Trial design
This observer-blinded, randomized, placebo-controlled, ascending dose Phase 1 study is being conducted at one site in Canada (Manna Research, Toronto, Ontario). Eligible participants included healthy men and nonpregnant women between 18 and 64 years of age, with a body mass index of 18–30 kg/mTwo doses of 16-µg (Cohort 1), 40-µg (Cohort 2), and 100-µg (Cohort 3) PTX-COVID19-B were compared to placebo with 20 participants in each cohort. Vaccine or placebo were administered on days 1 and 28. The sentinel group had five participants in each of the dose cohorts, who were randomized in a 4:1 ratio (vaccine: placebo). After review of the safety data of the sentinel group, the trial was followed by a cohort expansion of 15 participants randomized in a 11:4 ratio (vaccine:placebo). Randomization codes were generated using a computer program and provided as a paper listing of vaccine or placebo assignment by an unblinded statistician. The pharmacist and staff members that prepared and administered the doses based on the paper randomization were unblinded; all others involved in the conduct of the study (Principal Investigator, site coordinator, site staff) and the participants were blinded.PT was the sponsor of the study, which was conducted under a protocol approved by Advarra. This study was conducted in accordance with the provisions of the Declaration of Helsinki, and in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use E6 Guidelines on Good Clinical Practice (GCP). All participants provided written informed consent prior to enrollment. Full text of the trial protocol, including detailed statistical analysis plan are provided in the Supplementary Information.