primary and secondary endpoints were met. This required the lower bound of the 95% confidence interval (CI) for the proportion of subjects with a TNA NF50 value to be greater than 40% at Day 63 (primary), Day 70 (secondary) and Days 63-100 (secondary). At Day 63, 71% of subjects achieved a TNA NF50 threshold value ≥ 0.56, with a lower bound of the 95% CI ≥ 40% (64%). The percentage of subjects achieving a TNA NF50 threshold value ≥ 0.56 at Day 70 was 58% (95% CI: 50%, 65%), and the mean value on Days 63-100 (inclusive) was 53% (95% CI: 41%, 55%). The threshold TNA NF50 value of 0.56 was developed from previous rabbit challenge and human immunogenicity studies. No related serious AEs occurred during the study, and no subjects withdrew from the study because of an AE. Tenderness and pain at the injection site were recorded most often in subject diaries following vaccination. CONCLUSIONS: BioThrax, administered as three SC doses at 0, 2, and 4 weeks, was well tolerated. The prospectively defined success criteria for TNA levels on Days 63, 70, and 63-100 were achieved.

Immunogenicity, reactogenicity and safety of an inactivated quadrivalent influenza vaccine candidate versus inactivated trivalent influenza vaccine: a phase III, randomized trial in adults aged ≥18 years.

BACKGROUND: Two antigenically distinct influenza B lineages have co-circulated since the 1980s, yet inactivated trivalent influenza vaccines (TIVs) include strains of influenza A/H1N1, A/H3N2, and only one influenza B from either the Victoria or Yamagata lineage. This means that exposure to B-lineage viruses mismatched to the TIV is frequent, reducing vaccine protection. Formulations including both influenza B lineages could improve protection against circulating influenza B viruses. We assessed a candidate inactivated quadrivalent influenza vaccine (QIV) containing both B lineages versus TIV in adults in stable health. METHODS: A total of 4659 adults were randomized 5:5:5:5:3 to receive one dose of QIV (one of three lots) or a TIV containing either a B/Victoria or B/Yamagata strain. Hemagglutination-inhibition assays were performed pre-vaccination and 21-days after vaccination. Lot-to-lot consistency of QIV was assessed based on geometric mean titers (GMT). For QIV versus TIV, non-inferiority against the three shared strains was demonstrated if the 95% confidence interval (CI) upper limit for the GMT ratio was ≤1.5 and for the seroconversion difference was ≤10.0%; superiority of QIV versus TIV for the alternate B lineage was demonstrated if the 95% CI lower limit for the GMT ratio was > 1.0 and for the seroconversion difference was > 0%. Reactogenicity and safety profile of each vaccine were assessed. Clinicaltrials.gov: NCT01204671. RESULTS: Consistent immunogenicity was demonstrated for the three QIV lots. QIV was non-inferior to TIV for the shared vaccine strains, and was superior for the added alternate-lineage B strains. QIV elicited robust immune responses against all four vaccine strains; the seroconversion rates were 77.5% (A/H1N1), 71.5% (A/H3N2), 58.1% (B/Victoria), and 61.7% (B/Yamagata). The reactogenicity and safety profile of QIV was consistent with TIV. CONCLUSIONS: QIV provided superior immunogenicity for the additional B strain compared with TIV, without interfering with antibody responses to the three shared antigens. The additional antigen did not appear to alter the safety profile of QIV compared with TIV. This suggests that the candidate QIV is a viable alternative to TIV for use in adults, and could potentially improve protection against influenza B. TRIAL REGISTRATION: Clinical Trials.gov: NCT01204671/114269.

Randomized, double-blind, placebo-controlled, safety and immunogenicity study of 4 formulations of Anthrax Vaccine Adsorbed plus CPG 7909 (AV7909) in healthy adult volunteers.

A new anthrax vaccine that could accelerate the immune response and possibly reduce the number of injections needed for protection would be desirable in a post-exposure setting. This Phase 1 study compared the safety and immunogenicity of 2 IM doses (Days 0 and 14) of 4 formulations of AV7909 (AVA plus CPG 7909) with 2 IM doses of BioThrax(®) (Anthrax Vaccine Adsorbed) and 2 IM doses of saline placebo administered on Days 0 and 14. A total of 105 healthy adults 18-50 years of age were randomized to 1 of 6 study groups: BioThrax (0.5 mL), AV7909 Formulation 1 (0.5 mL AVA+0.5mg CPG 7909), AV7909 Formulation 2 (0.5 mL AVA+0.25mg CPG 7909), AV7909 Formulation 3 (0.25 mL AVA+0.5mg CPG 7909), AV7909 Formulation 4 (0.25 mL AVA+0.25mg CPG 7909), or saline placebo (0.5 mL). All randomized subjects received at least 1 vaccination, and 100 subjects completed the trial. After 2 doses, mean peak normalized toxin neutralizing antibody responses (TNA NF50) in the AV7909 groups were higher than in the BioThrax group. Differences among the 4 AV7909 groups were not statistically significant. Subjects who received AV7909 reached peak titers on Day 28 vs. Day 35 in the BioThrax group. The most common adverse events (AEs) in the BioThrax and AV7909 groups assessed as related to vaccination were injection site reactions. Transient lymphopenia was observed after the first dose in each AV7909 group. Frequencies of injection site and systemic reactions recorded by subjects in diaries for 7 days after each injection were highest with AV7909 Formulation 1. No AEs of special interest (autoimmune events) were observed in the study. Further studies of doses and dosing regimens are planned to assess the immunogenicity and reactogenicity of AV7909.

Immunogenicity of a quadrivalent Ann Arbor strain live attenuated influenza vaccine delivered using a blow-fill-seal device in adults: a randomized, active-controlled study*.

BACKGROUND: Influenza B strains from two distinct lineages (Yamagata and Victoria) have cocirculated over recent years. Current seasonal vaccines contain a single B lineage resulting in frequent mismatches between the vaccine strain and the circulating strain. An Ann Arbor strain quadrivalent live attenuated influenza vaccine (Q/LAIV) containing B strains from both lineages is being developed to address this issue. OBJECTIVES: The goal of this study was to evaluate whether Q/LAIV administered intranasally as a single dose to a single nostril, using a blow-fill-seal (BFS) delivery system had a similar immunogenicity and safety profile compared with the licensed trivalent vaccine delivered using the Accuspray device. PATIENTS/METHODS: Adults aged 18-49 years were randomized to receive one intranasal dose of Q/LAIV delivered using a BFS device (Q/LAIV-BFS; n=1202) or one of two trivalent live attenuated influenza vaccines (T/LAIV) containing one of the corresponding B strains (total T/LAIV, n=598). Primary endpoints were the post-vaccination strain-specific serum hemagglutination inhibition antibody geometric mean titers for each strain. Secondary immunogenicity endpoints, safety, and acceptability of the BFS device were also assessed. RESULTS: Q/LAIV was immunogenically non-inferior to T/LAIV for all four influenza strains. Secondary immunogenicity outcomes were consistent with the primary endpoint. Solicited symptoms and AEs were comparable in both groups. Subjects considered the BFS device to be acceptable. CONCLUSIONS: Immune responses to vaccination with Ann Arbor strain Q/LAIV-BFS were non-inferior to those with T/LAIV. Q/LAIV may confer broader protection against seasonal influenza B by targeting both major influenza B lineages.

A phase 1, randomized, open-label, active-controlled trial to assess the safety of a meningococcal serogroup B bivalent rLP2086 vaccine in healthy adults.

Neisseria meningitidis serogroup B (MnB) is a significant cause of invasive meningococcal disease, but no broadly protective vaccine is yet approved. We assessed the safety and immunogenicity of a bivalent MnB vaccine composed of lipidated subfamily A and B variants of recombinant LP2086 (rLP2086, also known as factor H binding protein, fHBP). Forty-eight adults, ages 18-40 y, were randomized to receive 60, 120 or 200 µg of the bivalent rLP2086 vaccine or control at 0, 2 and 6 mo. Immunogenicity was assessed by rLP2086-specific immunoglobulin G (IgG) geometric mean titers for subfamily A and B proteins. Safety was determined by laboratory assessments of blood and urine and by reporting of solicited and unsolicited adverse events (AEs). The bivalent rLP2086 vaccine elicited high IgG titers following the second and third vaccination at all dose levels. In each of the four study arms, 11 of the 12 participating subjects reported ≥ 1 AE, and no serious AEs were reported. Local and systemic reactions were mainly mild to moderate. Laboratory abnormalities (including increased sodium, decreased neutrophils, and proteinuria) were not associated with clinical events and were not considered to be related to the study vaccine. Vaccinations were generally well-tolerated. Strong IgG antibody responses and the absence of clinically significant laboratory abnormalities support further development of the bivalent rLP2086 vaccine (www.clinicaltrials.gov; identifier: NCT00879814).

Development of VAX128, a recombinant hemagglutinin (HA) influenza-flagellin fusion vaccine with improved safety and immune response.

BACKGROUND: We evaluated the safety and immunogenicity profiles of 3 novel influenza vaccine constructs consisting of the globular head of the HA1 domain of the Novel H1N1 genetically fused to the TLR5 ligand, flagellin. HA1 was fused to the C-terminus of flagellin in VAX128A, replaced the D3 domain of flagellin in VAX128B and was fused in both positions in VAX128C. METHODS: In a dose escalation trial, 112 healthy subjects 18-49 and 100 adults ≥65 years old were enrolled in a double blind, placebo controlled clinical trial at two centers. Vaccines were administered IM at doses ranging from 0.5 to 20 µg. VAX128C was selected for second study performed in 100 subjects 18-64 years old comparing 1.25 and 2.5 µg doses. All subjects were followed for safety and sera collected pre- and post-vaccination were tested by hemagglutination-inhibition (HAI). Serum C-reactive protein and cytokine levels were also measured. CONCLUSIONS: In the first study high HAI titers and high seroconversion and seroprotection rates were observed at doses ≥2.5 µg in adults 18-49. In adults ≥65 years, the vaccines doses of ≥4 µg were required to induce a ≥4-fold rise in HAI titer, 50% seroconversion and 70% seroprotection. Based on safety, VAX128A was tested up to 8 µg, VAX128B to 16 µg and VAX128C to 20 µg. Dose escalation for VAX128A was stopped at 8 µg because one subject had temperature 101.6°F associated with a high CRP response, VAX128B was stopped at 16 µg because of a severe AE associated with a high CRP and IL-6 response. VAX128C was not stopped before reaching the 20 µg dose. In the second study VAX128C was well tolerated among 100 subjects who received 1.25 or 2.5 µg. The peak GMT was 385 (95%CI 272-546), 79% (71-87%) seroconversion and 92% (84-96%) seroprotection. DISCUSSION: Flagellin adjuvanted vaccines can be designed to minimize reactogenicity and retain immunogenicity, thereby representing a promising next generation vaccine technology.

Safety and long-term humoral immune response in adults after vaccination with an H1N1 2009 pandemic influenza vaccine with or without AS03 adjuvant.

BACKGROUND: In this study (NCT00985088) we evaluated different formulations of an H1N1 2009 pandemic influenza vaccine that deliver various viral hemagglutinin (HA) doses with or without AS03 (a tocopherol-based oil-in-water adjuvant system). METHODS: A total of 1340 healthy subjects aged ≥18 years were randomized to receive 1 or 2 doses of an adjuvanted (3.75-µg HA/AS03(A) or 1.9-µg HA/AS03(B)) or nonadjuvanted vaccine formulation. Safety and immunogenicity (by hemagglutination-inhibition [HI] assay) after each dose and 6 months after dose 1 are reported here. RESULTS: A single dose of AS03(A)-adjuvanted 3.75-µg HA H1N1 2009 induced the strongest immune responses in subjects aged 18-64 years (seroprotection rate [SPR], 97.2%; seroconversion rate [SCR], 90.1%) as well as in subjects aged >64 years (SPR, 91.1%; SCR, 78.2%) 21 days after vaccination. Six months after dose 1, subjects who received 2 doses of either the adjuvanted formulation or 1 dose of the adjuvanted 3.75-µg HA formulation continued to meet all Center for Biologics Evaluation and Research and Committee for Medicinal Products for Human Use criteria. All formulations had clinically acceptable safety profiles. CONCLUSION: A single dose of the 3.75-µg HA AS03(A)-adjuvanted H1N1 2009 influenza vaccine was highly immunogenic in both age strata (18-64 and >64 years), inducing long-term persistence of the immune response until at least 6 months after dose 1.

A randomized, double-blind noninferiority study of quadrivalent live attenuated influenza vaccine in adults.

BACKGROUND: Trivalent seasonal influenza vaccines contain 2 A strains and 1 B strain. B strains of 2 antigenically distinct lineages, Yamagata and Victoria, have been co-circulating annually, and the B strain included in vaccines often has not been a lineage match to the major circulating strain. Thus, a vaccine containing B strains from both lineages could broaden protection against influenza. Quadrivalent live attenuated influenza vaccine (Q/LAIV) is an investigational 4-strain formulation of LAIV that contains 2 A strains, A/H1N1 and A/H3N2, and 2 B strains, 1 from each lineage. METHODS: A randomized, double-blind, active-controlled study of Q/LAIV was conducted in 1800 adults aged 18-49 years to compare the immunogenicity and safety of Q/LAIV to trivalent LAIV (T/LAIV). Subjects were randomized 4:1:1 to receive an intranasal dose of Q/LAIV (n=1200) or 1 of 2 matching T/LAIV vaccines, each containing 1 of the B strains included in Q/LAIV (n=600 total). The primary endpoint was the comparison of the post-vaccination strain-specific geometric mean titers (GMT) of hemagglutination inhibition antibody in Q/LAIV recipients to those in T/LAIV recipients, with immunologic noninferiority of Q/LAIV to be demonstrated if the upper bound of the 2-sided 95% confidence interval (CI) for the ratio of the GMTs [T/LAIV divided by Q/LAIV] was ≤1.5 for all strains. RESULTS AND CONCLUSION: Q/LAIV met the criteria for noninferiority: the ratios of the GMTs for the A/H1N1, A/H3N2, B/Yamagata, and B/Victoria strains were 1.09 (95% CI, 1.01-1.18), 1.05 (95% CI, 0.96-1.14), 1.10 (95% CI, 0.97-1.25), and 0.92 (95% CI, 0.82-1.03), respectively. Solicited symptoms and adverse events were similar in the Q/LAIV and T/LAIV arms. Q/LAIV may confer increased protection against influenza by targeting B strains from both lineages.