How safe PN-881 is and how it behaves in healthy adults

A Randomized, Double-Blind, Placebo-Controlled Study of Single and Multiple Ascending Doses of PN-881 in Healthy Subjects

This will test the safety, tolerability, and how the body absorbs and clears PN-881 in healthy adults.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 142 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: Protagonist Therapeutics, Inc. (Industry-sponsored)
• Locations: 1 site (Melbourne, Victoria)
• Trial ID: NCT07153146 on ClinicalTrials.gov

What this trial studies

Healthy adults aged 18–65 with BMI 18–32 will receive PN-881 as oral solution or tablet in a five-part Phase 1 program. Parts 1 and 2 are randomized, double-blind, placebo-controlled single and multiple ascending dose cohorts to define safety, tolerability, pharmacokinetics, and pharmacodynamics. Parts 3 and 4 are open-label crossover comparisons of tablet formulations and fed versus fasted conditions to characterize formulation and food effects, and Part 5 is an open-label randomized comparison of once-daily versus twice-daily dosing. Participants must be medically healthy, off other medications, and attend clinic visits at the Melbourne site for supervised dosing and serial blood sampling.

Who should consider this trial

Good fit: Healthy adults 18–65 years old with BMI 18–32 who are medically well, not taking other medications, and who agree to contraception and study procedures are ideal candidates.

Not a fit: People with significant cardiovascular, hepatic, renal, neurological, psychiatric, or other medical conditions, positive hepatitis/HIV tests, recent infection, substance abuse history, pregnancy or childbearing potential, or current medication use would not be expected to benefit and are excluded.

Why it matters

Potential benefit: If PN-881 is safe and shows predictable pharmacokinetics, the data could enable further clinical development that may lead to new treatments in later trials.

How similar studies have performed: This five-part Phase 1 format is a standard, well-established approach for first-in-human safety and PK/PD testing, although PN-881 itself appears novel and not previously reported in published human studies.

Eligibility criteria

Inclusion Criteria:

1. Healthy male and female participants of non-childbearing potential, aged 18-65 years inclusive
2. Body mass index (BMI) between 18 and 32 kg/m² (inclusive) at screening
3. Willing and able to comply with all study requirements and provide written informed consent
4. Male participants with female partners of childbearing potential must agree to use highly effective contraception during the study and for 90 days after the last dose

Exclusion Criteria:

1. Clinically significant history or presence of cardiovascular, gastrointestinal, hepatic, renal, neurological, psychiatric, or allergic diseases
2. History of neoplastic disease (except adequately treated non-melanoma skin cancer)
3. Positive test for hepatitis B, hepatitis C, or HIV at screening
4. History of substance abuse or recreational IV drug use within the past 2 years
5. Clinically significant infection or fever (\>38°C) within 2 weeks prior to screening
6. Use of any prescription/non-prescription drugs or herbal supplements within 7 days or 5 half-lives before dosing (unless approved by investigator)
7. Supine blood pressure or ECG abnormalities outside protocol-defined ranges
8. Use of tobacco/nicotine products exceeding 5 cigarettes/day or 2 chews/day
9. Consumption of \>21 alcohol units/week (males) or \>14 units/week (females)

Where this trial is running

Melbourne, Victoria

• Nucleus Network — Melbourne, Victoria, Australia (Recruiting)

Study contacts

• Study coordinator: Clinical Study Director

Conditions Healthy Volunteer; PN-881