Efficacy and immunogenicity following dengue virus-1 human challenge after a tetravalent prime-boost dengue vaccine regimen: an open-label, phase 1 trial.

BACKGROUND: Dengue human infection models (DHIMs) are important tools to down-select dengue vaccine candidates and establish tetravalent efficacy before advanced clinical field trials. We aimed to provide data for the safety and immunogenicity of DHIM and evaluate dengue vaccine efficacy. METHODS: We performed an open-label, phase 1 trial at the University of Maryland (Baltimore, MD, USA). Eligible participants were healthy individuals aged 18-50 years who either previously received a tetravalent dengue purified inactivated vaccine prime followed by a live-attenuated vaccine boost (ie, the vaccinee group), or were unvaccinated flavivirus-naive participants (ie, the control group). Participants in the vaccinee group with detectable pre-challenge dengue virus-1 neutralising antibody titres and flavivirus-naive participants in the control group were inoculated with dengue virus-1 strain 45AZ5 in the deltoid region, 27-65 months following booster dosing. These participants were followed-up from days 4-16 following dengue virus-1 live virus human challenge, with daily real-time quantitative PCR specific to dengue virus-1 RNA detection, and dengue virus-1 solicited local and systemic adverse events were recorded. The primary outcomes were safety (ie, solicited local and systemic adverse events) and vaccine efficacy (ie, dengue virus-1 RNAaemia) following dengue challenge. This study is registered with ClinicalTrials.gov, number NCT04786457. FINDINGS: In January 2021, ten eligible participants were enrolled; of whom, six (60%) were in the vaccinee group and four (40%) were in the control group. Daily quantitative PCR detected dengue virus-1 RNA in nine (90%) of ten participants (five [83%] of six in the vaccinee group and all four [100%] in the control group). The mean onset of RNAaemia occurred on day 5 (SD 1·0) in the vaccinee group versus day 8 (1·5) in the control group (95% CI 1·1-4·9; p=0·007), with a trend towards reduced RNAaemia duration in the vaccinee group compared with the control group (8·2 days vs 10·5 days; 95% CI -0·08 to 4·68; p=0·056). Mild-to-moderate symptoms (nine [90%] of ten), leukopenia (eight [89%] of nine), and elevated aminotransferases (seven [78%] of nine) were commonly observed. Severe adverse events were detected only in the vaccinee group (fever ≥38·9°C in three [50%] of six, headache in one [17%], and transient grade 4 aspartate aminotransferase elevation in one [17%]). No deaths were reported. INTERPRETATION: Participants who had tetravalent dengue purified inactivated vaccine prime and live-attenuated vaccine boost were unprotected against dengue virus-1 infection and further showed increased clinical, immunological, and transcriptomic evidence for inflammation potentially mediated by pre-existing infection-enhancing antibodies. This study highlights the impact of small cohort, human challenge models studying dengue pathogenesis and downstream vaccine development. FUNDING: Military Infectious Disease Research Program and Medical Technology Enterprise Consortium and Advanced Technology International.

Single Ascending and Multiple-Dose Trial of Zerlasiran, a Short Interfering RNA Targeting Lipoprotein(a): A Randomized Clinical Trial.

Importance: Lipoprotein(a) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic stenosis, with no pharmacological treatments approved by regulatory authorities. Objectives: To assess the safety and tolerability of zerlasiran, a short interfering RNA targeting hepatic synthesis of apolipoprotein(a), and effects on serum concentrations of lipoprotein(a). Design, Setting, and Participants: Single- and multiple-dose study in healthy participants and patients with stable ASCVD, respectively, with lipoprotein(a) serum concentrations greater than 150 nmol/L, conducted at 7 research sites in the US, the Netherlands, UK, and Australia between November 18, 2020, and February 8, 2023, with last follow-up on August 23, 2023. Interventions: Participants were randomized to receive (1) a single subcutaneous dose of placebo (n = 8), zerlasiran 300 mg (n = 6) or 600 mg (n = 6); or (2) 2 doses of placebo (n = 9), zerlasiran 200 mg (n = 9) at a 4-week interval or 300 mg (n = 9) or 450 mg (n = 9) at an 8-week interval. Main Outcomes Measures: The primary outcome was safety and tolerability. Secondary outcomes included serum levels of zerlasiran and effects on lipoprotein(a) serum concentrations. Results: Among 37 patients in the multiple-dose group (mean age, 56 [SD, 10.4] years; 15 [42%] women), 36 completed the trial. Among 14 participants with extended follow-up after single doses, 13 completed the trial. There were no serious adverse events. Median baseline lipoprotein(a) concentrations in the multiple-dose group were 288 (IQR, 199-352) nmol/L. Median changes in lipoprotein(a) concentration at 365 days after single doses were 14% (IQR, 13% to 15%) for the placebo group, -30% (IQR, -51% to -18%) for the 300 mg of zerlasiran group, and -29% (IQR, -39% to -7%) for the 600-mg dose group. After 2 doses, maximal median changes in lipoprotein(a) concentration were 19 (IQR, -17 to 28) nmol/L for the placebo group, -258 (IQR, -289 to -188) nmol/L for the 200 mg of zerlasiran group, -310 (IQR, -368 to -274) nmol/L for the 300-mg dose group, and -242 (IQR, -343 to -182) nmol/L for the 450-mg dose group, with maximal median percent change of 7% (IQR, -4% to 21%), -97% (IQR, -98% to -95%), -98% (IQR, -99% to -97%), and -99% (IQR, -99% to -98%), respectively, attenuating to 0.3% (IQR, -2% to 21%), -60% (IQR, -71% to -40%), -90% (IQR, -91% to -74%), and -89% (IQR, -91% to -76%) 201 days after administration. Conclusions: Zerlasiran was well tolerated and reduced lipoprotein(a) concentrations with infrequent administration. Trial Registration: ClinicalTrials.gov Identifier: NCT04606602.

An "Inclisiran First" Strategy vs Usual Care in Patients With Atherosclerotic Cardiovascular Disease.

BACKGROUND: Most patients with atherosclerotic cardiovascular disease fail to achieve guideline-directed low-density lipoprotein cholesterol (LDL-C) goals. Twice-yearly inclisiran lowers LDL-C by ∼50% when added to statins. OBJECTIVES: This study evaluated the effectiveness of an "inclisiran first" implementation strategy (adding inclisiran immediately upon failure to reach LDL-C <70 mg/dL despite receiving maximally tolerated statins) vs representative usual care in U.S. patients with atherosclerotic cardiovascular disease. METHODS: VICTORION-INITIATE, a prospective, pragmatically designed trial, randomized patients 1:1 to inclisiran (284 mg at days 0, 90, and 270) plus usual care (lipid management at treating physician's discretion) vs usual care alone. Primary endpoints were percentage change in LDL-C from baseline and statin discontinuation rates. RESULTS: We randomized 450 patients (30.9% women, 12.4% Black, 15.3% Hispanic); mean baseline LDL-C was 97.4 mg/dL. The "inclisiran first" strategy led to significantly greater reductions in LDL-C from baseline to day 330 vs usual care (60.0% vs 7.0%; P < 0.001). Statin discontinuation rates with "inclisiran first" (6.0%) were noninferior vs usual care (16.7%). More "inclisiran first" patients achieved LDL-C goals vs usual care (<70 mg/dL: 81.8% vs 22.2%; <55 mg/dL: 71.6% vs 8.9%; P < 0.001). Treatment-emergent adverse event (TEAE) and serious TEAE rates compared similarly between treatment strategies (62.8% vs 53.7% and 11.5% vs 13.4%, respectively). Injection-site TEAEs and TEAEs causing treatment withdrawal occurred more commonly with "inclisiran first" than usual care (10.3% vs 0.0% and 2.6% vs 0.0%, respectively). CONCLUSIONS: An "inclisiran first" implementation strategy led to greater LDL-C lowering compared with usual care without discouraging statin use or raising new safety concerns. (A Randomized, Multicenter, Open-label Trial Comparing the Effectiveness of an "Inclisiran First" Implementation Strategy to Usual Care on LDL Cholesterol [LDL-C] in Patients With Atherosclerotic Cardiovascular Disease and Elevated LDL-C [≥70 mg/dL] Despite Receiving Maximally Tolerated Statin Therapy [VICTORION-INITIATE]; NCT04929249).

PCSK9 inhibition with orally administered NNC0385-0434 in hypercholesterolaemia: a randomised, double-blind, placebo-controlled and active-controlled phase 2 trial.

BACKGROUND: Currently available injectable drugs that target proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce serum LDL cholesterol and improve cardiovascular outcomes. This phase 2 study assessed NNC0385-0434, an oral PCSK9 inhibitor, in individuals receiving oral lipid-lowering therapy. METHODS: In this randomised, double-blind, placebo-controlled and active-controlled trial, 42 research sites across seven countries (Belgium, Germany, Greece, Japan, the Netherlands, Poland, and the USA) recruited individuals with established atherosclerotic cardiovascular disease (aged ≥40 years) or at high risk of atherosclerotic cardiovascular disease (aged >50 years), who had LDL cholesterol concentration of at least 1·8 mmol/L and were receiving maximum tolerated statins and stable lipid-lowering therapy. The study randomly allocated participants (3:1) with an interactive web response system to receive either NNC0385-0434 (15 mg, 40 mg, or 100 mg) once a day co-formulated with the oral absorption enhancer sodium N-[8-(2-hydroxybenzoyl)amino] caprylate (500 mg); placebo; or open-label evolocumab (140 mg) every 2 weeks administered subcutaneously. Blinding was performed within each dose level. The primary endpoint was percentage change from baseline in LDL cholesterol measured by ß quantification at week 12. All randomly assigned participants received at least one dose of treatment and were included in both safety and efficacy analyses. The trial was registered on ClinicalTrials.gov, NCT04992065, and is completed. FINDINGS: Between Aug 16, 2021, and Jan 28, 2022, we randomly assigned 267 patients to one of the three NNC0385-0434 dose cohorts (n=53 per cohort), matching placebo (n=54), or open-label evolocumab (n=54). The study population comprised 82 (31%) women and 185 (69%) men; mean age was 64·3 years (SD 9·0). Baseline mean LDL cholesterol concentration was 2·7 mmol/L (SD 0·8). Treatment with NNC0385-0434 resulted in reductions in LDL cholesterol from baseline to week 12, of 32·0 percentage points (95% CI 20·9 to 43·0) in the 15 mg cohort, 44·9 percentage points (33·8 to 56·0) in the 40 mg cohort, and 61·8 percentage points (50·7 to 72·9) in the 100 mg cohort, compared with the placebo group (p<0·0001 for each). Patients treated with evolocumab had similar LDL cholesterol reductions (59·6% [SE 4·1] decrease from baseline) to patients receiving NNC0385-0434 100 mg (56·2% [4·0]). The estimated treatment difference between NNC0385-0434 100 mg and evolocumab 140 mg was 3·4 percentage points [95% CI -7·8 to 14·7]. The most frequently reported adverse event was COVID-19, which affected 31 (12%) of 267 patients, with similar numbers across treatment groups. Investigative sites reported gastrointestinal disorders as the most frequent treatment-related adverse event (26 patients and 35 events total in the three NNC0385 cohorts and one patient and one event each in the placebo and evolocumab cohorts). No deaths or treatment-related serious adverse events occurred. INTERPRETATION: This study showed excellent 12-week LDL cholesterol lowering efficacy and good patient tolerance of an oral PCSK9 inhibitor, NNC0835-0434, similar to an injectable drug. However, the sponsor chose to discontinue further development of NNC0835-0434 due to portfolio considerations. FUNDING: Novo Nordisk.

A randomized, double-blinded Phase 3 study to demonstrate lot-to-lot consistency and to confirm immunogenicity and safety of the live-attenuated chikungunya virus vaccine candidate VLA1553 in healthy adults†.

BACKGROUND: The global spread of the chikungunya virus (CHIKV) increases the exposure risk for individuals travelling to or living in endemic areas. This Phase 3 study was designed to demonstrate manufacturing consistency between three lots of the single shot live-attenuated CHIKV vaccine VLA1553, and to confirm the promising immunogenicity and safety data obtained in previous trials. METHODS: This randomized, double-blinded, lot-to-lot consistency, Phase 3 study, assessed immunogenicity and safety of VLA1553 in 408 healthy adults (18-45 years) in 12 sites across the USA. The primary endpoint was a comparison of the geometric mean titre (GMT) ratios of CHIKV-specific neutralizing antibodies between three VLA1553 lots at 28 days post-vaccination. Secondary endpoints included immunogenicity and safety over 6 months post-vaccination. RESULTS: GMTs were comparable between the lots meeting the acceptance criteria for equivalence. The average GMT (measured by 50% CHIKV micro plaque neutralization test; µPRNT50) peaked with 2643 at 28 days post-vaccination and decreased to 709 at 6 months post-vaccination. An excellent seroresponse rate (defined as µPRNT50 titre ≥ 150 considered protective) was achieved in 97.8% of participants at 28 days post-vaccination and still persisted in 96% at 6 months after vaccination. Upon VLA1553 immunization, 72.5% of participants experienced adverse events (AEs), without significant differences between lots (related solicited systemic AE: 53.9% of participants; related solicited local AE: 19.4%). Overall, AEs were mostly mild or moderate and resolved without sequela, usually within 3 days. With 3.9% of participants experiencing severe AEs, 2.7% were classified as related, whereas none of the six reported serious adverse events was related to the administration of VLA1553. CONCLUSIONS: All three lots of VLA1553 recapitulated the safety and immunogenicity profiles of a preceding Phase 3 study, fulfilling pre-defined consistency requirements. These results highlight the manufacturability of VLA1553, a promising vaccine for the prevention of CHIKV disease for those living in or travelling to endemic areas.

Priming with Japanese encephalitis virus or yellow fever virus vaccination led to the recognition of multiple flaviviruses without boosting antibody responses induced by an inactivated Zika virus vaccine.

BACKGROUND: Complex patterns of cross-reactivity exist between flaviviruses, yet there is no precise understanding of how sequential exposures due to flavivirus infections or vaccinations impact subsequent antibody responses. METHODS: We investigated whether B cell priming from Japanese encephalitis virus (JEV) or yellow fever virus (YFV) vaccination impacted binding and functional antibody responses to flaviviruses following vaccination with a Zika virus (ZIKV) purified inactivated virus (ZPIV) vaccine. Binding antibody responses and Fc gamma receptor engagement against 23 flavivirus antigens were characterized along with neutralization titres and Fc effector responses in 75 participants at six time points. FINDINGS: We found no evidence that priming with JEV or YFV vaccines improved the magnitude of ZPIV induced antibody responses to ZIKV. Binding antibodies and Fc gamma receptor engagement to ZIKV antigens did not differ significantly across groups, while antibody-dependent cellular phagocytosis (ADCP) and neutralizing responses were higher in the naïve group than in the JEV and YFV primed groups following the second ZPIV immunization (p ≤ 0.02). After a third dose of ZPIV, ADCP responses remained higher in the naïve group than in the primed groups. However, priming affected the quality of the response following ZPIV vaccination, as primed individuals recognized a broader array of flavivirus antigens than individuals in the naïve group. INTERPRETATION: While a priming vaccination to either JEV or YFV did not boost ZIKV-specific responses upon ZIKV vaccination, the qualitatively different responses elicited in the primed groups highlight the complexity in the cross-reactive antibody responses to flaviviruses. FUNDING: This work was supported by a cooperative agreement between The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., and the U.S. Department of the Army [W81XWH-18-2-0040]. The work was also funded in part by the National Institute of Allergy and Infectious Diseases (NIAID) R01AI155983 to SJK and KM.

Safety and immunogenicity of a purified inactivated Zika virus vaccine candidate in adults primed with a Japanese encephalitis virus or yellow fever virus vaccine in the USA: a phase 1, randomised, double-blind, placebo-controlled clinical trial.

BACKGROUND: Zika virus infection is a threat to at-risk populations, causing major birth defects and serious neurological complications. Development of a safe and efficacious Zika virus vaccine is, therefore, a global health priority. Assessment of heterologous flavivirus vaccination is important given co-circulation of Japanese encephalitis virus and yellow fever virus with Zika virus. We investigated the effect of priming flavivirus naive participants with a licensed flavivirus vaccine on the safety and immunogenicity of a purified inactivated Zika vaccine (ZPIV). METHODS: This phase 1, placebo-controlled, double-blind trial was done at the Walter Reed Army Institute of Research Clinical Trials Center in Silver Spring, MD, USA. Eligible participants were healthy adults aged 18-49 years, with no detectable evidence of previous flavivirus exposure (by infection or vaccination), as measured by a microneutralisation assay. Individuals with serological evidence of HIV, hepatitis B, or hepatitis C infection were excluded, as were pregnant or breastfeeding women. Participants were recruited sequentially into one of three groups (1:1:1) to receive no primer, two doses of intramuscular Japanese encephalitis virus vaccine (IXIARO), or a single dose of subcutaneous yellow fever virus vaccine (YF-VAX). Within each group, participants were randomly assigned (4:1) to receive intramuscular ZPIV or placebo. Priming vaccinations were given 72-96 days before ZPIV. ZPIV was administered either two or three times, at days 0, 28, and 196-234. The primary outcome was occurrence of solicited systemic and local adverse events along with serious adverse events and adverse events of special interest. These data were analysed in all participants receiving at least one dose of ZPIV or placebo. Secondary outcomes included measurement of neutralizing antibody responses following ZPIV vaccination in all volunteers with available post-vaccination data. This trial is registered at ClinicalTrials.gov, NCT02963909. FINDINGS: Between Nov 7, 2016, and Oct 30, 2018, 134 participants were assessed for eligibility. 21 did not meet inclusion criteria, 29 met exclusion criteria, and ten declined to participate. 75 participants were recruited and randomly assigned. 35 (47%) of 75 participants were male and 40 (53%) were female. 25 (33%) of 75 participants identified as Black or African American and 42 (56%) identified as White. These proportions and other baseline characteristics were similar between groups. There were no statistically significant differences in age, gender, race, or BMI between those who did and did not opt into the third dose. All participants received the planned priming IXIARO and YF-VAX vaccinations, but one participant who received YF-VAX dropped out before receipt of the first dose of ZPIV. 50 participants received a third dose of ZPIV or placebo, including 14 flavivirus-naive people, 17 people primed with Japanese encephalitis virus vaccine, and 19 participants primed with yellow fever vaccine. Vaccinations were well tolerated across groups. Pain at the injection site was the only adverse event reported more frequently in participants who received ZPIV than in those who received placebo (39 [65%] of 60 participants, 95% CI 51·6-76·9 who received ZPIV vs three [21·4%] of 14 who received placebo; 4·7-50·8; p=0·006). No patients had an adverse event of special interest or serious adverse event related to study treatment. At day 57, the flavivirus-naive volunteers had an 88% (63·6-98·5, 15 of 17) seroconversion rate (neutralising antibody titre ≥1:10) and geometric mean neutralising antibody titre (GMT) against Zika virus of 100·8 (39·7-255·7). In the Japanese encephalitis vaccine-primed group, the day 57 seroconversion rate was 31·6% (95% CI 12·6-56·6, six of 19) and GMT was 11·8 (6·1-22·8). Participants primed with YF-VAX had a seroconversion rate of 25% (95% CI 8·7-49·1, five of 20) and GMT of 6·6 (5·2-8·4). Humoral immune responses rose substantially following a third dose of ZPIV, with seroconversion rates of 100% (69·2-100; ten of ten), 92·9% (66·1-99·8; 13 of 14), and 60% (32·2-83·7, nine of 15) and GMTs of 511·5 (177·6-1473·6), 174·2 (51·6-587·6), and 79 (19·0-326·8) in the flavivirus naive, Japanese encephalitis vaccine-primed, and yellow fever vaccine-primed groups, respectively. INTERPRETATION: We found ZPIV to be well tolerated in flavivirus naive and primed adults but that immunogenicity varied significantly according to antecedent flavivirus vaccination status. Immune bias towards the flavivirus antigen of initial exposure and the timing of vaccination may have impacted responses. A third ZPIV dose overcame much, but not all, of the discrepancy in immunogenicity. The results of this phase 1 clinical trial have implications for further evaluation of ZPIV's immunisation schedule and use of concomitant vaccinations. FUNDING: Department of Defense, Defense Health Agency; National Institute of Allergy and Infectious Diseases; and Division of Microbiology and Infectious Disease.

Lectin-Like Oxidized Low-Density Lipoprotein Receptor 1 Inhibition in Type 2 Diabetes: Phase 1 Results.

Background Blockade of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a potentially attractive mechanism for lowering inflammatory and lipid risk in patients with atherosclerosis. This study aims to assess the safety, tolerability, and target engagement of MEDI6570, a high-affinity monoclonal blocking antibody to LOX-1. Methods and Results This phase 1, first-in-human, placebo-controlled study (NCT03654313) randomized 88 patients with type 2 diabetes to receive single ascending doses (10, 30, 90, 250, or 500 mg) or multiple ascending doses (90, 150, or 250 mg once monthly for 3 months) of MEDI6570 or placebo. Primary end point was safety; secondary and exploratory end points included pharmacokinetics, immunogenicity, free soluble LOX-1 levels, and change in coronary plaque volume. Mean age was 57.6/58.1 years in the single ascending doses/multiple ascending doses groups, 31.3%/62.5% were female, and mean type 2 diabetes duration was 9.7/8.7 years. Incidence of adverse events was similar among cohorts. MEDI6570 exhibited nonlinear pharmacokinetics, with terminal half-life increasing from 4.6 days (30 mg) to 11.2 days (500 mg), consistent with target-mediated drug disposition. Dose-dependent reductions in mean soluble LOX-1 levels from baseline were observed (>66% at 4 weeks and 71.61-82.96% at 10 weeks in the single ascending doses and multiple ascending doses groups, respectively). After 3 doses, MEDI6570 was associated with nonsignificant regression of noncalcified plaque volume versus placebo (-13.45 mm3 versus -8.25 mm3). Conclusions MEDI6570 was well tolerated and demonstrated dose-dependent soluble LOX-1 suppression and a pharmacokinetic profile consistent with once-monthly dosing. Registration URL: https://clinicaltrials.gov/; Unique identifier: NCT03654313.

A First-in-Human Study of AMG 986, a Novel Apelin Receptor Agonist, in Healthy Subjects and Heart Failure Patients.

PURPOSE: AMG 986 is a novel apelin receptor (APJ) agonist that improves cardiac contractility in animal models without adversely impacting hemodynamics. This phase 1b study evaluated the safety/tolerability, pharmacokinetics, and pharmacodynamics of AMG 986 in healthy subjects and patients with heart failure (HF). METHODS: Healthy adults (Parts A/B) and HF patients (Part C) aged 18-85 years were randomized 3:1 to single-dose oral/IV AMG 986 or placebo (Part A); multiple-dose oral/IV AMG 986 or placebo (Part B); or escalating-dose oral AMG 986 or placebo (Part C). PRIMARY ENDPOINT: treatment-emergent adverse events, laboratory values/vital signs/ECGs; others included AMG 986 pharmacokinetics, left ventricular (LV) function. RESULTS: Overall, 182 subjects were randomized (AMG 986/healthy: n = 116, placebo, n = 38; AMG 986/HF: n = 20, placebo, n = 8). AMG 986 had acceptable safety profile; no clinically significant dose-related impact on safety parameters up to 650 mg/day was observed. AMG 986 exposures increased nonlinearly with increasing doses; minimal accumulation was observed. In HF with reduced ejection fraction patients, there were numerical increases in percent changes from baseline in LV ejection fraction and stroke volume by volumetric assessment with AMG 986 vs placebo (stroke volume increase not recapitulated by Doppler). CONCLUSIONS: In healthy subjects and HF patients, short-term AMG 986 treatment was well tolerated. Consistent with this observation, clinically meaningful pharmacodynamic effects in HF patients were not observed. Changes in ejection fraction and stroke volume in HF patients suggest additional studies may be needed to better define the clinical utility and optimal dosing for this molecule. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT03276728. DATE OF REGISTRATION: September 8, 2017.

An evaluation of a supratherapeutic dose of inclisiran on cardiac repolarization in healthy volunteers: A phase I, randomized study.

Inclisiran is a small interfering RNA molecule that has been shown to provide an effective and sustained reduction in low-density lipoprotein cholesterol levels. This study aimed to determine whether a supratherapeutic dose of inclisiran affects cardiac repolarization and conduction in healthy volunteers. A phase I, randomized, double-blind, double-dummy, placebo- and positive-controlled, three-way crossover study was performed in 48 healthy volunteers. Volunteers were assigned to three treatments in a randomized sequence: a supratherapeutic dose of inclisiran sodium (900 mg), placebo, or moxifloxacin 400 mg as a positive control, with a minimum 7-day washout period between treatments. Continuous electrocardiogram monitoring was performed from >60 min before dosing until 48 h after dosing. Pharmacokinetics, pharmacodynamics, and safety were also assessed. Inclisiran, at a supratherapeutic dose, did not show a clinically significant effect on the QT interval (Fridericia correction formula [QTcF]; maximal placebo- and baseline-corrected change: 2.5 ms [90% confidence interval: 0.6, 4.5]) near the maximal plasma concentrations at 4 h. In addition, inclisiran did not show any effects on other electrocardiogram intervals or ST- and T-wave morphology. The positive control, moxifloxacin, demonstrated the expected changes in QTcF interval, validating the adequate sensitivity of the study. A supratherapeutic dose of inclisiran sodium (900 mg) had no effect on the QTcF interval or other electrocardiogram parameters, providing additional insight and reassurance regarding the safety profile of inclisiran.

Time-averaged low-density lipoprotein cholesterol lowering with evolocumab: Pooled analysis of phase 2 trials.

LDL-C is the pivotal risk factor for atherosclerotic cardiovascular disease, and the benefit from LDL-C lowering is proportional to the magnitude of reduction. Clinical trials demonstrate that evolocumab reduces LDL-C levels by approximately 60% when measured at the trough of drug effect, which may underestimate cumulative LDL-C reduction. We obtained a time-averaged estimate of LDL-C lowering that included both peaks and troughs. Pooled analysis of 5 phase 2 trials included patients with hypercholesterolemia who received placebo or evolocumab (140 mg every 2 weeks [Q2W] or 420 mg monthly [QM]). Percent changes from baseline LDL-C and free serum PCSK9 were averaged across weeks 9-12. In 372 patients, time-averaged percent reduction from baseline in LDL-C with evolocumab vs placebo was 67.6% (95% CI: 63.9-71.3) with Q2W dosing and 65.0% (95% CI: 60.7-69.3) with QM dosing. The time-averaged measure yielded LDL-C reductions for evolocumab that exceeded measurements at the end of dosing intervals and may provide a better estimate of cardiovascular benefit during long-term therapy.

Single Ascending Dose Study of a Short Interfering RNA Targeting Lipoprotein(a) Production in Individuals With Elevated Plasma Lipoprotein(a) Levels.

Importance: Lipoprotein(a) (Lp[a]) is an important risk factor for atherothrombotic cardiovascular disease and aortic stenosis, for which there are no treatments approved by regulatory authorities. Objectives: To assess adverse events and tolerability of a short interfering RNA (siRNA) designed to reduce hepatic production of apolipoprotein(a) and to assess associated changes in plasma concentrations of Lp(a) at different doses. Design, Setting, and Participants: A single ascending dose study of SLN360, an siRNA targeting apolipoprotein(a) synthesis conducted at 5 clinical research unit sites located in the US, United Kingdom, and Australia. The study enrolled adults with Lp(a) plasma concentrations of 150 nmol/L or greater at screening and no known clinically overt cardiovascular disease. Participants were enrolled between November 18, 2020, and July 21, 2021, with last follow-up on December 29, 2021. Interventions: Participants were randomized to receive placebo (n = 8) or single doses of SLN360 at 30 mg (n = 6), 100 mg (n = 6), 300 mg (n = 6), or 600 mg (n = 6), administered subcutaneously. Main Outcomes and Measures: The primary outcome was evaluation of safety and tolerability. Secondary outcomes included change in plasma concentrations of Lp(a) to a maximum follow-up of 150 days. Results: Among 32 participants who were randomized and received the study intervention (mean age, 50 [SD, 13.5] years; 17 women [53%]), 32 (100%) completed the trial. One participant experienced 2 serious adverse event episodes: admission to the hospital for headache following SARS-CoV-2 vaccination and later for complications of cholecystitis, both of which were judged to be unrelated to study drug. Median baseline Lp(a) concentrations were as follows: placebo, 238 (IQR, 203-308) nmol/L; 30-mg SLN360, 171 (IQR, 142-219) nmol/L; 100-mg SLN360, 217 (IQR, 202-274) nmol/L; 300-mg SLN360, 285 (IQR, 195-338) nmol/L; and 600-mg SLN360, 231 (IQR, 179-276) nmol/L. Maximal median changes in Lp(a) were -20 (IQR, -61 to 3) nmol/L, -89 (IQR, -119 to -61) nmol/L, -185 (IQR, -226 to -163) nmol/L, -268 (IQR, -292 to -189) nmol/L, and -227 (IQR, -270 to -174) nmol/L, with maximal median percentage changes of -10% (IQR, -16% to 1%), -46% (IQR, -64% to -40%), -86% (IQR, -92% to -82%), -96% (IQR, -98% to -89%), and -98% (IQR, -98% to -97%), for the placebo group and the 30-mg, 100-mg, 300-mg, and 600-mg SLN360 groups, respectively. The duration of Lp(a) lowering was dose dependent, persisting for at least 150 days after administration. Conclusions and Relevance: In this phase 1 study of 32 participants with elevated Lp(a) levels and no known cardiovascular disease, the siRNA SLN360 was well tolerated, and a dose-dependent lowering of plasma Lp(a) concentrations was observed. The findings support further study to determine the safety and efficacy of this siRNA. Trial Registration: ClinicalTrials.gov Identifier: NCT04606602; EudraCT Identifier: 2020-002471-35.

Safety and Efficacy of a Third Dose of BNT162b2 Covid-19 Vaccine.

BACKGROUND: Active immunization with the BNT162b2 vaccine (Pfizer-BioNTech) has been a critical mitigation tool against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during the coronavirus disease 2019 (Covid-19) pandemic. In light of reports of waning protection occurring 6 months after the primary two-dose vaccine series, data are needed on the safety and efficacy of offering a third (booster) dose in persons 16 years of age or older. METHODS: In this ongoing, placebo-controlled, randomized, phase 3 trial, we assigned participants who had received two 30-µg doses of the BNT162b2 vaccine at least 6 months earlier to be injected with a third dose of the BNT162b2 vaccine or with placebo. We assessed vaccine safety and efficacy against Covid-19 starting 7 days after the third dose. RESULTS: A total of 5081 participants received a third BNT162b2 dose and 5044 received placebo. The median interval between dose 2 and dose 3 was 10.8 months in the vaccine group and 10.7 months in the placebo group; the median follow-up was 2.5 months. Local and systemic reactogenicity events from the third dose were generally of low grade. No new safety signals were identified, and no cases of myocarditis or pericarditis were reported. Among the participants without evidence of previous SARS-CoV-2 infection who could be evaluated, Covid-19 with onset at least 7 days after dose 3 was observed in 6 participants in the vaccine group and in 123 participants in the placebo group, which corresponded to a relative vaccine efficacy of 95.3% (95% confidence interval, 89.5 to 98.3). CONCLUSIONS: A third dose of the BNT162b2 vaccine administered a median of 10.8 months after the second dose provided 95.3% efficacy against Covid-19 as compared with two doses of the BNT162b2 vaccine during a median follow-up of 2.5 months. (Funded by BioNTech and Pfizer; C4591031 ClinicalTrials.gov number, NCT04955626.).

Randomized Clinical Trial on the Long-Term Efficacy and Safety of Lumasiran in Patients With Primary Hyperoxaluria Type 1.

Introduction: Primary hyperoxaluria type 1 (PH1) is a rare genetic disease caused by hepatic overproduction of oxalate, leading to kidney stones, nephrocalcinosis, kidney failure, and systemic oxalosis. In the 6-month double-blind period (DBP) of ILLUMINATE-A, a phase 3, randomized, placebo-controlled trial in patients with PH1 ≥6 years old, treatment with lumasiran, an RNA interference therapeutic, led to substantial reductions in urinary oxalate (UOx) levels. Methods: We report data to month 12 in the extension period (EP) of ILLUMINATE-A, including patients who continued lumasiran (lumasiran/lumasiran) or crossed over from placebo to lumasiran (placebo/lumasiran). Results: In the lumasiran/lumasiran group (n = 24), the reduction in 24-hour UOx level was sustained to month 12 (mean reduction from baseline, 66.9% at month 6; 64.1% at month 12). The placebo/lumasiran group (n = 13) had a similar time course and magnitude of 24-hour UOx reduction (mean reduction, 57.3%) after 6 months of lumasiran. Kidney stone event rates seemed to be lower after 6 months of lumasiran in both groups compared with the 12 months before consent, and this reduction was maintained at month 12 in the lumasiran/lumasiran group. At study start, 71% of patients in the lumasiran/lumasiran group and 92% in the placebo/lumasiran group had nephrocalcinosis. Nephrocalcinosis grade improved after 6 months of lumasiran in the lumasiran/lumasiran and placebo/lumasiran groups (13% and 8% of patients, respectively). After an additional 6 months of lumasiran, 46% of patients had improvement in nephrocalcinosis grade within the lumasiran/lumasiran group. Estimated glomerular filtration rate (eGFR) remained stable during the course of lumasiran treatment. The most common adverse events (AEs) related to lumasiran were mild, transient injection-site reactions (ISRs). Conclusion: Long-term lumasiran treatment enabled sustained lowering of UOx levels with acceptable safety and encouraging results on clinical outcomes.

Preclinical development and phase 1 trial of a novel siRNA targeting lipoprotein(a).

Compelling evidence supports a causal role for lipoprotein(a) (Lp(a)) in cardiovascular disease. No pharmacotherapies directly targeting Lp(a) are currently available for clinical use. Here we report the discovery and development of olpasiran, a first-in-class, synthetic, double-stranded, N-acetylgalactosamine-conjugated small interfering RNA (siRNA) designed to directly inhibit LPA messenger RNA translation in hepatocytes and potently reduce plasma Lp(a) concentration. Olpasiran reduced Lp(a) concentrations in transgenic mice and cynomolgus monkeys in a dose-responsive manner, achieving up to over 80% reduction from baseline for 5-8 weeks after administration of a single dose. In a phase 1 dose-escalation trial of olpasiran (ClinicalTrials.gov: NCT03626662 ), the primary outcome was safety and tolerability, and the secondary outcomes were the change in Lp(a) concentrations and olpasiran pharmacokinetic parameters. Participants tolerated single doses of olpasiran well and experienced a 71-97% reduction in Lp(a) concentration with effects persisting for several months after administration of doses of 9 mg or higher. Serum concentrations of olpasiran increased approximately dose proportionally. Collectively, these results validate the approach of using hepatocyte-targeted siRNA to potently lower Lp(a) in individuals with elevated plasma Lp(a) concentration.

LEGACY: Phase 2a Trial to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamic Effects of the Anti-EL (Endothelial Lipase) Antibody MEDI5884 in Patients With Stable Coronary Artery Disease.

OBJECTIVE: Functional HDL (high-density lipoprotein) particles that facilitate cholesterol efflux may be cardioprotective. EL (endothelial lipase) hydrolyzes phospholipids promoting catabolism of HDL and subsequent renal excretion. MEDI5884 is a selective, humanized, monoclonal, EL-neutralizing antibody. We sought to determine the safety, pharmacokinetics, and pharmacodynamic effects of multiple doses of MEDI5884 in patients with stable coronary artery disease. Approach and Results: LEGACY was a phase 2a, double-blind, placebo-controlled, parallel-design trial that randomized 132 patients with stable coronary artery disease receiving high-intensity statin therapy to 3 monthly doses of 1 of 5 dose levels of MEDI5884 (50, 100, 200, 350, or 500 mg SC) or matching placebo. The primary end point was the safety and tolerability of MEDI5884 through the end of the study (day 151). Additional end points included change in HDL cholesterol and cholesterol efflux from baseline to day 91, hepatic uptake of cholesterol at day 91, changes in various other lipid parameters. The incidence of adverse events was similar between the placebo and MEDI5884 groups. In a dose-dependent manner, MEDI5884 increased HDL cholesterol up to 51.4% (P<0.0001) and global cholesterol efflux up to 26.2% ([95% CI, 14.3-38.0] P<0.0001). MEDI5884 increased HDL particle number up to 14.4%. At the highest dose tested, an increase in LDL (low-density lipoprotein) cholesterol up to 28.7% (P<0.0001) and apoB (apolipoprotein B) up to 13.1% (P=0.04) was observed with MEDI5884. However, at the potential target doses for future studies, there was no meaningful increase in LDL cholesterol or apoB. CONCLUSIONS: Inhibition of EL by MEDI5884 increases the quantity and quality of functional HDL in patients with stable coronary artery disease on high-intensity statin therapy without an adverse safety signal at the likely dose to be used. These data support further clinical investigation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03351738.

MEDI6012: Recombinant Human Lecithin Cholesterol Acyltransferase, High-Density Lipoprotein, and Low-Density Lipoprotein Receptor-Mediated Reverse Cholesterol Transport.

Background MEDI6012 is recombinant human lecithin cholesterol acyltransferase, the rate-limiting enzyme in reverse cholesterol transport. Infusions of lecithin cholesterol acyltransferase have the potential to enhance reverse cholesterol transport and benefit patients with coronary heart disease. The purpose of this study was to test the safety, pharmacokinetic, and pharmacodynamic profile of MEDI6012. Methods and Results This phase 2a double-blind study randomized 48 subjects with stable coronary heart disease on a statin to a single dose of MEDI6012 or placebo (6:2) (NCT02601560) with ascending doses administered intravenously (24, 80, 240, and 800 mg) and subcutaneously (80 and 600 mg). MEDI6012 demonstrated rates of treatment-emergent adverse events that were similar to those of placebo. Dose-dependent increases in high-density lipoprotein cholesterol were observed with area under the concentration-time curves from 0 to 96 hours of 728, 1640, 3035, and 5318 should be: mg·h/mL in the intravenous dose groups and 422 and 2845 mg·h/mL in the subcutaneous dose groups. Peak mean high-density lipoprotein cholesterol percent change was 31.4%, 71.4%, 125%, and 177.8% in the intravenous dose groups and 18.3% and 111.2% in the subcutaneous dose groups, and was accompanied by increases in endogenous apoA1 (apolipoprotein A1) and non-ATP-binding cassette transporter A1 cholesterol efflux capacity. Decreases in apoB (apolipoprotein B) were observed across all dose levels and decreases in atherogenic small low-density lipoprotein particles by 41%, 88%, and 79% at the 80-, 240-, and 800-mg IV doses, respectively. Conclusions MEDI6012 demonstrated an acceptable safety profile and increased high-density lipoprotein cholesterol, endogenous apoA1, and non-ATP-binding cassette transporter A1 cholesterol efflux capacity while reducing the number of atherogenic low-density lipoprotein particles. These findings are supportive of enhanced reverse cholesterol transport and a functional high-density lipoprotein phenotype. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02601560.

Pre-existing Immunity to Japanese Encephalitis Virus Alters CD4 T Cell Responses to Zika Virus Inactivated Vaccine.

The epidemic spread of Zika virus (ZIKV), associated with devastating neurologic syndromes, has driven the development of multiple ZIKV vaccines candidates. An effective vaccine should induce ZIKV-specific T cell responses, which are shown to improve the establishment of humoral immunity and contribute to viral clearance. Here we investigated how previous immunization against Japanese encephalitis virus (JEV) and yellow fever virus (YFV) influences T cell responses elicited by a Zika purified-inactivated virus (ZPIV) vaccine. We demonstrate that three doses of ZPIV vaccine elicited robust CD4 T cell responses to ZIKV structural proteins, while ZIKV-specific CD4 T cells in pre-immunized individuals with JEV vaccine, but not YFV vaccine, were more durable and directed predominantly toward conserved epitopes, which elicited Th1 and Th2 cytokine production. In addition, T cell receptor repertoire analysis revealed preferential expansion of cross-reactive clonotypes between JEV and ZIKV, suggesting that pre-existing immunity against JEV may prime the establishment of stronger CD4 T cell responses to ZPIV vaccination. These CD4 T cell responses correlated with titers of ZIKV-neutralizing antibodies in the JEV pre-vaccinated group, but not in flavivirus-naïve or YFV pre-vaccinated individuals, suggesting a stronger contribution of CD4 T cells in the generation of neutralizing antibodies in the context of JEV-ZIKV cross-reactivity.

Lumasiran, an RNAi Therapeutic for Primary Hyperoxaluria Type 1.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is a rare genetic disease caused by hepatic overproduction of oxalate that leads to kidney stones, nephrocalcinosis, kidney failure, and systemic oxalosis. Lumasiran, an investigational RNA interference (RNAi) therapeutic agent, reduces hepatic oxalate production by targeting glycolate oxidase. METHODS: In this double-blind, phase 3 trial, we randomly assigned (in a 2:1 ratio) patients with PH1 who were 6 years of age or older to receive subcutaneous lumasiran or placebo for 6 months (with doses given at baseline and at months 1, 2, 3, and 6). The primary end point was the percent change in 24-hour urinary oxalate excretion from baseline to month 6 (mean percent change across months 3 through 6). Secondary end points included the percent change in the plasma oxalate level from baseline to month 6 (mean percent change across months 3 through 6) and the percentage of patients with 24-hour urinary oxalate excretion no higher than 1.5 times the upper limit of the normal range at month 6. RESULTS: A total of 39 patients underwent randomization; 26 were assigned to the lumasiran group and 13 to the placebo group. The least-squares mean difference in the change in 24-hour urinary oxalate excretion (lumasiran minus placebo) was -53.5 percentage points (P<0.001), with a reduction in the lumasiran group of 65.4% and an effect seen as early as month 1. The between-group differences for all hierarchically tested secondary end points were significant. The difference in the percent change in the plasma oxalate level (lumasiran minus placebo) was -39.5 percentage points (P<0.001). In the lumasiran group, 84% of patients had 24-hour urinary oxalate excretion no higher than 1.5 times the upper limit of the normal range at month 6, as compared with 0% in the placebo group (P<0.001). Mild, transient injection-site reactions were reported in 38% of lumasiran-treated patients. CONCLUSIONS: Lumasiran reduced urinary oxalate excretion, the cause of progressive kidney failure in PH1. The majority of patients who received lumasiran had normal or near-normal levels after 6 months of treatment. (Funded by Alnylam Pharmaceuticals; ILLUMINATE-A ClinicalTrials.gov number, NCT03681184.).

Immunogenicity of a Live-Attenuated Dengue Vaccine Using a Heterologous Prime-Boost Strategy in a Phase 1 Randomized Clinical Trial.

BACKGROUND: Dengue is a global health problem and the development of a tetravalent dengue vaccine with durable protection is a high priority. A heterologous prime-boost strategy has the advantage of eliciting immune responses through different mechanisms and therefore may be superior to homologous prime-boost strategies for generating durable tetravalent immunity. METHODS: In this phase 1 first-in-human heterologous prime-boost study, 80 volunteers were assigned to 4 groups and received a tetravalent dengue virus (DENV-1-4) purified inactivated vaccine (TDENV-PIV) with alum adjuvant and a tetravalent dengue virus (DENV-1-4) live attenuated vaccine (TDENV-LAV) in different orders and dosing schedules (28 or 180 days apart). RESULTS: All vaccination regimens had acceptable safety profiles and there were no vaccine-related serious adverse events. TDEN-PIV followed by TDEN-LAV induced higher neutralizing antibody titers and a higher rate of tetravalent seroconversions compared to TDEN-LAV followed by TDEN-PIV. Both TDEN-PIV followed by TDEN-LAV groups demonstrated 100% tetravalent seroconversion 28 days following the booster dose, which was maintained for most of these subjects through the day 180 measurement. CONCLUSIONS: A heterologous prime-boost vaccination strategy for dengue merits additional evaluation for safety, immunogenicity, and potential for clinical benefit. CLINICAL TRIALS REGISTRATION: NCT02239614.