RSS0343 safety and how the body processes it in healthy adults

A Randomized, Double-blind, Placebo-controlled Phase I Clinical Study to Evaluate the Safety, Tolerability and Pharmacokinetics of RSS0343 Following Multiple Oral Doses in Healthy Subjects, as Well as Its Effects on the QT/QTc Interval

This trial will test whether multiple oral doses of RSS0343 are safe, well‑tolerated, and how the drug is processed in healthy adults, including any effects on heart rhythm (QT/QTc).

Quick facts

• Phase: PHASE1
• Study type: Interventional
• Enrollment: 48 (estimated)
• Ages: 18 Years to 55 Years
• Sex: All
• Sponsor: Reistone Biopharma Company Limited (industry)
• Locations: 1 site (Wuhan, Hubei)
• Trial ID: NCT07289464 on ClinicalTrials.gov

What this trial studies

This Phase 1, single‑center trial gives multiple oral doses of RSS0343 or matching placebo to healthy adult volunteers to characterize safety, tolerability, and pharmacokinetics. Participants will undergo scheduled clinical assessments and ECG monitoring to detect any effects on the QT/QTc interval. Enrollment requires specified age, weight, and BMI ranges and adherence to contraception and smoking restrictions. The sponsor is Reistone Biopharma and the study site is Zhongnan Hospital of Wuhan University in Wuhan, Hubei, China.

Who should consider this trial

Good fit: Healthy men and women aged 18–55 years with BMI 19–28 and minimum weight thresholds who do not smoke heavily and agree to the study contraception requirements are the intended participants.

Not a fit: Individuals with active respiratory disease, pregnant or breastfeeding women, heavy smokers, people outside the age/BMI/weight limits, or those with disqualifying health conditions are unlikely to benefit from participation.

Why it matters

Potential benefit: If RSS0343 is safe and shows acceptable pharmacokinetics, it could move forward as a potential oral therapy for conditions such as non‑cystic fibrosis bronchiectasis.

How similar studies have performed: Phase 1 safety and pharmacokinetic studies of oral respiratory candidates are standard and often establish dosing and safety, but effectiveness of RSS0343 for bronchiectasis has not yet been demonstrated.

Eligibility criteria

Inclusion Criteria:

1. Subjects who provided written informed consent after being fully informed of the trial's purpose, significance, and protocol requirements.
2. Healthy individuals aged 18 to 55 years, inclusive. Males and females
3. Body weight ≥ 50 kg for males and ≥ 45 kg for females. Body mass index (BMI) = weight (kg)/height 2 (m²). BMI between 19 and 28 kg/m², inclusive.
4. Fertile male and female subjects and their partners must agree to use highly effective contraception as stipulated in the protocol, from screening until 6 months (for females) or 3 months (for males) after the last dose. Additionally, fertile female subjects must have a negative serum pregnancy test at screening and prior to the first dose (baseline) and must not be lactating.

Exclusion Criteria:

1. Subjects who smoked more than 5 cigarettes (or equivalent nicotine products) daily within 3 months prior to screening or intended to use tobacco products during the trial.
2. Subjects with frequent alcohol consumption (\>15 g/day for females or \>25 g/day for males \[5g of alcohol is equivalent to 150 mL of beer, 50 mL of wine or approximately 17 mL of low-alcohol liquor\], on more than 2 occasions per week) within 6 months prior to screening, or were unable to abstain during the trial, or who tested positive on the alcohol breath test at baseline.
3. Subjects with a history of, or current, drug abuse, or drug dependence (during consultation), or with a positive urine drug screening result.
4. Subjects who had donated blood or experienced a total blood loss of ≥200 mL within 1 month, or ≥400 mL within 3 months prior to dosing, or who had received a blood transfusion within 8 weeks prior to dosing.
5. Subjects with dysphagia; or a history of needle or blood phobia, poor venous access, or inability to tolerate venipuncture.
6. Subjects deemed by the investigators to be unsuitable for the trial for any other reason.
7. Subjects with any clinically significant abnormalities, as determined by the investigator, in physical examination, vital signs, laboratory tests (including hematology, urinalysis, blood biochemistry, coagulation), chest imaging, abdominal ultrasonography, or electrocardiogram.
8. Subjects who tested positive for hepatitis B surface antigen, hepatitis C antibody, syphilis antibody or HIV antibody.
9. Subjects with a known or suspected allergy to the investigational drug or its excipients, or a history of severe allergic reactions (e.g., to drugs, food, toxins).
10. Subjects with any active autoimmune disease or immunodeficiency at screening.
11. Subjects with any history of severe clinical disease, or any condition that, in the investigator's judgment, could compromise trial outcomes, affect drug absorption, distribution, metabolism, or excretion (pharmacokinetics), or pose an undue risk to the subject. This includes, but is not limited to, significant disorders of the circulatory, endocrine, nervous, digestive, urinary, hematological, immune, psychiatric, or metabolic systems.
12. Subjects who had undergone any surgery within 3 months prior to screening, had not fully recovered as determined by the investigator, or planned to undergo surgery during the trial or within 1 month after its completion.

Where this trial is running

Wuhan, Hubei

• Zhongnan Hospital of Wuhan University — Wuhan, Hubei, China (RECRUITING)

Study contacts

• Study coordinator: Ye Xu

Conditions: Non-cystic Fibrosis Bronchiectasis