Infusion Reactions After Receiving the Broadly Neutralizing Antibody VRC01 or Placebo to Reduce HIV-1 Acquisition: Results From the Phase 2b Antibody-Mediated Prevention Randomized Trials

BACKGROUND

The antibody-mediated prevention (AMP) studies (HVTN 703/HPTN 081 and HVTN 704/HPTN 085) are harmonized phase 2b trials to assess HIV prevention efficacy and safety of intravenous infusion of anti-gp120 broadly neutralizing antibody VRC01. Antibodies for other indications can elicit infusion-related reactions (IRRs), often requiring premedication and limiting their application. We report on AMP study IRRs.

METHODS

From 2016 to 2018, 2699 HIV-uninfected, at-risk men and transgender adults in the Americas and Switzerland (704/085) and 1924 at-risk heterosexual women in sub-Saharan Africa (703/081) were randomized 1:1:1 to VRC01 10 mg/kg, 30 mg/kg, or placebo. Participants received infusions every 8 weeks (n = 10/participant) over 72 weeks, with 104 weeks of follow-up. Safety assessments were conducted before and after infusion and at noninfusion visits. A total of 40,674 infusions were administered.

RESULTS

Forty-seven participants (1.7%) experienced 49 IRRs in 704/085; 93 (4.8%) experienced 111 IRRs in 703/081 (P < 0.001). IRRs occurred more frequently in VRC01 than placebo recipients in 703/081 (P < 0.001). IRRs were associated with atopic history (P = 0.046) and with younger age (P = 0.023) in 703/081. Four clinical phenotypes of IRRs were observed: urticaria, dyspnea, dyspnea with rash, and "other." Urticaria was most prevalent, occurring in 25 (0.9%) participants in 704/085 and 41 (2.1%) participants in 703/081. Most IRRs occurred with the initial infusion and incidence diminished through the last infusion. All reactions were managed successfully without sequelae.

CONCLUSIONS

IRRs in the AMP studies were uncommon, typically mild or moderate, successfully managed at the research clinic, and resolved without sequelae. Analysis is ongoing to explore potential IRR mechanisms.

Effect of Bamlanivimab vs Placebo on Incidence of COVID-19 Among Residents and Staff of Skilled Nursing and Assisted Living Facilities: A Randomized Clinical Trial

IMPORTANCE

Preventive interventions are needed to protect residents and staff of skilled nursing and assisted living facilities from COVID-19 during outbreaks in their facilities. Bamlanivimab, a neutralizing monoclonal antibody against SARS-CoV-2, may confer rapid protection from SARS-CoV-2 infection and COVID-19.

OBJECTIVE

To determine the effect of bamlanivimab on the incidence of COVID-19 among residents and staff of skilled nursing and assisted living facilities.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, single-dose, phase 3 trial that enrolled residents and staff of 74 skilled nursing and assisted living facilities in the United States with at least 1 confirmed SARS-CoV-2 index case. A total of 1175 participants enrolled in the study from August 2 to November 20, 2020. Database lock was triggered on January 13, 2021, when all participants reached study day 57.

INTERVENTIONS

Participants were randomized to receive a single intravenous infusion of bamlanivimab, 4200 mg (n = 588), or placebo (n = 587).

MAIN OUTCOMES AND MEASURES

The primary outcome was incidence of COVID-19, defined as the detection of SARS-CoV-2 by reverse transcriptase-polymerase chain reaction and mild or worse disease severity within 21 days of detection, within 8 weeks of randomization. Key secondary outcomes included incidence of moderate or worse COVID-19 severity and incidence of SARS-CoV-2 infection.

RESULTS

The prevention population comprised a total of 966 participants (666 staff and 300 residents) who were negative at baseline for SARS-CoV-2 infection and serology (mean age, 53.0 [range, 18-104] years; 722 [74.7%] women). Bamlanivimab significantly reduced the incidence of COVID-19 in the prevention population compared with placebo (8.5% vs 15.2%; odds ratio, 0.43 [95% CI, 0.28-0.68]; P < .001; absolute risk difference, -6.6 [95% CI, -10.7 to -2.6] percentage points). Five deaths attributed to COVID-19 were reported by day 57; all occurred in the placebo group. Among 1175 participants who received study product (safety population), the rate of participants with adverse events was 20.1% in the bamlanivimab group and 18.9% in the placebo group. The most common adverse events were urinary tract infection (reported by 12 participants [2%] who received bamlanivimab and 14 [2.4%] who received placebo) and hypertension (reported by 7 participants [1.2%] who received bamlanivimab and 10 [1.7%] who received placebo).

CONCLUSIONS AND RELEVANCE

Among residents and staff in skilled nursing and assisted living facilities, treatment during August-November 2020 with bamlanivimab monotherapy reduced the incidence of COVID-19 infection. Further research is needed to assess preventive efficacy with current patterns of viral strains with combination monoclonal antibody therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04497987.

A Phase 2b Study to Evaluate the Safety and Efficacy of VRC01 Broadly Neutralizing Monoclonal Antibody in Reducing Acquisition of HIV-1 Infection in Women in Sub-Saharan Africa: Baseline Findings

BACKGROUND

HIV Vaccine Trials Network 703/HIV Prevention Trials Network 081 is a phase 2b randomized, double-blind, placebo-controlled trial to assess the safety and efficacy of passively infused monoclonal antibody VRC01 in preventing HIV acquisition in heterosexual women between the ages of 18 and 50 years at risk of HIV. Participants were enrolled at 20 sites in Botswana, Kenya, Malawi, Mozambique, South Africa, Tanzania, and Zimbabwe. It is one of the 2 Antibody Mediated Prevention efficacy trials, with HIV Vaccine Trials Network 704/HIV Prevention Trials Network 085, evaluating VRC01 for HIV prevention.

METHODS

Intense community engagement was used to optimize participant recruitment and retention. Participants were randomly assigned to receive intravenous VRC01 10 mg/kg, VRC01 30 mg/kg, or placebo in a 1:1:1 ratio. Infusions were given every 8 weeks with a total of 10 infusions and 104 weeks of follow-up after the first infusion.

RESULTS

Between May 2016 and September 2018, 1924 women from sub-Saharan Africa were enrolled. The median age was 26 years (interquartile range: 22-30), and 98.9% were Black. Sexually transmitted infection prevalence at enrollment included chlamydia (16.9%), trichomonas (7.2%), gonorrhea (5.7%), and syphilis (2.2%). External condoms (83.2%) and injectable contraceptives (61.1%) were the methods of contraception most frequently used by participants. In total, through April 3, 2020, 38,490 clinic visits were completed with a retention rate of 96% and 16,807 infusions administered with an adherence rate of 98%.

CONCLUSIONS

This proof-of-concept, large-scale monoclonal antibody study demonstrates the feasibility of conducting complex trials involving intravenous infusions in high incidence populations in sub-Saharan Africa.

Feasibility and Successful Enrollment in a Proof-of-Concept HIV Prevention Trial of VRC01, a Broadly Neutralizing HIV-1 Monoclonal Antibody

BACKGROUND

The Antibody-Mediated Prevention trials (HVTN 704/HPTN 085 and HVTN 703/HPTN 081) are the first efficacy trials to evaluate whether VRC01, a broadly neutralizing monoclonal antibody targeting the CD4-binding site of the HIV envelope protein, prevents sexual transmission of HIV-1. HVTN 704/HPTN 085 enrolled 2701 cisgender men and transgender (TG) individuals who have sex with men at 26 sites in Brazil, Peru, Switzerland, and the United States.

METHODS

Participants were recruited and retained through early, extensive community engagement. Eligible participants were randomized 1:1:1 to 10 mg/kg or 30 mg/kg of VRC01 or saline placebo. Visits occurred monthly, with intravenous (IV) infusions every 8 weeks over 2 years, for a total of 10 infusions. Participants were followed for 104 weeks after first infusion.

RESULTS

The median HVTN 704/HPTN 085 participant age was 28 years; 99% were assigned male sex; 90% identified as cisgender men, 5% as TG women and the remaining as other genders. Thirty-two percent were White, 15% Black, and 57% Hispanic/Latinx. Twenty-eight percent had a sexually transmitted infection at enrollment. More than 23,000 infusions were administered with no serious IV administration complications. Overall, retention and adherence to the study schedule exceeded 90%, and the dropout rate was below 10% annually (7.3 per 100 person-years) through week 80, the last visit for the primary end point.

CONCLUSIONS

HVTN 704/HPTN 085 exceeded accrual and retention expectations. With exceptional safety of IV administration and operational feasibility, it paves the way for future large-scale monoclonal antibody trials for HIV prevention and/or treatment.

Two Randomized Trials of Neutralizing Antibodies to Prevent HIV-1 Acquisition

BACKGROUND

Whether a broadly neutralizing antibody (bnAb) can be used to prevent human immunodeficiency virus type 1 (HIV-1) acquisition is unclear.

METHODS

We enrolled at-risk cisgender men and transgender persons in the Americas and Europe in the HVTN 704/HPTN 085 trial and at-risk women in sub-Saharan Africa in the HVTN 703/HPTN 081 trial. Participants were randomly assigned to receive, every 8 weeks, infusions of a bnAb (VRC01) at a dose of either 10 or 30 mg per kilogram (low-dose group and high-dose group, respectively) or placebo, for 10 infusions in total. HIV-1 testing was performed every 4 weeks. The VRC01 80% inhibitory concentration (IC80) of acquired isolates was measured with the TZM-bl assay.

RESULTS

Adverse events were similar in number and severity among the treatment groups within each trial. Among the 2699 participants in HVTN 704/HPTN 085, HIV-1 infection occurred in 32 in the low-dose group, 28 in the high-dose group, and 38 in the placebo group. Among the 1924 participants in HVTN 703/HPTN 081, infection occurred in 28 in the low-dose group, 19 in the high-dose group, and 29 in the placebo group. The incidence of HIV-1 infection per 100 person-years in HVTN 704/HPTN 085 was 2.35 in the pooled VRC01 groups and 2.98 in the placebo group (estimated prevention efficacy, 26.6%; 95% confidence interval [CI], -11.7 to 51.8; P = 0.15), and the incidence per 100 person-years in HVTN 703/HPTN 081 was 2.49 in the pooled VRC01 groups and 3.10 in the placebo group (estimated prevention efficacy, 8.8%; 95% CI, -45.1 to 42.6; P = 0.70). In prespecified analyses pooling data across the trials, the incidence of infection with VRC01-sensitive isolates (IC80 <1 μg per milliliter) per 100 person-years was 0.20 among VRC01 recipients and 0.86 among placebo recipients (estimated prevention efficacy, 75.4%; 95% CI, 45.5 to 88.9). The prevention efficacy against sensitive isolates was similar for each VRC01 dose and trial; VRC01 did not prevent acquisition of other HIV-1 isolates.

CONCLUSIONS

VRC01 did not prevent overall HIV-1 acquisition more effectively than placebo, but analyses of VRC01-sensitive HIV-1 isolates provided proof-of-concept that bnAb prophylaxis can be effective. (Supported by the National Institute of Allergy and Infectious Diseases; HVTN 704/HPTN 085 and HVTN 703/HPTN 081 ClinicalTrials.gov numbers, NCT02716675 and NCT02568215.).

Immunobiology of influenza vaccines

Vaccination is the primary strategy for prevention and control of influenza. The surface hemagglutinin (HA) protein of the influenza virus contains two structural elements (head and stalk) that differ in their potential utility as vaccine targets. The head of the HA protein is the primary target of antibodies that confer protective immunity to influenza viruses. The underlying health status, age, and gene polymorphisms of vaccine recipients and, just as importantly, the extent of the antigenic match between the viruses in the vaccine and those that are circulating modulate influenza vaccine protection. Vaccine adjuvants and live attenuated influenza vaccine improve the breadth of immunity to seasonal and pandemic virus strains. Eliciting antibodies against the conserved HA stem region that cross-react with HAs within influenza virus types or subtypes would allow for the development of a universal influenza vaccine. The highly complex network of interactions generated after influenza infection and vaccination can be studied with the use of systems biology tools, such as DNA microarray chips. The use of systems vaccinology has allowed for the generation of gene expression signatures that represent key transcriptional differences between asymptomatic and symptomatic host responses to influenza infection. Additionally, the use of systems vaccinology tools have resulted in the identification of novel surrogate gene markers that are predictors of the magnitude of host responses to vaccines, which is critical to both vaccine development and public health. Identifying associations between variations in vaccine immune responses and gene polymorphisms is critical in the development of universal influenza vaccines.