A Phase 1, SAD and MAD Study to Evaluate the Safety and Tolerability of FB418

A Phase 1, Randomized, Double-Blind, Placebo-Controlled, SAD and MAD Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Oral FB418 in Healthy Adult Subjects and Healthy Elderly Subjects

A Phase 1, SAD and MAD Study to Evaluate the Safety and Tolerability of FB418 (NCT05995782) is a Phase 1 interventional studying Parkinson Disease Psychosis and Amyotrophic Lateral Sclerosis (ALS), sponsored by 1ST Biotherapeutics, Inc.. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The purpose of this study is to evaluate the safety, tolerability and pharmacokinetics and pharmacodynamics of oral doses of FB418 in healthy adult subjects and healthy elderly subjects.

What Stage of Research Is This?

Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For Parkinson Disease Psychosis, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 64 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Parkinson Disease Psychosis subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Key Who May Qualify: 1. Healthy, adult, male 19 55 years of age, inclusive, at the screening. 2. For elderly subjects(Part A Cohort 5 only), healthy, elderly, male or female (of non childbearing potential only) over 60 years of age, inclusive, at screening. 3. In the case of the elderly(Part A Cohort 5 only), they have a history of mild disease, but can participate if the researcher judges that they can stop taking the drug at least 2 weeks before the expected first dose or before the half-life is 5 times or more) 4. The continuous non smoker who have not used nicotine containing products for at least 3 months prior to (the first) dosing and throughout the study are based on subjective self reporting. 5. Body mass index (BMI) ≥ 18 and ≤ 32 kg/m2 at the screening. 6. Medically healthy with no clinically significant medical history, physical examination, simplified neurological examination, laboratory profiles, vital signs or ECGs, as deemed by the PI or designee. 7. In Cohort 5, A female subject must be of non childbearing potential Key Who Should NOT Join This Trial: 1. Is mentally or legally incapacitated or has significant emotional problems at the time of the screening visit or expected during the conduct of the study. 2. History or presence of a clinically significant medical or psychiatric condition or disease in the opinion of the PI or designee. 3. History of any illness that, in the opinion of the PI or designee, might confound the results of the study or poses an additional risk to the subject by their participation in the study. 4. Is at suicidal risk in the opinion of the PI as per the following criteria: 1. Any suicide attempts within 12 months prior to screening or any suicidal intent, including a plan, within 3 months prior to screening. 2. C-SSRS answer of "YES" on suicidal ideation within 3 months prior to screening. 5. History or presence of alcoholism or drug abuse within the past 2 years prior to (the first) dosing. ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Key Inclusion Criteria: 1. Healthy, adult, male 19 55 years of age, inclusive, at the screening. 2. For elderly subjects(Part A Cohort 5 only), healthy, elderly, male or female (of non childbearing potential only) over 60 years of age, inclusive, at screening. 3. In the case of the elderly(Part A Cohort 5 only), they have a history of mild disease, but can participate if the researcher judges that they can stop taking the drug at least 2 weeks before the expected first dose or before the half-life is 5 times or more) 4. The continuous non smoker who have not used nicotine containing products for at least 3 months prior to (the first) dosing and throughout the study are based on subjective self reporting. 5. Body mass index (BMI) ≥ 18 and ≤ 32 kg/m2 at the screening. 6. Medically healthy with no clinically significant medical history, physical examination, simplified neurological examination, laboratory profiles, vital signs or ECGs, as deemed by the PI or designee. 7. In Cohort 5, A female subject must be of non childbearing potential Key Exclusion Criteria: 1. Is mentally or legally incapacitated or has significant emotional problems at the time of the screening visit or expected during the conduct of the study. 2. History or presence of a clinically significant medical or psychiatric condition or disease in the opinion of the PI or designee. 3. History of any illness that, in the opinion of the PI or designee, might confound the results of the study or poses an additional risk to the subject by their participation in the study. 4. Is at suicidal risk in the opinion of the PI as per the following criteria: 1. Any suicide attempts within 12 months prior to screening or any suicidal intent, including a plan, within 3 months prior to screening. 2. C-SSRS answer of "YES" on suicidal ideation within 3 months prior to screening. 5. History or presence of alcoholism or drug abuse within the past 2 years prior to (the first) dosing. 6. History or presence of hypersensitivity or idiosyncratic reaction to the study drug or related compounds. 7. History of seizures (childhood febrile seizures are excepted). 8. Positive urine drug or alcohol results at screening or check in. 9. Has an abnormal screening ECG indicating a second- or third- degree AV block, or one or more of the following: QRS \> 120 msec, QTcF \> 450 msec for males and \> 460 msec for females, PR interval \> 220 msec. Any rhythm other than normal sinus rhythm, which is interpreted by the PI or designee to be clinically significant at screening or check-in. 10. Has any medical or surgical condition in which lumbar puncture is contraindicated in the opinion of the PI.

Treatments Being Tested

DRUG

FB418

Oral dose

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Seoul National University

Seoul, South Korea

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05995782), the sponsor (1ST Biotherapeutics, Inc.), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05995782 clinical trial studying?

The purpose of this study is to evaluate the safety, tolerability and pharmacokinetics and pharmacodynamics of oral doses of FB418 in healthy adult subjects and healthy elderly subjects. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05995782?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05995782?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05995782. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05995782. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.