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. 2023 Mar 14;2023(3):CD015769. doi: 10.1002/14651858.CD015769

NCT05534984.

Study name STOMP
Methods Double‐blinded, placebo‐controlled, randomized trial with 3 arms
Arm A: tecovirimat oral capsule
Arm B: placebo
Arm C: tecovirimat open‐label.
Randomized 2:1
Dates of recruitment: recruitment started 12 September 2022
Inclusion criteria (all participants; Arms A, B, and C)

  1. Laboratory‐confirmed or presumptive mpox infection (presumptive infection not defined).

  2. mpox illness of < 14 days duration immediately prior to study entry.

  3. At least one active (not yet scabbed) skin lesion, mouth lesion, or proctitis with or without visible ulcers.

  4. Non‐pregnant people of reproductive potential must agree to use at least one effective means of contraception when engaging in sexual activities that can result in pregnancy, from the time of enrolment through the end of study participation.


Additional Inclusion Criteria for Arms A and B

  1. Age ≥ 18 years at the time of study entry


Additional Inclusion Criteria for Arm C
Participants who meet the above entry criteria who also meet any of the following criteria will be registered to Arm C.

  1. Participants age < 18 years at the time of study entry

  2. Those with severe mpox disease


Those with or without severe disease and with one or more of the following will also be enrolled into Arm C

  1. Severe immunosuppression

  2. Skin conditions placing the person at higher risk for disseminated infection.


Exclusion criteria (all participants; Arms A, B, and C)

  1. Prior or concomitant receipt of tecovirimat (e.g. under an alternative access mechanism).

  2. Planned initiation of intramuscular cabotegravir/rilpivirine during study drug administration or for 2 weeks following completion of study drug administration. Participants who are stable on long‐acting intramuscular cabotegravir/rilpivirine may enrol.

  3. Participants who, in the judgement of the investigator, will be at significantly increased risk as a result of participation in the study.

  4. Participants who require intravenous dosing of tecovirimat.


Length of follow‐up: 57 days.
Loss to follow‐up: not applicable, ongoing trial.
Adherence to assigned treatment: not applicable, ongoing trial.
Participants Number of participants: 530
Source of participants: hospitals and health centres at 64 sites in the USA
Age: any
Sex: any
Disease severity: any
Vaccination status: not stated
Concurrent treatments: not stated
Pregnancy: participants who are pregnant or breastfeeding will receive open‐label tecovirimat after discussion of the potential risks and benefits.
Comorbidities: participants with significant skin conditions or severe immune suppression will receive open label tecovirimat.
Interventions Intervention
Therapeutic: tecovirimat
Route of administration: oral capsule
Dosage
Arm A

  1. Participants weighing 25 kg to less than 40 kg: 400 mg

  2. Participants weighing 40 kg to less than 120 kg: 600 mg

  3. Participants weighing 120 kg and over: 600 mg


Arm C

  1. Participants weighing 4 to < 6 kg and > 7 days old: 50 mg every 12 hours for 14 days

  2. Participants weighing 2.5 to < 4 kg and > 7 days to < 4 weeks old: 20 mg every 12 hours for 14 days

  3. Participants weighing 4 to < 6 kg and ≤ 7 days old: 50 mg every 24 hours for 14 days

  4. Participants weighing 2.5 to < 4 kg and ≤ 7 days old: 20mg

  5. Participants weighing 6 kg to less than 13 kg: 100 mg

  6. Participants weighing 13 kg to < 25 kg: 200 mg

  7. Participants weighing 25 kg to < 40 kg: 400 mg

  8. Participants weighing 40 kg to < 120 kg ‐ 600 mg

  9. Participants weighing 120 kg and over: 600 mg


Timing, frequency and duration of treatment
Arm A

  1. Participants weighing 25 kg to < 40 kg: every 12 hours for 14 days

  2. Participants weighing 40 kg to < 120 kg ‐ every 12 hours for 14 days

  3. Participants weighing 120 kg and over: every 8 hours for 14 days


Arm C

  1. Participants weighing 4 to < 6 kg and > 7 days old: every 12 hours for 14 days

  2. Participants weighing 2.5 to < 4 kg and > 7 days to < 4 weeks old: every 12 hours for 14 days

  3. Participants weighing 4 to < 6 kg and ≤ 7 days old: every 24 hours for 14 days

  4. Participants weighing 2.5 to < 4 kg and ≤ 7 days old: every 24 hours for 14 days

  5. Participants weighing 6 kg to < 13 kg: every 12 hours for 14 days

  6. Participants weighing 13 kg to < 25 kg: every 12 hours for 14 days

  7. Participants weighing 25 kg to < 40 kg: every 12 hours for 14 days

  8. Participants weighing 40 kg to < 120 kg: every 12 hours for 14 days

  9. Participants weighing 120 kg and over: every 8 hours for 14 days.


Duration of follow‐up: 57 days. As per the different outcomes in length of follow‐up box.
Control
Type: placebo
Route of administration: oral capsule
Dosage, timing and frequency: participants weighing 25 kg to < 40 kg: placebo 400 mg every 12 hours for 14 days
Participants weighing 40 kg to < 120 kg: placebo 600 mg every 12 hours for 14 days
Participants weighing 120 kg and over: placebo 600 mg every 8 hours for 14 days
Duration of treatment: 14 days
Duration of follow‐up: 57 days. As per the different outcomes in length of follow‐up box.
Outcomes Primary

  1. Time to clinical resolution, defined as the first day on which all skin lesions are scabbed, desquamated, or healed, and visible mucosal lesions are healed (up to day 29)


Secondary

  1. Pain assessed by 11‐point numerical rating scale for pain (through day 29)

  2. Time to development of severe mpox in those without severe mpox at baseline (through day 57)

  3. Level of mpox virus in blood (through day 57)

  4. Level of mpox virus in skin lesions (through day 57)

  5. Level of mpox virus in oropharynx (through day 57)

  6. Level of mpox virus in rectum (through day 57)

  7. Level of mpox virus in genital secretions (through day 57)

  8. Time to complete lesion healing defined as all lesions being re‐epithelialized (up to day 29)

  9. Participant‐reported adherence (through day 15)

  10. Participant‐reported quality‐of‐life as measured by EQ‐5D‐5L (through day 29)

  11. Occurrence of Grade 3 or greater adverse event (through day 57)

  12. All‐cause mortality (through day 57)

  13. Tecovirimat concentrations in blood in children less than 18 years of age (through day 15)
Starting date Registered 10 September 2022
Contact information  
Notes Authors: Timothy Wilkin, Cornell
Official title: A Randomized, Placebo‐Controlled, Double‐Blinded Trial of the Safety and Efficacy of Tecovirimat for the Treatment of Human Monkeypox Virus Disease
Publication date: ongoing, estimated completion date: 30 September 2023
Country: USA, 64 locations, including Puerto Rico.
Funding details: sponsor: National Institute of Allergy and Infectious Diseases (NIAID)
Collaborator: SIGA technologies
CoI statement: not stated