Healthy Study ParticipantsPhase 1NCT05845645

A Study to Test Bioavailability of of 2 New Formulations of UCB0599 in Healthy Participants in Part A and to Test Safety, Tolerability, and Pharmacokinetic (PK) of UCB0599 in Healthy Japanese and Chinese Participants in Part B

A Phase 1 study testing UCB0599 and Esomeprazole in people with Healthy Study Participants, run by UCB Biopharma SRL at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

The purpose of the study is to estimate the relative bioavailability of 2 new UCB0599 formulations under elevated and normal gastric pH conditions in healthy participants (Part A) and to asess the safety, tolerability and pharmacokinetics of UCB0599 in healthy participants of Japanese and Chinese origins (Part B). Read more about this study

Who is it for?: Ages 18 to 55 yearsHealthy volunteers can take part
Conditions the study is for: Healthy Study Participants
What is being tested?: UCB0599 and Esomeprazole
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 73 participants
Where: 1 siteUnited States
Study dates: 31 May 2023to 13 Apr 2024
Phase: Phase 1
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 55 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

Part A only: all healthy study participants except for those participants who are eligible for Part B of the study
For participants of Japanese origin (Part B): study participant is of Japanese descent as evidenced by appearance and verbal confirmation of familial heritage (a participant has all 4 Japanese grandparents born in Japan). For participants of Chinese origin (Part B): study participant is of Chinese descent as evidenced by appearance and verbal confirmation of familial heritage (a participant has all 4 Chinese grandparents born in China).
Body weight within 45 to 100 kg (female) and 50 to 100 kg (male) and body mass index (BMI) within the range 18 to 30 kg/m^2 (inclusive at screening)
Healthy male and female study participants

Who cannot join

Participant has any medical or psychiatric condition that, in the opinion of the Investigator, could jeopardize or would compromise the study participant's ability to participate in this study
Participant has a history or presence of/significant history of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrinological, hematological, or neurological disorders capable of significantly altering the absorption, metabolism, or elimination of drugs; constituting a risk when taking the study intervention; or interfering with the interpretation of data
Participant has had lymphoma, leukemia, or any malignancy within the past 5 years, except for basal cell carcinomas that have been resected, squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 3 years
Participant has had breast cancer within the past 10 years
Participant has a history of alcohol or drug abuse within the last 1 year from Screening, as defined according to the Diagnostic and Statistical Manual of Mental Disorders
Participant has a known hypersensitivity to any components of the study medication or comparative drugs as stated in this protocol

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Participant has a consumption of more than 600 mg of caffeine/day at screening and throughout the study
Participant has consumed any grapefruit, grapefruit juice, grapefruit-containing products, or star fruit within 14 days prior to administration of study medication or is not willing to refrain from consuming these products for the duration of the study
Participant has previously participated in this study or participant has previously been assigned to treatment in a study of the medication under investigation in this study
Participant has participated in another study of a study medication (and/or an investigational device) within the previous 30 days or 5 half-lives, whichever is greatest, or is currently participating in another study of an study medication (and/or an investigational device)
Presence of hepatitis B surface antigen (HBsAg) at screening or within 3 months prior to dosing
Positive hepatitis C antibody test (HCVAb) result at screening or within 3 months prior to starting study intervention
Positive hepatitis C ribonucleic acid (RNA) test result at screening or within 3 months prior to first dose of study medication
Current or chronic history of liver disease or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones)
For women of childbearing potential, study participant is pregnant, planning on becoming pregnant during the study, or is breastfeeding
Participants who may have a history of confirmed gastric ulceration

Trial locations and contacts

1 site in 1 country.

United States1 site

Up0073 10001
Glendale, California, 91206

Other trials in United States

About this study

Official title: A 2-Part Study to Evaluate the Relative Bioavailability of 2 New Formulations of UCB0599 and the Effect of Esomeprazole on the PK of UCB0599 in Healthy Participants (Part A, Open-Label) and to Assess the Safety/Tolerability and PK of UCB0599 in Healthy Participants of Japanese and Chinese Origins (Part B, Double-Blind)

Conditions: Healthy Study Participants
Being tested: UCB0599, Esomeprazole, Placebo
Keywords: Phase 1, Healthy Study Participants, UCB0599, Bioavailability study

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

UCB0599Drug
Study participants will receive pre-specified doses of UCB0599 in 3 different formulations administered orally in a pre-specified sequence during the Treatment Periods of Part A and B
EsomeprazoleOther
Study participants will receive fixed dose of esomeprazole administered orally in a pre-specified sequence during the Treatment Period of Part A. This is a non-investigational medicinal product (NIMP) in this study.
PlaceboOther
Also called PBO
Study participants will receive placebo comparator administered orally in a a pre-specified sequence during the Treatment Period of Part B.

Study groups in NCT05845645
Study group	Role	What they receive
Part A	Experimental	Study participants enrolled and randomized to this arm will receive a single dose of UCB0599 in 3 different formulations according to a pre-specified sequence during both Treatment Periods in the absence of esomeprazole, and the Treatment Periods in the presence of esomeprazole. Receives: Drug: UCB0599; Other: Esomeprazole
Part B	Experimental	Study participants enrolled to this arm will receive pre-specified doses of UCB0599 or Placebo in a pre-specified sequence during the Treatment Period. Receives: Drug: UCB0599; Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Maximum Plasma Concentration (Cmax) of UCB0599 in Part A
Cmax was maximum (peak) observed drug concentration following a single dose administration of UCB0599 under normal and elevated gastric pH condition.
Measured: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A
Area Under the Plasma Concentration-time Curve From Time 0 to the Last Quantifiable Concentration (AUC(0-t)) of UCB0599 in Part A
AUC(0-t) was area under the plasma concentration-time curve from time 0 to the last quantifiable concentration of UCB0599 under normal and elevated gastric pH condition.
Measured: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A
Area Under the Plasma Concentration-time Curve From Time 0 to Infinity (AUC Inf) of UCB0599 in Part A
AUC inf was area under the plasma concentration-time curve from time 0 to infinity of UCB0599 under normal and elevated gastric pH condition.
Measured: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A
Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) in Part B
An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study medication, whether or not considered related to the study medication. A TEAE was defined as AEs starting on/after the date/time of first treatment \& upto including 4 days after last treatment or any unresolved event already present before administration of treatment that worsens in intensity following exposure to treatment.
Measured: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15)
Percentage of Study Participants With Serious Treatment-emergent Adverse Events (Serious TEAEs) in Part B
Serious TEAEs were any untoward medical incidence in a participant during administered study treatment, whether or not these events were related to study treatment and additionally were emergent untoward medical occurrence that at any dose:
1. Results in death
2. Is life-threatening
3. Required in patient hospitalisation or prolongation of existing hospitalisation
4. Results in persistent disability/incapacity
5. Was a congenital anomaly or birth defect
6. Important medical events
Measured: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15)
Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) Leading to Withdrawal From Study in Part B
: An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study medication, whether or not considered related to the study medication. A TEAE was defined as AEs starting on/after the date/time of first treatment \& upto including 4 days after last treatment or any unresolved event already present before administration of treatment that worsens in intensity following exposure to treatment.
Measured: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15)
Maximum Plasma Concentration (Cmax) of UCB0599 in Part B
Cmax was maximum (peak) observed drug concentration following a single dose administration of UCB0599.
Measured: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, and 6 in Part B
Area Under the Plasma Concentration-time Curve From Time 0 to the Last Quantifiable Concentration (AUC(0-t)) of UCB0599 in Part B
AUC(0-t) was area under the plasma concentration-time curve from time 0 to the last quantifiable concentration of UCB0599.
Measured: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, and 6 in Part B
Area Under the Plasma Concentration-time Curve From Time 0 to Infinity (AUC (Inf)) of UCB0599 in Part B
AUC inf was area under the plasma concentration-time curve from time 0 to infinity of UCB0599.
Measured: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, and 6 in Part B

Secondary outcomes (3)

Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) in Part A
An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study medication, whether or not considered related to the study medication. A TEAE was defined as AEs starting on/after the date/time of first treatment \& upto including 4 days after last treatment or any unresolved event already present before administration of treatment that worsens in intensity following exposure to treatment.
Measured: From Baseline (Day 1) to Safety Follow-up Period of Part A (up to Day 39)
Percentage of Study Participants With Serious Treatment-emergent Adverse Events (TEAEs) in Part A
Serious TEAEs were any untoward medical incidence in a participant during administered study treatment, whether or not these events were related to study treatment and additionally were emergent untoward medical occurrence that at any dose:
1. Results in death
2. Is life-threatening
3. Required in patient hospitalisation or prolongation of existing hospitalisation
4. Results in persistent disability/incapacity
5. Was a congenital anomaly or birth defect
6. Important medical events
Measured: From Baseline (Day 1) to Safety Follow-up Period of Part A (up to Day 39)
Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) Leading to Withdrawal From Study in Part A
Measured: From Baseline (Day 1) to Safety Follow-up Period of Part A (up to Day 39)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

31 May 202313 Apr 2024

First posted6 May 2023
Study start31 May 2023
Primary completion13 Apr 2024
Study completion13 Apr 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Healthy Study ParticipantsStudies of the same condition, open and under way.
More trials run by UCB Biopharma SRLThe sponsor's other registered studies.
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: Basic science
Allocation: Randomised
Intervention model: Crossover
Model description: Part A of the study is following a full crossover design and Part B is a parallel design with crossover character referring to the dose levels.
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 73 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05845645
Sponsor's protocol ID: UP0073
Status last verified: Dec 2025
First submitted: 25 Apr 2023
Last updated: 22 Dec 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No: Due to the small sample size in this trial, IPD cannot be adequately anonymized i.e., there is a reasonable likelihood that individual participants could be re-identified. For this reason, data from this trial cannot be shared.

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 22 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A 2-Part Study to Evaluate the Relative Bioavailability of 2 New Formulations of UCB0599 and the Effect of Esomeprazole on the PK of UCB0599 in Healthy Participants (Part A, Open-Label) and to Assess the Safety/Tolerability and PK of UCB0599 in Healthy Participants of Japanese and Chinese Origins (Part B, Double-Blind)
ClinicalTrials.gov ID: NCT05845645
Acronym / sponsor ID: UP0073
Conditions: Healthy Study Participants
Keywords: Phase 1, Healthy Study Participants, UCB0599, Bioavailability study
Phase: Phase 1
Study type: Interventional
Recruitment status: Completed
Enrolment: 73 participants (actual)
Lead sponsor: UCB Biopharma SRLIndustry (pharma, biotech, devices)
Study start: 31 May 2023 (actual)
Primary completion: 13 Apr 2024 (actual)
Study completion: 13 Apr 2024 (actual)
First posted: 6 May 2023 (actual)
Results: Posted 22 Dec 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose: Basic science
Allocation: Randomised
Intervention model: Crossover
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 2
Model description: Part A of the study is following a full crossover design and Part B is a parallel design with crossover character referring to the dose levels.

Arm	Type	Receives
Part A	Experimental	Drug: UCB0599, Other: EsomeprazoleStudy participants enrolled and randomized to this arm will receive a single dose of UCB0599 in 3 different formulations according to a pre-specified sequence during both Treatment Periods in the absence of esomeprazole, and the Treatment Periods in the presence of esomeprazole.
Part B	Experimental	Drug: UCB0599, Other: PlaceboStudy participants enrolled to this arm will receive pre-specified doses of UCB0599 or Placebo in a pre-specified sequence during the Treatment Period.

Who may qualify

Ages: 18 to 55 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (4 listed)

Part A only: all healthy study participants except for those participants who are eligible for Part B of the study
For participants of Japanese origin (Part B): study participant is of Japanese descent as evidenced by appearance and verbal confirmation of familial heritage (a participant has all 4 Japanese grandparents born in Japan). For participants of Chinese origin (Part B): study participant is of Chinese descent as evidenced by appearance and verbal confirmation of familial heritage (a participant has all 4 Chinese grandparents born in China).
Body weight within 45 to 100 kg (female) and 50 to 100 kg (male) and body mass index (BMI) within the range 18 to 30 kg/m^2 (inclusive at screening)
Healthy male and female study participants

Key exclusion criteria (16 listed)

Participant has any medical or psychiatric condition that, in the opinion of the Investigator, could jeopardize or would compromise the study participant's ability to participate in this study
Participant has a history or presence of/significant history of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrinological, hematological, or neurological disorders capable of significantly altering the absorption, metabolism, or elimination of drugs; constituting a risk when taking the study intervention; or interfering with the interpretation of data
Participant has had lymphoma, leukemia, or any malignancy within the past 5 years, except for basal cell carcinomas that have been resected, squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 3 years
Participant has had breast cancer within the past 10 years
Participant has a history of alcohol or drug abuse within the last 1 year from Screening, as defined according to the Diagnostic and Statistical Manual of Mental Disorders

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
UCB0599Study participants will receive pre-specified doses of UCB0599 in 3 different formulations administered orally in a pre-specified sequence during the Treatment Periods of Part A and B	Drug	Part A, Part B
EsomeprazoleStudy participants will receive fixed dose of esomeprazole administered orally in a pre-specified sequence during the Treatment Period of Part A. This is a non-investigational medicinal product (NIMP) in this study.	Other	Part A
PlaceboAlso: PBOStudy participants will receive placebo comparator administered orally in a a pre-specified sequence during the Treatment Period of Part B.	Other	Part B

Primary outcome

Maximum Plasma Concentration (Cmax) of UCB0599 in Part A
Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A
Cmax was maximum (peak) observed drug concentration following a single dose administration of UCB0599 under normal and elevated gastric pH condition.
Area Under the Plasma Concentration-time Curve From Time 0 to the Last Quantifiable Concentration (AUC(0-t)) of UCB0599 in Part A
Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A
AUC(0-t) was area under the plasma concentration-time curve from time 0 to the last quantifiable concentration of UCB0599 under normal and elevated gastric pH condition.
Area Under the Plasma Concentration-time Curve From Time 0 to Infinity (AUC Inf) of UCB0599 in Part A
Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A
AUC inf was area under the plasma concentration-time curve from time 0 to infinity of UCB0599 under normal and elevated gastric pH condition.
Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) in Part B
Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15)
An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study medication, whether or not considered related to the study medication. A TEAE was defined as AEs starting on/after the date/time of first treatment \& upto including 4 days after last treatment or any unresolved event already present before administration of treatment that worsens in intensity following exposure to treatment.
Percentage of Study Participants With Serious Treatment-emergent Adverse Events (Serious TEAEs) in Part B
Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15)
Serious TEAEs were any untoward medical incidence in a participant during administered study treatment, whether or not these events were related to study treatment and additionally were emergent untoward medical occurrence that at any dose: 1. Results in death 2. Is life-threatening 3. Required in patient hospitalisation or prolongation of existing hospitalisation 4. Results in persistent disability/incapacity 5. Was a congenital anomaly or birth defect 6. Important medical events
Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) Leading to Withdrawal From Study in Part B
Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15)
: An AE was any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study medication, whether or not considered related to the study medication. A TEAE was defined as AEs starting on/after the date/time of first treatment \& upto including 4 days after last treatment or any unresolved event already present before administration of treatment that worsens in intensity following exposure to treatment.
Maximum Plasma Concentration (Cmax) of UCB0599 in Part B
Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, and 6 in Part B
Cmax was maximum (peak) observed drug concentration following a single dose administration of UCB0599.
Area Under the Plasma Concentration-time Curve From Time 0 to the Last Quantifiable Concentration (AUC(0-t)) of UCB0599 in Part B
Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, and 6 in Part B
AUC(0-t) was area under the plasma concentration-time curve from time 0 to the last quantifiable concentration of UCB0599.
Area Under the Plasma Concentration-time Curve From Time 0 to Infinity (AUC (Inf)) of UCB0599 in Part B
Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, and 6 in Part B
AUC inf was area under the plasma concentration-time curve from time 0 to infinity of UCB0599.

3 secondary outcomes

Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) in Part A
Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part A (up to Day 39)
Percentage of Study Participants With Serious Treatment-emergent Adverse Events (TEAEs) in Part A
Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part A (up to Day 39)
Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) Leading to Withdrawal From Study in Part A
Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part A (up to Day 39)

Results and safety

Results posted to the registry on 22 Dec 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Part A: Treatment Sequence: ABC	7	7
Part A: Treatment Sequence: ACB	7	7
Part A: Treatment Sequence: BCA	7	7
Part A: Treatment Sequence: BAC	7	7
Part A: Treatment Sequence: CAB	7	7
Part A: Treatment Sequence: CBA	7	7
Part B: Treatment Sequence: Placebo 90 mg/Placebo 180 mg	0	0
Part B: Treatment Sequence: UCB0599 90 mg/UCB0599 180 mg	0	0
Part B: Treatment Sequence: Placebo 180 mg/Placebo 360 mg	0	0
Part B: Treatment Sequence: UCB0599 180 mg/ UCB0599 360 mg	0	0
Part B: Treatment Sequence:Placebo 360 mg/Placebo 90 mg	0	0
Part B: Treatment Sequence: UCB0599 360 mg/ UCB0599 90 mg	0	0

Primary outcome: Maximum Plasma Concentration (Cmax) of UCB0599 in Part A

Time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A. Geometric mean (Geometric Coefficient of Variation). Unit: nanograms per milliliter (ng/mL)

Measure	Part A: UCB0599: Capsule 180 mg n = 42	Part A: UCB0599: Non-encapsulated Tablet 180 mg n = 42	Part A: UCB0599: Encapsulated Tablet 180 mg n = 42
Normal	876.2 (30.2)	724.6 (39.4)	618.0 (38.2)
Elevated	449.3 (54.9)	694.4 (43.8)	631.4 (42.8)

Part A: UCB0599: Capsule 180 mg vs Part A: UCB0599: Non-encapsulated Tablet 180 mg: GLSM Ratio: 0.8269 (90% CI 0.7535 to 0.9076)
Part A: UCB0599: Capsule 180 mg vs Part A: UCB0599: Encapsulated Tablet 180 mg: GLSM ratio: 0.7053 (90% CI 0.6427 to 0.7741)
Part A: UCB0599: Non-encapsulated Tablet 180 mg vs Part A: UCB0599: Encapsulated Tablet 180 mg: GLSM ratio: 0.8529 (90% CI 0.7771 to 0.9361)

Population analysed: Pharmacokinetic Set Part A (PKS A) included all randomized participants who received at least 1 total dose of study medication and have at least 1 observable PK measurement. Here, "number analyzed" signifies participants who were evaluable for specified categories.

Primary outcome: Area Under the Plasma Concentration-time Curve From Time 0 to the Last Quantifiable Concentration (AUC(0-t)) of UCB0599 in Part A

Measure	Part A: UCB0599: Capsule 180 mg n = 42	Part A: UCB0599: Non-encapsulated Tablet 180 mg n = 42	Part A: UCB0599: Encapsulated Tablet 180 mg n = 42
Normal	5774 (35.5)	5503 (41.0)	5324 (43.1)
Elevated	5489 (49.2)	5779 (43.9)	5641 (41.3)

Part A: UCB0599: Capsule 180 mg vs Part A: UCB0599: Non-encapsulated Tablet 180 mg: GLSM ratio: 0.9529 (90% CI 0.9052 to 1.003)
Part A: UCB0599: Capsule 180 mg vs Part A: UCB0599: Encapsulated Tablet 180 mg: GLSM ratio: 0.9220 (90% CI 0.8758 to 0.9706)
Part A: UCB0599: Non-encapsulated Tablet 180 mg vs Part A: UCB0599: Encapsulated Tablet 180 mg: GLSM ratio: 0.9676 (90% CI 0.9191 to 1.019)

Population analysed: PKS A included all randomized participants who received at least 1 total dose of study medication and have at least 1 observable PK measurement. Here, "number analyzed" signifies participants who were evaluable for specified categories.

Primary outcome: Area Under the Plasma Concentration-time Curve From Time 0 to Infinity (AUC Inf) of UCB0599 in Part A

Measure	Part A: UCB0599: Capsule 180 mg n = 40	Part A: UCB0599: Non-encapsulated Tablet 180 mg n = 39	Part A: UCB0599: Encapsulated Tablet 180 mg n = 42
Normal	5829 (36.8)	5561 (42.3)	5374 (44.5)
Elevated	5538 (49.5)	5835 (44.9)	5720 (41.4)

Part A: UCB0599: Capsule 180 mg vs Part A: UCB0599: Non-encapsulated Tablet 180 mg: GLSM ratio: 0.9519 (90% CI 0.9011 to 1.006)
Part A: UCB0599: Capsule 180 mg vs Part A: UCB0599: Encapsulated Tablet 180 mg: GLSM ratio: 0.9255 (90% CI 0.8762 to 0.9777)
Part A: UCB0599: Non-encapsulated Tablet 180 mg vs Part A: UCB0599: Encapsulated Tablet 180 mg: GLSM ratio: 0.9723 (90% CI 0.9204 to 1.027)

Population analysed: PKS A included all randomized participants who received at least 1 total dose of study medication and have at least 1 observable PK measurement. Here, "overall number of participants analyzed" signifies participants who were evaluable for this outcome measure and "number analyzed" signifies participants who were evaluable for specified categories.

Primary outcome: Percentage of Study Participants With Treatment-emergent Adverse Events (TEAEs) in Part B

Time frame: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15). Number. Unit: percentage of participants

Measure	Part B: Pooled Placebo (Japanese Participants) n = 3	Part B: UCB0599 90 mg (Japanese Participants) n = 8	Part B: UCB0599 180 mg (Japanese Participants) n = 8	Part B: UCB0599 360 mg (Japanese Participants) n = 8	Part B: Pooled Placebo (Chinese Participants) n = 3	Part B: UCB0599 90 mg (Chinese Participants) n = 8	Part B: UCB0599 180 mg (Chinese Participants) n = 9	Part B: UCB0599 360 mg (Chinese Participants) n = 8
Value	33.3	25.0	0	0	33.3	12.5	33.3	25.0

Population analysed: Safety Set Part B (SS B) included all study participants who were randomized and received full or partial study medication according to the treatment that the participants actually received.

3 secondary outcomes are reported in the full results.

Adverse events

Time frame: For Part A: From Baseline (Day 1) of Part A until Safety Follow-Up (up to Day 39) and for Part B: From Baseline (Day 1) to Safety Follow-up Period of Part B (up to Day 15). Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Part A: UCB0599 180 mg/Day Capsules	0 of 42 (0%)	5 of 42 (11.9%)	0 of 42
Part A: UCB0599: Non-encapsulated Tablet 180 mg	0 of 42 (0%)	11 of 42 (26.2%)	0 of 42
Part A: UCB0599 180 mg/Day Encapsulated Tablets	0 of 42 (0%)	6 of 42 (14.3%)	0 of 42
Part B: Pooled Placebo (Japanese Participants)	0 of 3 (0%)	1 of 3 (33.3%)	0 of 3
Part B: UCB0599 90 mg (Japanese Participants)	0 of 8 (0%)	2 of 8 (25%)	0 of 8
Part B: UCB0599 180 mg (Japanese Participants)	0 of 8 (0%)	0 of 8 (0%)	0 of 8
Part B: UCB0599 360mg (Japanese Participants)	0 of 8 (0%)	0 of 8 (0%)	0 of 8
Part B: Pooled Placebo (Chinese Participants)	0 of 3 (0%)	1 of 3 (33.3%)	0 of 3
Part B: UCB0599 90 mg (Chinese Participants)	0 of 8 (0%)	1 of 8 (12.5%)	0 of 8
Part B: UCB0599 180 mg (Chinese Participants)	0 of 9 (0%)	3 of 9 (33.3%)	0 of 9
Part B: UCB0599 360 mg (Chinese Participants)	0 of 8 (0%)	2 of 8 (25%)	0 of 8

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 22 Dec 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No. Due to the small sample size in this trial, IPD cannot be adequately anonymized i.e., there is a reasonable likelihood that individual participants could be re-identified. For this reason, data from this trial cannot be shared.

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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.

UCB Cares study director

001 844 599 2273 (UCB)

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 UCB0599 and Esomeprazole in people with Healthy Study Participants, run by UCB Biopharma SRL 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 16 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 22 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. 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?

Yes. Results are posted in the registry (first posted 22 Dec 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Maximum Plasma Concentration (Cmax) of UCB0599 in Part A (time frame: Predose and at 0.25, 0.5, 1, 1.5, 2, 4, 8, 12, 24, 36, 48, 72, and 96 hours after UCB0599 administration on Days 1, 6, 11, 19, 24 and 29 in Part A). The study lists 9 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05845645.

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 22 Dec 2025.