Primary Immune Thrombocytopenia (ITP)Phase 2ORBITNCT07400250
Phase II Study of Orelabrutinib in Combination With Romiplostim N01 in Patients With Primary Immune Thrombocytopenia (ITP) Who Have Received At Least One Prior Line of Therapy
A Phase 2 study testing Orelabrutinib and Romiplostim N01 in people with Primary Immune Thrombocytopenia (ITP), run by Peking Union Medical College Hospital at 1 site in China.
Trial summary
To evaluate whether orelabrutinib combined with romiplostim N01 can improve the quality of remission, increase the probability of successful drug withdrawal, and prolong the time to treatment failure in patients with primary immune thrombocytopenia (ITP) who have received at least one line of prior therapy. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Primary Immune Thrombocytopenia (ITP)
- What is being tested?
- Orelabrutinib and Romiplostim N01
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteChina
- Study dates
- 1 Apr 2026to 1 Oct 2028
- Phase
- Phase 2
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 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Subjects voluntarily participate in this study and provide written informed consent；
- Age 18-80 years, inclusive, regardless of gender；
- ECOG score 0 to 2；
- Documented diagnosis of chronic primary Immune Thrombocytopenia (ITP) with a disease duration >12 months；
- Patients with an inadequate sustained response, relapse, intolerance, or insufficient response to first-line ITP therapy (corticosteroids and/or intravenous immunoglobulin). Prior receipt of other ITP treatments is allowed, with no limit on the number of prior lines；
- A history of response to prior standard ITP therapy (defined as achieving a platelet count ≥50×10⁹/L)；
- During or following the most recent ITP treatment, patients must have experienced either: treatment failure (platelet count <30×10⁹/L after treatment, or failure to double the baseline count, or occurrence of bleeding), relapse after initial response (platelet count decreased to <30×10⁹/L, or fell below twice the baseline, or bleeding symptoms recurred), treatment intolerance, or an inability to maintain response after treatment discontinuation；
- Subjects demonstrate adequate comprehension of and are able to comply with the study protocol requirements, and are willing to complete the study according to the schedule.
Who cannot join
- Subjects suffer from severe ITP at screening;
- Subjects have other diseases which mention in protocol;
- Subjects develop intracranial hemorrhage within 6 months prior to screening;
- Active and uncontrollable infection;
- 6. Subjects have a history of coagulopathy other than ITP; 7. Subjects with a history of malignancies; 8. History of major organ transplantation or hematopoietic stem cell/bone marrow transplantation; 9. Subjects with a known history of hypersensitivity to the investigational drug as described in the Protocol, or any ingredients; 10. Subjects with a Medication history and surgical history which mention in protocol; 11. Subjects do not meet the criterion of the laboratory test in protocol.
- Withdrawal Criteria:
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- If, after 4 consecutive weeks of Romiplostim N01 administration at the maximum dose (10 µg/kg once weekly), the platelet count remains <50×10⁹/L and the investigator judges the investigational product to be ineffective for the subject, such that continued use is not in the subject's best interest；
- Subjects who are unable to successfully undergo treatment tapering or discontinuation；
- Subjects who, during the treatment period, require rescue therapy based on clinical assessment；
- Subjects who withdraw their informed consent.
- Occurrence of pregnancy during the trial period
- Poor subject compliance or a significant protocol violation；
- Loss to follow-up；
- The investigator decides that withdrawal is necessary for the subject's safety；
- Presence of other conditions, as determined by the investigator, that may affect the study results or lead to premature termination of the study；
- Study completion or early termination of the entire study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
Peking Union Medical College Hospital
Beijing, Beijing Municipality, 100010
Tienan Zhu, M.D., 010-69155027, zhutn@pumch.cn
About this study
Official title: Phase II Study of Orelabrutinib in Combination With Romiplostim in Patients With Primary Immune Thrombocytopenia (ITP) Who Have Received at Least One Prior Line of Therapy
To evaluate whether orelabrutinib combined with romiplostim N01 can improve the quality of remission, increase the probability of successful drug withdrawal, and prolong the time to treatment failure in patients with primary immune thrombocytopenia (ITP) who have received at least one line of prior therapy.
Read the detailed description
This is a prospective, single-arm, open-label Phase II study, enrolling adult patients with chronic primary immune thrombocytopenia (ITP) who failed first-line therapy. The study evaluates the efficacy and safety of orelabrutinib combined with romiplostim N01, focusing on the treatment regimen as follows:
- Core Treatment Phase (Weeks 1-24) Patients receive orelabrutinib 50mg orally once daily (fixed dose) and romiplostim N01 subcutaneously. Romiplostim N01 starts at 250ug/week (≈3ug/Kg) and is titrated within 1-10ug/Kg/week to maintain platelet count (PLT) at 50-200×10⁹/L. Dose adjustments: increase by 1-3ug/Kg/week if PLT <50×10⁹/L; decrease by 1-3ug/Kg/week if PLT 200-400×10⁹/L; suspend if PLT >400×10⁹/L. Patients with PLT <50×10⁹/L after 28 days of maximum-dose romiplostim N01 withdraw.
- Romiplostim N01 Tapering Phase (Weeks 25-32) Patients with PLT ≥50×10⁹/L in the last two core phase visits discontinue orelabrutinib. Romiplostim N01 is tapered: doses >3ug/Kg/week are reduced to 2-3ug/Kg/week, then dosing intervals extended (weekly→every 10 days→every 2 weeks). Patients with two consecutive PLT <30×10⁹/L withdraw.
- Follow-up Phase (Weeks 33-56) Successfully tapered patients are followed up every 4 weeks to monitor PLT and adverse events (graded per NCI-CTC AE 5.0). Relevant events are reported to the sponsor's Pharmacovigilance Department.
- Conditions
- Primary Immune Thrombocytopenia (ITP)
- Being tested
- Orelabrutinib, Romiplostim N01
- Keywords
- primary immune thrombocytopenia, orelabrutinib, romiplostim N01
- Medical subject headings
- Purpura, Thrombocytopenic, Idiopathic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OrelabrutinibDrug
Orelabrutinib will be given as 50mg per day orally, week 1-24
Romiplostim N01Drug
Core Treatment Phase Recommended starting dose: 3 μg/kg subcutaneously once weekly. Monitor platelet count (PLT) and symptoms weekly for dose adjustment, max 10 μg/kg/week. Therapeutic target: Maintain PLT within the range of 50-200×10⁹/L.
- PLT < 50×10⁹/L: Increase by 1-3 μg/kg/week to max dose. Discontinue study if PLT remains < 50×10⁹/L after 28d of max dose.
- 50-200×10⁹/L: Maintain the minimum effective dose to reduce bleeding risk.
- 200-400×10⁹/L: Decrease by 1-3 μg/kg/week. Discontinue if PLT ≥200×10⁹/L at 250 μg/week; resume when PLT <50×10⁹/L (extend interval if needed).
- PLT >400×10⁹/L: Suspend; resume at 1-3 μg/kg lower dose when PLT <200×10⁹/L (weekly monitoring).
Tapering Phase For maintenance dose >3 μg/kg/week: Taper by 1-3 μg/kg/week to ≤3 μg/kg (250 μg/week), then extend intervals (weekly→every 10 days→every 2 weeks).
- PLT <30×10⁹/L: Maintain current dose.
- Two consecutive PLT <30×10⁹/L: Discontinue study.
| Study group | Role | What they receive |
|---|---|---|
| Orelabrutinib combined with Romiplostim N01 | Experimental | The experimental arm will be treated orelabrutinib plus romiplostim N01. The study consists of three phases: 1) Core Treatment Phase (Weeks 1-24): Orelabrutinib 50mg orally once daily (fixed dose) + romiplostim N01 subcutaneously (starting dose 3ug/kg/week, administered once weekly). Platelet count and clinical symptoms are assessed weekly to adjust the dose of romiplostim N01 as appropriate, with a maximum dose of 10ug/kg/week. Patients with platelet count (PLT) <50×10⁹/L after 28 days of maximum-dose romiplostim N01 withdraw. 2) Tapering Phase (Weeks 25-32): Eligible patients (PLT ≥50×10⁹/L in the last two core phase visits) discontinue orelabrutinib, then taper romiplostim N01 (dose reduction + extended intervals); patients with two consecutive PLT <30×10⁹/L withdraw. 3) Follow-up Phase (Weeks 33-56): Successfully tapered patients are followed up every 4 weeks to monitor PLT and adverse events (graded per NCI-CTC AE 5.0). Receives: Drug: Orelabrutinib; Drug: Romiplostim N01 |
What is being measured
The primary outcome is the main question the study is designed to answer.
24-Week Sustained Platelet Response Rate
The proportion of subjects with a platelet count (PLT) ≥ 50×10⁹/L in at least 4 out of the last 6 visits during the 24-week treatment period, without rescue therapy administered in the previous 4 weeks
Measured: Up to 24 weeks
Secondary outcomes (11)
The sustained remission off-treatment (SROT)
At the end of follow-up (Week 56), the platelet count (PLT) is ≥ 30×10⁹/L and at least doubled compared to baseline, with no bleeding events and no rescue therapy administered during the period.
Measured: Week 56
The cumulative number of weeks of platelet response
Up to Week 24, the cumulative number of weeks with a platelet count (PLT) ≥ 50×10⁹/L
Measured: Up to 24 weeks
The time to first achievement of a platelet count ≥ 50×10⁹/L
The time to first achievement of a platelet count ≥ 50×10⁹/L
Measured: Up to 24 weeks
Cumulative response time
Number of cumulative weeks with platelet counts ≥ 30 × 10⁹/L and doubling of the baseline count and without bleeding by Week 24
Measured: Up to 24 weeks
Complete response rate
The proportion of patients with a platelet count ≥ 100 × 10⁹/L on 3 consecutive visits at least 7 days apart and without bleeding
Measured: Up to 24 weeks
Time to First Rescue Therapy(TFRT)
Measured: Up to 24 Weeks
Bleeding Events
Assessed using the World Health Organization (WHO) Bleeding Scale. Clinically significant bleeding is defined and graded as follows:
Grade 0 = No bleeding Grade 1 = Petechiae Grade 2 = Mild blood loss Grade 3 = Gross blood loss Grade 4 = Debilitating blood loss
Measured: Up to 56 Weeks
Change From Baseline to Week 24 in ITP-PAQ Symptoms Score
Measured: Up to 24 Weeks
Treatment-emergent Adverse Events (TEAEs)
Common indicators include abnormalities in clinical symptoms and vital signs, as well as laboratory test abnormalities. The clinical manifestations, severity, time of onset, duration, management measures, and prognosis of these events are documented. The causal relationship to the investigational product(s) (Orelabrutinib or Ropylstimin N01) is assessed.
Drug safety is evaluated according to the NCI-CTCAE version 5.0.
Measured: Up to 56 Weeks
Exploratory Biomarkers
Including peripheral T/B cell subsets (including Th1, Th17, Th2, Treg, Breg).
Measured: Up to 56 Weeks
Platelet membrane glycoprotein-specific antibodies; Cytokines: IL-4, IL-6, IL-17F, IL-9, IL-22, TGF-β, etc.
Measured: Up to 56 Weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Feb 2026
- Study start1 Apr 2026 (estimated)
- Primary completion1 Oct 2026 (estimated)
- Study completion1 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Primary Immune Thrombocytopenia (ITP)Studies of the same condition, open and under way.
- More trials run by Peking Union Medical College HospitalThe 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Peking Union Medical College Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Tienan Zhu, M.D., Principal investigator, Peking Union Medical College Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07400250
- Sponsor's protocol ID
- PUMCH-ITP-II
- Other IDs
- InnoCare-ITP-001
- Acronym
- ORBIT
- Status last verified
- Jan 2026
- First submitted
- 3 Feb 2026
- Last updated
- 10 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No