臨床研究等提出・公開システム

An open-label, single-arm study to investigate the efficacy and safety of smallpox vaccine as postexposure prophylaxis in monkeypox (MKP1)

Smallpox vaccine trial as post-exposure prophylaxis in monkeypox (MKP1)

6

The number of enrolled cases was 6 (with a history of smallpox inoculation: 5 with no history, 1 with a history of inoculation). 100% were male. The average age was 42 +- 6.5 years. Smallpox inoculation history: Primary inoculation (number of punctures: 5) 5 cases (83.3%). Reinoculation (number of punctures: 10) 1 case (16.7%). Medical history: Pneumonia 1 case (16.7%). Comorbidities: HIV infection 2 cases (33.3%), Dyslipidemia 2 cases (33.3%), Diabetes mellitus 2 cases (33.3%), Hyperuricemia 1 case (16.7%), Keloid 1 case (16.7%), Hypertension 1 case (16.7%). Concomitant drug use 3 cases (50.0%). Situation of close contact with mpox patient: Contact with mucous membranes 1 case (16.7%). Family members or cohabitants who live together 6 cases (100%). Inoculation from close contact with mpox patient: Within 4 days 5 cases (83.3%), 5 to 14 days 1 case (16.7%).

The study began on June 15th, 2022, and the first subject was enrolled on July 28th, 2022. After that, 5 subjects who were confirmed to be eligible in the same way were enrolled, and the final 6 subjects were enrolled on October 5th, 2022. The observation period ended on August 24th, 2022 for the first case and November 4th, 2022 for the last case, respectively. After that, the observation period ended on December 20, 2022, because no study subjects who had close contact with mpox patients were registered.

The following 18 adverse events occurred in this study, but all recovered. All outcomes were recovery: Rash 7 cases, fever 3 cases, Axillary lymphadenopathy 1 case, Cervical lymphadenopathy 1 case, headache 1 case, shoulder pain 1 case, pruritus (back) 1 case, pruritus (left shoulder) 1 case, 1 fatigue, COVID-19 1 case.

The primary endpoint are as follows: Mpox onset after 21 days from close contact is as follows. Among LC16 inoculated individuals within 4 days from the date of close contact, 0 of 5 cases developed the disease. Among LC16 vaccinees within 5-14 days from the day of close contact, 0 of 1 case developed. Secondary endpoints are as follows: Severity of mpox symptoms, mortality, and incidence of complications 28 days after LC16 inoculation. Symptoms: fever, headache, rash, lymphadenopathy 0 cases (0%) Severity: ICU admission, lying down, minimal getting out of bed: 0 cases (0%) Ability to carry out normal activities: 6 cases (100%) Death: 0 (0%) Complications: secondary skin infection, bronchopneumonia, sepsis, encephalitis, conjunctivitis 0 cases (0%) Adverse reactions and adverse events confirmed within 28 days after LC16 inoculation Rash (Inoculation side 5 cases (83.3%) mild, others (back) 1 case (16.7%) mild), fever 1 case (16.7%) moderate, 2 cases (33.3%) mild, lymphadenopathy (vaccine side Axillary 1 case (16.7%) mild, inoculated side neck 1 case (16.7%) mild), headache 1 case (16.7%) mild, fatigue 1 case (16.7%) mild, pruritus (inoculated side axillary 1 case (16.7%) mild, 1 case (16.7%) mild on the neck of the inoculation side, 1 case (16.7%) mild pain on the shoulder of the inoculation side, 1 case (16.7%) mild COVID-19 Local adverse events confirmed within 28 days after LC16 inoculation.: Erythema 6 cases (100.0%), swelling 6 cases (100.0%), lump 3 cases (50.0%), pain 3 cases (50.0%) Confirmation of take: 6 cases (100.0%)

It was suggested that LC16 vaccination within 14 days of close contact, whether primary or revaccination, may be effective in preventing the development of mpox, but the target number of cases was not reached, making it difficult to present clear efficacy. The results of this study also suggest the safety of the LC16 vaccine for close contacts, including those with specific pre-existing conditions/comorbidities.

Sept. 01, 2023

No

N/A

https://jrct.niph.go.jp/latest-detail/jRCTs031220137

Mugen Ujiie

Center Hospital of the National Center for Global Health and Medicine

1-21-1, Toyama, Shinjuku-ku, Tokyo

mgujiie@hosp.ncgm.go.jp

Junko Terada-Hirashima

Center for Clinical Sciences, the National Center for Global Health and Medicine

1-21-1, Toyama, Shinjuku-ku, Tokyo

+81-3-3202-7181

after_e_mkp1@hosp.ncgm.go.jp

Complete

June. 15, 2022

Interventional

non-randomized controlled trial

open(masking not used)

no treatment control/standard of care control

single assignment

prevention purpose

1) Persons who have given written consent to participate in the research, either in person or by proxy.
2)Men and women who are at least one year of age at the time consent is obtained
3)Persons who have been in close contact with a person who has been diagnosed with monkeypox within 14 days
4) Persons who have not developed monkeypox.

1) Persons with diseases that are clearly abnormal in immune function
2) Persons using corticosteroids or immunosuppressive drugs (cyclosporine, tacrolimus, azathioprine, etc.)
3) Persons with an apparent history of anaphylaxis caused by components of the smallpox vaccine
4) Patients with apparent fever
5) Persons who are obviously suffering from a serious acute disease
6) Those who are obviously pregnant
7) Persons suffering from a spreading skin disease, which may be impaired by immunization.
8) Persons who are in an inappropriate condition to be immunized.
9) Persons who are judged by the principal investigator to be inappropriate for inclusion in the study.

Both

Monkeypox

Vaccinate concentrated contacts of monkeypox with smallpox vaccine.

Monkeypox

postexposure prophylaxis, smallpox vaccine

D045908

D012899

Onset of disease 21 days after intense contact

Percent severe, death, symptoms (fever, headache, lymphadenopathy), complications (secondary skin infection, bronchopneumonia, sepsis, encephalitis, keratitis)

+81-3-3202-7181

none