New NIAID-supported science presented at the 2024 HIV Research for Prevention (HIVR4P) conference in Lima, Peru features a breadth of HIV discovery and translational findings and enriches the evidence base on HIV pre-exposure prophylaxis (PrEP) within the context of reproductive health. Select Institute-supported science highlights are summarized below. Full HIVR4P abstracts are posted on the official conference Web site.

Using PrEP Modalities Alongside Contraception and in the First Trimester of Pregnancy

The monthly dapivirine vaginal ring for HIV prevention was safe in cisgender women who used the ring during early pregnancy and then discontinued use as soon as they learned that they were pregnant. In a pre-licensure open-label study of the dapivirine vaginal ring, participants stopped using it if they became pregnant because ring use during pregnancy was beyond the scope of the study. Pregnant study participants remained enrolled after discontinuing the ring and were monitored for safety throughout their pregnancies. An analysis of data from 72 pregnancies found that there were no notable adverse effects among the participants or their infants when the ring was used in early pregnancy. These findings add to the growing evidence that the dapivirine vaginal ring is safe to use throughout pregnancy. Data presented from another study previously confirmed the safety of the ring when participants initiated use during the second trimester and continued to use it until delivery.

An analysis from the Phase 3 study of long-acting injectable cabotegravir (CAB-LA) PrEP in cisgender women found the drug did not interact with long-acting reversible contraceptive (LARC) drugs. A subset of study participants taking the LARCs etonogestrel, medroxyprogesterone acetate or norethindrone provided additional blood samples so that the study team could analyze how taking LARCs together with CAB-LA or oral PrEP with tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) could affect the levels of the antiretroviral drugs and contraceptive agents in the body. There were no drug interactions between CAB-LA and any of the LARCs. Interaction between TDF/FTC and LARCs could not be determined because adherence to TDF/FTC was low in the participating cohort. CAB-LA and TDF/FTC were previously shown to be safe for use in pregnancy. 

Early-Stage Findings on HIV Vaccines to Produce HIV Broadly Neutralizing Antibodies

Several studies of germline targeting—a promising HIV vaccine strategy that stimulates the immune system to generate antibodies capable of neutralizing diverse HIV strains—reported results to inform the next stages of vaccine development. Findings in people and animal models showed that several immunogens—molecules used in a vaccine to elicit a specific immune system response—began to prompt immune responses that could generate HIV broadly neutralizing antibodies (bNAbs). In one study of 53 participants without HIV, a vaccine containing a nanoparticle immunogen called 426.mod.core-C4b was safe at multiple dosing levels and appeared to generate B cells capable of producing bNAbs if stimulated further. These findings are informing the development of more advanced HIV vaccine concepts involving the 426.mod.core-C4b immunogen. 

Understanding the HIV Reservoir and HIV Remission Off Antiretroviral Therapy

HIV is difficult to cure because the virus is skilled at “hiding” in the body and can reappear in the blood stream shortly after antiretroviral therapy (ART) is stopped. These hiding places, called reservoirs, are unaffected by ART. NIAID-supported scientists are exploring strategies to clear HIV and its reservoirs from the body or to reduce HIV to levels that can be suppressed by a person’s own immune system. A new small study found that monocytes—a type of white blood cell—expressing a gene called interleukin 1 beta (IL1B) are associated with smaller HIV reservoirs after a person acquires HIV. Further understanding of the influence of IL1B on HIV reservoir size could guide future novel HIV remission strategies.

Clinical trials and animal studies of HIV remission approaches reported outcomes of interventions designed to maintain HIV viral suppression or remission after ART was paused. When ART is paused in an HIV remission study it is called an analytical treatment interruption (ATI). In one study, researchers infected 16 infant monkeys with the simian version of HIV (SHIV), then placed them into three different treatment groups, each including ART with various combinations of the investigational HIV drug leronlimab and the HIV bNAbs called PGT121-LS and VRC07-523-LS. After 27 weeks of treatment, the research team conducted an ATI and observed outcomes by treatment group. Animals that received ART and both HIV bNAbs experienced rapid rebound of detectable SHIV. Two of 6 animals that received ART and leronlimab remained free of detectable virus through 20 weeks after ATI. All of the animals that received ART, leronlimab and the two HIV bNAbs remained free of detectable virus at the time of abstract submission, 15 weeks after ATI. Monitoring and assessment of monkeys’ SHIV reservoirs is ongoing, and further studies are warranted to understand the effects observed, according to the authors.

Novel PrEP Implant Technology 

Available PrEP methods currently include oral pill, long-acting injectable, and controlled release vaginal ring formulations. A novel refillable controlled-release antiretroviral drug (ARV) implant was found to be safe and capable of delivering one or more ARVs. The implant, placed subdermally—just under the skin—was examined in monkeys and demonstrated that it could provide sustained release of the investigational ARVs islatravir and MK-8527 as well as the lenacapavir, which is licensed for ART and being studied for PrEP, and bictegravir and dolutegravir, both licensed for ART. Implants containing islatravir were evaluated for efficacy as PrEP and found to completely protect the animals from SHIV challenge—direct administration of the virus vaginally and rectally—through 29 months. The implant is being studied for delivery of ARVs for PrEP and ART.

HIV clinical research builds upon basic science discoveries, preclinical studies, and consultations with communities affected by HIV. Further, clinical research relies on the dedication of study participants and the people who support them. NIAID is grateful to all who contribute to advancing HIV research.

References

P Ehrenberg et al. Single-cell analyses reveal that monocyte gene expression impacts HIV-1 reservoir size in acutely treated cohorts. HIV Research for Prevention Conference. Tuesday, October 8, 2024.

W Hahn et al. Vaccination with a novel fractional escalating dose strategy improves early humoral responses with a novel germline targeting HIV vaccine (426.mod.core-C4b): preliminary results from HVTN 301. HIV Research for Prevention Conference. Wednesday, October 9, 2024. 

N. Haigwood et al. Short-term combination immunotherapy with broadly neutralizing antibodies and CCR5 blockade mediates ART-free viral control in infant rhesus macaques. HIV Research for Prevention Conference. Wednesday, October 9, 2024.

M Marzinke et al. Evaluation of potential pharmacologic interactions between CAB-LA or TDF/FTC and hormonal contraceptive agents: a tertiary analysis of HPTN 084. HIV Research for Prevention Conference. Thursday, October 10, 2024.

A Mayo et al. Pregnancy and infant outcomes among individuals exposed to dapivirine ring during the first trimester of pregnancy in the MTN-025/HOPE open-label extension trial. HIV Research for Prevention Conference. Thursday, October 10, 2024.

F Pons-Faudoa et al. Drug-agnostic transcutaneously-refillable subdermal implant for ultra-long-acting delivery of antiretrovirals for HIV prevention. HIV Research for Prevention Conference. Wednesday, October 9, 2024.

Discovery, Development and Delivery for an Increasingly Interconnected HIV Landscape 

By Carl Dieffenbach, Ph.D., director, Division of AIDS, NIAID

This blog is the third in a series about the future of NIAID's HIV clinical research enterprise. For more information, please visit the HIV Clinical Research Enterprise page.

The NIAID HIV clinical research enterprise has celebrated important scientific advances since awards were made to the current networks in 2020. These achievements include the culminating steps in decades of research that led to approval of the first generation of long-acting medications for HIV prevention—a milestone that raises the standard for any future antiretroviral drug development to levels unimaginable even a decade ago. Our research has highlighted opportunities to maintain the overall health of people with HIV throughout their lifespans. We continue to expand the boundaries of scientific innovation in pursuit of durable technologies that could hasten an end to the HIV pandemic, especially preventive vaccines and curative therapy. During the COVID-19 public health emergency, our networks stepped forward to deliver swift results that advanced vaccines and therapeutics within a year of the World Health Organization declaring the global pandemic, while maintaining progress on our HIV research agenda. The impact of this collective scientific progress is evident worldwide.

Together with my NIH colleagues, I express sincere gratitude to the leaders and staff of current clinical trials networks, our research and civil society partners, and most importantly, clinical study participants and their loved ones, for their enduring commitment to supporting science that changes lives.

As we do every seven years, we are at a point in the funding cycle when our Institute engages research partners, community representatives, and other public health stakeholders in a multidisciplinary evaluation of network progress toward short- and long-term scientific goals. This process takes account of knowledge gained since the networks were last funded and identifies essential course corrections based on the latest scientific and public health evidence and priorities. Subsequent NIAID HIV research investments will build on the conclusions of these discussions.

Looking to the future, we envision an HIV research enterprise that follows a logical evolution in addressing new scientific priorities informed by previous research progress. We will fund our next networks to align with updated research goals to take us through the end of 2034. The HIV research community’s outstanding infrastructure is the model for biomedical research. Now, our capacity must reflect an increasing interdependence across clinical practice areas and public health contexts. Our goals for the next networks are to:

• Maintain our support for core discovery and translational research to address gaps in biomedical HIV prevention and treatment, including a vaccine and therapeutic remission or cure. Our objective is to identify effective interventions that expand user choice and access, as well as improve quality of life across the lifespan;
• Provide the multidisciplinary leadership required to address the intersections between HIV and other diseases and conditions throughout the lifespan, including noncommunicable diseases, such as diabetes mellitus and substance use disorder, and infectious diseases that share health determinants with HIV, such tuberculosis and hepatitis;
• Compress protocol development and approval timelines for small and early-stage trials to enable more timely translation of research concepts to active studies; 
• Respond to discrete implementation science research questions as defined by our implementation counterparts, including federal partners at the Centers for Disease Control and Prevention, Health Resources and Services Administration, U.S. Agency for International Development, agencies implementing the U.S. President’s Emergency Plan for AIDS Relief, and other nongovernmental funders and implementing organizations worldwide;  
• Draw from nimble and effective partnerships at all levels to leverage the necessary combination of financial resources, scientific expertise, and community leadership and operational capacity to perform clinical research that is accessible to and representative of the populations most affected by HIV, especially people and communities that have been underserved in the HIV response; 
• Leverage our partners’ platforms if called on to close critical evidence gaps for pandemic response; and,
• Plan for impact by mapping clear pathways to rapid regulatory decisions, scalable production, and fair pricing before the start of any efficacy study.

Our shared goal is to produce tools and evidence to facilitate meaningful reductions in HIV incidence, morbidity and mortality globally. I invite you to continue sharing your thoughts with us to help shape the future of HIV clinical research, and to review the blogs on specialized topics that we will continue to post on the HIV Clinical Research Enterprise page in the coming weeks. Please share your feedback, comments, and questions at NextNIAIDHIVNetworks@mail.nih.gov. Submissions will be accepted through December 2024. 

This blog is the second in a series about the future of NIAID's HIV clinical research enterprise. For more information, please visit the HIV Clinical Research Enterprise page.

The impact of clinical research is often measured by its outcomes. From trials that provide groundbreaking evidence of efficacy to those stopped early for futility, the end results of clinical trials shape practice and future research priorities. However, years of effort from scientists, study teams and study participants while a trial is underway are sometimes overshadowed by final study outcomes. In this regard, trial implementation requires clinical research sites’ operational excellence for the duration of a study. Access to relevant populations depends on the location of each clinical research site as well as investigators' and clinical care providers’ engagement with the local community and understanding of their needs and preferences. A high-functioning clinical research site anchored in the communities it works in and comprised of cohesive, well-integrated components is essential to producing high-quality outputs. 

Currently, NIAID supports four research networks as part of its HIV clinical research enterprise. The networks are made up of more than 100 clinical research sites, each with local experts, robust research infrastructure, and well-trained, cross-functional staff who maintain standardized procedures and quality controls aligned with their network.

Every seven years, NIAID engages research partners, community representatives, and other public health stakeholders in a multidisciplinary evaluation of network progress toward short- and long-term scientific goals. This process takes account of knowledge gained since the networks were last funded and identifies essential course corrections based on the latest scientific and public health evidence. Subsequent NIAID HIV research investments build on the conclusions of these discussions. This process includes examining the networks’ infrastructure model, which the Institute updates and refines to stay aligned with its scientific priorities. 

The HIV clinical trials network sites have made tremendous contributions to NIH’s scientific priorities by offering direct access to and consultation with populations most affected by HIV globally, and by delivering high-quality clinical research with strong connections to trusted community outreach platforms. Their approach to community engagement anchors clinical research sites beyond the scope of any individual study, and when possible, aligns scientific questions and study protocols based on local context. 

Since the start of the 2020 research network grant cycle, HIV clinical research sites have enrolled about 93,000 participants across 78 clinical trials in 25 countries. The networks were able to quickly pivot to support NIAID’s emerging infectious disease priority areas, including COVID-19 and mpox. Of the 93,000 participants since 2020, approximately 78,000 were enrolled into COVID-19 clinical trials sponsored by NIAID’s Division of AIDS. 

Clinical trials sites currently operate with a hub-and-spoke model, with each hub providing centralized support to their linked clinical research sites. This model leverages shared resources where possible and practical, and ensures robust oversight to promote high-quality clinical trial operations. Hubs provide infrastructure and services including laboratory, pharmacy, regulatory, data management, and training to support execution of NIAID-sponsored clinical research. 

Future networks will need to maintain core strengths of current models while expanding capacity in areas vital to further scientific progress. These include operations that inform pandemic responses and extending our reach within communities impacted by HIV, including populations historically underrepresented in clinical research. Additionally, there may be opportunities for clinical research sites and other partners to conduct implementation science research based on their capacity and access to relevant populations in the context of specific scientific questions. 

Make seamless progress on established and emerging scientific priorities

Our goals include maintaining the strength and flexibility of our current network model and infrastructure to support established scientific priorities that improve the practice of medicine, including high-impact registrational trials to identify new biomedical interventions and support changes to product labelling. The networks also must remain capable of directing operations to generate evidence on interventions for pandemic responses. 

Engage underserved populations for more representative studies 

Building on its current reach, NIAID and its partners have identified opportunities to expand or strengthen our connections to medically underserved populations affected by HIV, and to increase representation of geographic areas with limited access to current clinical trials sites. We also are seeking clinical research sites with longstanding community relationships and experience conducting randomized clinical trials that include Black gay, bisexual, and other men who have sex with men, transgender people, people who sell sex, people who use drugs, and adolescent girls and young women, as well as populations in African countries with a high HIV prevalence. 

Integrate implementation science within clinical research practice

Implementation science is the scientific study of methods and strategies that facilitate the uptake of evidence-based practice and research into regular use by practitioners and policymakers. As biomedical HIV prevention, treatment, and diagnostic options expand, our scientific questions must expand to address not only whether an intervention works, but how it can be delivered to offer health care choices that people need, want and are able to use. This expanded scientific scope calls for research sites to have a diverse reach and skill sets, including experience and capacity for conducting implementation science research and fostering and maintaining partnerships with organizations that conduct implementation science research on key topics and interventions on which implementers seek stronger evidence.

The research community plays an essential role in shaping NIAID’s scientific direction and research enterprise operations. We want to hear from you. Please share your questions and comments at NextNIAIDHIVNetworks@mail.nih.gov.

About NIAID’s HIV Clinical Trials Networks

The clinical trials networks are supported through grants from NIAID, with co-funding from and scientific partnerships with NIH’s National Institute of Mental Health, National Institute on Drug Abuse, National Institute on Aging, and other NIH institutes and centers. There are four networks—Advancing Clinical Therapeutics Globally for HIV/AIDS and Other Infections, the HIV Vaccine Trials Network, the HIV Prevention Trials Network, and the International Maternal Pediatric Adolescent AIDS Clinical Trials Network.

A Year of Hepatitis Advances to Mark World Hepatitis Day

Viral hepatitis affects the lives of about one in twenty people in the world, resulting in over a million deaths each year. NIAID is working on many ways to prevent and treat the different types of hepatitis, including the development of vaccines and improved therapeutics and diagnostics. July 28 is observed annually as World Hepatitis Day, providing an opportunity to reflect on the impact of hepatitis on global health and focus on strategies to reduce its burden. To observe World Hepatitis Day, NIAID highlights recent advancements researchers have made in these areas.

Hepatitis is an inflammation of the liver, which can cause liver damage that is fatal in some cases. Most hepatitis cases are caused by viruses, although other infections, heavy alcohol use, exposure to toxins or some medications, or autoimmune disease can also cause hepatitis. There are five main virus types that cause hepatitis, types A, B, C, D and E. The different hepatitis viruses are spread in different ways, and each has unique impacts on health. Hepatitis A and E are generally spread through contaminated food and water, while hepatitis B, C and D are spread through body fluids. People with HIV have an increased risk of severe disease when hepatitis A, B, or C is present in the body. Additionally, presence of hepatitis B and C can affect treatment for HIV. Because of these interactions, people with HIV are disproportionately impacted by viral hepatitis.

Progress Towards Effective Hepatitis B Vaccines for People with HIV

Conventional vaccines against hepatitis B are sometimes unable to provide adequate immunity to people with HIV. An ongoing clinical trial is evaluating the effects of a vaccine against hepatitis B called HepB-CPG (also known as Heplisav-B) in people with HIV. HepB-CPG was shown to provide people with HIV high levels of immunity against hepatitis B. Researchers specifically looked at the effects of HepB-CPG vaccine in people with HIV who had previously not responded to conventional hepatitis B vaccines. The HepB-CPG vaccine uses an adjuvant—or immune booster—called CPG-1018. In the study, they compared HepB-CPG to a hepatitis vaccine that uses alum, a more conventional adjuvant, instead of CPG-1018. The researchers found that the vaccine containing CPG-1018 was superior to the conventional hepatitis B vaccine. The vaccines were safe and well tolerated. This work provides important evidence supporting the further development of vaccines for prevention of hepatitis B in people with HIV. The study is being led by ACTG, an NIAID-led clinical trials network. 

Exploring New Pathways of Immunity Against Hepatitis C

Hepatitis C can be cured with antivirals, but there are currently no vaccines against this type of hepatitis, due in part to the large number of variants and rapid evolution of the virus. People cured from hepatitis C can also become reinfected. The number of people diagnosed with hepatitis C is increasing, and a vaccine would be an important tool in preventing the spread of this dangerous virus, which can cause liver failure and cancer. Some people naturally clear hepatitis C from their bodies and have protective immunity against developing the disease when re-exposed to the virus. NIAID-funded researchers are investigating the immune responses in these individuals compared to those who develop persistent infections. The researchers found that neutralizing antibodies contributed to the clearance of hepatitis C virus from people’s bodies, and that these antibodies were directed to specific sites on the surface of the virus. Investigating how these antibodies are produced and how they target the virus may help researchers develop vaccines against hepatitis C. 

Advancing the Development of Vaccines Against Hepatitis E

Hepatitis E is the leading cause of acute hepatitis worldwide, causing about 20 million infections and 70,000 deaths each year, with greater impacts in regions with limited access to resources. There are no treatments for acute hepatitis E or approved vaccines against the virus. A vaccine is in development, called HEV-239, which was recently found in a NIAID-supported trial to be safe and achieve a durable immune response in adults in the United States. These promising results support the evaluation of the vaccine in in further clinical trials.

Understanding Hepatitis B-Associated Liver Cancer

NIAID researchers are studying diseases resulting from viral hepatitis-related liver damage, including a type of liver cancer called hepatitis B-associated hepatocellular carcinoma (HCC), which causes malignant tumors in the liver. Although immunotherapy can be effective to treat various forms of solid tumors, HCC-related tumors often do not respond to this treatment. To understand why, researchers carefully studied the tumor microenvironment—the specific molecular and cellular conditions that exist inside tumors—in 12 people with HCC. They found that two distinct subtypes of tumors existed in people with HCC. In about half of the people, the microenvironments of the tumors had high levels of immune activity, while lower levels were observed in the tumors in the other half of the people. This finding may help scientists understand how people with these types of HCC respond to treatments and could allow for development of treatments tailored to individuals with different subtypes.

New Animal Models for Hepatitis B and C

NIAID is funding several new projects focused on developing small animal models to understand and combat hepatitis B and C. This work is important because research on these viruses has been hindered by the lack of available animal models to study promising preventive and therapeutic concepts. Recipients of the new awards include:

• Wake Forest University for a project titled “Novel mouse models of hepatitis B virus infection and replication.” Guangxian Luo is the principal investigator. (Grant number: R01 AI183855-01.)
• The Research Institute at Nationwide Children’s Hospital for a project titled “Animal Model to study heterogeneous outcomes of HCV Infection and Pathogenesis. Amit Kapoor is the principal investigator. (Grant number: R01 AI183877-01.)
• The Rockefeller University for a project titled “Breaching the species barrier: Towards an immunocompetent HBV-susceptible mouse model.” Charles Rice is the principal investigator. (Grant number: R01 AI183884-01.)
• Georgetown University for a project called “Developing woodchucks susceptible to hepatitis B virus infection by modifying the virus or host.” Stephan Menne and Jianming Hu (at Penn State College of Medicine) are the principal investigators. (Grant number: R01 AI183788-01.) 

These advances and active projects underscore the important work NIAID is doing to prevent and treat viral hepatitis, with the aim of reducing the global burden of this disease. 

For more information, please visit NIAID’s hepatitis research page.