Safety and immunogenicity of a thermostable ID93 + GLA-SE tuberculosis vaccine candidate in healthy adults.

Adjuvant-containing subunit vaccines represent a promising approach for protection against tuberculosis (TB), but current candidates require refrigerated storage. Here we present results from a randomized, double-blinded Phase 1 clinical trial (NCT03722472) evaluating the safety, tolerability, and immunogenicity of a thermostable lyophilized single-vial presentation of the ID93 + GLA-SE vaccine candidate compared to the non-thermostable two-vial vaccine presentation in healthy adults. Participants were monitored for primary, secondary, and exploratory endpoints following intramuscular administration of two vaccine doses 56 days apart. Primary endpoints included local and systemic reactogenicity and adverse events. Secondary endpoints included antigen-specific antibody (IgG) and cellular immune responses (cytokine-producing peripheral blood mononuclear cells and T cells). Both vaccine presentations are safe and well tolerated and elicit robust antigen-specific serum antibody and Th1-type cellular immune responses. Compared to the non-thermostable presentation, the thermostable vaccine formulation generates greater serum antibody responses (p < 0.05) and more antibody-secreting cells (p < 0.05). In this work, we show the thermostable ID93 + GLA-SE vaccine candidate is safe and immunogenic in healthy adults.

Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: A randomized, double-blind, placebo-controlled, phase 1 clinical trial.

The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15µg H7N9, 1B) IB160 + 7.5µg H7N9, 1C) IB160 + 3.75µg H7N9, 2A) SE + 15µg H7N9, 2B) SE + 7.5µg H7N9, 2C) SE + 3.75µg H7N9, 3) unadjuvanted vaccine 15µg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

Lyophilization Process Engineering and Thermostability of ID93 + GLA-SE, a Single-Vial Adjuvanted Subunit Tuberculosis Vaccine Candidate for Use in Clinical Studies.

Promising clinical efficacy results have generated considerable enthusiasm for the potential impact of adjuvant-containing subunit tuberculosis vaccines. The development of a thermostable tuberculosis vaccine formulation could have significant benefits on both the cost and feasibility of global vaccine distribution. The tuberculosis vaccine candidate ID93 + GLA-SE has reached Phase 2 clinical testing, demonstrating safety and immunogenicity as a two-vial point-of-care mixture. Earlier publications have detailed efforts to develop a lead candidate single-vial lyophilized thermostable ID93 + GLA-SE vaccine formulation. The present report describes the lyophilization process development and scale-up of the lead candidate thermostable ID93 + GLA-SE composition. The manufacture of three full-scale engineering batches was followed by one batch made and released under current Good Manufacturing Practices (cGMP). Up to 4.5 years of stability data were collected. The cGMP lyophilized ID93 + GLA-SE passed all manufacturing release test criteria and maintained stability for at least 3 months when stored at 37°C and up to 24 months when stored at 5°C. This work represents the first advancement of a thermostable adjuvant-containing subunit tuberculosis vaccine to clinical testing readiness.

The TLR-4 agonist adjuvant, GLA-SE, improves magnitude and quality of immune responses elicited by the ID93 tuberculosis vaccine: first-in-human trial.

Tuberculosis (TB) is the leading cause of infectious death worldwide. Development of improved TB vaccines that boost or replace BCG is a major global health goal. ID93 + GLA-SE is a fusion protein TB vaccine candidate combined with the Toll-like Receptor 4 agonist adjuvant, GLA-SE. We conducted a phase 1, randomized, double-blind, dose-escalation clinical trial to evaluate two dose levels of the ID93 antigen, administered intramuscularly alone or in combination with two dose levels of the GLA-SE adjuvant, in 60 BCG-naive, QuantiFERON-negative, healthy adults in the US (ClinicalTrials.gov identifier: NCT01599897). When administered as 3 injections, 28 days apart, all dose levels of ID93 alone and ID93 + GLA-SE demonstrated an acceptable safety profile. All regimens elicited vaccine-specific humoral and cellular responses. Compared with ID93 alone, vaccination with ID93 + GLA-SE elicited higher titers of ID93-specific antibodies, a preferential increase in IgG1 and IgG3 subclasses, and a multifaceted Fc-mediated effector function response. The addition of GLA-SE also enhanced the magnitude and polyfunctional cytokine profile of CD4+ T cells. The data demonstrate an acceptable safety profile and indicate that the GLA-SE adjuvant drives a functional humoral and T-helper 1 type cellular response.

The adjuvant GLA-AF enhances human intradermal vaccine responses.

Adjuvants are key to shaping the immune response to vaccination, but to date, no adjuvant suitable for human use has been developed for intradermal vaccines. These vaccines could be self-administered and sent through the mail as they do not require long needles or technical expertise in immunization. In the event of a pandemic outbreak, this approach could alleviate the congregation of patients in health centers and thus reduce the potential of these centers to enhance the spread of lethal infection. A reliable and potent vaccine system for self-administration would provide an effective countermeasure for delivery through existing product distribution infrastructure. We report results from preclinical and clinical trials that demonstrate the feasibility of an adjuvanted, intradermal vaccine that induced single shot protection in ferrets and seroprotection in humans against one of the more lethal strains of pandemic flu, Indonesia H5N1. In the human trial, the vaccine was safe and clinical responses were above approvable endpoints for a protective flu vaccine. Inclusion of a modern TLR4 (Toll-like receptor 4) agonist-based adjuvant was critical to the development of the response in the intradermal groups. In humans, this is the first report of a safe and effective intradermal adjuvant, GLA-AF (aqueous formulation of glucopyranosyl lipid adjuvant), and provides a future path for developing a vaccine-device combination for distribution by mail and self-administration in case of a pandemic.

A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1+MPL-SE vaccine for use in the prevention of visceral leishmaniasis.

Healthy Indian adult volunteers, with or without a history of leishmaniasis, were evaluated for evidence of previous infection with Leishmania donovani based on the direct agglutination test (DAT). Three cohorts of 6 DAT-negative and 6 DAT-positive subjects were enrolled in an open-label, dose-escalating, uncontrolled clinical trial and received three injections of the LEISH-F1+MPL-SE vaccine (consisting of 5µg, 10µg, or 20µg recombinant Leishmania polyprotein LEISH-F1 antigen+25µg MPL®-SE adjuvant). The study injections were given subcutaneously on days 0, 28, and 56, and the subjects were followed through day 168 for safety and immunological endpoints. The vaccine was safe and well-tolerated in DAT-negative and DAT-positive subjects and induced T-cell production of IFN-γ and other cytokines in response to stimulation with the LEISH-F1 antigen. This clinical trial shows that the LEISH-F1+MPL-SE vaccine is safe and immunogenic in healthy subjects with and without history of previous infection with Leishmania donovani.

A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1+MPL-SE vaccine when used in combination with sodium stibogluconate for the treatment of mucosal leishmaniasis.

Adult patients with mucosal leishmaniasis (ML) were enrolled in a randomized, double-blind, placebo-controlled, dose-escalating clinical trial and were randomly assigned to receive three injections of either the LEISH-F1+MPL-SE vaccine (consisting of 5, 10, or 20 µg recombinant Leishmania polyprotein LEISH-F1 antigen+25 µg MPL(®)-SE adjuvant) (n=36) or saline placebo (n=12). The study injections were given subcutaneously on Days 0, 28, and 56, and the patients were followed through Day 336 for safety, immunological, and clinical evolution endpoints. All patients received standard chemotherapy with sodium stibogluconate starting on Day 0. The vaccine was safe and well tolerated, and induced both humoral and cell-mediated immune responses. Furthermore, intracellular cytokine staining showed an increase in the proportion of memory LEISH-F1-specific IL-2(+) CD4 T-cells after vaccination, which was associated with clinical cure. This clinical trial shows that the LEISH-F1+MPL-SE vaccine is safe and immunogenic in patients with ML.

A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1+MPL-SE vaccine when used in combination with meglumine antimoniate for the treatment of cutaneous leishmaniasis.

Forty-four adult patients with cutaneous leishmaniasis (CL) were enrolled in a randomized, double-blind, controlled, dose-escalating clinical trial and were randomly assigned to receive three injections of either the LEISH-F1+MPL-SE vaccine (consisting of 5, 10, or 20 µg recombinant Leishmania polyprotein LEISH-F1 antigen+25 µg MPL-SE adjuvant) (n=27), adjuvant alone (n=8), or saline placebo (n=9). The study injections were given subcutaneously on Days 0, 28, and 56, and the patients were followed through Day 336 for safety, immunological, and clinical evolution endpoints. All patients received chemotherapy with meglumine antimoniate starting on Day 0. The vaccine was safe and well tolerated. Nearly all vaccine recipients and no adjuvant-alone or placebo recipients demonstrated an IgG antibody response to LEISH-F1 at Day 84. Also at Day 84, 80% of vaccine recipients were clinically cured, compared to 50% and 38% of adjuvant-alone and placebo recipients. The LEISH-F1+MPL-SE vaccine was safe and immunogenic in CL patients and appeared to shorten their time to cure when used in combination with meglumine antimoniate chemotherapy.

Safety and immunogenicity of a defined vaccine for the prevention of cutaneous leishmaniasis.

Healthy Colombian adult volunteers with no history of leishmaniasis were evaluated for evidence of previous subclinical infection with Leishmania based on the Montenegro skin test (MST). Twelve MST-positive subjects were enrolled in an open-label, uncontrolled clinical trial (the "MST-positive trial") and received three injections of the LEISH-F1+MPL-SE vaccine (consisting of 10 microg recombinant Leishmania polyprotein LEISH-F1 antigen [TSA+LmSTI1+LeIF]+25 microg MPL-SE adjuvant). Sixty-eight MST-negative subjects were enrolled in a randomized, double-blind, controlled trial (the "MST-negative trial") and were randomly assigned to receive three injections of either the vaccine (n=34), 10 microg LEISH-F1 protein alone (n=17), or saline placebo (n=17). In both trials, the study injections were given subcutaneously on Days 0, 28, and 56, and subjects were followed for safety and immunological endpoints. The LEISH-F1+MPL-SE vaccine was safe and well tolerated in MST-positive and MST-negative subjects. In both trials, an IFN-gamma response to the LEISH-F1 antigen at Day 84 was observed in more than half of the vaccine recipients. In the MST-negative trial, the IFN-gamma response was significantly more frequent and of greater magnitude in vaccine recipients than in protein-alone or placebo recipients. An IgG antibody response to LEISH-F1 was observed in all vaccine recipients. In both trials, delayed-type hypersensitivity (DTH) to LEISH-F1 was observed in most of the vaccine recipients. In the MST-negative trial, DTH was significantly higher in vaccine than placebo recipients. These clinical trials of the first defined vaccine for leishmaniasis show that the LEISH-F1+MPL-SE vaccine is safe and immunogenic in healthy subjects with and without evidence of previous subclinical infection with Leishmania.