Phase 1 trial evaluating safety and pharmacokinetics of HIV-1 broadly neutralizing mAbs 10E8VLS and VRC07-523LS.

BACKGROUNDBroadly neutralizing monoclonal antibodies (bNAbs) represent a promising strategy for HIV-1 immunoprophylaxis and treatment. 10E8VLS and VRC07-523LS are bNAbs that target the highly conserved membrane-proximal external region (MPER) and the CD4-binding site of the HIV-1 viral envelope glycoprotein, respectively.METHODSIn this phase 1, open-label trial, we evaluated the safety and pharmacokinetics of 5 mg/kg 10E8VLS administered alone, or concurrently with 5 mg/kg VRC07-523LS, via s.c. injection to healthy non-HIV-infected individuals.RESULTSEight participants received either 10E8VLS alone (n = 6) or 10E8VLS and VRC07-523LS in combination (n = 2). Five (n = 5 of 8, 62.5%) participants who received 10E8VLS experienced moderate local reactogenicity, and 1 participant (n = 1/8, 12.5%) experienced severe local reactogenicity. Further trial enrollment was stopped, and no participant received repeat dosing. All local reactogenicity resolved without sequelae. 10E8VLS retained its neutralizing capacity, and no functional anti-drug antibodies were detected; however, a serum t1/2 of 8.1 days was shorter than expected. Therefore, the trial was voluntarily stopped per sponsor decision (Vaccine Research Center, National Institute of Allergy and Infectious Diseases [NIAID], NIH). Mechanistic studies performed to investigate the underlying reason for the reactogenicity suggest that multiple mechanisms may have contributed, including antibody aggregation and upregulation of local inflammatory markers.CONCLUSION10E8VLS resulted in unexpected reactogenicity and a shorter t1/2 in comparison with previously tested bNAbs. These studies may facilitate identification of nonreactogenic second-generation MPER-targeting bNAbs, which could be an effective strategy for HIV-1 immunoprophylaxis and treatment.TRIAL REGISTRATIONClinicaltrials.gov, accession no. NCT03565315.FUNDINGDivision of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH.

Low-dose intravenous and subcutaneous CIS43LS monoclonal antibody for protection against malaria (VRC 612 Part C): a phase 1, adaptive trial.

BACKGROUND: Human monoclonal antibodies might offer an important new approach to reduce malaria morbidity and mortality. In the first two parts of a three-part clinical trial, the antimalarial monoclonal antibody CIS43LS conferred high protection against parasitaemia at doses of 20 mg/kg or 40 mg/kg administered intravenously followed by controlled human malaria infection. The ability of CIS43LS to confer protection at lower doses or by the subcutaneous route is unknown. We aimed to provide data on the safety and optimisation of dose and route for the human antimalaria monoclonal antibody CIS43LS. METHODS: VRC 612 Part C was the third part of a three-part, first-in-human, phase 1, adaptive trial, conducted at the University of Maryland, Baltimore Center for Vaccine Development and Global Health, Baltimore, MD, USA. We enrolled adults aged 18-50 years with no previous malaria vaccinations or infections, in a sequential, dose-escalating manner. Eligible participants received the monoclonal antibody CIS43LS in a single, open-label dose of 1 mg/kg, 5 mg/kg, or 10 mg/kg intravenously, or 5 mg/kg or 10 mg/kg subcutaneously. Participants underwent controlled human malaria infection by the bites of five mosquitoes infected with Plasmodium falciparum 3D7 strain approximately 8 weeks after their monoclonal antibody inoculation. Six additional control participants who did not receive CIS43LS underwent controlled human malaria infection simultaneously. Participants were followed-up daily on days 7-18 and day 21, with qualitative PCR used for P falciparum detection. Participants who tested positive for P falciparum were treated with atovaquone-proguanil and those who remained negative were treated at day 21. Participants were followed-up until 24 weeks after dosing. The primary outcome was safety and tolerability of CIS43LS at each dose level, assessed in the as-treated population. Secondary outcomes included protective efficacy of CIS43LS after controlled human malaria infection. This trial is now complete and is registered with ClinicalTrials.gov, NCT04206332. FINDINGS: Between Sept 1, 2021, and Oct 29, 2021, 47 people were assessed for eligibility and 31 were enrolled (one subsequently withdrew and was replaced) and assigned to receive doses of 1 mg/kg (n=7), 5 mg/kg (n=4), and 10 mg/kg (n=3) intravenously and 5 mg/kg (n=4) and 10 mg/kg (n=4) subcutaneously, or to the control group (n=8). CIS43LS administration was safe and well tolerated; no serious adverse events occurred. CIS43LS protected 18 (82%) of 22 participants who received a dose. No participants developed parasitaemia following dosing at 5 mg/kg intravenously or subcutaneously, or at 10 mg/kg intravenously or subcutaneously. All six control participants and four of seven participants dosed at 1 mg/kg intravenously developed parasitaemia after controlled human malaria infection. INTERPRETATION: CIS43LS was safe and well tolerated, and conferred protection against P falciparum at low doses and by the subcutaneous route, providing evidence that this approach might be useful to prevent malaria across several clinical use cases. FUNDING: National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Safety, tolerability, and immunogenicity of the chimpanzee adenovirus type 3-vectored Marburg virus (cAd3-Marburg) vaccine in healthy adults in the USA: a first-in-human, phase 1, open-label, dose-escalation trial.

BACKGROUND: WHO has identified Marburg virus as an emerging virus requiring urgent vaccine research and development, particularly due to its recent emergence in Ghana. We report results from a first-in-human clinical trial evaluating a replication-deficient recombinant chimpanzee adenovirus type 3 (cAd3)-vectored vaccine encoding a wild-type Marburg virus Angola glycoprotein (cAd3-Marburg) in healthy adults. METHODS: We did a first-in-human, phase 1, open-label, dose-escalation trial of the cAd3-Marburg vaccine at the Walter Reed Army Institute of Research Clinical Trials Center in the USA. Healthy adults aged 18-50 years were assigned to receive a single intramuscular dose of cAd3-Marburg vaccine at either 1 × 1010 or 1 × 1011 particle units (pu). Primary safety endpoints included reactogenicity assessed for the first 7 days and all adverse events assessed for 28 days after vaccination. Secondary immunogenicity endpoints were assessment of binding antibody responses and T-cell responses against the Marburg virus glycoprotein insert, and assessment of neutralising antibody responses against the cAd3 vector 4 weeks after vaccination. This study is registered with ClinicalTrials.gov, NCT03475056. FINDINGS: Between Oct 9, 2018, and Jan 31, 2019, 40 healthy adults were enrolled and assigned to receive a single intramuscular dose of cAd3-Marburg vaccine at either 1 × 1010 pu (n=20) or 1 × 1011 pu (n=20). The cAd3-Marburg vaccine was safe, well tolerated, and immunogenic. All enrolled participants received cAd3-Marburg vaccine, with 37 (93%) participants completing follow-up visits; two (5%) participants moved from the area and one (3%) was lost to follow-up. No serious adverse events related to vaccination occurred. Mild to moderate reactogenicity was observed after vaccination, with symptoms of injection site pain and tenderness (27 [68%] of 40 participants), malaise (18 [45%] of 40 participants), headache (17 [43%] of 40 participants), and myalgia (14 [35%] of 40 participants) most commonly reported. Glycoprotein-specific antibodies were induced in 38 (95%) of 40 participants 4 weeks after vaccination, with geometric mean titres of 421 [95% CI 209-846] in the 1 × 1010 pu group and 545 [276-1078] in the 1 × 1011 pu group, and remained significantly elevated at 48 weeks compared with baseline titres (39 [95% CI 13-119] in the 1 ×1010 pu group and 27 [95-156] in the 1 ×1011 pu group; both p<0·0001). T-cell responses to the glycoprotein insert and neutralising responses against the cAd3 vector were also increased at 4 weeks after vaccination. INTERPRETATION: This first-in-human trial of this cAd3-Marburg vaccine showed the agent is safe and immunogenic, with a safety profile similar to previously tested cAd3-vectored filovirus vaccines. 95% of participants produced a glycoprotein-specific antibody response at 4 weeks after a single vaccination, which remained in 70% of participants at 48 weeks. These findings represent a crucial step in the development of a vaccine for emergency deployment against a re-emerging pathogen that has recently expanded its reach to new regions. FUNDING: National Institutes of Health.

Safety and immunogenicity of an HIV-1 prefusion-stabilized envelope trimer (Trimer 4571) vaccine in healthy adults: A first-in-human open-label, randomized, dose-escalation, phase 1 clinical trial.

Background: Advances in therapeutic drugs have increased life-expectancies for HIV-infected individuals, but the need for an effective vaccine remains. We assessed safety and immunogenicity of HIV-1 vaccine, Trimer 4571 (BG505 DS-SOSIP.664) adjuvanted with aluminum hydroxide (alum), in HIV-negative adults. Methods: We conducted a phase I, randomized, open-label, dose-escalation trial at the National Institutes of Health Clinical Center in Bethesda, MD, USA. Eligible participants were HIV-negative, healthy adults between 18-50 years. Participants were randomized 1:1 to receive Trimer 4571 adjuvanted with 500 mcg alum by either the subcutaneous (SC) or intramuscular (IM) route at weeks 0, 8, and 20 in escalating doses of 100 mcg or 500 mcg. The primary objectives were to evaluate the safety and tolerability of Trimer 4571 with a secondary objective of evaluating vaccine-induced antibody responses. The primary and safety endpoints were evaluated in all participants who received at least one dose of Trimer 4571. Trial results were summarized using descriptive statistics. This trial is registered at ClinicalTrials.gov, NCT03783130. Findings: Between March 7 and September 11, 2019, 16 HIV-negative participants were enrolled, including six (38%) males and ten (62%) females. All participants received three doses of Trimer 4571. Solicited reactogenicity was mild to moderate in severity, with one isolated instance of severe injection site redness (6%) following a third 500 mcg SC administration. The most commonly reported solicited symptoms included mild injection site tenderness in 14 (88%) and mild myalgia in six (38%) participants. The most frequent unsolicited adverse event attributed to vaccination was mild injection site pruritus in six (38%) participants. Vaccine-induced seropositivity occurred in seven (44%) participants and resolved in all but one (6%). No serious adverse events occurred. Trimer 4571-specific binding antibodies were detected in all groups two weeks after regimen completion, primarily focused on the glycan-free trimer base. Neutralizing antibody activity was limited to the 500 mcg dose groups. Interpretation: Trimer 4571 was safe, well tolerated, and immunogenic in this first-in-human trial. While this phase 1 trial is limited in size, our results inform and support further evaluation of prefusion-stabilized HIV-1 envelope trimers as a component of vaccine design strategies to generate broadly neutralizing antibodies against HIV-1. Funding: Intramural Research Program of the Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Safety and tolerability of AAV8 delivery of a broadly neutralizing antibody in adults living with HIV: a phase 1, dose-escalation trial.

Adeno-associated viral vector-mediated transfer of DNA coding for broadly neutralizing anti-HIV antibodies (bnAbs) offers an alternative to attempting to induce protection by vaccination or by repeated infusions of bnAbs. In this study, we administered a recombinant bicistronic adeno-associated virus (AAV8) vector coding for both the light and heavy chains of the potent broadly neutralizing HIV-1 antibody VRC07 (AAV8-VRC07) to eight adults living with HIV. All participants remained on effective anti-retroviral therapy (viral load (VL) <50 copies per milliliter) throughout this phase 1, dose-escalation clinical trial ( NCT03374202 ). AAV8-VRC07 was given at doses of 5 × 1010, 5 × 1011 and 2.5 × 1012 vector genomes per kilogram by intramuscular (IM) injection. Primary endpoints of this study were to assess the safety and tolerability of AAV8-VRC07; to determine the pharmacokinetics and immunogenicity of in vivo VRC07 production; and to describe the immune response directed against AAV8-VRC07 vector and its products. Secondary endpoints were to assess the clinical effects of AAV8-VRC07 on CD4 T cell count and VL and to assess the persistence of VRC07 produced in participants. In this cohort, IM injection of AAV8-VRC07 was safe and well tolerated. No clinically significant change in CD4 T cell count or VL occurred during the 1-3 years of follow-up reported here. In participants who received AAV8-VRC07, concentrations of VRC07 were increased 6 weeks (P = 0.008) and 52 weeks (P = 0.016) after IM injection of the product. All eight individuals produced measurable amounts of serum VRC07, with maximal VRC07 concentrations >1 µg ml-1 in three individuals. In four individuals, VRC07 serum concentrations remained stable near maximal concentration for up to 3 years of follow-up. In exploratory analyses, neutralizing activity of in vivo produced VRC07 was similar to that of in vitro produced VRC07. Three of eight participants showed a non-idiotypic anti-drug antibody (ADA) response directed against the Fab portion of VRC07. This ADA response appeared to decrease the production of serum VRC07 in two of these three participants. These data represent a proof of concept that adeno-associated viral vectors can durably produce biologically active, difficult-to-induce bnAbs in vivo, which could add valuable new tools to the fight against infectious diseases.

A Monoclonal Antibody for Malaria Prevention.

BACKGROUND: Additional interventions are needed to reduce the morbidity and mortality caused by malaria. METHODS: We conducted a two-part, phase 1 clinical trial to assess the safety and pharmacokinetics of CIS43LS, an antimalarial monoclonal antibody with an extended half-life, and its efficacy against infection with Plasmodium falciparum. Part A of the trial assessed the safety, initial side-effect profile, and pharmacokinetics of CIS43LS in healthy adults who had never had malaria. Participants received CIS43LS subcutaneously or intravenously at one of three escalating dose levels. A subgroup of participants from Part A continued to Part B, and some received a second CIS43LS infusion. Additional participants were enrolled in Part B and received CIS43LS intravenously. To assess the protective efficacy of CIS43LS, some participants underwent controlled human malaria infection in which they were exposed to mosquitoes carrying P. falciparum sporozoites 4 to 36 weeks after administration of CIS43LS. RESULTS: A total of 25 participants received CIS43LS at a dose of 5 mg per kilogram of body weight, 20 mg per kilogram, or 40 mg per kilogram, and 4 of the 25 participants received a second dose (20 mg per kilogram regardless of initial dose). No safety concerns were identified. We observed dose-dependent increases in CIS43LS serum concentrations, with a half-life of 56 days. None of the 9 participants who received CIS43LS, as compared with 5 of 6 control participants who did not receive CIS43LS, had parasitemia according to polymerase-chain-reaction testing through 21 days after controlled human malaria infection. Two participants who received 40 mg per kilogram of CIS43LS and underwent controlled human malaria infection approximately 36 weeks later had no parasitemia, with serum concentrations of CIS43LS of 46 and 57 µg per milliliter at the time of controlled human malaria infection. CONCLUSIONS: Among adults who had never had malaria infection or vaccination, administration of the long-acting monoclonal antibody CIS43LS prevented malaria after controlled infection. (Funded by the National Institute of Allergy and Infectious Diseases; VRC 612 ClinicalTrials.gov number, NCT04206332.).