Healthy VolunteersPhase 1/2NCT07641634
A Phase 1/2 Study of PRO-203 in Healthy Volunteers and Participants With Systemic Sclerosis.
A Phase 1/2 study testing PRO-203 in people with Healthy Volunteers and Systemic Sclerosis (SSc), run by Prolium Bioscience, Inc at 13 sites in 4 countries.
Trial summary
A two-part study of PRO-203 administered subcutaneously in healthy adult volunteers and participants with Systemic Sclerosis (SSc). Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Healthy Volunteers, Systemic Sclerosis (SSc), Scleroderma, Systemic
- What is being tested?
- PRO-203
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 44 participants
- Where
- 13 sitesin 4 countries
- Study dates
- 27 Oct 2025to Jan 2028
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
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
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Is male or female, age 18 to 65 years, inclusive, at Screening.
- Able to provide Informed Consent.
- Absolute B cell count > 25 cells/uL.
- Additional Inclusion for Part 1 (Closed to Enrollment)
- In good general health, determined by no clinically significant findings in the of the investigator from medical history, physical examination, 12-lead ECG, clinical laboratory findings, and vital signs at Screening and Day -1 (participants with Gilbert's disease with associated abnormalities of liver function tests are eligible for enrollment).
- Up to date vaccination status per local guidelines (including but not limited to influenza vaccine, COVID booster and hepatitis B vaccine).
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- Additional Inclusion for Part 2
- Fulfill 2013 ACR/ EULAR criteria for classification of SSc with a total score of ≥ 9.
- Active disease defined as at least two of the following at screening:
- Disease duration ≤ 2 years (since onset of first-non-Raynaud-symptom), or
- Elevated acute phase reactant levels (CRP ≥ 6 mg/L, erythrocytes sedimentation rate [ESR] ≥ 28 mm/1h, or platelet count ≥ 330,000/µL), or
- Baseline mRSS ≥10 with evidence of progression, defined as mRSS increase at least 3 units, or involvement of 1 new body area and mRSS increase at least 2 units, or involvement of 2 new body areas (each within the previous 6 months), or
- ≥ 1 tendon friction rub, or
- Elevation of CK or aldolase > 2 × the upper limit of normal (ULN) consistent with SSc-related myopathy, or
- Progressive fibrosing interstitial lung disease (ILD) as defined by at least one of the following criteria at any time within the prior 2 years:
- relative decline in forced vital capacity (FVC) % predicted ≥ 10%, or
- relative decline in FVC % predicted ≥ 5% to <10% and worsened respiratory symptoms, or
- relative decline in FVC % predicted ≥ 5% to <10% and increased extent of fibrosis on high-resolution computed tomography (HRCT), or
- worsened respiratory symptoms and increased extent of fibrosis on HRCT
- Intolerant or refractory to at least 1 line of standard therapy, including methotrexate, azathioprine, IVIG, mycophenolic acid derivatives, cyclophosphamide, TNF-inhibitors, rituximab, or tocilizumab.
Who cannot join
- Any clinically significant underlying illness in the opinion of the investigator.
- Active infection within 4 weeks prior to screening. Participants receiving IV antibiotics or having received IV antibiotics within 14 days prior to enrollment are excluded.
- Positive QuantiFERON-Gold TB test at screening.
- Plan to receive live, attenuated vaccine after signing ICF (inactive vaccines, such as the flu vaccine, are allowed).
- Evidence of malignant disease or malignancies diagnosed within the previous 5 years (except for treated local basal or squamous cell carcinoma of the skin or carcinoma in situ of the cervix uteri that had been excised and cured).
- Currently enrolled in another investigational device or drug study, or less than 30 days or 5 half-lives of the prior investigational agent (whichever is longer) have passed since ending another investigational device or drug study or plans to enroll in another investigational device or drug study during the course of this study.
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- Social smokers e.g. up to 10 cigarettes per week (or equivalent amounts of nicotine containing products) and willing to abstain during inpatient stay, are allowed
- Additional Exclusion Criteria for Part 1 (Closed to Enrollment)
- Use of any prescription medication within 14 days and OTC medications, vitamins, herbal medications (e.g., St. John's wort), or cannabis, except for contraceptive medications and as needed (prn) acetaminophen/paracetamol (not exceeding 2 grams/day) within 7 days prior to administration of the study drug and throughout the study.
- Additional Exclusion Criteria for Part 2
- Rheumatic autoimmune disease other than SSc.
- Positive anti-centromere antibodies.
- Pulmonary disease with FVC ≤ 45% of predicted, or DLCO ≤ 35% of predicted.
- Class 2 or higher pulmonary arterial hypertension or evidence of other moderately severe pulmonary disease.
- Renal crisis within 6 months prior to Screening.
- Prior treatment with cellular immunotherapy (eg, CAR-T) or gene therapy product directed at any target.
- Previous treatment with chlorambucil, bone marrow transplantation, or total lymphoid irradiation.
- Previous treatment with thalidomide, anti-thymocyte globulin, plasmapheresis, or extracorporeal photopheresis.
- Unable to washout current immunosuppressive therapy within 2 months
- Has received anti-CD19 or CD20 therapies, within 6 months prior to start of therapy
- Plan to receive live or live-attenuated vaccines within 8 weeks prior to first dose of study drug and during treatment until B cell reconstitution to 80% of baseline (inactive vaccines, such as the flu vaccine, are allowed)
Trial locations and contacts
13 sites in 4 countries. Contact the study team or a site near you to ask about taking part.
13 sites in 4 countries
China8 sites, 8 recruiting
- Recruiting
Peking University Third Hospital
Beijing
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
Guangdong Provincial People's Hospital
Guangzhou
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
The Third Affiliated Hospital of Sun Yat-Sen University
Guangzhou
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
The First Affiliated Hospital of Zhengzhou University
Henan
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
The First Affiliated Hospital of Nanchang University
Nanchang
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
The Second Affiliated Hospital of Nanchang University
Nanchang
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
Nanjing Drum Tower Hospital
Nanjing
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
Pingxiang People's Hospital
Pingxiang
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
Mexico2 sites, 2 recruiting
- Recruiting
Hospital Angeles Chihuahua
Chihuahua City
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
Unidad Médica para la Salud Integral (UMSI)
San Nicolás de los Garza
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
South Korea2 sites, 2 recruiting
- Recruiting
Kyung Hee University Hospital
Seoul
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
- Recruiting
Seoul National University Hospital
Seoul
Sergio Rodriguez, (646) 597-6980, info@proliumbio.com
About this study
Official title: A Two-part, Phase 1/2, Randomized, Double-blind, Placebo-controlled, Single-ascending-dose Study of PRO-203 in Healthy Adult Volunteers Followed by an Open-label, Single-ascending-dose With Priming Study of PRO-203 in Participants With Systemic Sclerosis
A two-part study of PRO-203 administered subcutaneously in healthy adult volunteers and participants with Systemic Sclerosis (SSc).
Read the detailed description
This two-part study is designed to characterize the first-in-human safety, tolerability, PK, and PD profile of PRO-203 across ascending dose levels.
Part 1 - Healthy Volunteers (HV) Part 1 enrollment is complete and has enrolled 20 healthy volunteers across 3 cohorts. Participants within each cohort received a single SC dose of PRO-203 or matching placebo. Part 1 has completed enrollment.
Part 2 - Systemic Sclerosis (SSc) Up to 24 participants with SSc will be enrolled in multiple cohorts (with optional additional cohorts) Participants within each cohort will receive a single SC cycle of PRO-203. Part 2 includes a Main Study and an optional Long-term Extension (LTE). In the LTE, eligible participants may receive retreatment if they meet retreatment criteria. Total study duration per participant is up to 53 weeks.
- Being tested
- PRO-203, Placebo
- Keywords
- Systemic sclerosis, SSc, Scleroderma, B cell depletion
- Medical subject headings
- Scleroderma, Systemic, Scleroderma, Diffuse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PRO-203Drug
PRO-203 administered as escalating single dose in healthy participants or as a single cycle in participants with systemic sclerosis.
PlaceboOther
Matching placebo comparator for Part 1 participants.
| Study group | Role | What they receive |
|---|---|---|
| Part 1: PRO-203 | Experimental | Healthy participants receive single ascending dose of PRO-203 in dose escalation cohorts Receives: Drug: PRO-203 |
| Part 1: Placebo | Placebo comparator | Matching SC placebo administered to randomized Part 1 participants Receives: Other: Placebo |
| Part 2: Multiple Doses of PRO-203 | Experimental | Participants with systemic sclerosis receive a single cycle of PRO-203 across cohorts, including additional treatment as needed. Receives: Drug: PRO-203 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Adverse Events and Laboratory Abnormalities [Safety and Tolerability]
Incidence and severity of treatment-emergent adverse events, serious adverse events, and dose-limiting toxicities, including changes in clinical laboratory values, ECGs, and vital signs.
Measured: 13 weeks (Part 1) / 49 weeks (Part 2)
Secondary outcomes (3)
Pharmacokinetics of PRO-203
Serum drug levels of PRO-203 over time
Measured: 13 weeks (Part 1) / 49 weeks (Part 2)
Pharmacodynamic-related biomarkers of PRO-203
Peripheral blood B lymphocyte levels over time
Measured: 13 weeks (Part 1) / 49 weeks (Part 2)
Immunogenicity of PRO-203
Level of anti-drug antibodies
Measured: 13 weeks (Part 1) / 49 weeks (Part 2)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2026
- Study start27 Oct 2025
- Primary completionJan 2027 (estimated)
- Study completionJan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy VolunteersStudies 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 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Sequential
- Model description
- Dose escalation
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 44 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Prolium Bioscience, Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Salim Mujais, Study director, Prolium Bioscience, Inc
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07641634
- Sponsor's protocol ID
- PRO-203-101
- Status last verified
- Oct 2026
- First submitted
- 10 Dec 2025
- Last updated
- 9 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Two-part, Phase 1/2, Randomized, Double-blind, Placebo-controlled, Single-ascending-dose Study of PRO-203 in Healthy Adult Volunteers Followed by an Open-label, Single-ascending-dose With Priming Study of PRO-203 in Participants With Systemic Sclerosis
- ClinicalTrials.gov ID
- NCT07641634
- Acronym / sponsor ID
- PRO-203-101
- Keywords
- Systemic sclerosis, SSc, Scleroderma, B cell depletion
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 44 participants (estimated)
- Lead sponsor
- Prolium Bioscience, IncIndustry (pharma, biotech, devices)
- Study start
- 27 Oct 2025 (actual)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Jan 2028 (estimated)
- First posted
- 11 Jun 2026 (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.
A two-part study of PRO-203 administered subcutaneously in healthy adult volunteers and participants with Systemic Sclerosis (SSc).
Detailed description
This two-part study is designed to characterize the first-in-human safety, tolerability, PK, and PD profile of PRO-203 across ascending dose levels.
Part 1 - Healthy Volunteers (HV) Part 1 enrollment is complete and has enrolled 20 healthy volunteers across 3 cohorts. Participants within each cohort received a single SC dose of PRO-203 or matching placebo. Part 1 has completed enrollment.
Part 2 - Systemic Sclerosis (SSc) Up to 24 participants with SSc will be enrolled in multiple cohorts (with optional additional cohorts) Participants within each cohort will receive a single SC cycle of PRO-203. Part 2 includes a Main Study and an optional Long-term Extension (LTE). In the LTE, eligible participants may receive retreatment if they meet retreatment criteria. Total study duration per participant is up to 53 weeks.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
- Model description
- Dose escalation
| Arm | Type | Receives |
|---|---|---|
| Part 1: PRO-203 | Experimental | Drug: PRO-203Healthy participants receive single ascending dose of PRO-203 in dose escalation cohorts |
| Part 1: Placebo | Placebo comparator | Other: PlaceboMatching SC placebo administered to randomized Part 1 participants |
| Part 2: Multiple Doses of PRO-203 | Experimental | Drug: PRO-203Participants with systemic sclerosis receive a single cycle of PRO-203 across cohorts, including additional treatment as needed. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (20 listed)
- Is male or female, age 18 to 65 years, inclusive, at Screening.
- Able to provide Informed Consent.
- Absolute B cell count > 25 cells/uL.
- Additional Inclusion for Part 1 (Closed to Enrollment)
- In good general health, determined by no clinically significant findings in the of the investigator from medical history, physical examination, 12-lead ECG, clinical laboratory findings, and vital signs at Screening and Day -1 (participants with Gilbert's disease with associated abnormalities of liver function tests are eligible for enrollment).
Key exclusion criteria (21 listed)
- Any clinically significant underlying illness in the opinion of the investigator.
- Active infection within 4 weeks prior to screening. Participants receiving IV antibiotics or having received IV antibiotics within 14 days prior to enrollment are excluded.
- Positive QuantiFERON-Gold TB test at screening.
- Plan to receive live, attenuated vaccine after signing ICF (inactive vaccines, such as the flu vaccine, are allowed).
- Evidence of malignant disease or malignancies diagnosed within the previous 5 years (except for treated local basal or squamous cell carcinoma of the skin or carcinoma in situ of the cervix uteri that had been excised and cured).
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 |
|---|---|---|
| PRO-203PRO-203 administered as escalating single dose in healthy participants or as a single cycle in participants with systemic sclerosis. | Drug | Part 1: PRO-203, Part 2: Multiple Doses of PRO-203 |
| PlaceboMatching placebo comparator for Part 1 participants. | Other | Part 1: Placebo |
Primary outcome
Incidence of Adverse Events and Laboratory Abnormalities [Safety and Tolerability]
Time frame: 13 weeks (Part 1) / 49 weeks (Part 2)
Incidence and severity of treatment-emergent adverse events, serious adverse events, and dose-limiting toxicities, including changes in clinical laboratory values, ECGs, and vital signs.
3 secondary outcomes
Pharmacokinetics of PRO-203
Time frame: 13 weeks (Part 1) / 49 weeks (Part 2)
Pharmacodynamic-related biomarkers of PRO-203
Time frame: 13 weeks (Part 1) / 49 weeks (Part 2)
Immunogenicity of PRO-203
Time frame: 13 weeks (Part 1) / 49 weeks (Part 2)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Oct 2026.
- Individual participant dataSharing planned: Yes
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Screening Protocol
Pain
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.
Salim Mujais study director
Prolium Bioscience, Inc
13 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing PRO-203 in people with Healthy Volunteers and Systemic Sclerosis (SSc), run by Prolium Bioscience, Inc at 13 sites in 4 countries.
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 20 inclusion and 21 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: looking for participants now, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 13 sites in China, Mexico, South Korea, Australia. 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 combined 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.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sergio Rodriguez ((646) 597-6980, info@proliumbio.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Adverse Events and Laboratory Abnormalities [Safety and Tolerability] (time frame: 13 weeks (Part 1) / 49 weeks (Part 2)). 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 9 Oct 2026.