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

NCT07881991 | Not Yet Recruiting Phase 2

• 1 other identifier: SYH2066-002
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief 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

Conditions

Respiratory Syncytial Virus Infections

Outcome Measures

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.

  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

  Up to Day 14

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

  Up to Day 14

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

  Up to Day 14

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

  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

  Up to Day 14

Study Arms (4)

SYH2066 low dose

EXPERIMENTAL

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

Drug: SYH2066

SYH2066 medium dose

EXPERIMENTAL

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

Drug: SYH2066

SYH2066 high dose

EXPERIMENTAL

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

Drug: SYH2066

Placebo

PLACEBO COMPARATOR

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

Drug: Placebo

Interventions

SYH2066 DRUG

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

SYH2066 high dose; SYH2066 low dose; SYH2066 medium dose

Placebo DRUG

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

Placebo

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participants must meet all of the following criteria to be eligible for enrollment in this study:
• \. Aged 18 to 85 years (inclusive), male or female.
• \. Body mass index (BMI) between 18 kg/m² and 35 kg/m² (inclusive).
• \. 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.
• \. 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.
• \. Diagnosis of RSV infection confirmed by antigen or RT-PCR testing within 36 hours prior to the first dose.
• \. 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.
• \. Participants voluntarily participate in the study and sign the informed consent form (ICF).

You may not qualify if:

• Participants meeting any of the following criteria will be excluded from this study:
• \. Patients with definite diagnosis of pneumonia.
• \. Known concomitant acute respiratory infection other than RSV (e.g., influenza, COVID-19, mycoplasma) within 3 days prior to screening.
• \. 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.).
• \. 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.
• \. Awaiting or having received bone marrow transplantation, stem cell transplantation, or solid organ transplantation within 1 year prior to screening.
• \. 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).
• \. 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.
• \. 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).
• \. Known allergy to the study drug or its components.
• \. 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.
• \. 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).
• \. At screening, clinical laboratory values meeting the following criteria: ALT ≥3×ULN or AST ≥3×ULN; serum TBIL ≥1.5×ULN.
• \. Positive HIV-Ab test result.
• \. Positive pregnancy test or breastfeeding female patients.

Sponsors & Collaborators

• CSPC Ouyi Pharmaceutical Co., Ltd.: lead

Study Sites (1)

China-Japan Friendship Hospital

Beijing, Beijing Municipality, China

Location

MeSH Terms

Conditions

Respiratory Syncytial Virus Infections

Condition Hierarchy (Ancestors)

Pneumovirus Infections; Paramyxoviridae Infections; Mononegavirales Infections; RNA Virus Infections; Virus Diseases; Infections

Central Study Contacts

Clinical Trials Information Group NA officer

CONTACT

86+0311-69085587; ctr-contact@cspc.cn

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: multicenter, randomized, parallel-group, placebo-controlled study

Study Record Dates

• First Submitted: October 11, 2026
• First Posted: October 20, 2026
• Study Start (Estimated): November 13, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): March 31, 2028
• Last Updated: October 20, 2026

Record last verified: 2026-10

Locations

CN (1)