A Clinical Trial Evaluating the Monkeypox Recombinant Protein Vaccine

A Phase I Randomized Double-blind Placebo-controlled Clinical Trial to Evaluate the Safety, Tolerability, and Immunogenicity of Recombinant Monkeypox Protein Vaccine JT118 in Healthy Adults.

This study is a randomized, double-blind, placebo-controlled Phase I clinical trial representing the first-in-human (FIH) investigation of the Monkeypox recombinant protein vaccine JT118. The primary objectives are to evaluate the safety, tolerability, and immunogenicity of two doses of JT118 in healthy adults and to conduct preliminary exploration of vaccination regimens.

The study will sequentially proceed from the low-dose group to the high-dose group with Subgroup 1 (participants without prior Smallpox vaccination history) and Subgroup 2 (participants with prior Smallpox vaccination history) being conducted concurrently within each dose group. It will explore single-dose, two-dose, and three-dose vaccination regimens with approximately 180 healthy adult participants planned for enrollment.

Study Overview

• Status: Not yet recruiting
• Conditions: Health Volunteer
• Intervention / Treatment: Biological: JT118 experimental group; Biological: JT118 placebo group

• Study Type: Interventional
• Enrollment (Estimated): 180
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Yu Hao; Phone Number: 18045174019; Email: yu_hao@junshipharma.com

Study Locations

• China
  • Guangdong
    • Shenzhen, Guangdong, China, 518112
      • Shenzhen Third People's Hospital
      • Principal Investigator: Hongzhou Lu, Ph.D
      • Contact: Hongzhou Lu, Ph.D; Phone Number: 18930810088; Email: luhongzhou@szsy.sustech.edu.cn
      • Contact: PP

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Male or female participants aged 18 to 59 years (inclusive) at the time of signing the informed consent form.
2. Participants with fertility (including male participants) and their spouses are willing to avoid pregnancy (including sperm donation and egg donation plans) from 14 days before screening until six months after the last administration of the investigational vaccine, and are willing to use effective contraception.
3. Ability to understand the study procedures, sign a written informed consent form, and complete the study according to the protocol requirements.
4. Body temperature <37.3°C (axillary temperature) on the day of enrollment.

Exclusion Criteria:

1. Individuals with a history of Smallpox infection or Monkeypox infection or close contact with individuals infected with Monkeypox.
2. Individuals whose medical history or clinical evidence indicates presence of significant comorbidities (including but not limited to cardiovascular system disorders; respiratory system disorders; digestive system disorders; urinary system disorders; neurological disorders; hematological disorders; immunological disorders; endocrine/metabolic disorders; infectious diseases; psychiatric/psychological disorders) where the investigator determines them unsuitable for enrollment.
3. Individuals whose pre-vaccination baseline assessments (including vital signs examination/physical examination/laboratory test/ECG) show clinically significant abnormalities where the investigator determines them unsuitable for enrollment.
4. Individuals testing positive for human immunodeficiency virus antibody/HBV surface antigen (HBsAg)/HCV virus antibody/Syphilis spirochete antibody .
5. Individuals who have previously received an approved or investigational Monkeypox vaccine.
6. Use of any immunosuppressive drugs within 28 days before the first dose.
7. Receipt of an inactivated vaccine within 14 days before the first dose or receipt of a live attenuated vaccine within 30 days before the first dose.

8 .Major surgery received within six months before receiving the first dose or anticipated major surgery during study participation.

9. Blood donation history (excluding physiological female bleeding) or significant haemorrhage (≥200 mL) within three months prior to receiving the first dose; or planned blood donation (including component blood donation) within one hundred eighty days after last vaccination.

10. Use of immunoglobulins and/or any blood products within three months prior to receiving initial vaccination; or planned use during trial participation.

11 .Participants who have used any investigational or unregistered products (including drugs, vaccines, biologics, or devices) within 3 months prior to receiving the first dose of study medication, or plan to use such products during the study period.

12. Participants with known allergy to any excipient(s) of this product. 13 .Participants with extensive scars or skin disorders at potential injection sites.

14 .Women who are pregnant or lactating/breastfeeding. 15 .Participants with a history of drug abuse within 12 months prior to screening OR positive drug screen results before randomization.

16. History of alcohol dependence within 6 months prior to screening, or positive alcohol breath test result before randomization.

17. Participants deemed unsuitable for participation by investigators due to other reasons (e.g., presence of concomitant medical conditions/history, poor compliance).

18 .Participants who experienced a severe allergic reaction after administration of the first or second dose* of vaccination.

19. Participants who experienced a serious adverse event (SAE) likely or definitely related to investigational vaccine following administration of first/second dose*, with decision on continued participation made by investigators.

20. Participants who failed initial dose eligibility criteria (inclusion/exclusion) following administration of first/second dose*, with decision on continued participation made by investigators .

21 .Presence of any other medical condition considered unsuitable for vaccination by investigators.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental：JT118; The vaccine was administered by Subcutaneous Injection	Biological: JT118 experimental group; The vaccine was administered by Subcutaneous Injection
Experimental: Placebo :JT118; The vaccine was administered by Subcutaneous Injection	Biological: JT118 placebo group; The vaccine was administered by Subcutaneous Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Solicited adverse events Incidence Rate	Rate of solicited adverse events (Adverse event) occurring within 14 days after each dose of vaccination	up to 70 days
Unsolicited adverse events Incidence Rate	Incidence rate of unsolicited adverse events within 28 days after each dose of vaccination	up to 84 days
Incidence Rate of Laboratory Test Abnormal Findings	Incidence rate of Laboratory test abnormal 、Electrocardiogram abnormalities within 14 days after each vaccine dose	up to 70 days
Incidence Rate of Serious Adverse Events (SAE)	Incidence rate of serious adverse events (SAEs) within 12 months after the last dose	up to 416 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of cellular immune responses (IFN-γ)	Cellular Immune Response (IFN-γ) Status at Days 14 and Day 28 Post-Vaccination Per Dose，Participants were followed up for a period of 12 months after their last vaccination, and the durability of the immune response to JT-007 was monitored.	up to 416 days
incidence o of binding antibodies	The production status of binding antibodies 28 days after each vaccination dose.	up to 84 days
incidence o of Neutralising antibodies	The production status of Neutralising antibodies 28 days after each vaccination dose.	up to 84 days

Collaborators and Investigators

• Sponsor: Shanghai JunTop Biosciences Co., LTD

Study record dates

Study Major Dates

• Study Start (Estimated): March 30, 2026
• Primary Completion (Estimated): November 7, 2027
• Study Completion (Estimated): November 7, 2027

Study Registration Dates

• First Submitted: March 13, 2026
• First Submitted That Met QC Criteria: March 22, 2026
• First Posted (Actual): March 27, 2026

Study Record Updates

• Last Update Posted (Actual): March 27, 2026
• Last Update Submitted That Met QC Criteria: March 22, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: JT118-001-I

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No