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Not yet recruitingNCT07881991Updated Oct 20, 2026

Phase 2 Study of SYH2066 Tablets Compared With Placebo in Chinese Adult Patients With Respiratory Syncytial Virus Infection.

A Phase 2 interventional study of SYH2066 and Placebo in Respiratory Syncytial Virus Infections, sponsored by CSPC Ouyi Pharmaceutical Co., Ltd.. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 85 Years. Per ClinicalTrials.gov, last updated 2026-10-20.

Sponsored by CSPC Ouyi Pharmaceutical Co., Ltd. (part of CSPC Pharmaceutical Group Limited) · Phase 2, Interventional, and Treatment

Updated Oct 20, 2026Newly registeredGo to Updates ↓
Phase
Phase 2
Study type
Interventional
Enrollment
80
Allocation
Randomized
Ages
18 Years to 85 Years
Sex
All
01

Study summary

This study is a multicenter, randomized, double-blind, placebo-controlled Phase II clinical trial designed to evaluate the efficacy, safety, and pharmacokinetic profile of SYH2066 tablets in adult patients with RSV infection. Approximately 80 adult patients with RSV infection are expected to be enrolled and assigned to three active treatment groups and one placebo group, with approximately 20 eligible participants per group. The study consists of a 3-day screening period, a 5-day treatment period, and an 8- to 10-day follow-up period. Throughout the study, safety assessments, PK blood sampling, nasopharyngeal (NP) swab collection, and RSV symptom recording will be performed

02

Conditions studied

  • Respiratory Syncytial Virus Infections
03

In context

Respiratory Syncytial Virus Infections

302 studies on the registry are indexed under Respiratory Syncytial Virus Infections; 48 are open to participants now.

This study's planned enrollment of 80 is below the median of 89 across 219 interventional studies indexed under Respiratory Syncytial Virus Infections.

Browse Respiratory Syncytial Virus Infections studies →

Lead sponsor

CSPC Ouyi Pharmaceutical Co., Ltd. is the lead sponsor of 30 studies on the registry; 15 are open to participants now.

Browse CSPC Ouyi Pharmaceutical Co., Ltd. studies →All CSPC Pharmaceutical Group Limited studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 85 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Participants must meet all of the following criteria to be eligible for enrollment in this study:

  • 1. Aged 18 to 85 years (inclusive), male or female.
  • 2. Body mass index (BMI) between 18 kg/m² and 35 kg/m² (inclusive).

  • 3. Presence of at least one of the following newly occurring respiratory tract infection symptoms or systemic symptoms (total symptom score ≥3 points); or worsening of pre-existing respiratory symptoms (total symptom score ≥3 points and an increase of at least 2 points from baseline):

    • Respiratory symptoms: cough, sore throat, nasal congestion, wheezing (whistling sound during breathing), cough with phlegm, and shortness of breath;
    • Systemic symptoms: headache, feeling feverish, body aches, fatigue, neck pain, sleep disturbance, and loss of appetite.
  • 4. Onset of RSV infection symptoms or worsening of pre-existing non-RSV infection symptoms meeting criterion 3 at enrollment, occurring within ≤72 hours prior to the first dose.
  • 5. Diagnosis of RSV infection confirmed by antigen or RT-PCR testing within 36 hours prior to the first dose.
  • 6. Participants and their partners agree to have no pregnancy plan and no sperm/egg donation plan from screening until 3 months after the last administration of the investigational product, and voluntarily agree to use effective contraceptive measures.
  • 7. Participants voluntarily participate in the study and sign the informed consent form (ICF).

Exclusion criteria

Exclusion Criteria:

Participants meeting any of the following criteria will be excluded from this study:

  • 1. Patients with definite diagnosis of pneumonia.
  • 2. Known concomitant acute respiratory infection other than RSV (e.g., influenza, COVID-19, mycoplasma) within 3 days prior to screening.
  • 3. Known severe gastrointestinal diseases affecting absorption of the study drug (e.g., severe persistent vomiting, malabsorption syndrome, short-bowel syndrome due to necrotizing enterocolitis, etc.).
  • 4. Any of the following cardiovascular or cerebrovascular events within 6 months prior to screening: unstable angina requiring hospitalization, myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention (diagnostic angiography and PCI performed >3 months ago are permitted), heart failure (NYHA Class III or IV), atrial or ventricular arrhythmias requiring hospitalization (e.g., atrial fibrillation, ventricular tachycardia, etc.), pacemaker or defibrillator implantation, transient ischemic attack, or cerebrovascular event (e.g., stroke); or planned revascularization procedures (e.g., coronary artery bypass surgery) during the study.
  • 5. Awaiting or having received bone marrow transplantation, stem cell transplantation, or solid organ transplantation within 1 year prior to screening.
  • 6. History of current or previous malignancy (except for malignancies that are well controlled and do not affect the study progress or efficacy evaluation, such as completely resected basal cell carcinoma of the skin, carcinoma in situ of the cervix, or thyroid cancer).
  • 7. Severe or uncontrolled concomitant diseases, including but not limited to autoimmune, cardiovascular, hematologic, respiratory, hepatobiliary, gastrointestinal, endocrine, urinary, psychiatric, or neurologic disorders, which, in the investigator's judgment, would increase the risk to the participant if enrolled.
  • 8. History of drug abuse, drug addiction, and/or alcohol abuse within 6 months prior to screening (alcohol abuse defined as weekly consumption of >14 units of alcohol: 1 unit = 360 mL beer, or 45 mL of 40% spirits, or 150 mL wine).
  • 9. Known allergy to the study drug or its components.
  • 10. Use of medications that may affect the efficacy or mechanism of the study drug within 5 half-lives prior to randomization (per the drug label; if half-life is unclear, within 7 days prior to randomization) or planned use during the study, including but not limited to: systemic antivirals (ribavirin, interferons, etc., excluding nucleos(t)ide analogues for hepatitis B and direct-acting antivirals for hepatitis C), inhaled corticosteroids (except for COPD and asthma patients on stable prior inhaled corticosteroid therapy), immunomodulators, and Chinese herbal medicines with antiviral activity, etc.
  • 11. Participation in another clinical trial within 3 months (or 5 half-lives, whichever is longer) prior to screening (except for those not receiving any intervention).
  • 12. At screening, clinical laboratory values meeting the following criteria: ALT ≥3×ULN or AST ≥3×ULN; serum TBIL ≥1.5×ULN.
  • 13. Positive HIV-Ab test result.
  • 14. Positive pregnancy test or breastfeeding female patients.
  • 15. Patients who, after instruction by the investigator, are still unable to complete the Respiratory Infection Severity and Impact Questionnaire.
  • 16. Any other condition that, in the investigator's judgment, makes the participant unsuitable for participation in the study.

Additional exclusion criteria for COPD participants:

  • 17. Acute exacerbation of COPD within 6 weeks prior to screening requiring treatment with systemic corticosteroids and/or antibiotics, or emergency room visit or hospitalization.
  • 18. More than 3 acute exacerbations of COPD in the past 12 months.
  • 19. Resting pulse oximetry (SpO₂) reading \<88% at screening, or long-term oxygen therapy (i.e., prescribed for ≥12 hours per day).
05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
80 participants (estimated)

Study arms

  • Experimental
    SYH2066 low dose

    Eligible participants will receive the protocol-specified dose orally for 5 days.

    Drug: SYH2066

  • Experimental
    SYH2066 medium dose

    Eligible participants will receive the protocol-specified dose orally for 5 days.

    Drug: SYH2066

  • Experimental
    SYH2066 high dose

    Eligible participants will receive the protocol-specified dose orally for 5 days.

    Drug: SYH2066

  • Placebo comparator
    Placebo

    Eligible participants will receive the protocol-specified dose orally for 5 days.

    Drug: Placebo

Interventions

  • DrugSYH2066

    Protocol-specified dose of SYH2066 tablets administered orally for 5 days.

  • DrugPlacebo

    Protocol-specified dose of placebo tablets administered orally for 5 days.

06

What researchers measure

Primary outcomes

  1. Area under the curve (AUC) of RSV RNA viral load measured by RT-qPCR in nasopharyngeal swab samples

    Nasopharyngeal swabs will be taken from Day 1 to Day 14 for RSV RNA quantification, and the area under the RSV RNA load-time curve will be derived from the measured values plotted against time.

    Time frame: Up to Day 14

Secondary outcomes

  1. Change from baseline in RSV RNA viral load at each visit （D2, D3, D4, D5, D6, D9, D14, ETV）during the study period

    Time frame: Up to Day 14

  2. Time from first dose to RSV RNA viral load falling below the lower limit of quantification (LLOQ)

    Time frame: Up to Day 14

  3. Percentage of participants with RSV RNA viral load below LLOQ from first dose

    Time frame: Up to Day 14

  4. Area under the curve (AUC) of the Respiratory Infection Severity and Impact Questionnaire score from Day 1 to Day 14

    Participants need complete the RIIQ questionnaire daily from Day 1 through Day 14, and the area under the time-based score curve will be estimated.

    Time frame: Up to Day 14

  5. Change from baseline in the Respiratony Infection Severity and lmpact Questionnaire score at each visit (02, D3,D4,D5, D6, D9, D14, ETV) after first dose

    Respiratory Infection Severity and Impact Questionnaire(RiiQ questionnaire) is mainly used to assess RSV symptoms in patients, including upper respiratory tract infection symptoms (sore throat and nasal congestion), symptoms of lower respiratory tract infection (cough, wheezing, sputum, shortness of breath), and system symptoms (fever, headache, neck pain, fatigue, lack of appetite, interrupted sleep, body aches). The questionnaire is divided into four grading categories of severity including none (0), mild (1), moderate (2) and severe (3).

    Time frame: Up to Day 14

  6. Time from first dose to resolution/recovery of all RSV symptoms

    Resolution/recovery of all RSV symptoms is defined as the concurrent fulfillment of all predefined symptom criteria as specified below, with the response sustained for ≥48 hours: * For symptoms not present before infection: reduction to a score of 0; * For symptoms present before infection: return to pre-infection level or better. RSV symptoms include following: 2 upper respiratory (stuffy nose, sore throat), 4 lower respiratory (cough, expectoration, wheezing, shortness of breath), and 7 systemic (feeling feverish, headache, body aches/pains, neck pain, trouble sleeping, tiredness, poor appetite).

    Time frame: Up to Day 14

  7. Time from first dose to relief of all RSV symptoms

    Relief of all RSV symptoms is defined as the concurrent fulfillment of all predefined symptom criteria as specified below, with the response sustained for ≥48 hours: * For symptoms not present before infection: reduction to a score of 0 or 1; * For symptoms present before infection and worsened by the current RSV infection: improvement of at least 1 point from baseline (pre-treatment); * For symptoms present before infection but not worsened by the current infection: maintained at pre-infection level or better. RSV symptoms include following: 2 upper respiratory (stuffy nose, sore throat), 4 lower respiratory (cough, expectoration, wheezing, shortness of breath), and 7 systemic (feeling feverish, headache, body aches/pains, neck pain, trouble sleeping, tiredness, poor appetite).

    Time frame: Up to Day 14

  8. Time-weighted average burden of RSV core symptoms (nasal congestion, body aches, sore throat, and cough with phlegm) over 0-96 h post-first dose

    It is defined as the AUC of the core symptom burden curve over 0-96 h divided by 96 h, where lower values indicate less overall symptom burden or faster improvement.

    Time frame: Up to Day 14

  9. Incidence and severity of adverse events (AEs)

    Any abnormalities in vital signs, physical examinations, laboratory tests, 12-lead electrocardiograms (ECGs), or other parameters observed in participants post-dose will be recorded as AEs.

    Time frame: Up to Day 14

  10. Time from first dose to resolution/recovery of RSV core symptoms (nasal congestion, body aches, sore throat, cough with phlegm)

    Resolution/recovery of RSV core symptoms is defined as the concurrent fulfillment of RSV core symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0; * For symptoms present before infection: return to pre-infection level or better.

    Time frame: Up to Day 14

  11. Time from first dose to resolution/recovery of respiratory symptoms

    Resolution/recovery of respiratory symptoms is defined as the concurrent fulfillment of respiratory symptoms criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0; * For symptoms present before infection: return to pre-infection level or better. Respiratory symptoms include following：stuffy nose, sore throat, cough, expectoration, wheezing, shortness of breath.

    Time frame: Up to Day 14

  12. Time from first dose to resolution/recovery of lower respiratory tract symptoms

    Resolution/recovery of lower respiratory tract is defined as the concurrent fulfillment of lower respiratory tract symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0; * For symptoms present before infection: return to pre-infection level or better. Lower respiratory tract symptoms include following: cough, expectoration, wheezing, shortness of breath.

    Time frame: Up to Day 14

  13. Time from first dose to resolution/recovery of upper respiratory tract symptoms

    Resolution/recovery of upper respiratory tract is defined as the concurrent fulfillment of upper respiratory tract symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0; * For symptoms present before infection: return to pre-infection level or better. Upper respiratory tract symptoms include following: stuffy nose, sore throat.

    Time frame: Up to Day 14

  14. Time from first dose to resolution/recovery of systemic symptoms

    Resolution/recovery of systemic symptoms is defined as the concurrent fulfillment of systemic symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0; * For symptoms present before infection: return to pre-infection level or better. Systemic symptoms include following: feeling feverish, headache, body aches/pains, neck pain, trouble sleeping, tiredness, poor appetite.

    Time frame: Up to Day 14

  15. Time from first dose to relief of RSV core symptoms (nasal congestion, body aches, sore throat, cough with phlegm)

    Relief of RSV core symptoms is defined as the concurrent fulfillment of RSV core symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0 or 1; * For symptoms present before infection and worsened by the current RSV infection: improvement of at least 1 point from baseline (pre-treatment); * For symptoms present before infection but not worsened by the current infection: maintained at pre-infection level or better.

    Time frame: Up to Day 14

  16. Time from first dose to relief of respiratory symptoms

    Relief of respiratory symptoms is defined as the concurrent fulfillment of respiratory symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0 or 1; * For symptoms present before infection and worsened by the current RSV infection: improvement of at least 1 point from baseline (pre-treatment); * For symptoms present before infection but not worsened by the current infection: maintained at pre-infection level or better. Respiratory symptoms include following: stuffy nose, sore throat, cough, expectoration, wheezing, shortness of breath.

    Time frame: Up to Day 14

  17. Time from first dose to relief of lower respiratory tract symptoms

    Relief of lower respiratory tract symptoms is defined as the concurrent fulfillment of lower respiratory tract symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0 or 1; * For symptoms present before infection and worsened by the current RSV infection: improvement of at least 1 point from baseline (pre-treatment); * For symptoms present before infection but not worsened by the current infection: maintained at pre-infection level or better. Lower respiratory tract symptoms include following: cough, expectoration, wheezing, shortness of breath.

    Time frame: Up to Day 14

  18. Time from first dose to relief of upper respiratory tract symptoms

    Relief of upper respiratory tract symptoms is defined as the concurrent fulfillment of upper respiratory tract symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0 or 1; * For symptoms present before infection and worsened by the current RSV infection: improvement of at least 1 point from baseline (pre-treatment); * For symptoms present before infection but not worsened by the current infection: maintained at pre-infection level or better. Upper respiratory tract symptoms include following: stuffy nose, sore throat.

    Time frame: Up to Day 14

  19. Time from first dose to relief of systemic symptoms

    Relief of systemic symptoms is defined as the concurrent fulfillment of systemic symptom criteria as specified below, with the response sustained for ≥24 hours: * For symptoms not present before infection: reduction to a score of 0 or 1; * For symptoms present before infection and worsened by the current RSV infection: improvement of at least 1 point from baseline (pre-treatment); * For symptoms present before infection but not worsened by the current infection: maintained at pre-infection level or better. Systemic symptoms include following: feeling feverish, headache, body aches/pains, neck pain, trouble sleeping, tiredness, poor appetite.

    Time frame: Up to Day 14

  20. Change from baseline in MxA expression levels at each visit (D2, D3, D4, D5, D6, ETV) during the study

    Time frame: Up to Day 14

  21. Peak plasma concentration (Cmax)

    Time frame: Up to Day 14

  22. Time to maximum plasma concentration (Tmax)

    Time frame: Up to Day 14

  23. Terminal elimination half-life (t½)

    Time frame: Up to Day 14

  24. Apparent clearance (CL/F)

    Time frame: Up to Day 14

  25. Area under the plasma concentration-time curve

    Time frame: Up to Day 14

07

Study locations

1 site
  • China-Japan Friendship Hospital
    Beijing, Beijing Municipality, China
08

Updates

1 registry update since Sep 25, 2026
Registered
First appeared on the registry. No changes since
Oct 20, 2026
Show all 1 update
  1. Oct 20, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

09

Registry details

Key details

Study ID
NCT07881991
Lead sponsor
CSPC Ouyi Pharmaceutical Co., Ltd.
Responsible party
Sponsor
First posted
Oct 20, 2026
Start date
Nov 13, 2026 (estimated)
Primary completion
Dec 31, 2027 (estimated)
Completion
Mar 31, 2028 (estimated)
Last update
Oct 20, 2026

Study contacts

Clinical Trials Information Group NA officer
Contact
ctr-contact@cspc.cn
86+0311-69085587

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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