2018 NIAID Strategic Plan for Research on Vaccine Adjuvants

2018 NIAID

STRATEGIC PLAN

FOR

RESEARCH

VACCINE

ADJUVANTS

NIAID

National Institute of Allergy and Infectious Diseases

TABLE OF CONTENTS

1. INTRODUCTION ................................................................................................................... 3

1.1. BRIEF OVERVIEW OF ADJUVANTS IN LICENSED VACCINES ........................... 3

1.2. THE NEED FOR NEW VACCINE ADJUVANTS

1.3. NIAID’S MISSION AND EXTRAMURAL FOCUS ON VACCINE ADJUVANT

........................................................ 4

RESEARCH ............................................................................................................................ 4

1.4. NIAID’S STRATEGIC PLAN FOR RESEARCH ON VACCINE ADJUVANTS ....... 5

2. FUNDAMENTAL IMMUNOLOGY AND ADJUVANT DISCOVERY ............................. 8

2.1. RECENT PROGRESS IN NIAID-SUPPORTED ACTIVITIES .................................... 8

2.2. PROGRAM GOALS AND RESEARCH CHALLENGES ........................................... 12

2.3. NIAID’S STRATEGY TO ADVANCE ADJUVANT DISCOVERY .......................... 13

3. ADJUVANT DEVELOPMENT AND PRECLINICAL EVALUATION ........................... 16

3.1. RECENT PROGRESS IN NIAID-SUPPORTED ACTIVITIES .................................. 16

3.2. PROGRAM GOALS AND RESEARCH CHALLENGES .. ......................................... 19

3.3. NIAID’S APPROACH TO ADVANCE ADJUVANT DEVELOPMENT AND

PRECLINICAL EVALUATION .......................................................................................... 21

4. CLINICAL EVALUATION OF ADJUVANTED VACCINES ........................................... 23

4.1. RECENT PROGRESS IN NIAID-SUPPORTED ACTIVITIES ............................ 23

4.2. PROGRAM GOALS AND RESEARCH CHALLENGES ........................................... 25

4.3. NIAID’S APPROACH TO ADVANCE THE CLINICAL EVALUATION OF

ADJUVANTED VACCINES ............................................................................................... 27

5. SUMMARY .......................................................................................................................... 28

6. APPENDICES ....................................................................................................................... 29

6.1. APPENDIX A: ABBREVIATIONS.............................................................................. 29

6.2. APPENDIX B: BLUE RIBBON PANEL MEMBERS ................................................. 31

6.3. APPENDIX C: NIAID-SPONSORED CLINICAL TRIALS FOR NON-HIV

ADJUVANTED VACCINES, RECENTLY COMPLETED OR ONGOING (AS OF APRIL

2018) ...................................................................................................................................... 33

6.4. APPENDIX D: NIAID-SPONSORED CLINICAL TRIALS FOR HIV ADJUVANTED

VACCINES, COMPLETED OR ONGOING (AS OF APRIL 2018) .................................. 34

1. INTRODUCTION

1.1. BRIEF OVERVIEW OF ADJUVANTS IN LICENSED VACCINES

The use of adjuvants began in 1920 when the French veterinarian Gaston Ramon

discovered that co-administration of inactivated diphtheria toxoid with starch,

breadcrumbs, or other substances led to an increase in antitoxin responses to diphtheria. In

1926, this finding was followed by Alexander Glenny’s discovery of the adjuvanticity of

aluminum salts and their clinical utility in diphtheria immunization.

Until 2009, aluminum-based adjuvants, collectively termed “alum,” were the only

adjuvants in vaccines licensed for use in the United States. That year, the U.S. Food and

Drug Administration (FDA) licensed the first of five vaccines containing novel adjuvants,

which are described below and summarized in Table 1:

• Cervarix

, a human papillomavirus (HPV) vaccine containing AS04, a combination of

alum and 3-O-desacyl-4'-monophosphoryl lipid A (MPL), an immune-stimulating lipid

developed by GlaxoSmithKline (GSK). In the United States, Cervarix

is approved for

use in females 10 through 25 years of age to prevent infection from HPV types 16 and

18, which cause about 70% of cervical cancer cases.

• Q-Pan H5N1, a pandemic H5N1 influenza vaccine containing AS03, an oil-in-water

emulsion combination adjuvant developed by GSK. This vaccine is part of the U.S.

vaccine stockpile but is not commercially available. It is intended for use in people 18

years of age and older.

• FLUAD

, an influenza vaccine containing MF59

, a squalene-based oil-in-water

emulsion adjuvant developed by Novartis, for use in people 65 years of age and older.

FLUAD

was first licensed in Italy in 1997 and is now used as a pediatric and adult

influenza vaccine in more than 30 countries.

• Shingrix

, a shingles (herpes zoster) vaccine containing AS01, a liposome-based

combination adjuvant containing MPL and the saponin QS-21, developed by GSK.

Shingrix

is for use in adults 50 years of age and older.

• Heplisav-B

, a hepatitis B vaccine containing CpG-oligodeoxynucleotide (ODN), a

short, single-stranded DNA molecule that mimics unmethylated bacterial DNA and

triggers innate immune responses through activation of Toll-like receptor 9 (TLR9),

developed by Dynavax. This vaccine is for use in people 18 years of age and older.

Table 1. FDA-approved vaccines containing novel adjuvants (2009-2018)

Year Adjuvant Vaccine Name

2009 AS04 Cervarix

2013 AS03 Q-Pan H5N1

2015 MF59

FLUAD

2017 AS01B Shingrix

2017 CpG-oligodeoxynucleotide Heplisav-B

1.2. THE NEED FOR NEW VACCINE ADJUVANTS

Live-attenuated vaccines and some vaccines based on inactivated or killed agents do not

require exogenous adjuvants, because the vaccines contain their own natural/endogenous

adjuvants that can stimulate both the innate and adaptive arms of the immune system.

However, subunit vaccines, which contain specific purified molecular entities, generally

lack immune stimulators found in whole organism–based vaccines, leading to a need for

exogenous adjuvants to induce protective immunity and desirable vaccine efficacy.

Unfortunately, not all adjuvanted vaccines induce the types of immune responses required

for durable protective immunity. New or improved adjuvants may enhance the safety and

efficacy of current vaccines, and they also are needed to improve vaccine efficacy in at-risk

populations such as neonates, young children, pregnant women, the immunocompromised,

and the elderly. Finally, vaccines do not exist for many known and newly emerging

infectious agents, and the availability of new adjuvants, along with an understanding of

their mode of action, may facilitate development of such vaccines.

1.3. NIAID’S MISSION AND EXTRAMURAL FOCUS ON VACCINE ADJUVANT

RESEARCH

The overall mission of the National Institute of Allergy and Infectious Diseases (NIAID),

part of the National Institutes of Health (NIH), is to improve human health by supporting

research to understand, treat, and prevent infectious and immune-mediated diseases.

Critical components of NIAID’s research agenda in support of this mission are the

discovery and development of adjuvants, traditionally defined as vaccine components that

augment and target immune responses.

NIAID’s three extramural divisions—the Division of Allergy, Immunology, and

Transplantation (DAIT); the Division of Microbiology and Infectious Diseases (DMID);

and the Division of AIDS (DAIDS)—all support aspects of adjuvant research that are

described in detail in Sections 2, 3, and 4. Briefly, the mission of each division and its

adjuvant research focus is described below.

DAIT supports basic and clinical research to understand immune system development;

define the mechanisms governing immune system function across the lifespan, providing

knowledge that can be applied to develop and improve treatment and prevention strategies

for inducing immunity against pathogenic infections; and develop better diagnostic, treatment,

and prevention strategies for immune-mediated diseases and the rejection of transplanted

organs. DAIT adjuvant research focuses on fundamental immunology, adjuvant discovery, and

early-stage development. The latter includes compound screening, determination of adjuvant

mechanisms of action, lead compound optimization and formulation, efficacy testing in

animals, and investigational new drug (IND)–enabling studies. Adjuvant science programs

supported by DAIT began in 2004 and include the Adjuvant Discovery Program, the

Adjuvant Development Program, and the Molecular Mechanisms of Combination

Adjuvants Program. Through these programs, more than 2 million compounds have been

screened, and numerous adjuvant candidates, encompassing eight different adjuvant types

or classes, are being further developed. Other programs invested in characterizing immune

responses to adjuvants include the NIAID Systems Approach to Immunity and

Inflammation Program and the Human Immunology Project Consortium (HIPC).

DMID supports basic and applied research to control and prevent diseases caused by

virtually all human infectious agents except HIV. The DMID portfolio includes a broad

range of research from early discovery through product development for vaccines,

therapeutics, and diagnostics, including novel vaccines (adjuvanted and unadjuvanted) and

platform technologies. Currently, DMID is testing more than 100 different adjuvant

candidates/formulations encompassing all stages of vaccine development. DMID also

offers a comprehensive suite of preclinical services for the development and evaluation of

adjuvanted and unadjuvanted vaccines.

DAIDS supports a comprehensive research portfolio to advance biological knowledge of

HIV/AIDS and its related coinfections and comorbidities. The ultimate goal is to halt the

spread of HIV through the development and implementation of an effective vaccine and

biomedical prevention strategies that are safe and desirable. The adjuvants used in HIV

vaccine candidates, as of April 2018, are listed in Appendix D.

1.4. NIAID’S STRATEGIC PLAN FOR RESEARCH ON VACCINE ADJUVANTS

As technologic and scientific advances increased our understanding of the pathways

regulating innate and adaptive immune responses, NIAID recognized opportunities to

develop novel adjuvants or modify existing adjuvants to safely trigger long-term protective

immunity and durable vaccine efficacy. In 2010, NIAID prepared its first Strategic Plan for

Research on Vaccine Adjuvants and convened an Adjuvant Blue Ribbon Panel (BRP) to

review the plan.

The 2010 BRP made the following recommendations:

• Support additional research to understand how new and existing adjuvants and

combinations of adjuvants enhance vaccine-specific immune protection

• Foster discovery and advancement of promising adjuvant candidates through

optimization and preclinical testing stages

• Develop/improve and standardize animal models to evaluate adjuvant safety and

efficacy, including development/use of animal models that more faithfully reflect

immune responses of neonates/young children and the elderly

• Expand/standardize reagents for adjuvant discovery and development, including

pathogen-specific reagents, and immunologic reagents for animals beyond traditional

mouse models

• Identify more accurate predictors of adjuvant efficacy and/or reactogenicity

• Determine the effects of formulation on adjuvant mechanisms of action and safety and

effectiveness of adjuvanted vaccines

Between 2010 and 2018, NIAID’s extramural adjuvant discovery and development

research programs have implemented these recommendations. Because of significant

advances in adjuvant science, many of which were driven by NIAID-supported programs,

NIAID has updated its 2010 adjuvant research agenda, culminating in the 2018 Strategic

Plan, which focuses on three areas:

• Fundamental immunology and adjuvant discovery

• Adjuvant development and preclinical evaluation

• Clinical evaluation of adjuvanted vaccines

NIAID convened a second BRP on April 23-24, 2018, to assess this Plan and provide

insights and recommendations, which are included in appropriate sections of the Plan and

summarized in Table 2.

Table 2. 2018 Blue Ribbon Panel Recommendations

Fundamental Immunology and Adjuvant Discovery

Fundamental Immunology

• Expand fundamental mechanistic studies to:

o Identify innate correlates of adaptive immunity, including correlates of both protection

and persistent immunity, for healthy and at-risk populations

o Determine how antigen selection, including antigen processing/presentation

mechanisms, impacts adjuvant functionality

Adjuvant Discovery

• Expand discovery efforts beyond TLRs, to include adjuvants that trigger

inflammasome components, target specific immune cells, or mimic immunologic

outcomes of natural infections that induce long-term protective immunity

• Foster precision adjuvant discovery by first determining clinical/immunologic needs,

followed by designing a discovery process to identify compounds that meet those needs

• Support development of functional screening methods that better mimic in vivo responses,

taking into account human variability and at-risk populations

• Compare/optimize adjuvants for specific cell targeting and delivery routes

• Encourage development of standard operating procedures and best practices that maximize

screening efforts and data sharing for cross-study analyses and benchmarking to licensed

products

• Support central core services to further improve program integration: formulation

assistance, production of standardized reference antigens, and animal testing (multiple

models) for head-to-head adjuvant comparisons

• Emphasize importance of considering formulation at the early stages of adjuvant discovery

Adjuvant Development and Preclinical Evaluation

• Explore iterative testing of candidate adjuvants with a broad panel of antigens to identify

the most promising combinations for further development

• Establish a public database/portal that describes the characteristics, functionality, and

safety profiles of novel compounds developed in NIAID’s adjuvant programs, including

links to publications and clinical trials information, and procedures for requesting access to

these adjuvants

• Support studies that develop methods to extrapolate adjuvant outcomes seen with one

antigen to additional antigens

• Expand support of current Good Manufacturing Practice (cGMP) capabilities to support

small-scale cGMP production of promising adjuvants for clinical trials

Clinical Evaluation of Adjuvanted Vaccines

• Support clinical trials of novel adjuvants and expand clinical comparisons of different

adjuvants formulated with the same antigen

• Support clinical trials of adjuvanted vaccines in at-risk populations (e.g., elderly, children)

• Support comprehensive immunological analyses of samples from clinical trials to generate

detailed immune profiles of adjuvant functionality

• Increase use of human challenge models, where applicable, to better assess the efficacy of

adjuvanted vaccines

• Ensure at least a 12-month post-vaccination assessment for safety and immune durability

2. FUNDAMENTAL IMMUNOLOGY AND ADJUVANT DISCOVERY

2.1. RECENT PROGRESS IN NIAID-SUPPORTED ACTIVITIES

Fundamental Immunology

Fundamental immunology research supported by NIAID’s portfolio of investigator-

initiated grants and solicited research programs has identified many novel innate immune

molecules and increased our understanding of innate and adaptive immunity. For example,

investigator-initiated studies have led to the discovery of pathogen-associated molecular

patterns (PAMPs), which trigger innate immune responses and are the basis of many

adjuvants (e.g., they mimic PAMP-induced immune function). More recently, NIAID-

supported investigators have determined that live/viable bacteria contain a unique class of

PAMPs, termed vita-PAMPs, which are bacterial messenger RNAs (mRNAs) and cyclic

di-adenosine monophosphate (c-di-AMP) that serve as signatures of viability and trigger

specific innate immune responses. Similarly, investigators supported by one of NIAID’s

solicited research programs, Systems Approach to Immunity and Inflammation, have:

• Identified novel functions for more than 260 genes, many of which provide insights

into signaling pathways triggered by innate immune receptors and will aid in

mechanism-of-action studies of novel candidate adjuvants

• Developed a suite of ENU-mutant mice (https://mutagenetix.utsouthwestern.edu/) and

Collaborative Cross (CC) mice (http://csbio.unc.edu/CCstatus/index.py) that can be

used to confirm or determine an adjuvant’s mechanism of action. Mice from both

resources can be used in various ways to identify immune receptors or signaling

pathways responsible for adjuvant function.

Novel animal models also have been developed through investigator-initiated research

projects. For example, researchers at the University of Minnesota have developed the “dirty

mouse” model by determining that the microbiome of pet store mice dramatically impacts

immune system function. Dirty mice exhibit immune functionality more reflective of adult

human responses, while immune function in laboratory mice is more similar to that of

human infants. Co-housing the pet store mice with laboratory mice increases the

microbiome diversity of the laboratory mice and changes their immune functionality to that

of the pet store mice (e.g., more similar to adult human responses).

Adjuvant Discovery

NIAID began its first solicited program in adjuvant science in 2003 with the Adjuvant

Discovery Program. This contract program supported the identification and

characterization of novel, effective, and safe vaccine adjuvants. The scientific scope of this

program included:

• Use of high-throughput screening methods for adjuvant identification

• Validation of adjuvant activity in human cells

• Optimization of lead adjuvant candidates through formulation and medicinal chemistry

guided by structure–activity relationship (SAR) studies

• Mechanism of action studies

• Verification of adjuvanticity in animal models

The program was renewed in 2009. Building on knowledge gained from the 2003 and 2009

programs and to address recommendations made by the 2010 Adjuvant BRP, the 2014

program renewal emphasized discovery of adjuvants (1) for use in at-risk populations and

(2) that induced mucosal immune responses. Recognizing the limitations of a program that

renews only every five years, and following the recommendations of the 2010 Adjuvant

Blue Ribbon Panel to increase the investment in adjuvant research, in 2017, NIAID began

using the annual Small Business Innovation Research (SBIR) contract solicitation to

support additional adjuvant discovery activities. This program, while new, already has

expanded the investigator pool and increased the diversity of adjuvant candidates for the

development pipeline.

Since its inception, researchers funded by NIAID’s Adjuvant Discovery Program have

screened more than 2 million compounds in vitro and more than 10

in silico and

identified a wide variety of promising adjuvant candidates, including:

• Synthetic TLR2, 4, 5, 7, 8, 7/8, and 9 agonists; nanoemulsions (for mucosal

delivery)

• C-type lectin receptor (CLR) agonists

• CD1d ligands (natural killer T [NKT] cell inducers)

• Synthetic RIG-I agonists

• Carbohydrate-based adjuvants

Figure 1 shows representative immune receptors and pathways targeted by compounds and

formulations that have resulted from the NIAID Adjuvant Discovery Program.

Fig. 1

Figure 1: Vaccine adjuvants from NIAID’s adjuvant discovery and adjuvant

development programs target a variety of cellular receptors and signaling pathways.

Some of these adjuvants (solid arrows) engage cell-surface and intracellular RIG-I-like

receptors and C-type lectin receptors. In addition, adjuvants have been developed that

directly act on signaling molecules of these receptors, act by rearranging lipid rafts and

associated receptors, or provide adjuvanticity through yet undefined mechanisms

(dashed-line arrows).

Specific accomplishments of these programs include identification of the following

molecules with adjuvant activity, including:

• Novel CpG-ODNs that exhibit higher adjuvanticity than previously published CpG-

ODN and are not species specific (e.g., able to trigger both mouse and human TLR9).

One of these novel CpG-ODNs, originally identified through in silico screening, is now

part of an inulin-CpG combination adjuvant that has been used in two clinical trials of

influenza vaccines.

• Co-adjuvants in the form of small molecules that enhance the activity of an adjuvant

but do not exhibit intrinsic adjuvant activity themselves. Such co-adjuvants have been

shown to extend NF-KB signaling in antigen-presenting cells (APCs) and thus enhance

lymphocyte activation.

• Novel oxoadenine-based TLR7/8 agonists with high potency and low reactogenicity

• Amphotericin B as a novel TLR2/TLR4 agonist with adjuvant activity and low

reactogenicity

• Adjuvant formulations that target adjuvant activity to specific APCs or lymph nodes,

reducing reactogenicity of potent imidazoquinoline (IMDQ)-based TLR7 agonists, such

as:

o Lysophospholipid conjugates of IMDQ

o IMDQ-ligated nanogel

o Hyaluronic-acid conjugated IMDQ

• First small-molecule TLR4 agonist, which is currently being developed as a

combination adjuvant with TLR7 agonists for influenza vaccines

• Novel RIG-I agonists, as follows:

o A small molecule compound called KIN, currently being developed for vaccines

against emerging RNA viruses, including pandemic influenza and Zika

o Synthetic, Sendai-virus-derived double-strand RNA (dsRNA) adjuvant for

intranasal immunization against influenza

• Nanoemulsions (NEs) for intranasal or intramuscular injection, which act as delivery

platform and adjuvant. NEs inactivate viruses and bacteria and can be used to produce

killed, whole organism adjuvanted vaccines. Intranasal formulations can elicit strong

Th1/Th17 responses upon boost with NE-adjuvanted vaccine, overcoming preexisting

antigen-specific Th2 dominance. This approach is being developed for a recombinant

influenza vaccine and a B. pertussis vaccine.

• Selective TLR8-agonist (methylpyrimidine-diamine) without TLR7 activity and ultra-

low inflammatory profile

• Dendrimeric IMDQ construct with pure TLR7 activity, which has low reactogenicity

and enhanced adjuvanticity (compared to monomeric IMDQ) and promotes antibody

affinity maturation and epitope spreading

• First chemokine receptor CCR1 agonist adjuvant (bis-quinoline)

• NOD-1 agonist adjuvant (glutamyldiaminopimelic acid-derivative)

• Novel water-soluble TLR2 agonist

• Synthetic CRX compounds (MPL-derivatives), which are TLR4 agonists with high

safety profiles. Several of these compounds were developed as adjuvants for

intramuscular delivery and sublingual formulation (combination adjuvant with

methylglycol chitosan) for influenza vaccines. They also are being developed as

combination adjuvants with novel TLR7/8 agonists.

• Protein cage nanoparticles (PCN) for mucosal delivery to induce tertiary lymphatic

tissue

The Adjuvant Discovery Program has also identified molecules with valuable, non-

adjuvant properties that include:

• Novel antimicrobials

o Antivirals against Zika and dengue viruses

o Antibiotics such as a modified TLR7/8 agonist without TLR activity, which acts as

a potent inhibitor of Gram-positive bacteria, including methicillin-resistant

Staphylococcus aureus (MRSA)

o Pure TLR7 agonists currently being evaluated as HIV latency-reversal agents

• Large libraries of TLR7, TLR8, and TLR7/8 agonists that modulate immune responses

and can be used as tools to study TLR7 and TLR8 signaling pathways

2.2. PROGRAM GOALS AND RESEARCH CHALLENGES

Goal 1: Strengthen Immunology Research

The most significant advances in NIAID’s Adjuvant Discovery Programs have come from

increased knowledge of innate immune receptors and their mechanisms of action (Figure

1).

The first innate immune receptor agonists developed as adjuvants targeted TLR4 and

TLR9. NIAID-supported researchers have expanded screening to include molecules that

bind to NOD-like receptors and C-type lectin receptors, as well as molecules involved in

signal transduction from innate immune receptors, such as various kinases and interferon

regulatory factors. Furthermore, an increased understanding of how innate and adaptive

immune cell subsets contribute to vaccine-induced immunity is leading to the discovery of

adjuvants that target cells other than macrophages and dendritic cells. These cells include B

cells, mast cells, and NKT cells.

While considerable progress has been made in discovery of innate immune receptors and

their mechanisms of action, several challenges remain. These include:

• Limitations of existing methods to evaluate potential adjuvant function in vivo.

Most screening approaches are based on a limited number of parameters, such as NF-

KB activation or the induction of select cytokines from either cell lines or primary cells.

In vitro induction of those factors may not translate into adjuvanticity in vivo. Better

methods to evaluate adjuvant function, based on increased knowledge of immunologic

mechanisms, will ensure that promising candidates are not being overlooked.

• Selection of appropriate animal models for adjuvant screening. Host species

differences in immune receptor specificity and cellular distribution, immunogenetics,

and pathogen susceptibility can complicate the discovery of adjuvants for human use.

One example is TLR8, which was thought to be nonfunctional in mice until the recent

discovery of the mouse TLR8 ligand and the realization that it differs significantly from

the human TLR8 ligand. The selection of appropriate animal models for adjuvant

screening is critically important.

• Adjuvants for at-risk populations, especially the very young and frail elderly.

The recent successes of the AS01-adjuvanted Shingrix

vaccine and MF59

adjuvanted influenza vaccine in the elderly and the AS03- and MF59

-adjuvanted

influenza vaccines licensed outside the U.S. for young children clearly demonstrate that

adjuvants can overcome age-associated immune deficits. However, additional adjuvants

are still needed for use in the very young and the frail elderly.

Goal 2: Support Technology Development for Adjuvant Discovery

Adjuvant discovery methods have improved in recent years for two main reasons:

• Technologic advances have allowed for more efficient in vitro screening of compounds

with progressively higher throughput rates.

• Advances in medicinal chemistry have enabled rapid and systematic modifications of

molecules to alter their immune stimulatory properties.

In addition, the focus of adjuvant discovery has shifted from natural compounds and/or

derivatives of known innate immune receptor agonists to small molecules that bear no

structural similarities to natural compounds. These molecules may bind to sites on an

immune molecule that may or may not overlap with the binding site for the natural ligand.

These types of adjuvants are identified by high-throughput screening of chemical libraries.

Recently, in silico approaches have been employed (1) to pre-screen compound libraries to

reduce the number of compounds that need to be screened in vitro or (2) to explore the

potential utility of computer-generated structures before synthesis and in vitro testing.

While in silico screening has the potential to revolutionize adjuvant science, this approach

still faces challenges, which include the needs to:

• Determine structure–activity relationship (SAR) to improve the accuracy of in

silico screening methods. SAR analysis defines the relationship between a

compound’s chemical or three-dimensional structure and its biological activity. Insights

gained through SAR analysis can be used to rationally alter structure and hence the

potency or functionality of a compound. Application of SAR to in silico screening of

adjuvants requires knowledge of the structure of the immune receptor being targeted.

• Define binding site requirements. Recent identification of small-molecule compounds

that can bind to innate immune receptors but lack structural similarity to the natural

receptor ligands highlights gaps in our understanding of the requirements for receptor

activation. In addition, ligand binding is not necessarily associated with receptor

activation. Thus, in silico modeling alone can be misleading and needs to be coupled

with laboratory validation to improve overall accuracy.

• Provide access to supercomputing facilities. The most frequently used algorithms for

in silico screening simulate static docking of putative ligands to their receptors, rather

than the dynamic interactions that occur naturally between receptor and ligands.

Modeling such dynamic interactions requires supercomputing capacity that is not

readily available to many researchers.

2.3. NIAID’S STRATEGY TO ADVANCE ADJUVANT DISCOVERY

Based on NIAID’s goals and recommendations from the BRP, NIAID’s 2018 Strategic

Plan for Research on Vaccine Adjuvants focuses on two major areas: strengthen

immunology research and support technology development.

• Strengthen immunology research, to specifically improve evaluation of adjuvant

function, provide new animal models for adjuvant screening, and facilitate the

discovery of adjuvants for use in at-risk populations. To meet this goal, NIAID will

continue to support and expand current programs, and develop new programs, as

follows:

o Current programs

 The Systems Approach to Immunity and Inflammation Program, which is

identifying novel immune response genes through development and analysis of

novel mouse models. The data and novel mouse models generated through this

program will enhance adjuvant discovery efforts.

 The Immunity in Neonates and Infants program and the Immunity in the Elderly

program, which are characterizing immune functionality and facilitating

identification of possible adjuvant targets in these at-risk populations.

 The Adjuvant Discovery Program, which continues screening, preclinical

testing, and early-stage development of new adjuvant candidates and will pursue

discovery of immune modulating or tolerogenic adjuvants.

 The Molecular Mechanisms of Combination Adjuvants (MMCA) program,

which is providing novel insights into the mechanisms of combination adjuvant

activity and the basis for synergistic adjuvanticity.

o FY 2019 new NIAID initiatives

 Maintaining Immunity After Immunization, which will increase understanding

of how durable immunity is induced and maintained in response to infection or

vaccination and will identify novel targets for adjuvant discovery

 Collaborative Cross (CC) Mouse Model Generation and Discovery of

Immunoregulatory Mechanisms, which will support the use of CC mouse lines

to increase understanding of the host genetics involved in immune regulation

and function

o NIAID will continue to use the SBIR contract mechanism to fund additional

adjuvant discovery by small business entrepreneurs and the development of

immunologic reagents for underrepresented animal models that may be better

models of human immune responses (e.g., ferrets for influenza research).

o In addition to its solicited adjuvant portfolio, NIAID will maintain and expand its

portfolio of unsolicited adjuvant grants using a variety of mechanisms, such as

SBIR, R01, R03, R21, and T grants.

• Support technology development for adjuvant discovery. For example:

o NIAID will expand support of structural immunology studies to enhance SAR

analyses and improve the accuracy of in silico adjuvant discovery methods.

Currently, most of the structural immunology research supported by NIAID is

through investigator-initiated grants. While these studies have provided valuable

insights into the structure–function relationships of many important immune

molecules, technologic advances in this area would increase the number of

available structures for use by the adjuvant discovery community. NIAID will

consider using the SBIR contract funding mechanism and other approaches to grow

this important research area.

o NIAID’s Office of Cyber Infrastructure and Computational Biology (OCICB)

provides sophisticated biocomputing resources to NIAID’s intramural researchers.

NIAID extramural staff will work with OCICB staff to make these supercomputing

capabilities available to adjuvant researchers in the extramural community.

3. ADJUVANT DEVELOPMENT AND PRECLINICAL EVALUATION

3.1. RECENT PROGRESS IN NIAID-SUPPORTED ACTIVITIES

Adjuvant Development Program

NIAID expanded its solicited program in adjuvant science in 2008 with the Adjuvant

Development Program. This contract program supports:

• Preclinical development of novel adjuvants coupled with specific vaccines, including

mechanistic analyses of the novel adjuvant/antigen combinations

• Formulation and dosing studies

• Optimization of immunization regimens and delivery routes

• cGMP production

This program was recompeted in 2013 and 2018 with the goal of ensuring further

development of promising adjuvant candidates through preclinical testing and IND-

enabling studies, thus expanding the number of adjuvants available for clinical evaluation.

Several of the compounds evaluated through the Adjuvant Development Program

originated from NIAID’s Adjuvant Discovery Program, and some have been or are

currently being tested in more than 20 clinical trials. In 2016, NIAID began using the

annual SBIR contract solicitation to support additional adjuvant development activities.

The adjuvant/antigen or adjuvant/vaccine combinations assessed through the Adjuvant

Development program and SBIR contract program include:

• Microcrystalline inulin with seasonal, pandemic, and universal influenza vaccine

candidates

• Nanoemulsions with a plant-derived, recombinant H5 influenza vaccine or HIV

envelope virus-like particle (VLP) vaccine

• Fully synthetic TLR4 agonists plus plant-derived saponin (QS-21), coupled with a

recombinant E protein from West Nile virus

• A small-molecule RIG-I agonist combined with split H5N1 influenza virus, UV-

inactivated West Nile virus, or a VLP-based vaccine for Zika virus

• The protein-based mucosal double-mutant heat-labile toxin (dmLT) adjuvant, with

BCG and the recombinant fusion protein, 5fu, from Mycobacterium tuberculosis and a

recombinant IpaB-IpaD fusion protein from Shigella sonnei

• A novel semi-synthetic analog of QS-21 (TiterQuil-1055™) with Fluzone

, Fluarix

and Flublok

influenza vaccines

Adjuvants in HIV Preclinical Vaccine Development

NIAID also supports adjuvant development within vaccine-focused research programs.

NIAID’s HIV preclinical vaccine development activities focus predominately on variations

of HIV Env immunogens in combination with an array of adjuvants and/or delivery

systems to enhance potency and durability. These studies are conducted in both small

animals and nonhuman primates. An extensive variety of adjuvants and adjuvant

combinations have been tested, with the most common adjuvants being Alhydrogel



and

other aluminum salts formulations, MF59

, AS0 series, Adjuplex, ISCOMATRIX

, pIL-

12, and multiple TLR agonists alone or in combination (3M-052, CpG, poly ICLC, R848,

GLA-SE).

Adjuvants in Non-HIV Preclinical Vaccine Development

NIAID’s vaccine research and development activities for non-HIV infectious diseases

include three different types of vaccines: live attenuated vaccines; inactivated vaccines; and

subunit vaccines composed of purified protein, recombinant protein, or carbohydrate. These

preclinical research and development efforts focus on early discovery of adjuvanted vaccine

targets and IND-enabling activities, including providing biological resources, animal

testing, process development, Good Laboratory Practice (GLP) toxicity assessment, and

cGMP production of vaccines or vaccine components. Early-stage research on adjuvanted

vaccines includes pairing of antigens with adjuvants, formulation studies, and the design

and construction of novel vaccine candidates in which an adjuvant is built into the vaccine

construct. Examples of this latter approach include co-display of the adjuvant and antigen

on the surface of nonpathogenic engineered microbes and nanoparticle molding

technologies for co-delivery of adjuvant and antigen. NIAID also supports development of

animal models that are relevant for or mimic natural infection or diseases of public health

importance to evaluate vaccine formulation. These models are especially important for

vaccine research for biodefense or emerging infectious diseases, since the data generated

may be utilized for vaccine emergency use authorization, accelerated approval, or pivotal

efficacy studies under the Animal Rule.

NIAID also supports the development of adjuvanted vaccines in some high-priority

research areas through investigator-initiated research grants and various program

initiatives, such as SBIR contracts, Centers of Excellence for Translational Research,

Advanced Development of Vaccine Candidates for Biodefense and Emerging Infectious

Diseases, and Research to Advance Vaccine Safety. Selected examples of current activities

include evaluation of:

• Candidate tuberculosis (TB) vaccines containing traditional and novel adjuvants or

adjuvant systems, as follows:

o The cyclic dinucleotide (CDN) class of molecules (a vita-PAMP), which includes c-

di-AMP, as regulators of M. tuberculosis physiology and the host immune response

to infection and vaccination. Research is underway to determine the adjuvant

potential of c-di-AMP in a preventative tuberculosis vaccine.

o The cationic liposomal adjuvant CAF09, which induces both CD4+ and CD8+ T

cells

o An adjuvant platform to produce micelles and vesicles incorporating mycolic acid,

CpG, and MPL for intranasal immunization

o A wide range of adjuvants, including alum, GLA-SE, GLA-AF, QS-21, CpG-SE,

and liposomes, which are being evaluated independently and in combination with

either anionic, neutral, or PEG liposomes to identify the optimal adjuvant pairing

with the M. tuberculosis antigen ID93

• Candidate malaria vaccines containing:

o The novel glycolipid adjuvant 7DW8-5 combined with a live attenuated sporozoite

vaccine

o Traditional adjuvants such as Alhydrogel



, MPL/Alhydrogel



, ISA 51 VG, ISA

720 VG, GLA-SE, GLA-LSQ, AddaVax

™

, and CpG 7909, in malaria subunit-based

vaccines

o Nano/microparticle technology platforms for a malaria transmission-blocking

vaccine

Programs in Support of Adjuvanted Vaccine Development

Several of NIAID’s basic immunology programs facilitate selection of appropriate antigens

and evaluation of antigen-specific immunity generated by candidate adjuvanted vaccines,

including:

• The Immune Epitope Database and Analysis Resource (IEDB, www.iedb.org), which

provides public access to B and T cell immune epitope information curated from the

scientific literature or through direct submission by the research community, and

sophisticated epitope prediction and analysis bioinformatics tools

• The B-Cell Epitope Discovery and Mechanisms of Antibody Protection program and

the Large-Scale T-Cell Epitope Discovery program

• The NIH Tetramer Core Facility (http://tetramer.yerkes.emory.edu/)

• The Human Immunology Project Consortium (HIPC) program, which uses novel

approaches, including metabolomics, transcriptomics, and proteomics, to conduct

comprehensive systems immunologic analyses of human immune responses to

infections, adjuvants, and/or vaccines

• The Cooperative Centers on Human Immunology (CCHI) program, which is

developing novel technologies and bioinformatics tools to conduct mechanistic

analyses of human immune responses to infections and vaccines (adjuvanted and

unadjuvanted)

• The Modeling Immunity for Biodefense program, which includes the development of

computational tools that analyze antibody-antigen interactions and facilitate design of

more immunogenic or cross-protective antigens that can be paired with adjuvants

Preclinical Development Services and Support

NIAID also provides a comprehensive suite of preclinical development services that fill

particular knowledge and experimental gaps critical to move adjuvanted vaccine candidates

along the product development pathway. These resources include:

• BEI Resources, a central repository that supplies organisms and reagents, including

those relevant for vaccine or adjuvant research to the research community

• The Preclinical Models of Infectious Diseases program, which provides services to

researchers to study the full range of pathogens, including bacteria, viruses, parasites,

fungi, and other agents such as toxins and prion proteins. The program’s main focus is

to help researchers who have developed a product such as a vaccine that needs to be

tested in an animal model, but who lack either the resources or expertise needed to

perform that testing, and to support the development and refinement of animal models

for infectious diseases of importance to humans.

• NIAID’s Vaccine Development Services, which are intended for use in the

investigation, control, prevention, and treatment of a wide range of infectious agents

and to support the development of vaccines; vaccine components, including adjuvants;

vaccine delivery systems; and challenge material. Vaccine testing services include

assay development, immunogenicity and efficacy studies, clinical and nonclinical

sample testing, and safety and toxicity testing. Vaccine manufacturing services include

writing product development plans, product optimization, non-cGMP and cGMP

manufacturing of antigens and adjuvants, assay development, and regulatory activities,

including audits.

NIAID will continue to support new program initiatives to address the development and

evaluation of important vaccines and vaccine technologies, including adjuvants. Examples

of some existing programs are:

• Centers of Excellence for Translational Research (for emerging/reemerging vaccine

technologies)

• Novel Vaccine Technologies and Strategies to Promote Sustained Vaccine Efficacy (for

malaria and pertussis)

• Advanced Development of Vaccine Candidates for Biodefense and Emerging

Infectious Disease (for vaccines, including influenza and TB; and technologies,

including adjuvants)

• Research to Advance Vaccine Safety

These services and programs support a wide range of preclinical development needs for

vaccines, including adjuvanted vaccine construction; in vitro and in vivo assessment of

candidate products; generation of data regarding optimization, synthesis, and formulation

of candidates; manufacturing using cGMP standards; and safety assessments such as GLP

toxicity studies.

3.2. PROGRAM GOALS AND RESEARCH CHALLENGES

Goal 1: Expand Availability of Novel Adjuvants for Preclinical Vaccine Development

and Clinical Evaluation

Vaccine developers tend to look for adjuvants with well-established safety records,

preferably in humans, when selecting an adjuvant for their candidate vaccines. NIAID’s

adjuvant development activities include mechanism-of-action studies to gain insights into

immune pathways triggered by adjuvants and ensure that off-target effects are identified

and mitigated early in the development process. These efforts will be crucial in assembling

a pool of well-characterized, potent adjuvants with proven safety records that can be used

to accelerate development of effective vaccines.

The major challenge associated with early stage development and preclinical assessment of

novel adjuvants and adjuvant vaccines is:

•

The ability to correlate safety and efficacy observed in animal models to human

responses. Animal models, while valuable, are not able to emulate many of the

factors affecting responses in humans. These factors include:

o Pre-existing conditions and medications; recent infection history and chronic

infection status (e.g., cytomegalovirus [CMV], Epstein-Barr virus [EBV])

o Genetics/epigenetics (e.g., species-specific TLR expression patterns and ligand

binding)

o Microbiome composition

o Behavior, including exercise and recreational drug use

o Nutrition and diet

o Environmental exposures

In addition, current animal models may not identify the most effective vaccine regimens or

predict adjuvant-vaccine reactogenicity in humans. Although certain cytokines, other

soluble molecules, and transcriptional networks have been associated with reactogenicity,

well-defined signatures that reliably predict reactogenicity have not been identified.

Concerns about adverse events have slowed the development and licensure of adjuvanted

vaccines, especially for at-risk populations such as the very young, pregnant women, and

the elderly.

Goal 2: Optimize Formulation, Antigen/Adjuvant Pairing, and Support cGMP

Production

Development of novel adjuvanted vaccines involves activities that require specialized,

multidisciplinary teams with strong formulation expertise. NIAID’s adjuvant and vaccine

development programs support formulation studies, including the iterative process required

to optimize antigen/adjuvant pairing, and cGMP production of lead adjuvant and adjuvant-

antigen formulations for further downstream preclinical development and clinical

evaluation. Formulation studies are crucial during adjuvant development and vaccine

construction. However, they also must be considered during the early stages of adjuvant

discovery and adjuvant-antigen pairing, since inadequate or suboptimal formulation may

prevent promising novel adjuvants or adjuvanted vaccines from moving forward in

development.

The major challenges associated with these activities include:

• Formulation considerations. Subtle differences in formulations can significantly

impact immunogenicity, stability, and safety of adjuvanted vaccines. In addition, due to

significant advances in antigen discovery and development of protein expression

platforms, most vaccines currently in development are subunit vaccines. Pairing the

correct protein antigens with the appropriate adjuvants during the early development

stage is critical for future success of a safe and efficacious vaccine. Currently, given the

lack of correlates or surrogates of protection for most pathogens, head-to-head

comparisons of multiple adjuvants with specific vaccine antigens may be the most

efficient process for identifying the optimal adjuvants for a given antigen.

Despite the vital importance of formulation, including co-formulation of

adjuvant/antigen pairing, adjuvant development efforts frequently lack adequate

consideration of formulation, which can impact:

o Proper adjuvant selection and retention of antigenicity/immunogenicity

o Targeting of the adjuvant to the correct immune cells and lymphatic tissues

o Co-localization of antigen and adjuvant, or proper antigen conformation

o Timed release of the adjuvant to prevent induction of excessive innate immune

responses and the potential for reactogenicity

o Selection of the optimal delivery system and vaccination strategy

• cGMP manufacturing. Bottlenecks for vaccine developers in academia and small

businesses are (1) limited access to proprietary adjuvants; (2) development of scalable,

robust manufacturing processes for promising novel adjuvants; and (3) lack of

sufficient quantities of cGMP material for well-characterized adjuvants/adjuvanted

vaccines required for early phase clinical trials.

3.3. NIAID’S APPROACH TO ADVANCE ADJUVANT DEVELOPMENT AND

PRECLINICAL EVALUATION

To address the issues raised above and to continue the development of promising

adjuvanted vaccine candidates, NIAID will support the following activities:

• Expand availability of novel adjuvants for preclinical vaccine development and clinical

evaluation by improving the ability to correlate safety and efficacy profiles generated in

animal models to human responses.

To accomplish these efforts, NIAID will:

o Continue NIAID’s Preclinical Models of Infectious Disease program, which

provides a central resource for development and refinement of animal models,

including traditional small laboratory animals, nonhuman primates, and

nontraditional animals such as swine. This program also offers in vivo screening

and efficacy testing in appropriate animal models.

o Continue NIAID’s SBIR contract program for the development of immunologic

reagents for underrepresented mammalian models, including ferrets, guinea pigs,

and swine, to expand the types of animal models that can be used for detailed

immunologic analyses of adjuvant function

o Maintain and expand development of novel animal models that more accurately

reflect human immune responses to adjuvanted vaccines across all age

groups/populations through NIAID’s Systems Approach to Immunity and

Inflammation program and through a new funding opportunity, starting in 2019, to

support the use of CC and CC-RIX mouse lines that more faithfully reproduce

human immune responses

o Increase support to HIPC and CCHI investigators to:

 Accelerate further development and validation of fully human artificial

“immune systems” and immune tissue explants

 Conduct additional systems immunology analyses of head-to-head comparisons

of novel adjuvant/antigen combinations

• Optimize formulation and antigen/adjuvant pairing activities.

To accomplish these efforts, NIAID will:

o Renew the Adjuvant Development Program in 2018, which includes a stronger

emphasis on formulation and head-to-head comparisons of adjuvant/antigen

combinations. NIAID also will continue to award SBIR contracts to increase

adjuvant development. Community access to adjuvants developed under these

programs will be expanded through targeted NIAID supplements.

o Expand development of novel adjuvanting technologies, including conjugation

technologies or self-adjuvanting vaccine platforms, through the SBIR adjuvant

development contracts and other funding mechanisms

o Expand development of co-adjuvants to include checkpoint inhibitors that enhance

APC or T-cell responses by extending immune activation or by blocking negative

regulators

o Continue to support adjuvant process development to enable cGMP production

capabilities for adjuvant production through NIAID’s Adjuvant Development

program

o Encourage and continue to support preclinical development of adjuvanted vaccines

in the areas of product optimization, process development, formulation studies,

cGMP production, and GLP safety assessment through NIAID’s Vaccine

Development Services, Broad Agency Announcements (BAAs), partnership

programs, and SBIR contract solicitations to accelerate the transition of adjuvanted

vaccine candidates into clinical evaluation

4. CLINICAL EVALUATION OF ADJUVANTED VACCINES

4.1. RECENT PROGRESS IN NIAID-SUPPORTED ACTIVITIES

Adjuvanted Vaccines for Non-HIV Infectious Diseases

Since 1998, NIAID has supported 133 vaccine clinical trials for non-HIV infectious

diseases, primarily through the Vaccine and Treatment Evaluation Units (VTEUs). Forty-

seven of these clinical trials have included adjuvanted vaccines, with adjuvants such as

Alum (used in 13 of these trials), MF59

, AS03, glucopyranosyl lipid adjuvant (GLA, a

synthetic TLR4 agonist), and GLA with QS-21 in liposomal formulation. Recently

completed and ongoing trials of adjuvanted vaccines for non-HIV infectious diseases are

summarized in Appendix C and described below:

• Phase I and II clinical trials of inactivated influenza vaccine candidates with established

adjuvants in multiple combinations, as part of its influenza pandemic preparedness

program

• Exploration of novel vaccination strategies, including heterologous prime-boost interval

studies using H7 influenza vaccines

• In collaboration with GSK, the direct comparison of two adjuvants, AS03 and MF59

with seasonal influenza vaccines. The trial has been completed and results will be

released to the public once data analyses are completed.

• A first-in-human Phase I clinical trial with a purified formalin-inactivated Zika virus

vaccine candidates with alum adjuvant, in a rapid response to this emerging viral

disease threat

• Two clinical trials exploring vaccines with novel adjuvants

o TLR7/8 agonist, Imiquimod, to enhance the efficacy of a pre-pandemic H5

influenza vaccine

o Recombinant double-mutant heat-labile toxin (dmLT), which acts as both antigen

and adjuvant in a vaccine against enterotoxigenic E. coli (ETEC). The dmLT

adjuvant can induce strong mucosal immune responses after parenteral delivery.

• Evaluation of tuberculosis (TB) vaccine candidates in Phase I clinical trials using new

combination adjuvants, GLA-LSQ and GLA-SE

• Evaluation of new combination adjuvants such as GLA-LSQ for a malaria vaccine or

Alhydrogel



plus GLA in Aqueous Formulation (GLA-AF) for schistosomiasis

vaccines

• Use of the human challenge models to evaluate, compare, or narrow the field of choices

of different vaccine formulations for hookworm vaccines

Adjuvanted Vaccines for HIV

NIAID’s HIV vaccine program has been exploring multiple vaccine platforms to achieve

protective immunity against HIV that include HIV DNA vaccines or viral vectors boosted

or combined with adjuvanted recombinant Env protein(s). Two complementary strategies

are being used: an empirical approach that builds on partial clinical success to

expeditiously move vaccine candidates into human testing and a theoretical approach that

selects vaccine candidates for further development based on an understanding of the

immune response to HIV infection. Completed and ongoing trials of HIV adjuvanted

vaccines are described below and summarized in Appendix D.

The Empirical Approach

• This approach relies mostly on the landmark RV144 study in Thailand, the first and

only (as of April 2018) large clinical trial to demonstrate modest efficacy for an

investigational HIV vaccine. RV144 evaluated the safety and estimated the efficacy of

a prime-boost combination of two vaccine components given sequentially: ALVAC-

HIV, which uses a canarypox virus as a vector—or carrier—to deliver HIV genes; and

the recombinant AIDSVAX B/E, HIV Env protein formulated with alum hydroxide gel

(Rehydragel). At the end of the 3.5-year study period, investigators observed a 31%

reduction in risk of HIV infection among vaccine recipients compared to those who

received a placebo.

Analysis of the immune responses induced by the vaccine suggests that a lower risk of

infection is associated with:

o Plasma immunoglobulin G (IgG) antibodies targeting the V1V2 region of HIV Env

o Low plasma levels of HIV-Env-specific IgA (which compete with protective IgG)

o Polyfunctional CD4+ T cells (CD154, interleukin-2 [IL-2], IL-4, interferon-gamma

[IFN-γ], and tumor necrosis factor alpha [TNF-α])

o IgG antibodies harboring Fc effector functions needed for antibody-dependent cell-

mediated cytotoxicity (ADCC), but only in vaccinees with low-plasma, HIV-Env-

specific IgA

To follow up on this encouraging outcome, the P5 partnership (Pox-Protein-Public-

Private-Partnership, http://www.vaccineenterprise.org/content/P5Partnership) was

established in 2010 to substantiate and improve upon RV144 using a modified pox-

protein HIV vaccine. Phase I studies include:

o Side-by-side comparison of adjuvant formulations

 Boost of HIV Env formulated with Rehydragel vs. MF59

after ALVAC

prime (HVTN 107)

 Boost of HIV Env formulated with MF59

vs. AS01B after DNA prime (HVTN

108)

 Boost of HIV Env formulated with MF59

vs. AS01B after ALVAC prime

(HVTN 120)

• Prior to completion of the RV144 trial, many adjuvants were tested in Phase I clinical

trials in combination with HIV immunogens: Rehydragel, Alhydrogel



, Adju-Phos



MF59

, AS01B, and GLA-SE. Two Phase IIb studies used similar recombinant Env

subunit proteins only (without the ALVAC prime) as part of the regimen (VAX003,

VAX004) that were formulated with Rehydragel, but these studies did not show

efficacy.

The Theoretical Approach

• This approach targets the induction of broadly neutralizing antibodies (bNAbs) against

HIV. Based on HIV natural infection studies and an exquisite characterization of the

structure of the HIV Env spike, there is a better understanding of the requirements to

induce bNAbs. The immunogens must first engage the B cell harboring the germline

lineage of desired antibodies, and then, through multiple cycles of affinity maturation,

the gene encoding immunoglobulins may acquire the mutations needed to provide

broad and potent HIV neutralization activity. T follicular helper (Tfh) cells, the drivers

of affinity maturation in the lymph node, also are sought to generate better bNAbs. In

addition to high levels of somatic hypermutation, other unusual structural features of

bNAbs include a long heavy chain complementarity-determining region 3 (HCDR3),

capable of reaching through the glycan shield of the virus, and autoreactivity.

• Two additional clinical trials involving direct comparisons of adjuvants are under

development. The first is supported by the HIV Vaccine Trials Network (HVTN) and

will use a stabilized trimer BG505 SOSIP.664 immunogen, adjuvanted with

3M052+Alum, CpG 1018, or GLA-LSQ. The second trial, a partnership between

NIAID and the U.S. Military HIV Research Program, will test a DNA prime, gp145

HIV Env protein boost, adjuvanted with several Army Liposome Formulations (ALFs),

Alhydrogel

, and dmLT.

4.2. PROGRAM GOALS AND RESEARCH CHALLENGES

Goal 1: Increase the Availability of Well-Characterized Novel Adjuvants for Use in

Vaccine Clinical Trials

One of NIAID’s major goals is to develop vaccines against pathogens and their toxins. This

goal includes clinical evaluation in both domestic and international populations, which

often have distinct pathogen exposure histories that can impact host immunity. Therefore,

adjuvants capable of inducing Th1/Th17, Tfh, CD8+ T cell, or mucosal immune responses

or that are effective in at-risk populations are especially needed.

Challenges associated with these activities include:

• Difficulty in reconciling human clinical data and animal preclinical data to

improve the design and further evaluation of adjuvanted vaccine candidates. The

primary endpoints of early-phase clinical trials of adjuvanted vaccines are safety and

immunogenicity. However, sample sizes are generally small and lack sufficient

statistical power to dissect safety or identify correlates of protection, both of which are

critical parameters in determining whether a vaccine candidate moves into later-phase

clinical trials or needs further refinement. Preclinical animal efficacy studies may

provide some insights regarding safety and efficacy, but species differences in

immunity, pharmacogenetics, and reactogenicity need to be considered.

• Limited number of adjuvants available from commercial sources. Although NIAID

has supported many clinical trials of vaccine candidates against infectious diseases,

those requiring adjuvants continue to rely on a limited number of sources. Access to

novel adjuvants already in clinical development is hampered by intellectual property

(IP) restrictions. In addition, adjuvant IP holders may either oppose or not be interested

in direct comparisons of their formulation with those they do not own. Bringing more

potent adjuvants into the clinic represents a significant financial and administrative

burden for any adjuvant developer. Many of these developers reside at academic

institutions or own small businesses and have neither experience with the process nor

the funding needed to bring products into the clinic.

Goal 2: Maximize Evaluation of Data from Clinical Trials

Although many well-designed clinical trials generate valuable datasets and contain a wealth

of information, the lack of correlates of protection for most pathogens complicates the

rational selection of an adjuvant for the clinical evaluation of a novel vaccine. Other issues

related to evaluation of data from clinical trials of adjuvanted vaccines include:

• Formulations identified in Phase I clinical trials as safe and immunogenic that may fail

in advanced clinical development or efficacy field trials

• Immunological analyses of clinical trial samples commonly focus on certain parameters

known or assumed to be associated with protection against a specific disease. However,

such assumptions limit the breadth of immunologic information produced and our

ability to identify and validate immune correlates of protection associated with adjuvant

functionality.

• The lack of standardized assays to measure the immunogenicity of an adjuvant

combined with different antigens. This data would establish immunological profiles of

adjuvants and determine how much those profiles are affected by the antigen

component of the vaccine.

Sample-sparing techniques, such as those supported by NIAID’s Sample Sparing Program,

have improved significantly in recent years allowing more parameters to be determined

with small numbers of cells or volumes of whole blood or serum. Simultaneously, the cost

of multiplex assays has decreased making the routine generation of high-density datasets

from clinical trials samples highly feasible.

The major challenge associated with this goal is:

• Access to data from adjuvant studies and adjuvanted vaccine and human

challenge clinical trials. Many investigators conducting adjuvant research or clinical

trials do not deposit their datasets into publicly accessible databases such as ImmPort,

because they either are unaware of relevant databases or lack incentives or the expertise

to comply with data submission requirements. These requirements may include the

collection of specific meta-data parameters, data types, and use of controlled

vocabularies.

4.3. NIAID’S APPROACH TO ADVANCE THE CLINICAL EVALUATION OF

ADJUVANTED VACCINES

To address the challenges raised above and to continue the evaluation of novel adjuvants in

clinical trials, NIAID plans to foster/support the following activities:

• Generation, collection, curation, and public availability of clinical data on the

immunological activity of vaccine adjuvants to inform their use in subsequent trials

• Expansion of NIAID-sponsored research using human challenge models to evaluate the

efficacy of candidate adjuvanted vaccine formulations

• Support of clinical trials to compare and down-select novel adjuvanted vaccine

candidates

• Continued/expanded investment in the development of computational models that can

reconcile data from human clinical trials and preclinical animal studies to improve the

design and efficacy of adjuvanted vaccines

• Continued investment in the development of sample sparing assays to enable evaluation

of more immunological parameters in small clinical samples

• Use of NIAID-sponsored programs such as HIPC, CCHI, and Systems Biology

programs to:

o Conduct research to identify biomarkers and correlates/surrogates of immune

protection or safety/reactogenicity

o Assist in the design of immunological analyses of clinical trials samples

o Enable collaborations between existing NIAID networks and clinical trials sites

through targeted administrative supplements

• Expansion of NIAID’s Bioinformatics resources, including ImmPort

(www.immport.org), to:

o Develop a public database of reference adjuvants and their immunologic activity

o Provide access to immunologic and other datasets generated by NIAID-supported

clinical trials

5. SUMMARY

The goal of NIAID’s adjuvant discovery and development programs is to generate a diverse

panel of well-defined, safe, and effective adjuvants that can be paired with candidate vaccines

to induce the desired protective immune profiles in all relevant populations.

To achieve this goal, NIAID will continue to:

• Support and expand its fundamental immunology research portfolio to identify the

requirements for inducing effective immune responses and long-lasting protection in all

individuals

• Advance adjuvant discovery and early stage development, specifically targeting the critical

immunologic parameters described in the relevant sections above

• Support the discovery of adjuvanted vaccines; animal testing and screening, including GLP

safety assessment of adjuvanted vaccine formulations; process development; and

production of clinical grade materials of vaccines and vaccine adjuvants

• Explore the feasibility of a NIAID-sponsored cGMP vaccine/adjuvant manufacturing

facility for small-scale clinical trials

• Explore creative approaches to promote and accelerate clinical testing of promising vaccine

candidates formulated with novel adjuvants

6. APPENDICES

6.1. APPENDIX A: ABBREVIATIONS

ADCC Antibody-Dependent Cell-Mediated Cytotoxicity

ALF Army Liposome Formulation

APC Antigen-Presenting Cell

BAA Broad Agency Announcement

bNAb Broadly Neutralizing Antibody

BRP Blue Ribbon Panel

CC Collaborative Cross

CCHI Cooperative Centers for Human Immunology

c-di-AMP Cyclic Di-Adenosine Monophosphate

CDN Cyclic Dinucleotide

cGMP Current Good Manufacturing Practice

CLR C-Type Lectin Receptor

CMV Cytomegalovirus

DAIDS Division of AIDS

DAIT Division of Allergy, Immunology, and Transplantation

DMID Division of Microbiology and Infectious Diseases

dmLT Double-Mutant Heat-Labile E. coli Toxin

dsRNA double-strand RNA

EBV Epstein-Barr virus

ETEC Enterotoxigenic E. coli

FDA Food and Drug Administration

GLA Glucopyranosyl Lipid Adjuvant

GLP Good Laboratory Practice

GSK GlaxoSmithKline

HCDR3 Heavy Chain Complementarity-Determining Region 3

HIPC Human Immunology Project Consortium

HPV Human Papillomavirus

HVTN HIV Vaccine Trials Network

IEDB Immune Epitope Database and Analysis Resource

IgG immunoglobulin G

IL-2 interleukin-2

IFN-γ interferon-gamma

MMCA Molecular Mechanisms of Combination Adjuvants

MPL Monophosphoryl Lipid

MRSA Methicillin-Resistant Staphylococcus aureus

NE Nanoemulsion

NIAID National Institute of Allergy and Infectious Diseases

NIH National Institutes of Health

NKT Natural Killer T

OCICB Office of Cyber Infrastructure and Computational Biology

ODN Oligodeoxynucleotide

PAMP Pathogen-Associated Molecular Patterns

PCN Protein Cage Nanoparticles

SAR Structure–Activity Relationship

SBIR Small Business Innovation Research

TB Tuberculosis

Tfh T Follicular Helper

TLR Toll-Like Receptor

TNF-α tumor necrosis factor alpha

VLP Virus-Like Particle

VTEU Vaccine and Treatment Evaluation Units

6.2. APPENDIX B: BLUE RIBBON PANEL MEMBERS

Rafi Ahmed, Ph.D.

Professor

Emory University School of Medicine

James Baker, M.D.

Director, Michigan Nanotechnology Institute for Medicine and Biological Sciences

University of Michigan

Mario Barro, Ph.D.

Senior Director

Head of Technology and External Networks

Sanofi Pasteur

John Clements, Ph.D.

Professor

Tulane University

Robert Coffman, Ph.D.

Senior Vice President and Chief Scientific Officer

Dynavax Technologies

Victor DeFilippis, Ph.D.

Assistant Professor

Oregon Health and Sciences University/Vaccine and Gene Therapy Institute

Jay Evans, Ph.D.

Professor

Director, Center for Translational Medicine

University of Montana

Michael Gale, Ph.D.

Professor

University of Washington

Hana Golding, Ph.D.

Chief, Laboratory of Retroviruses

Center for Biologics Evaluation and Research

FDA

Nir Hacohen, Ph.D.

Professor

Broad Institute and Massachusetts General Hospital

Ross Kedl, Ph.D.

Professor

University of Colorado

Marian Kohut, Ph.D.

Professor

Iowa State University

Ofer Levy, M.D., Ph.D.

Director

Precision Vaccines Program

Boston Children’s Hospital

Julie McElrath, M.D., Ph.D.

Senior Vice President

Director, Vaccine and Infectious Disease Division

Fred Hutchinson Cancer Research Center

Nikolai Petrovsky, M.B.B.S., Ph.D.

Professor

Vaxine/Flinders University

Rino Rappuoli, Ph.D.

Chief Scientist

GSK Vaccines

Steven Reed, Ph.D.

President and CEO

Infectious Disease Research Institute

Amy Weiner, Ph.D.

Senior Program Officer, Discovery & Translational Sciences

Bill & Melinda Gates Foundation

6.3. APPENDIX C: NIAID-SPONSORED CLINICAL TRIALS FOR NON-HIV

ADJUVANTED VACCINES, RECENTLY COMPLETED OR ONGOING (AS

OF APRIL 2018)

Adjuvant Pathogen

Pathogen

Vaccine Antigen/Approach

Phase

ClinicalTrials.gov

Identifier

dmLT

Enterotoxigenic

E. coli

dmLT antigen

Phase I

NCT02531685

AS03 vs.

MF59

Influenza

A/H5N8

A/gyrfalcon/Washington/41088-

6/2014

Phase I

NCT02624219

AS03 vs.

MF59

Influenza

A/H5N8

A/gyrfalcon/Washington/41088-

6/2014

Phase I

NCT03014310

AS03

Influenza

A/H7N9

Monovalent A/Hong

Kong/125/2017

Phase II

NCT03312231

AS03

Influenza

A/H7N9

Monovalent A/Hong

Kong/125/2017, with seasonal

IIV4

Phase II

NCT03318315

AS03

Influenza

A/H7N9

Monovalent A/H7N9

A/Shanghai/2/2013

Phase II

NCT02921997

MF59

Influenza

A/H7N9

Monovalent A/H7N9

A/Shanghai/2/2013, with live

attenuated H7N9

Phase I

NCT02251288

GLA-SE vs.

AP10-602

M. tuberculosis

ID93 antigen

Phase I

NCT02508376

Alhydrogel



+/− GLA-AF

N. americanus

Co-administered Na-GST-1 and

Na-APR-1 antigens

Phase Ib

NCT02476773

Alhydrogel



+/− GLA-AF or

CpG 10104

N. americanus

Na-GST-1 antigen

Phase II

NCT03172975

Alhydrogel



+/− GLA-AF

(AP 10-701)

Schistosoma

spp.

Sm-TSP-2 antigen

Phase Ia

NCT02337855

Alhydrogel

+/− GLA-AF

(AP 10-701)

Schistosoma

spp.

Sm-TSP-2 antigen

Phase Ib

NCT03110757

Alum Zika

Zika virus purified inactivated

vaccine

Phase I

NCT02963909

6.4. APPENDIX D: NIAID-SPONSORED CLINICAL TRIALS FOR HIV

ADJUVANTED VACCINES, COMPLETED OR ONGOING (AS OF APRIL

2018)

Adjuvant HIV Vaccine Antigen/Approach

Phase

ClinicalTrials.gov Identifier

Adju-Phos



Ad26.Mos.HIV or Ad26.Mos4.HIV

boosted by gp140 Clade C protein

Phase I

NCT02788045

Adju-Phos



Ad26.Mos4.HIV boosted by gp140

Clade C protein

Phase I

NCT03060629

Alhydrogel



gp145 Clade C Env protein

Phase I

NCT03382418

GLA-SE EnvSeq1: CH505 TF gp120 series

Phase I

NCT03220724

GLA-SE

Polyvalent DNA boosted by gp120 (A,

B, C, AE)

Phase I

NCT03409276

pIL-12 PENNVAX

-GP DNA

Phase I

NCT02431767

MF59

ALVAC (vCP2438) boosted by

bivalent subtype C gp120

Phase I/II

NCT02404311

MF59

ALVAC (vCP2438) boosted by

bivalent subtype C gp120

Phase IIb/III

NCT02968849

MF59

DNA-HIV-PT123 boosted by bivalent

subtype C gp120

Phase I

NCT02997969

MF59

gp140 Clade C boost to HVTN073

Phase I

NCT01423825

MF59

gp140 Clade C

Phase I

NCT01376726

MF59

MVA-C boosted by gp140, DNA-C2

boosted by MVA-C, or DNA-C2

boosted by MVA-C and gp140

Phase I

NCT01418235

Rehydragel

DNA-HIV-PT123 or NYVAC-HIV-

PT1/PT4 prime with AIDSVAX B/E

boost

Phase I

NCT01799954

Rehydragel

ALVAC (vCP1521) boosted by

AIDSVAX gp120 B/E

Phase I

NCT02109354

Rehydragel

DNA-HIV-PT123 boosted by

AIDSVAX gp120 B/E

Phase I

NCT02207920

Adjuvant HIV Vaccine Antigen/Approach

Phase

ClinicalTrials.gov Identifier

Rehydragel

ALVAC (vCP1521) boosted by

AIDSVAX gp120 B/E

Phase III

NCT00223080

pIL-12 and pIL-15 PENNVAX-B DNA

Phase I

NCT00528489

MF59

vs. AS01B

DNA-HIV-PT123 boosted by bivalent

subtype C gp120

Phase I

NCT02915016

MF59

vs. AS01B

ALVAC (vCP2438) boosted by

bivalent subtype C gp120

Phase I/IIa

NCT03122223

MF59

vs.

Rehydragel

ALVAC (vCP2438) boosted by

bivalent subtype C gp120

Phase I

NCT03284710