CompletedPhase 1/2

A Clinical Study Investigating the Safety and Immune Responses After Immunization With Investigational Monkeypox Vaccines

United States, United Kingdom96 participantsStarted 2023-09-21

Plain-language summary

This is a dose-escalation, Phase I/II study evaluating the safety, tolerability, reactogenicity and immunogenicity of the investigational RNA-based multivalent vaccine candidate BNT166a for active immunization against monkeypox (mpox). This study started with substudy A (SSA) and substudy B (SSB) for which recruitment has been completed. A Substudy C (SSC) was planned, but the sponsor decided not to conduct it. This study will therefore continue with substudy D (SSD). In SSA and SSB, dosing started with an initial sentinel group, followed by the expansion cohort. This study was initially planned to investigate two vaccine candidates (the quadrivalent BNT166a and the trivalent BNT166c). The sponsor decided to not activate the groups with BNT166c.

Who can participate

Age range

18 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria (applicable to all substudies unless otherwise specified): * Have given informed consent by signing and dating the informed consent form (ICF) before initiation of any study-specific procedures. * Are willing and able to comply with scheduled visits, treatment schedule, laboratory tests, and other requirements of the study, including the prohibited concomitant medications. This includes that they are able to understand and follow study-related instructions. * SSA and SSD only: Are 18 through 45 years of age (inclusive) at the time of informed consent. * SSB only: Are 50 through 65 years of age (inclusive) at the time of informed consent. * Have a body mass index over 18.5 kg/m\^2 and under 30 kg/m\^2 and weigh at least 50 kg at Visit 0. * Are healthy, in the clinical judgment of the investigator based on volunteer-reported medical history data, physical examination, 12-lead electrocardiogram (ECG), vital signs, and clinical laboratory test results. * SSA and SSD only: Have no prior history of known or suspected smallpox vaccination and no detectable smallpox vaccination characteristic scar (vaccinia-naïve participants). * SSB only: Have a history of prior smallpox vaccination (i.e., are vaccinia-experienced), determined based on medical records and/or presence of smallpox vaccination characteristic scar. The most recent smallpox vaccination should have been received before 1980. * Agree not to enroll in another study with an investigational medicinal produ…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

SSA, SSB, and SSD - Proportion (%) of participants reporting solicited local reactions at the injection site (pain, erythema/redness, induration/swelling)

Timeframe: From Dose 1 through Day 7 post-Dose1 inclusive; and from Dose 2 through Day 7 post-Dose 2 inclusive

SSA, SSB, and SSD - Proportion (%) of participants reporting solicited systemic events (vomiting, diarrhea, headache, fatigue, myalgia, arthralgia, chills, and fever)

Timeframe: From Dose 1 through Day 7 post-Dose1 inclusive; and from Dose 2 through Day 7 post-Dose 2 inclusive

SSA, SSB, and SSD - Proportion (%) of participants with at least one unsolicited adverse event (AE) occurring from Dose 1 through Day 28 post-Dose 1 inclusive

Timeframe: From Dose 1 through Day 28 post-Dose 1 inclusive

SSA, SSB, and SSD - Proportion (%) of participants with at least one unsolicited AE occurring from Dose 2 through Day 28 post-Dose 2 inclusive

Timeframe: from Dose 2 through Day 28 post-Dose 2 inclusive

SSA, SSB, and SSD - Proportion (%) of participants with at least one serious adverse event (SAE) occurring from Dose 1 through Day 201 post-Dose 1 inclusive

Timeframe: From Dose 1 through Day 201 post-Dose 1 inclusive

Trial details

NCT IDNCT05988203

SponsorBioNTech SE

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-08-25

View on ClinicalTrials.gov More Monkeypox trials

Plain-language summary

Who can participate

Age range

18 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

SSA, SSB, and SSD - Proportion (%) of participants reporting solicited local reactions at the injection site (pain, erythema/redness, induration/swelling)

Timeframe: From Dose 1 through Day 7 post-Dose1 inclusive; and from Dose 2 through Day 7 post-Dose 2 inclusive

SSA, SSB, and SSD - Proportion (%) of participants reporting solicited systemic events (vomiting, diarrhea, headache, fatigue, myalgia, arthralgia, chills, and fever)

Timeframe: From Dose 1 through Day 7 post-Dose1 inclusive; and from Dose 2 through Day 7 post-Dose 2 inclusive

SSA, SSB, and SSD - Proportion (%) of participants with at least one unsolicited adverse event (AE) occurring from Dose 1 through Day 28 post-Dose 1 inclusive

Timeframe: From Dose 1 through Day 28 post-Dose 1 inclusive

SSA, SSB, and SSD - Proportion (%) of participants with at least one unsolicited AE occurring from Dose 2 through Day 28 post-Dose 2 inclusive

Timeframe: from Dose 2 through Day 28 post-Dose 2 inclusive

SSA, SSB, and SSD - Proportion (%) of participants with at least one serious adverse event (SAE) occurring from Dose 1 through Day 201 post-Dose 1 inclusive

Timeframe: From Dose 1 through Day 201 post-Dose 1 inclusive