key: cord-0913924-q07avnkq
authors: Dang, A. D.; Vu, T. D.; Vu, H. H.; Ta, V. T.; Pham, A. T. V.; Dang, M. T. N.; Le, B. V.; Duong, T. H.; Nguyen, D. V.; Lawpoolsri, S.; Chinwangso, P.; McLellan, J. S.; Hsieh, C.-L.; Garcia-Sastre, A.; Palese, P.; Sun, W.; Martinez, J. L.; Gonzalez-Dominguez, I.; Slamanig, S.; Carreno, J. M.; Tcheou, J.; Krammer, F.; Raskin, A.; Vu, H. M.; Tran, T. C.; Nguyen, H. M.; Mercer, L. D.; Raghunandan, R.; Lal, M.; White, J. A.; Hjorth, R.; Innis, B. L.; Scharf, R.
title: Safety and Immunogenicity of An Egg-Based Inactivated Newcastle Disease Virus Vaccine Expressing SARS-CoV-2 Spike: Interim Results of a Randomized, Placebo-Controlled, Phase 1/2 Trial in Vietnam
date: 2022-02-05
journal: nan
DOI: 10.1101/2022.02.01.22270253
sha: 0d8834d6250efea837da5a8246d2f39f5d8130ec
doc_id: 913924
cord_uid: q07avnkq

Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based Newcastle disease virus (NDV) vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Wuhan-Hu-1. The spike protein was stabilized and incorporated into NDV virions by removing the polybasic furin cleavage site, introducing the transmembrane domain and cytoplasmic tail of the fusion protein of NDV, and introducing six prolines for stabilization in the prefusion state. Vaccine production and clinical development was initiated in Vietnam, Thailand, and Brazil. Here the interim results from the first stage of the randomized, dose-escalation, observer-blind, placebo-controlled, phase 1/2 trial conducted at the Hanoi Medical University (Vietnam) are presented. Healthy adults aged 18-59 years, non-pregnant, and with self-reported negative history for SARS-CoV-2 infection were eligible. Participants were randomized to receive one of five treatments by intramuscular injection twice, 28 days apart: 1 mcg +/- CpG1018 (a toll-like receptor 9 agonist), 3 mcg alone, 10 mcg alone, or placebo. Participants and personnel assessing outcomes were masked to treatment. The primary outcomes were solicited adverse events (AEs) during 7 days and subject-reported AEs during 28 days after each vaccination. Investigators further reviewed subject-reported AEs. Secondary outcomes were immunogenicity measures (anti-spike immunoglobulin G [IgG] and pseudotyped virus neutralization). This interim analysis assessed safety 56 days after first vaccination (day 57) in treatment-exposed individuals and immunogenicity through 14 days after second vaccination (day 43) per protocol. Between March 15 and April 23, 2021, 224 individuals were screened and 120 were enrolled (25 per group for active vaccination and 20 for placebo). All subjects received two doses. The most common solicited AEs among those receiving active vaccine or placebo were all predominantly mild and included injection site pain or tenderness (<58%), fatigue or malaise (<22%), headache (<21%), and myalgia (<14%). No higher proportion of the solicited AEs were observed for any group of active vaccine. The proportion reporting vaccine-related AEs during the 28 days after either vaccination ranged from 4% to 8% among vaccine groups and was 5% in controls. No vaccine-related serious adverse event occurred. The immune response in the 10 mcg formulation group was highest, followed by 1 mcg+CpG1018, 3 mcg, and 1 mcg formulations. Fourteen days after the second vaccination, the geometric mean concentrations (GMC) of 50% neutralizing antibody against the homologous Wuhan-Hu-1 pseudovirus ranged from 56.07 IU/mL (1 mcg, 95% CI 37.01, 84.94) to 246.19 IU/mL (10 mcg, 95% CI 151.97, 398.82), with 84% to 96% of vaccine groups attaining a [≥] 4-fold increase over baseline. This was compared to a panel of human convalescent sera (N=29, 72.93 95% CI 33.00-161.14). Live virus neutralization to the B.1.617.2 (Delta) variant of concern was reduced but in line with observations for vaccines currently in use. Since the adjuvant has shown modest benefit, GMC ratio of 2.56 (95% CI, 1.4 - 4.6) for 1 mcg +/- CpG1018, a decision was made not to continue studying it with this vaccine. NDV-HXP-S had an acceptable safety profile and potent immunogenicity. The 3 mcg dose was advanced to phase 2 along with a 6 mcg dose. The 10 mcg dose was not selected for evaluation in phase 2 due to potential impact on manufacturing capacity. ClinicalTrials.gov NCT04830800.

per dose) was measured by direct enzyme-linked immunosorbent assay (ELISA) using a human 176 monoclonal antibody (CR3022) (8) . which binds to the receptor binding domain on the SARS-177 CoV-2 spike glycoprotein S1 (LakePharma, Inc.) and an NDV-HXP-S standard that had been 178 calibrated to a purified HXP-S reference (4) by sodium dodecyl sulphate polyacrylamide gel CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) CoV-2 immunoglobulin, using a conversion factor determined during assay validation (1/1.872).

The assay's cut-off and LLOQ were 5.3 IU/mL (10 as NT50) and 5.9 IU/mL, respectively. CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted February 5, 2022. ; https://doi.org/10.1101/2022.02.01.22270253 doi: medRxiv preprint symptom onset from cases, consecutively collected, of mild to moderate COVID-19 illness among 252 health care personnel seen as outpatients in Quebec, Canada during mid-2020.

Live virus neutralization by sera from vaccinees was also assessed as previously described (12) Table 1 . Baseline characteristics of the exposed population of the phase 1 stage of the 332 COVIVAC phase 1/2 study. Data are median (quartile 1-quartile 3) or n (%). Sex . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2022. All four formulations of NDV-HXP-S were well tolerated with no dose-limiting reactogenicity (Table   336 2 headache, and myalgia, all generally in less than one-third of subjects. Fever was uncommon.

AEs occurring during 28 days after vaccination ( Table 3 ) and judged by the investigator to be . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2022. . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2022. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2022. ; https://doi.org/10.1101/2022.02.01.22270253 doi: medRxiv preprint first dose (three in the placebo group, one in the 1 g group and one in the 10 g group), were 361 excluded from the per protocol analysis. Induction of anti-S IgG was modest following dose one 362 but a marked anamnestic response was observed 14 days after vaccine dose two ( Figure 3A) . 363 Seronegative individuals in the vaccine groups responded 28 days after first vaccination with 364 GMCs of anti-S IgG between 9.89 (1 µg) and 29.33 (10 µg) BAU/mL (Figure 3 A) , with a ≥ 4-fold 365 increase in 44-84%. The second dose considerably increased anti-S-IgG antibody responses 366 after 14 days to GMCs between 122.54 (1 µg) and 446.5 (10 µg) BAU/mL ( Figure 3A , Table 4 ).

All individuals in the 3, 10, and 1 μg + CpG vaccine groups had a ≥ 4-fold increase over baseline 368 after the second dose ( Figure 3C , Table 5 ). Ninety-six percent (96%) of individuals in the 1 μg 369 vaccine group also had a ≥ 4-fold increase over baseline after the second dose ( Figure 3C , Table   370 5). All individuals in the 3 µg group had a ≥ 10-fold increase, as did > 90% of vaccinees in the 371 other three vaccine groups ( Figure 3C ). In this study, the adjuvant effect of CpG 1018 was limited 372 after two vaccine doses ( . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2022. 

Functional antibody responses were assessed by PNA. Low NT50 GMCs were detected in all 393 vaccine groups after the first vaccination (between 5.7 IU/mL and 12.55 IU/mL, Figure 3B ) with 394 ≥ 4-fold rises in 13% to 40% of the vaccine groups. The second vaccine dose strongly boosted 395 neutralization GMCs ( Figure 3B) Table 5 ) and a ≥10-fold rise in most individuals (92%) in the 10 µg and 1 398 µg+CpG1018 groups ( Figure 3D) . A ≥ 10-fold rise was observed in 56% and 76% of individuals Based on the vaccine-homologous binding and neutralizing antibody responses, a clear ranking 410 of immunogenicity for the unadjuvanted formulations was apparent, with the 10 µg formulation 411 performing best followed by the 3 µg and 1 µg formulations. The 1 µg+CpG1018 ranked between 412 . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Table 4 ). The neutralization titers at day 43 417 highly correlated with anti-S-protein specific binding IgG (Figure 5, r=0.94) . The study had strengths as well. The vaccine construct is a novel platform expressing a second-495 generation prefusion-stabilized S protein in a membrane-bound trimeric conformation. We 496 hypothesize that these characteristics contribute to the vaccine's immunogenicity, even without 497 the CpG1018 adjuvant. The anti-S ELISA and PNA used to assess vaccine-homologous NT50 498 potency were validated and results are expressed in international units (9) for future comparisons.

The induction of anti-S binding and neutralizing antibodies was contrasted with mean levels in 500 human convalescent serum and found to be superior, especially in the mid-and high-dose groups.

Furthermore, we have shown with a live neutralization assay that the vaccine candidate elicits 502 neutralizing activity against the Delta variant of concern. The neutralizing capacity of NDV-HXP-503 S vaccine will be further assessed in the phase 2 stage of this study, using the most relevant 504 variants of concern. 505 506 Originally, this study was designed as a phase 1/2 study with two-part selection design with 507 elimination of two candidate groups after the first part (i.e., phase 1). The study was designed to 508 have greater than 90% power to identify the candidate with the highest response as measured by 509 the NT50 by ranked GMCs, assuming the true GMC is at least 1.5-fold larger than the second 510 highest candidate group and to provide a preliminary safety evaluation of the candidates. After 511 the phase 1 interim analysis, however, proceeding in development with an independent active-512 controlled phase 2 was deemed more appropriate. Thus, after the interim analysis, one candidate 513 was selected to advance, in addition to a new dose form (6 µg S), as well as an active comparator 514 (AZD1222), at which time 375 additional subjects were randomized 1:1:1 to the two candidate 515 groups and the active control, respectively.

In summary, we show that the inactivated NDV-HXP-S vaccine candidate (COVIVAC) has an 517 acceptable safety profile and is highly immunogenic. The technology for this vaccine can be 518 rapidly transferred to and produced at low cost in any facility designed for production of IIV; CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2022. LDM RS, BLI ; methodology, LDM, RR, ML, JAW, RH ; software, ; validation, SL, PC, JMC, LDM   528   ; formal analysis, SL, JMC, JT, LDM ; investigation, ADD, TDV, VTT, ATP, HHV, MTD, WS, JMC,   529   JT, AR, IGD, SS, AR, JAW; resources, ADD, TDV, VTT, HHV, ATP, MTD, BVL, THD, DVN, . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted February 5, 2022. ; https://doi.org/10.1101/2022.02.01.22270253 doi: medRxiv preprint

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