HealthyPhase 1NCT06425861
A First in Human Trial Evaluating THB335 in Healthy Participants
A Phase 1 study testing THB335 single dose, THB335 fasted/fed and THB335 multiple dose in people with Healthy, run by Third Harmonic Bio, Inc. at 1 site in United States.
Trial summary
This study is a double blind, randomized, placebo-controlled, Phase 1 study in three parts: single ascending doses and food effect (Part 1), multiple ascending doses (Part 2) and Relative Bioavailability of Two Formulations (Part 3). Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- THB335 single dose, THB335 fasted/fed and THB335 multiple dose
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 2 May 2024to 18 Dec 2024
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- In good health, determined by no clinically significant findings from medical history, 12 lead electrocardiogram (ECG), vital sign measurements, and clinical laboratory evaluations
- Males or females, of any race, between 18 and 65 years of age, inclusive.
- Participants must understand the nature of the study and must provide signed and dated written informed consent in accordance with local regulations before the conduct of any study related procedures
- Body weight of ≥ 50.0 kg for men and ≥ 45.0 kg for women and Body Mass Index (BMI) of 17.5-32.0 kg/m2 (inclusive) at Screening
Who cannot join
- Significant history or clinical manifestation of cancer or any metabolic, allergic, dermatological, hepatic, biliary, renal, hematological, pulmonary, cardiovascular, gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder
- Vaccinated within 14 days prior to Day -1 or intention to receive vaccination during the study
- A positive urine drug screen/alcohol breath test
- The participant currently smokes, vapes, or uses nicotine-containing products.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Randomized, Double-Blind, Placebo-Controlled, Phase 1, Single and Multiple Ascending Dose Study to Assess the Safety, Pharmacokinetics, Pharmacodynamics, and Food Effect of THB335 in Healthy Participants
This study is a double blind, randomized, placebo-controlled, Phase 1 study in three parts: single ascending doses and food effect (Part 1), multiple ascending doses (Part 2) and Relative Bioavailability of Two Formulations (Part 3).
Read the detailed description
THB335 is a highly potent and selective inhibitor of the receptor tyrosine kinase KIT that is expressed on mast cells.
The study will evaluate the safety, pharmacokinetics, pharmacodynamics, and food effect profile of THB335 administered orally in healthy participants.
- Conditions
- Healthy
- Being tested
- THB335 single dose, Single dose placebo, THB335 fasted/fed, Placebo fasted/fed, THB335 multiple dose
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
THB335 single doseDrug
Single dose as oral capsule
Single dose placeboDrug
Single dose as oral capsule
THB335 fasted/fedDrug
Single dose fasted and fed as oral capsule
Placebo fasted/fedDrug
Single dose fasted and fed as oral capsule
THB335 multiple doseDrug
Multiple ascending doses oral capsule
Multiple dose placeboDrug
Multiple doses oral capsule
| Study group | Role | What they receive |
|---|---|---|
| THB335 single dose | Experimental | Single dose of THB335 fasted Receives: Drug: THB335 single dose |
| THB335 fasted and fed | Experimental | Single dose of THB335 fasted and then fed Receives: Drug: THB335 fasted/fed |
| THB335 multiple dose | Experimental | 14 days of multiple ascending doses of THB335 Receives: Drug: THB335 multiple dose |
| Single dose placebo | Placebo comparator | Single dose of placebo capsule, fasted Receives: Drug: Single dose placebo |
| Fasted and fed placebo | Placebo comparator | Single dose of placebo capsule fasted and then fed Receives: Drug: Placebo fasted/fed |
| Multiple dose placebo | Placebo comparator | 14 days of multiple doses of placebo capsule Receives: Drug: Multiple dose placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with Treatment-Related Adverse Events
Measured: Part 1 Day 1 through Day 9 (end of study), and Part 2 Day 1 through Day 29 (end of study)
Secondary outcomes (3)
Maximum observed plasma concentration (Cmax)
Measured: Part 1, and Part 2 on Day 1. Part 2 on Day 14
Time to Cmax (Tmax)
Measured: Part 1, and Part 2 on Day 1. Part 2 on Day 14
Area under the plasma concentration-time curve (AUC)
Measured: Part 1, and Part 2 on Day 1. Part 2 on Day 14
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 May 2024
- Study start2 May 2024
- Primary completion18 Dec 2024
- Study completion18 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Third Harmonic Bio, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Principal Investigator, Principal investigator, QPS Holdings LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06425861
- Sponsor's protocol ID
- THB335-101
- Status last verified
- Dec 2025
- First submitted
- 15 May 2024
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-Blind, Placebo-Controlled, Phase 1, Single and Multiple Ascending Dose Study to Assess the Safety, Pharmacokinetics, Pharmacodynamics, and Food Effect of THB335 in Healthy Participants
- ClinicalTrials.gov ID
- NCT06425861
- Acronym / sponsor ID
- THB335-101
- Conditions
- Healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Third Harmonic Bio, Inc.Industry (pharma, biotech, devices)
- Study start
- 2 May 2024 (actual)
- Primary completion
- 18 Dec 2024 (actual)
- Study completion
- 18 Dec 2024 (actual)
- First posted
- 22 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a double blind, randomized, placebo-controlled, Phase 1 study in three parts: single ascending doses and food effect (Part 1), multiple ascending doses (Part 2) and Relative Bioavailability of Two Formulations (Part 3).
Detailed description
THB335 is a highly potent and selective inhibitor of the receptor tyrosine kinase KIT that is expressed on mast cells.
The study will evaluate the safety, pharmacokinetics, pharmacodynamics, and food effect profile of THB335 administered orally in healthy participants.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| THB335 single dose | Experimental | Drug: THB335 single doseSingle dose of THB335 fasted |
| THB335 fasted and fed | Experimental | Drug: THB335 fasted/fedSingle dose of THB335 fasted and then fed |
| THB335 multiple dose | Experimental | Drug: THB335 multiple dose14 days of multiple ascending doses of THB335 |
| Single dose placebo | Placebo comparator | Drug: Single dose placeboSingle dose of placebo capsule, fasted |
| Fasted and fed placebo | Placebo comparator | Drug: Placebo fasted/fedSingle dose of placebo capsule fasted and then fed |
| Multiple dose placebo | Placebo comparator | Drug: Multiple dose placebo14 days of multiple doses of placebo capsule |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- In good health, determined by no clinically significant findings from medical history, 12 lead electrocardiogram (ECG), vital sign measurements, and clinical laboratory evaluations
- Males or females, of any race, between 18 and 65 years of age, inclusive.
- Participants must understand the nature of the study and must provide signed and dated written informed consent in accordance with local regulations before the conduct of any study related procedures
- Body weight of ≥ 50.0 kg for men and ≥ 45.0 kg for women and Body Mass Index (BMI) of 17.5-32.0 kg/m2 (inclusive) at Screening
Key exclusion criteria (4 listed)
- Significant history or clinical manifestation of cancer or any metabolic, allergic, dermatological, hepatic, biliary, renal, hematological, pulmonary, cardiovascular, gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder
- Vaccinated within 14 days prior to Day -1 or intention to receive vaccination during the study
- A positive urine drug screen/alcohol breath test
- The participant currently smokes, vapes, or uses nicotine-containing products.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| THB335 single doseSingle dose as oral capsule | Drug | THB335 single dose |
| Single dose placeboSingle dose as oral capsule | Drug | Single dose placebo |
| THB335 fasted/fedSingle dose fasted and fed as oral capsule | Drug | THB335 fasted and fed |
| Placebo fasted/fedSingle dose fasted and fed as oral capsule | Drug | Fasted and fed placebo |
| THB335 multiple doseMultiple ascending doses oral capsule | Drug | THB335 multiple dose |
| Multiple dose placeboMultiple doses oral capsule | Drug | Multiple dose placebo |
Primary outcome
Number of Participants with Treatment-Related Adverse Events
Time frame: Part 1 Day 1 through Day 9 (end of study), and Part 2 Day 1 through Day 29 (end of study)
3 secondary outcomes
Maximum observed plasma concentration (Cmax)
Time frame: Part 1, and Part 2 on Day 1. Part 2 on Day 14
Time to Cmax (Tmax)
Time frame: Part 1, and Part 2 on Day 1. Part 2 on Day 14
Area under the plasma concentration-time curve (AUC)
Time frame: Part 1, and Part 2 on Day 1. Part 2 on Day 14
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Principal Investigator principal investigator
QPS Holdings LLC
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing THB335 single dose, THB335 fasted/fed and THB335 multiple dose in people with Healthy, run by Third Harmonic Bio, Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants with Treatment-Related Adverse Events (time frame: Part 1 Day 1 through Day 9 (end of study), and Part 2 Day 1 through Day 29 (end of study)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025.