key: cord-0739566-9n5mmmfh
authors: Hsieh, S.-M.; Liu, W.-D.; Huang, Y.-S.; Lin, Y.-J.; Hsieh, E.-F.; Lian, W.-C.; Chen, C.; Tai, I.-C.; Chang, S.-C.
title: First-in-Human Trial of a Recombinant Stabilized Prefusion SARS-CoV-2 Spike Protein Vaccine with Adjuvant of Aluminum Hydroxide and CpG 1018
date: 2021-04-06
journal: nan
DOI: 10.1101/2021.03.31.21254668
sha: de33951c766f94f1855f37f24997afb3d6132ab3
doc_id: 739566
cord_uid: 9n5mmmfh

Design This is a phase 1, dose-escalation open-label trial to evaluate the safety and immunogenicity of MVC-COV1901, a recombinant stabilized prefusion SARS-CoV-2 spike (S-2P) protein vaccine with adjuvant of aluminum hydroxide and CpG 1018. Methods We enrolled 45 healthy adults from 20 to 49 years of age to be administered with two vaccinations of MVC-COV1901 in a low dose (LD), middle dose (MD), and high dose (HD) of spike protein at 28 days apart. There were 15 participants in each dose group, and all of them were followed up for 28 days after the second vaccination at the time of interim analysis. Adverse events (AEs) and laboratory data were recorded for safety evaluation. Blood samples were collected for wild-type SARS-CoV-2 and pseudovirus neutralization assays as well as SARS-CoV-2 spike-specific immunoglobulin G (IgG) at various times. Overall, the study duration will be 7 months. Results Solicited events were mostly mild and similar in the participants of all three dose groups. No subject experienced fever. There were no serious nor adverse events of special interest at the time point of this interim report. After the second vaccination, the SARS-CoV-2 spike specific IgG titers increased with peak geometric mean titers at 7178.245 (LD), 7746.086 (MD), and 11220.58 (HD), respectively. Serum neutralizing activity was detected by two methods in all participants of MD and HD groups, with geometric mean values generally comparable to those of a panel of control convalescent serum specimens. All of the participants in the MD and HD groups were seroconverted after the second vaccination. Conclusions The MVC-COV1901 vaccine is safe and elicits remarkable immune responses especially in the MD and HD groups.

production of the vaccine was conducted in Medigen Vaccine Biologics Corp. facility which 1 0 1

is compliant with the current good manufacturing practices (cGMP). 1 0 2 Participants 1 0 3

Eligible participants were healthy adults from 20 to 49 years of age. Eligibility was 1 0 4 determined based on medical history, physical examination, laboratory tests, and 1 0 5

investigators' clinical judgment. Exclusion criteria included a history of known potential 1 0 6 exposure to SARS CoV-1 or 2 viruses, having received any other COVID-19 vaccine, 1 0 7 impaired immune function, history of autoimmune disease, abnormal autoantibody tests, 1 0 8 febrile or acute illness within 2 days of first dose, and acute respiratory illness within 14 days 1 0 9

of first dose. 1 1 0 . CC-BY-NC-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 April 6, 2021. and Phase 1c would proceed. 1 2 8 . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10.1101/2021.03.31.21254668 doi: medRxiv preprint 8 Phase 1c 1 2 9

Another 4 sentinel participants would be enrolled to receive HD of S-2P protein with 1 3 0 adjuvant in phase 1c. If no ≥ Grade 3 AE or SAE occurred within 7 days after the first 1 3 1 vaccination in the 4 sentinel participants, dosing of the remaining participants in Phase 1c 1 3 2 would proceed. 1 3 3

An interim analysis of immunogenicity data and safety data from baseline to 28 days 1 3 4

after the second vaccination for all participants were carried out when all of the participants 1 3 5

have completed the visit (at 28 days after the second vaccination). 1 3 6

Safety Assessment 1 3 7

The primary endpoint was to evaluate the safety of MVC-COV1901 in three different card for up to 7 days after each vaccination. Unsolicited AEs were recorded for 28 days 1 4 4

following each vaccination; all other AEs, serious adverse events (SAEs) and adverse events 1 4 5 of special interests (AESIs) were recorded throughout the study period. 1 4 6

Serum samples were collected for safety evaluations. Hematology, biochemistry and 1 4 7 . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10.1101/2021.03.31.21254668 doi: medRxiv preprint 9 immunology tests were measured as well. 1 4 8

Immunogenicity Analysis 1 4 9

The immunogenicity endpoints were to evaluate the immunogenicity in terms of 1 5 0 neutralizing antibody titers and binding antibody titers at 14 days (Day 15) and 28 days (Day 1 5 1 29) after first and at 14 days (Day 43) and 28 days (Day 57) after second vaccination, as well 1 5 2 as 90 days and 180 days after the second vaccination. 1 5 3

Total serum anti-Spike IgG titers were detected with direct enzyme-linked 1 5 5 immunosorbent assay (ELISA) using customized 96-well plates coated with S-2P antigen. 1 5 6 SARS-CoV-2 pseudovirus neutralization assay 1 5 7

Pseudovirus production and titration followed the previous report. 7(p7) Serial dilutions of 1 5 8 the samples to be tested were performed (initial dilution of 1:20; diluted two-fold to a final 1 5 9 dilution of 1:2560). The diluted serum was mixed with equal volume of pseudovirus (1000 1 6 0 TU) and incubated before adding to the plates with HEK293-hAce2 cells (1 × 10 4 cells/well).

The amount of pseudovirus entering the cells was calculated by lysing and measuring the 1 6 2 relative luciferase units (RLU). Fifty percent inhibition dilution (concentration) titers (ID 50 ) 1 6 3

were calculated considering uninfected cells as 100% neutralization and cells transduced with 1 6 4 virus as 0% neutralization and reciprocal ID 50 geometric mean titers (GMT) were both 1 6 5 determined. 1 6 6 . CC-BY-NC-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 April 6, 2021. cells/well) were seeded in 96-well plates and incubated. The sera underwent a total of 11 1 7 0 two-fold dilutions with the final dilution being 1:8192, and the diluted sera were mixed with 1 7 1 equal volume of viral solution containing 100 TCID 50 . The serum-virus mixture was 1 7 2 incubated and then added to the cell plates containing the Vero E6 cells, followed by further 1 7 3

incubation. The neutralizing titer was defined as the reciprocal of the highest dilution capable 1 7 4

of inhibiting 50% of the CPE (NT 50 ), which was calculated in accordance with the formula of 1 7 5

the Reed-Muench method. 1 7 6

Statistical Analysis 1 7 7

Safety analysis was performed on the total vaccinated group (TVG) population who 1 7 8 received at least 1 dose of vaccine. The endpoints related to immunogenicity consisted of the 1 7 9

following: antigen specific immunoglobulins, neutralizing antibody titers of wild type virus 1 8 0 and pseudovirus, in terms of geometric mean titer (GMT) and seroconversion rate (SCR). . CC-BY-NC-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 April 6, 2021. malaise/fatigue in the HD group. None of the participants had fever after either dose 1 or 1 9 4 dose 2. Solicited adverse events after the first and the second vaccination were similar. 1 9 5

Evaluation of safety laboratory values, ECG interpretation, and unsolicited adverse events 1 9 6 revealed no specific concern. 1 9 7

Immunogenicity 1 9 8

The humoral immunogenicity results are summarized in Figure 1 . . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10. 1101 /2021 

BMI (kg/m 2 ) Mean (SD)

 9 participants in MD and HD groups were seroconverted in terms of wild-type SARS-CoV-2 2 4 0 neutralizing response. Besides, the wild type neutralizing antibody response profile also 2 4 1 demonstrated a good correlation with IgG and pseudovirus neutralizing antibody titers. 2 4 2 . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10.1101 https://doi.org/10. /2021 Although the correlation of protection is not available at present, serum neutralizing activity 2 4 3 has been shown to be correlate of protection for other viruses while developing vaccines, 2 4 4 such as yellow fever vaccine, polio vaccine, and Japanese encephalitis vaccine, 10 and is 2 4 5 generally accepted as a useful biomarker of the in vivo humoral response. Besides, the 2 4 6preclinical study of MVC-COV1901 11 had shown that hamsters were protected from 2 4 7 SARS-CoV-2 virus challenge after two vaccinations of S-2P protein adjuvanted with CpG 2 4 8 and aluminum hydroxide. The geometric mean titers in the MD and HD groups were 2 4 9comparable with those of a panel of control convalescent serum specimens with all 2 5 0 participants in both groups seroconverted after two vaccinations. Therefore, a MD of S-2P 2 5 1 combined with CpG 1018 and aluminum hydroxide was deemed adequate to elicit a profound 2 5 2 humoral immune response.

This interim report has some limitations: small size of the trial, the short period of 2 5 4follow-up at this time point, and the participants' young age and good health status. We were 2 5 5 not able to assess the durability of the immune responses after Day 57 in this interim report.

However, participants will be followed up for 6 months after the second vaccination with 2 5 7 scheduled blood collections throughout that period to evaluate the humoral immunologic 2 5 8responses. Although the level of immunity needed to protect from COVID-19 remains 2 5 9unknown, NIBSC 20/130 standard serum was tested in terms of wild-type SARS-CoV-2 2 6 0 neutralizing antibody titer for the development and evaluation of serological assays for the 2 6 1 . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10.1101/2021.03.31.21254668 doi: medRxiv preprint 1 5 detection of antibodies against SARS-CoV-2, as a positive control.

These safety and immunogenicity findings support further advancement of the 2 6 3 MVC-COV1901 vaccine to subsequent clinical trials. Of the three doses evaluated, both the 2 6 4 MD and HD elicited high neutralizing antibody responses with all participants seroconverted 2 6 5 after second vaccination. Further phase 2 trial with 3700 participants (including the 2 6 6 populations at greatest risk for serious Covid-19 such as those with chronic medical diseases 2 6 7and older adults) is on-going (ClinicalTrials.gov number, NCT04695652) 2 6 8 2 6 9. CC-BY-NC-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 April 6, 2021. of Health and Welfare, during the conduct of the study. In addition, Yi-Jiun Lin and Charles 2 8 8 . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10.1101/2021.03.31.21254668 doi: medRxiv preprint 1 7Chen have a patent US63/040,696 pending.

Funding/Support 2 9 0Taiwan Centers for Disease Control, Ministry of Health and Welfare provided grant funding 2 9 1 for this study, but does not necessarily stand by any commentary made in this paper.

Medigen Vaccine Biologics Corp. was the study sponsor and manufacturer of the 2 9 3investigational vaccine, and co-designed the trial, provided the study product, and 2 9 4 coordinated interactions with regulatory authorities. The sponsors used contract clinical 2 9 5 research organization to oversee clinical site operations. Data were collected by the clinical 2 9 6 site research staff, managed by a contract research organization data management team, 2 9 7 monitored by a contract research organization, and overseen by the sponsor and an 2 9 8 independent data and safety monitoring board. The interim analysis was performed by the 2 9 9contract research organization. Data interpretation, manuscript preparation were performed 3 0 0 by the authors and the decision to submit the manuscript for publication was made by the Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan for 3 0 7. CC-BY-NC-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 April 6, 2021. ; https://doi.org/10.1101/2021.03.31.21254668 doi: medRxiv preprint 1 8 providing technical guidance and helpful advice; The investigational staff at National Taiwan  3  0  8 University Hospital, Taiwan and A2 Healthcare Taiwan Corp. for the conduction of the trial; Chung Guei Huang as well as her team members at Chang Gung Memorial Hospital, 3 1 6Taoyuan, Taiwan for the wild type SARS-CoV-2 neutralization assay; Team members at 3 1 7Protech Pharmaservices Corporation for spike specific IgG ELISA assay. Dr. Chia En Lien, 3 1 8Dr. Meei-Yun Lin, Luke Tzu-Chi Liu, and Meng-Ju Tsai at Medigen Vaccine Biologics Corp., 3 1 9Taiwan for manuscript editing and revision. 3 2 0 3 2 1 . CC-BY-NC-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 April 6, 2021. 3 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 April 6, 2021. . CC-BY-NC-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 April 6, 2021. ; https://doi.org/10. 1101 /2021