Acute Respiratory Viral InfectionsPhase 2/3NCT04682444
Efficacy and Safety of Enisamium Iodide for the Treatment of Acute Respiratory Viral Infections, Including Influenza.
A Phase 2/3 study testing Enisamium Iodide in people with Acute Respiratory Viral Infections and Human Influenza, run by Joint Stock Company "Farmak".
Trial summary
This randomized, single blind clinical study was conducted to investigate the clinical efficacy and safety of the drug Amizon (enisamium iodide), in comparison with placebo for the treatment of patients with acute respiratory viral infections (ARVI), including influenza. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Acute Respiratory Viral Infections, Human Influenza
- What is being tested?
- Enisamium Iodide
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 13 Apr 2009to 15 Jan 2010
- Phase
- Phase 2/3
- 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 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patients aged between 18 to 60 years
- Patients with ARVI, including influenza, starting not later than for 1 day prior to inclusion in the study:
- The body temperature measured axillary above 37.2 °C
- Presence of one of the signs of respiratory disease (runny nose, cough, pain / tickling in the throat)
- Presence of one of the systemic symptoms (weakness, myalgia, headache , chills, sweating)
- Provide written informed consent
- Ability to understand the nature of the study and provide written informed consent in accordance with Good Clinical Practice (GCP) and local law
Who cannot join
- Age over 60 years and under 18 years old
- Presence of allergic reactions
- Intolerance to NSAIDs and iodine-containing drugs
- Hypersensitivity to the components of the drug
- Mental illness that impedes compliance with the research procedure
- Pregnancy or breast-feeding
Show all 16Show fewer
- Presence of acute, clinically significant respiratory and cardio vascular insufficiency, functional disorders of liver, kidney, digestive tract (ulcer disease) determined at physical examination or by laboratory screening tests
- Presence of congenital defects or serious chronic disease of the lungs, kidneys, cardiovascular system, nervous system, metabolic disorders, psychiatric disorders, confirmed by patients history or during initial examination
- The use of preparations of blood cytokine immunoglobulin in for 3 months prior to the study
- Chronic use of alcohol and / or drugs
- Presence or history of cancer diseases, HIV, hepatitis B and C
- Application of immunosuppressive or immunomodulatory drugs for 6-months prior to the study
- Women of child-bearing potential and who do not use acceptable measure of contraception or do not plan to use those throughout the study
- Any clinical condition that, according to the investigator, will not allow to safely carry out the protocol and take the studied drugs without risk to health
- Patients receiving antiviral therapy,
- Participation in other clinical trials at the present time or during the last 3 months.
About this study
Official title: A Prospective Single-blind Comparative Clinical Study of Efficacy and Safety of Amizon 0.25 g Tablets, Manufactured by Farmak JSC, in Patients With ARVI, Including Influenza.
This randomized, single blind clinical study was conducted to investigate the clinical efficacy and safety of the drug Amizon (enisamium iodide), in comparison with placebo for the treatment of patients with acute respiratory viral infections (ARVI), including influenza. Enisamium iodide is an antiviral small molecule.
Adult patients were enrolled and randomised into 2 groups. On the first day of the onset of symptoms of ARVI, one group of patients took Amizon tablets (active ingredient enisamium iodide) for 7 days; the other group of patients took matching placebo tablets for 7 days. Examination and observation of all participants was done for up to 14 days after the first intake of the study drug.
Read more
The effect of treatment was assessed by subjective reporting of the symptoms of ARVI and influenza, using a predefined symptom scale score system.
Objective assessment was performed by measuring vitals signs, laboratory tests (including blood and urine assessment), as well as evaluating the immune status (including measuring the relative concentration of interferon and immunoglobulins).
Read the detailed description
Numerous studies have shown that influenza vaccines, prepared against the relevant epidemic seasonal vaccine strains, are an effective remedy in prevention of this mass disease and are able to protect about 80% of otherwise healthy children and adults. However, to develop vaccines against the emerging new pandemic strain of the influenza virus and produce them in the necessary amounts requires at least 6 months. During such interim periods, sufficient protection of the population is essential by effective measures for treatment and prevention of influenza.
This randomized, single-blind, clinical study was conducted to investigate the clinical efficacy and safety of the drug Amizon (N-methyl-4-benzylcarbamidopyridinium iodide, international nonproprietary name enisamium iodide) compared with placebo, for the treatment of patients with ARVI, including influenza.
Enisamium iodide is an antiviral small molecule. Enisamium can directly inhibit influenza viral RNA replication.
The study design was: randomised, single-blind, 2 parallel groups. Adult patients (18-60 y) with symptoms of ARVI, including influenza took either Amizon tablets (active ingredient enisamium iodide) for 7 days; in the control group patients took placebo tablets for 7 days. Study visits occurred on Day 0 (screening, examination, check inclusion/exclusion criteria, enrollment, randomization, and first intake of study drug); further study visits were on Day 3, Day 7, and Day 14.
The effect of treatment was assessed by questioning the patients regarding ARVI and influenza symptoms that included pain, headache, general weakness, sore throat, pain in the joints, fatigue, runny and itchy nose. The severity of symptoms was recorded using a 4-point Likert scale.
Further evaluation of the treatment was performed by measuring the vitals signs, laboratory tests that included blood and urine analysis, biochemical analysis, as well as assessing the immune status (including measuring the absolute lymphocytes count, and evaluating the relative concentration of interferon (IFN)-alpha and IFN-gamma, and immunoglobulin (Ig) A, M, and G (IgA, IgM, and IgG).
- Being tested
- Enisamium Iodide, Placebo
- Keywords
- Viral infections, Amizon, Enisamium iodide, Influenza
- Medical subject headings
- Influenza, Human, Virus Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Enisamium IodideDrug
Also called Amizon
Patients ingested Amizon tablets without chewing, after meal, as follows: 2 tablets (total dose 500 mg) 3 times a day, for 7 days. Each tablet contains 250 mg of Nmethyl-4-N-methyl-4-benzylcarbamidopyridinium iodide (INN enisamium iodide).
PlaceboDrug
Patients ingested placebo tablets without chewing, after meal, in the dose 500 mg (2 tablets), 3 times a day, for 7 days.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 - Active Treatment - Amizon | Experimental | Patient who were randomized into Group 1 ingested Amizon tablets 500 mg (as 2 tablets, each tablet containing 250 mg enisamium iodide) after a meal, 3 times a day, for 7 days. Receives: Drug: Enisamium Iodide |
| Group 2 - Placebo | Placebo comparator | Patient who were randomized into Group 2 ingested placebo tablets 500 mg (2 tablets), after a meal 3 times a day, for 7 days. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Efficacy: Number of Participants -- Absence of Objective Symptoms -- Overall
Count of participants WITHOUT objective symptoms -- overall.
Objective symptoms of acute respiratory viral infection (ARVI), including influenza, were monitored: fever, pharyngeal hyperemia, rhinitis, arterial blood pressure, enlarged lymph nodes, auscultation findings for lung and heart. Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
A score system used to assess participants' health. A higher score implies worse outcome.
Objective symptoms scores were: normal or abnormal blood pressure: 0 or 4 score points; lung auscultation: 0 points; vesicular breath sound and wheezing or crepitation 2 or 4 points, respectively; clear and rhythmic heart sounds -- each 0 points; noisy and arrhythmic heart sounds -- each 2 score points.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Days Without Routine Activities -- Summary
Count of participants who had days WITHOUT routine activities.
Disability to perform routine tasks and activities were reported by the participants to the investigator at each study visit.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Viral Antigens -- Overall
Viral antigens that were evaluated: adenovirus, corona virus, influenza A, influenza B, parainfluenza virus, respiratory syncytial virus.
Virus antigens were isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Efficacy assessment was based on the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group.
Results represent the count of participants who did NOT have detectable viral antigens.
Measured: Day 0 (baseline), 3, 7.
Secondary outcomes (24)
Efficacy: Number of Participants -- Absence of Subjective Symptoms -- Overall
Count of participants WITHOUT overall subjective symptoms.
Subjective symptoms of acute respiratory viral infection (ARVI) including influenza, that were monitored: elevated body temperature, chills, cough, headache, myalgia, sore throat, weakness.
Evaluate the number of participants in the treatment and the placebo groups without the subjective symptoms from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of ARVI, including influenza.
The subjective symptoms were assessed using a 4-point Likert scale, ranging from score 1 (absent symptoms ) to score 4 (severe symptoms).
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Subjective Symptom Sum Score (4-point Likert Scale)
Subjective symptom sum score.
Subjective symptoms of acute respiratory viral infection (ARVI) including influenza, that were monitored: elevated body temperature, chills, cough, headache, myalgia, sore throat, weakness.
The subjective symptoms were assessed using a 4-point Likert scale for the individual assessment of the severity of the above 7 symptoms, ranging from absent (0), mild (1), moderate (2), or severe (3).
A higher score implies worse outcome.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Chills
Chills.
Count of participants WITHOUT the subjective symptom: chills.
Evaluate the number of participants in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Cough
Cough.
Count of participants WITHOUT the subjective symptom: cough.
Evaluate the number of participants in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Elevated Body Temperature
Count of participants WITHOUT perceived elevated body temperature.
Evaluate the number of patients in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Sore Throat
Subjective symptoms.
Count of participants WITHOUT the subjective symptom: sore throat.
Evaluate the number of patients in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Headache
Subjective symptoms.
Count of participants WITHOUT the subjective symptom: headache.
Evaluate the number of patients in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Myalgia
Myalgia.
Count of participants WITHOUT the subjective symptom: myalgia.
Evaluate the number of participants in the active treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Weakness
Subjective symptoms.
Count of participants WITHOUT the subjective symptom: weakness.
Evaluate the number of participants in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Objective Symptom -- Body Temperature
Efficacy: Count of participants WITHOUT objective symptom: Body temperature.
Evaluate the number of patients in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
A score system was used to assess patient health, as described under endpoint #1.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Objective Symptom: Body Temperature -- Body Temperature Ranges
Body temperature.
Count of participants in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Clinical improvement was assessed by the investigator, with respect to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Objective Symptom -- Lungs Auscultation
Efficacy: Count of participants WITHOUT objective symptom: Lungs auscultation (abnormal breath sounds, detected using a stethoscope).
Evaluate the number of patients in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start. A score system was used to assess patient health, as described under endpoint #1.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Objective Symptom -- Pharyngeal Hyperemia
Efficacy: Number of participants WITHOUT objective Symptom: Pharyngeal Hyperemia.
Evaluate the number of participants in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start. A score system was used to assess patient health, as described under endpoint #1.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy Objective Symptom: Number of Participants -- Pharyngeal Hyperemia -- Severity
Pharyngeal hyperemia.
Count of participants in the treatment and the placebo groups regarding clinical status from Day 3 after therapy start.
Severity was assessed by the investigator, using a 4-point score scale: 0 = absent; 1 = mild; 2 = moderate; 3 = severe.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Objective Clinical Sum Score
Objective clinical sum score.
Objective symptoms of acute respiratory viral infection (ARVI), were monitored. For the objective clinical sum score, clinical status was assessed by the investigator, relating to the severity of clinical symptoms of ARVI, including influenza.
A score system (score points) that was used to assess participants' health, was based on objective symptoms scores, shown below.
- Blood pressure: normal=0 points; abnormal=4 points.
- Lung auscultation: vesicular breath sound=0 points; wheezing=2 points; crepitation=4 points.
- Heart sound; clear heart sounds=0 points; rhythmic heart sounds=0 points; noisy heart sounds=2 points; arrhythmic heart sounds=2 points.
A higher score implies worse clinical outcome.
Measured: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Viral Antigens -- Baseline Status
Count of randomised participants and their viral antigen types at baseline.
Viral antigens evaluated: adenovirus, corona virus, influenza A (and subtypes), influenza B, parainfluenza virus, respiratory syncytial virus.
Virus antigens were isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Measured: Day 0 (baseline).
Efficacy: Number of Participants -- Viral Antigen -- Influenza Type A
Count of participants who did NOT have a detectable viral antigen -- influenza Type A
Virus antigen was isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Efficacy assessment was the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group.
Measured: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Influenza Type A or Type B
Viral antigen:
Count of participants who did NOT have detectable viral antigen -- influenza Type A or Type B.
Virus antigen was isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Efficacy assessment was the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group.
Measured: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Influenza Type B
Viral antigen:
Number of participants who did NOT have detectable viral antigen -- influenza Type B.
Virus antigen was isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Efficacy assessment was the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group.
Measured: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Adenovirus
Viral antigen:
Count of participants who did NOT have detectable viral antigen -- Adenovirus.
Virus antigen was isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Efficacy assessment was the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group.
Measured: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Viral Antigen Combination
Viral antigen:
Count of participants who did NOT have detectable viral antigen -- viral antigen combination.
Virus antigens were isolated from nasal swabs and detected by using validated immunofluorescence staining methods.
Efficacy assessment was the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group.
Measured: Day 0 (baseline), 3, 7.
Safety - Laboratory Parameters - Immune Status -- Immunoglobulin A, M, G
Assessment of the immune status was performed by evaluating the concentration in blood serum of immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G (IgG).
Determination of IgA, IgM, and IgG was performed by turbidimetry.
Measured: Day 0 (baseline), 7, 14.
Safety - Laboratory Parameters -- Immune Status -- Interferon Alpha (IFN-alpha), Interferon Gamma (IFN-gamma)
Assessment of the immune status was performed by evaluating the concentration in blood serum of IFN-alpha and IFN-gamma.
Determination of interferon alpha (INF-alpha) and interferon gamma (INF-gamma) in human blood serum was carried out using flow cytometer.
Measured: Day 0 (baseline), 7, 14.
Evaluation Health Status: Number of Participants -- Overall Treatment Efficacy (Assessment by Investigator and by Patient)
Overall treatment efficacy.
Evaluate the overall efficacy of the treatment by the investigator and by the participants.
Results show the number of participants for each assessed category of the health status.
Measured: Day 3, 7, 14.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Dec 2020
- Study start13 Apr 2009
- Primary completion15 Jan 2010
- Study completion15 Jan 2010
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 Acute Respiratory Viral InfectionsStudies 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 2/3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 100 participants (actual)
Sponsor and investigators
- Lead sponsor
- Joint Stock Company "Farmak"
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Ekatarina A. Okhapkina, Principal investigator, Smorodintsev Research Institute of Influenza
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04682444
- Sponsor's protocol ID
- AM-STP-2-2008
- Status last verified
- Nov 2025
- First submitted
- 17 Dec 2020
- Last updated
- 8 Jan 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Te Velthuis AJW, Zubkova TG, Shaw M, Mehle A, Boltz D, Gmeinwieser N, Stammer H, Milde J, Muller L, Margitich V. Enisamium Reduces Influenza Virus Shedding and Improves Patient Recovery by Inhibiting Viral RNA Polymerase Activity. Antimicrob Agents Chemother. 2021 Mar 18;65(4):e02605-20. doi: 10.1128/AAC.02605-20. Print 2021 Mar 18.
PubMed 33558285
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Single-blind Comparative Clinical Study of Efficacy and Safety of Amizon 0.25 g Tablets, Manufactured by Farmak JSC, in Patients With ARVI, Including Influenza.
- ClinicalTrials.gov ID
- NCT04682444
- Acronym / sponsor ID
- AM-STP-2-2008
- Keywords
- Viral infections, Amizon, Enisamium iodide, Influenza
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Joint Stock Company "Farmak"Industry (pharma, biotech, devices)
- Study start
- 13 Apr 2009 (actual)
- Primary completion
- 15 Jan 2010 (actual)
- Study completion
- 15 Jan 2010 (actual)
- First posted
- 23 Dec 2020 (actual)
- Results
- Posted 8 Jan 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized, single blind clinical study was conducted to investigate the clinical efficacy and safety of the drug Amizon (enisamium iodide), in comparison with placebo for the treatment of patients with acute respiratory viral infections (ARVI), including influenza. Enisamium iodide is an antiviral small molecule.
Adult patients were enrolled and randomised into 2 groups. On the first day of the onset of symptoms of ARVI, one group of patients took Amizon tablets (active ingredient enisamium iodide) for 7 days; the other group of patients took matching placebo tablets for 7 days. Examination and observation of all participants was done for up to 14 days after the first intake of the study drug.
The effect of treatment was assessed by subjective reporting of the symptoms of ARVI and influenza, using a predefined symptom scale score system.
Objective assessment was performed by measuring vitals signs, laboratory tests (including blood and urine assessment), as well as evaluating the immune status (including measuring the relative concentration of interferon and immunoglobulins).
Detailed description
Numerous studies have shown that influenza vaccines, prepared against the relevant epidemic seasonal vaccine strains, are an effective remedy in prevention of this mass disease and are able to protect about 80% of otherwise healthy children and adults. However, to develop vaccines against the emerging new pandemic strain of the influenza virus and produce them in the necessary amounts requires at least 6 months. During such interim periods, sufficient protection of the population is essential by effective measures for treatment and prevention of influenza.
This randomized, single-blind, clinical study was conducted to investigate the clinical efficacy and safety of the drug Amizon (N-methyl-4-benzylcarbamidopyridinium iodide, international nonproprietary name enisamium iodide) compared with placebo, for the treatment of patients with ARVI, including influenza.
Enisamium iodide is an antiviral small molecule. Enisamium can directly inhibit influenza viral RNA replication.
The study design was: randomised, single-blind, 2 parallel groups. Adult patients (18-60 y) with symptoms of ARVI, including influenza took either Amizon tablets (active ingredient enisamium iodide) for 7 days; in the control group patients took placebo tablets for 7 days. Study visits occurred on Day 0 (screening, examination, check inclusion/exclusion criteria, enrollment, randomization, and first intake of study drug); further study visits were on Day 3, Day 7, and Day 14.
The effect of treatment was assessed by questioning the patients regarding ARVI and influenza symptoms that included pain, headache, general weakness, sore throat, pain in the joints, fatigue, runny and itchy nose. The severity of symptoms was recorded using a 4-point Likert scale.
Further evaluation of the treatment was performed by measuring the vitals signs, laboratory tests that included blood and urine analysis, biochemical analysis, as well as assessing the immune status (including measuring the absolute lymphocytes count, and evaluating the relative concentration of interferon (IFN)-alpha and IFN-gamma, and immunoglobulin (Ig) A, M, and G (IgA, IgM, and IgG).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1 - Active Treatment - Amizon | Experimental | Drug: Enisamium IodidePatient who were randomized into Group 1 ingested Amizon tablets 500 mg (as 2 tablets, each tablet containing 250 mg enisamium iodide) after a meal, 3 times a day, for 7 days. |
| Group 2 - Placebo | Placebo comparator | Drug: PlaceboPatient who were randomized into Group 2 ingested placebo tablets 500 mg (2 tablets), after a meal 3 times a day, for 7 days. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Patients aged between 18 to 60 years
- Patients with ARVI, including influenza, starting not later than for 1 day prior to inclusion in the study:
- The body temperature measured axillary above 37.2 °C
- Presence of one of the signs of respiratory disease (runny nose, cough, pain / tickling in the throat)
- Presence of one of the systemic symptoms (weakness, myalgia, headache , chills, sweating)
Key exclusion criteria (16 listed)
- Age over 60 years and under 18 years old
- Presence of allergic reactions
- Intolerance to NSAIDs and iodine-containing drugs
- Hypersensitivity to the components of the drug
- Mental illness that impedes compliance with the research procedure
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 |
|---|---|---|
| Enisamium IodideAlso: AmizonPatients ingested Amizon tablets without chewing, after meal, as follows: 2 tablets (total dose 500 mg) 3 times a day, for 7 days. Each tablet contains 250 mg of Nmethyl-4-N-methyl-4-benzylcarbamidopyridinium iodide (INN enisamium iodide). | Drug | Group 1 - Active Treatment - Amizon |
| PlaceboPatients ingested placebo tablets without chewing, after meal, in the dose 500 mg (2 tablets), 3 times a day, for 7 days. | Drug | Group 2 - Placebo |
Primary outcome
Efficacy: Number of Participants -- Absence of Objective Symptoms -- Overall
Time frame: Day 0 (baseline), 3, 7, 14.
Count of participants WITHOUT objective symptoms -- overall. Objective symptoms of acute respiratory viral infection (ARVI), including influenza, were monitored: fever, pharyngeal hyperemia, rhinitis, arterial blood pressure, enlarged lymph nodes, auscultation findings for lung and heart. Clinical improvement was assessed by the investigator, relating to the severity of clinical symptoms of acute respiratory viral infection (ARVI), including influenza. A score system used to assess participants' health. A higher score implies worse outcome. Objective symptoms scores were: normal or abnormal blood pressure: 0 or 4 score points; lung auscultation: 0 points; vesicular breath sound and wheezing or crepitation 2 or 4 points, respectively; clear and rhythmic heart sounds -- each 0 points; noisy and arrhythmic heart sounds -- each 2 score points.
Efficacy: Number of Participants -- Days Without Routine Activities -- Summary
Time frame: Day 0 (baseline), 3, 7, 14.
Count of participants who had days WITHOUT routine activities. Disability to perform routine tasks and activities were reported by the participants to the investigator at each study visit.
Efficacy: Number of Participants -- Viral Antigens -- Overall
Time frame: Day 0 (baseline), 3, 7.
Viral antigens that were evaluated: adenovirus, corona virus, influenza A, influenza B, parainfluenza virus, respiratory syncytial virus. Virus antigens were isolated from nasal swabs and detected by using validated immunofluorescence staining methods. Efficacy assessment was based on the determination of viral antigen on treatment days (Day 3 and Day 7) compared with the baseline (Day 0) in the active treatment group and the placebo group. Results represent the count of participants who did NOT have detectable viral antigens.
24 secondary outcomes
Efficacy: Number of Participants -- Absence of Subjective Symptoms -- Overall
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Subjective Symptom Sum Score (4-point Likert Scale)
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Chills
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Cough
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Elevated Body Temperature
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Sore Throat
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Headache
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Myalgia
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Subjective Symptom -- Weakness
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Objective Symptom -- Body Temperature
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Objective Symptom: Body Temperature -- Body Temperature Ranges
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Objective Symptom -- Lungs Auscultation
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Absence of Objective Symptom -- Pharyngeal Hyperemia
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy Objective Symptom: Number of Participants -- Pharyngeal Hyperemia -- Severity
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Objective Clinical Sum Score
Time frame: Day 0 (baseline), 3, 7, 14.
Efficacy: Number of Participants -- Viral Antigens -- Baseline Status
Time frame: Day 0 (baseline).
Efficacy: Number of Participants -- Viral Antigen -- Influenza Type A
Time frame: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Influenza Type A or Type B
Time frame: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Influenza Type B
Time frame: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Adenovirus
Time frame: Day 0 (baseline), 3, 7.
Efficacy: Number of Participants -- Viral Antigen -- Viral Antigen Combination
Time frame: Day 0 (baseline), 3, 7.
Safety - Laboratory Parameters - Immune Status -- Immunoglobulin A, M, G
Time frame: Day 0 (baseline), 7, 14.
Safety - Laboratory Parameters -- Immune Status -- Interferon Alpha (IFN-alpha), Interferon Gamma (IFN-gamma)
Time frame: Day 0 (baseline), 7, 14.
Evaluation Health Status: Number of Participants -- Overall Treatment Efficacy (Assessment by Investigator and by Patient)
Time frame: Day 3, 7, 14.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jan 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 33558285Te Velthuis AJW, Zubkova TG, Shaw M, Mehle A, Boltz D, Gmeinwieser N, Stammer H, Milde J, Muller L, Margitich V. Enisamium Reduces Influenza Virus Shedding and Improves Patient Recovery by Inhibiting Viral RNA Polymerase Activity. Antimicrob Agents Chemother. 2021 Mar 18;65(4):e02605-20. doi: 10.1128/AAC.02605-20. Print 2021 Mar 18.
- Individual participant dataSharing planned: No
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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.
Ekatarina A. Okhapkina principal investigator
Smorodintsev Research Institute of Influenza
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Enisamium Iodide in people with Acute Respiratory Viral Infections and Human Influenza, run by Joint Stock Company "Farmak".
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 7 inclusion and 16 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 8 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
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 combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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 8 Jan 2026). 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?
Efficacy: Number of Participants -- Absence of Objective Symptoms -- Overall (time frame: Day 0 (baseline), 3, 7, 14.). The study lists 3 primary outcomes in all. 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 NCT04682444, 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 8 Jan 2026.