Respiratory Syncytial Virus InfectionsPhase 2NCT07881991
Phase 2 Study of SYH2066 Tablets Compared With Placebo in Chinese Adult Patients With Respiratory Syncytial Virus Infection.
A Phase 2 study testing SYH2066 in people with Respiratory Syncytial Virus Infections, run by CSPC Ouyi Pharmaceutical Co., Ltd. at 1 site in China.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Respiratory Syncytial Virus Infections
- What is being tested?
- SYH2066
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 80 participants
- Where
- 1 siteChina
- Study dates
- 13 Nov 2026to 31 Mar 2028
- Phase
- Phase 2
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 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
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- 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).
Who cannot join
- 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.
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- 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).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
China-Japan Friendship Hospital
Beijing, Beijing Municipality
Bin NA Cao, 86+010-84206086, caobin_ben@163.com
About this study
Official title: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Phase 2 Study to Evaluate the Efficacy, Safety, and Pharmacokinetic Profile of SYH2066 Tablets in Adult Participants With Respiratory Syncytial Virus Infection.
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
- Conditions
- Respiratory Syncytial Virus Infections
- Being tested
- SYH2066, Placebo
- Medical subject headings
- Respiratory Syncytial Virus Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SYH2066Drug
Protocol-specified dose of SYH2066 tablets administered orally for 5 days.
PlaceboDrug
Protocol-specified dose of placebo tablets administered orally for 5 days.
| Study group | Role | What they receive |
|---|---|---|
| SYH2066 low dose | Experimental | Eligible participants will receive the protocol-specified dose orally for 5 days. Receives: Drug: SYH2066 |
| SYH2066 medium dose | Experimental | Eligible participants will receive the protocol-specified dose orally for 5 days. Receives: Drug: SYH2066 |
| SYH2066 high dose | Experimental | Eligible participants will receive the protocol-specified dose orally for 5 days. Receives: Drug: SYH2066 |
| Placebo | Placebo comparator | Eligible participants will receive the protocol-specified dose orally for 5 days. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: Up to Day 14
Secondary outcomes (25)
Change from baseline in RSV RNA viral load at each visit （D2, D3, D4, D5, D6, D9, D14, ETV）during the study period
Measured: Up to Day 14
Time from first dose to RSV RNA viral load falling below the lower limit of quantification (LLOQ)
Measured: Up to Day 14
Percentage of participants with RSV RNA viral load below LLOQ from first dose
Measured: Up to Day 14
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.
Measured: Up to Day 14
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).
Measured: Up to Day 14
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).
Measured: Up to Day 14
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).
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
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.
Measured: Up to Day 14
Change from baseline in MxA expression levels at each visit (D2, D3, D4, D5, D6, ETV) during the study
Measured: Up to Day 14
Peak plasma concentration (Cmax)
Measured: Up to Day 14
Time to maximum plasma concentration (Tmax)
Measured: Up to Day 14
Terminal elimination half-life (t½)
Measured: Up to Day 14
Apparent clearance (CL/F)
Measured: Up to Day 14
Area under the plasma concentration-time curve
Measured: Up to Day 14
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Oct 2026
- Study start13 Nov 2026 (estimated)
- Primary completion31 Dec 2027 (estimated)
- Study completion31 Mar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Respiratory Syncytial Virus 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
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- multicenter, randomized, parallel-group, placebo-controlled study
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- CSPC Ouyi Pharmaceutical Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07881991
- Sponsor's protocol ID
- SYH2066-002
- Status last verified
- Oct 2026
- First submitted
- 11 Oct 2026
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No