SmallpoxPhase 3SIGA246-008NCT02474589

A Trial to Assess the Safety, Tolerability, and Pharmacokinetics of the Anti-Orthopoxvirus Compound Tecovirimat

A Phase 3 study testing tecovirimat in people with Smallpox, run by SIGA Technologies at 11 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

Multicenter, double-blind, placebo controlled, Phase 3 study to determine the safety and tolerability of oral tecovirimat, an anti orthopoxvirus compound, in subjects. Read more about this study

Who is it for?: Ages 18 to 80 yearsHealthy volunteers can take part
Conditions the study is for: Smallpox
What is being tested?: tecovirimat
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 449 participants
Where: 11 sitesUnited States
Study dates: 19 Jun 2015to 24 Aug 2016
Phase: Phase 3
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 80 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Who may be able to join

18 to 80 years old, inclusive
Available for clinical follow-up for the duration of the study
Able and willing to give informed consent
In good general health without clinically significant medical history; not have been hospitalized for a chronic medical condition for the last 2 years
Able to comply with dietary requirements throughout the study drug dosing period
Adequate venous access for those individuals participating in PK testing

Show all 16Show fewer

PE and laboratory results without clinically significant findings within the 14 days before receipt of study drug
Agree not to drink alcohol from the beginning of the Screening Period through the completion of the Day 28 Follow up Visit
Agree not to use any nicotine products, including electronic vapor cigarettes, nicotine patches or nicotine gum for at least 30 days before the Day 1 Visit and through completion of the Day 15 Dosing complete Visit
Agree not to consume caffeine during all study visits, including overnight stays if participating in PK subset
Agree not to receive any immunizations/vaccinations
Agree not to take herbal products
Able and willing to refrain from taking any prescriptions and nonprescription medications with exceptions
For women of childbearing potential, negative serum and urine pregnancy testing
If male, agree not to donate sperm
Meet 1 of the following criteria: The subject or their partner has undergone surgical sterilization; the subject is postmenopausal; the subject agrees to be abstinent; the subject agrees to consistently use a method of approved birth control.

Who cannot join

Pregnant or breast-feeding or planning pregnancy
Have a history of any clinically significant conditions
Have any limitation of activity related to cardiac disease
Have a bleeding disorder diagnosed by a doctor, or a history of significant bruising or bleeding with intramuscular injections or blood draws
Currently using certain medications
Have a malignancy that is active or a treated malignancy for which there is no reasonable assurance of sustained cure, or malignancy that is likely to recur during the study

Show all 25Show fewer

Have a history of seizure
Have a clinically significant blood dyscrasia
Have a history of drug allergy that contraindicates participation in the trial
Have a medical, psychiatric, or social condition or any occupational reason, or other responsibility that in the judgment of the investigator would render the subject unable to comply with the protocol
Have an inability to swallow medication
Have a clinically significant abnormal ECG
Have participated in a clinical trials within 30 days of study entry or planning to participate in any experimental treatment study during the study period
Have a history or current drug or alcohol abuse
Have received immunizations/vaccines
Have a current clinically significant acute bacterial, fungal, or mycobacterial infection requiring administration of systemic antibiotics
Have known chronic bacterial, mycobacterial, fungal, parasitic, or protozoal infection with the exception of clinically significant dermal infections
Have known hepatitis B or C infection, or positive test result
Have known HIV infection or AIDS or a positive test for HIV
Have a current clinically significant viral infection
Have known clinically significant chronic viral infection
have received treatment with greater than 20 mg prednisone or equivalent dose or any immunosuppressant or immunomodulary medication
Have abnormal laboratory testing during screening
Have a greater than or equal than 20% risk of suffering a major cardiovascular event
Have been previously enrolled in this or any clinical trial involving tecovirimat

Trial locations and contacts

11 sites in 1 country.

City, postcode or hospital

11 sites in 1 country

United States11 sites

Benchmark Research
Austin, Texas, 78705
Medical Research South
Charleston, South Carolina, 29407
Benchmark Research
Fort Worth, Texas, 76135
Center for Pharmaceutical Research
Kansas City, Missouri, 64114
Johnson County Clinical Trials
Lenexa, Kansas, 66219
Coastal Clinical Research, Inc.
Mobile, Alabama, 36608
Heartland Research Associates, LLC
Newton, Kansas, 67114
Meridien Clinical Research
Omaha, Nebraska, 68134
Paradigm Research
Redding, California, 96001
Paradigm Research
San Diego, California, 92117
Sundance Clinical Research LLC
St Louis, Missouri, 63141

Other trials in United States

About this study

Official title: An Expanded Double-Blind, Placebo Controlled, Multicenter Trial to Assess the Safety, Tolerability, and Pharmacokinetics of the Anti Orthopoxvirus Compound Tecovirimat When Administered Orally for 14 Days in Subjects

Multicenter, double-blind, placebo controlled, Phase 3 study to determine the safety and tolerability of oral tecovirimat, an anti orthopoxvirus compound, in subjects.

Read the detailed description

Pharmacokinetics and safety and tolerability data will be collected.

Conditions: Smallpox
Being tested: tecovirimat, Placebo
Keywords: Treatment, orthopoxvirus, smallpox
Medical subject headings: Smallpox

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

tecovirimatDrug
Also called ST-246
Study is based on Animal Regulatory Rule
PlaceboOther
Does not apply

Study groups in NCT02474589
Study group	Role	What they receive
Active	Active comparator	600 mg tecovirimat capsules BID to assess safety and tolerability and pharmacokinetics of the anit-orthopoxvirus compound Tecovirimat when administered orally in healthy subjects Receives: Drug: tecovirimat
Placebo	Placebo comparator	matching placebo capsules BID to assess safety and tolerability and pharmacokinetics of the anit-orthopoxvirus compound Tecovirimat when administered orally in healthy subjects Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

To Determine the Number of Participants With Adverse Events
To determine the safety and tolerability of oral tecovirimat
Measured: 45 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

19 Jun 201524 Aug 2016

First posted18 Jun 2015 (estimated)
Study start19 Jun 2015
Primary completion24 Aug 2016
Study completion24 Aug 2016

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for SmallpoxStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 3
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind
Who is masked: Participant, Investigator
Enrolment: 449 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT02474589
Sponsor's protocol ID: SIGA-246-008
Other IDs: HHSO100201100001C
Acronym: SIGA246-008
Status last verified: Oct 2017
First submitted: 1 Jun 2015
Last updated: 11 Sep 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
Individual data sharing: Undecided

Publications

Grosenbach DW, Honeychurch K, Rose EA, Chinsangaram J, Frimm A, Maiti B, Lovejoy C, Meara I, Long P, Hruby DE. Oral Tecovirimat for the Treatment of Smallpox. N Engl J Med. 2018 Jul 5;379(1):44-53. doi: 10.1056/NEJMoa1705688.
PubMed 29972742

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Active, not recruitingPhase 2
Study to Assess the Safety and Immunogenicity of TPOXX® When Administered Orally for 28 Days With JYNNEOS
Smallpox
Active, not recruitingPhase 4
Smallpox Vaccine for Mpox Post-Exposure Prophylaxis: A Cluster RCT
Monkeypox
RecruitingPhase 2
A Randomized Clinical Trial Investigating the Safety, Reactogenicity, and Immunogenicity After Immunization With an mRNA-based Mpox Vaccine Candidate in Africa
Mpox (Monkeypox), Smallpox
Enrolling by invitationObservational study
VA-005 Clinical Outcomes of VIGIV Treatment of Smallpox Vaccination Complications or Vaccinia Infection
Complication of Smallpox Vaccination
Active, not recruitingPhase 3
Phase 3 Infant Safety & Immunogenicity Trial of MVA-BN® in DRC
Mpox (Monkeypox), Vaccination

All Smallpox trials

Study at a glance

From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: An Expanded Double-Blind, Placebo Controlled, Multicenter Trial to Assess the Safety, Tolerability, and Pharmacokinetics of the Anti Orthopoxvirus Compound Tecovirimat When Administered Orally for 14 Days in Subjects
ClinicalTrials.gov ID: NCT02474589
Acronym / sponsor ID: SIGA246-008 / SIGA-246-008
Conditions: Smallpox
Keywords: Treatment, orthopoxvirus, smallpox
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 449 participants (actual)
Lead sponsor: SIGA TechnologiesIndustry (pharma, biotech, devices)
Collaborators: Biomedical Advanced Research and Development Authority
Study start: 19 Jun 2015 (actual)
Primary completion: 24 Aug 2016 (actual)
Study completion: 24 Aug 2016 (actual)
First posted: 18 Jun 2015 (estimated)
Results: Posted 28 Nov 2017

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Multicenter, double-blind, placebo controlled, Phase 3 study to determine the safety and tolerability of oral tecovirimat, an anti orthopoxvirus compound, in subjects.

Detailed description

Pharmacokinetics and safety and tolerability data will be collected.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind (participant, investigator)
Number of arms: 2

Arm	Type	Receives
Active	Active comparator	Drug: tecovirimat600 mg tecovirimat capsules BID to assess safety and tolerability and pharmacokinetics of the anit-orthopoxvirus compound Tecovirimat when administered orally in healthy subjects
Placebo	Placebo comparator	Other: Placebomatching placebo capsules BID to assess safety and tolerability and pharmacokinetics of the anit-orthopoxvirus compound Tecovirimat when administered orally in healthy subjects

Who may qualify

Ages: 18 to 80 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (16 listed)

18 to 80 years old, inclusive
Available for clinical follow-up for the duration of the study
Able and willing to give informed consent
In good general health without clinically significant medical history; not have been hospitalized for a chronic medical condition for the last 2 years
Able to comply with dietary requirements throughout the study drug dosing period

Key exclusion criteria (25 listed)

Pregnant or breast-feeding or planning pregnancy
Have a history of any clinically significant conditions
Have any limitation of activity related to cardiac disease
Have a bleeding disorder diagnosed by a doctor, or a history of significant bruising or bleeding with intramuscular injections or blood draws
Currently using certain medications

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
tecovirimatAlso: ST-246Study is based on Animal Regulatory Rule	Drug	Active
PlaceboDoes not apply	Other	Placebo

Primary outcome

To Determine the Number of Participants With Adverse Events
Time frame: 45 days
To determine the safety and tolerability of oral tecovirimat

Results and safety

Results posted to the registry on 28 Nov 2017, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Active	359	334
Placebo	90	85

Primary outcome: To Determine the Number of Participants With Adverse Events

Time frame: 45 days. Count of participants. Unit: Participants

Measure	Active n = 359	Placebo n = 90
Value	134	30

Adverse events

Time frame: Adverse event data was collected from Day 1 Randomization Visit after study drug dosing through the Day 28 Follow-up Visit. Subjects with unresolved AE/SAE at the Day 28 Follow-up Visit were required to complete a Day 45 AE/SAE only Follow up Visit. All AEs/SAEs were to be followed until the subject was no longer participating in the study, or the AE/SAE was stable or until resolution.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Active	1 of 359 (0.3%)	134 of 359 (37.3%)	Not reported
Placebo	0 of 90 (0%)	30 of 90 (33.3%)	Not reported

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 29972742Grosenbach DW, Honeychurch K, Rose EA, Chinsangaram J, Frimm A, Maiti B, Lovejoy C, Meara I, Long P, Hruby DE. Oral Tecovirimat for the Treatment of Smallpox. N Engl J Med. 2018 Jul 5;379(1):44-53. doi: 10.1056/NEJMoa1705688.
Individual participant dataSharing planned: Undecided

Related trials for Smallpox

Active, not recruitingPhase 2
Study to Assess the Safety and Immunogenicity of TPOXX® When Administered Orally for 28 Days With JYNNEOS
Smallpox
Active, not recruitingPhase 4
Smallpox Vaccine for Mpox Post-Exposure Prophylaxis: A Cluster RCT
Monkeypox
RecruitingPhase 2
A Randomized Clinical Trial Investigating the Safety, Reactogenicity, and Immunogenicity After Immunization With an mRNA-based Mpox Vaccine Candidate in Africa
Mpox (Monkeypox), Smallpox
Enrolling by invitationObservational study
VA-005 Clinical Outcomes of VIGIV Treatment of Smallpox Vaccination Complications or Vaccinia Infection
Complication of Smallpox Vaccination
Active, not recruitingPhase 3
Phase 3 Infant Safety & Immunogenicity Trial of MVA-BN® in DRC
Mpox (Monkeypox), Vaccination

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Dennis Hruby, Ph.D. study director

SIGA Technologies, Inc.

11 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing tecovirimat in people with Smallpox, run by SIGA Technologies at 11 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 16 inclusion and 25 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 11 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 28 Nov 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

To Determine the Number of Participants With Adverse Events (time frame: 45 days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02474589, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2026.