NCT06721013 · Eli Lilly and Company
A Study of Pirtobrutinib in Participants With Immune Thrombocytopenia
What this study is about
The purpose of the phase 1 part of this study is to evaluate how well pirtobrutinib is tolerated and what side effects may occur. The phase 2 part of the study will further investigate effectiveness and safety of multiple pirtobrutinib dosages versus placebo. The study drug will be administered taken by mouth in participants with Primary Immune Thrombocytopenia (ITP).
View original scientific description
The purpose of the phase 1 part of this study is to evaluate how well pirtobrutinib is tolerated and what side effects may occur. The phase 2 part of the study will further investigate efficacy and safety of multiple pirtobrutinib dosages versus placebo. The study drug will be administered orally in participants with Primary Immune Thrombocytopenia (ITP). Blood tests will be performed to check how much pirtobrutinib gets into the bloodstream and how long it takes the body to eliminate it.
Interventions
DRUG
Pirtobrutinib
Administered orally
DRUG
Placebo
Administered orally
Primary outcome measures
Phase 1-Number of Participants with One or More Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration
Time frame: Baseline Up to Week 4
A summary of TEAEs and SAEs regardless of causality, will be reported in the Reported Adverse Events module
Phase 1-Dose Limiting Toxicity (DLT) of Pirtobrutinib
Time frame: Baseline Up to Week 4
DLTs of Pirtobrutinib
Phase 1-Number of Participants with Treatment-Related Adverse Events as Assessed by Vital Signs: Blood Pressure, Pulse Rate, and Body Temperature
Time frame: Baseline Up to Week 16
Blood Pressure, Pulse Rate, and Body Temperature
Phase 1-Number of Participants with Treatment-Related Adverse Events as Assessed by Clinical Lab Tests: Hematology, Clinical Chemistry, Urinalysis, Pregnancy, Hepatitis Serology and Cytomegalovirus (CMV)
Time frame: Baseline Up to Week 16
Hematology, Clinical Chemistry, Urinalysis, Pregnancy, Hepatitis Serology and Cytomegalovirus (CMV)
Phase 1-Number of Participants with Treatment-Related Adverse Events as Assessed by Electrocardiograms (ECGs): ECG QT Interval
Time frame: Baseline Up to Week 16
ECG QT Interval
Phase 2-Efficacy of Pirtobrutinib Versus Placebo
Time frame: Baseline Up to Week 24
Stable platelet response rate is defined as the proportion of participants achieving platelet count of greater than or equal to 50 thousand per microliter (k/μL) and on at least 4 of the 6 consecutive biweekly visits between weeks 14 and 24 in the absence of rescue therapy and prohibited concomitant medication that may impact efficacy
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Have a diagnosis of primary ITP, defined as isolated thrombocytopenia not associated with another known disease process
- Have documented history of response, defined as 2 or more platelet counts greater than or equal to 50,000/microliter (μL), to at least 1 prior line of therapy. Splenectomy is considered a line of therapy
- Have relapsed or treatment-resistant primary ITP, with no available therapies known to provide clinical benefit
- Have a platelet count less than 30,000/μL on 2 occasions more than 5 days apart in the 15 days before randomization
- Have adequate liver, renal, and hematologic functions as defined by a table
- Are willing to follow contraception requirements
Exclusion criteria
- Have a history of any thrombotic or embolic event within 12 months before screening
- Had a transfusion with blood or blood products or plasmapheresis within 14 days (Phase 1) or within 28 days (Phase 2) of randomization
- Have significant cardiovascular disease
Where
- Los Angeles, California
- Stanford, California
- Washington D.C., District of Columbia
- Miami, Florida
- Peoria, Illinois
- New Orleans, Louisiana
- Rochester, Minnesota
- Westbury, New York
- Austin, Texas
- Houston, Texas
- The Woodlands, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 25, 2026 · Source of record for eligibility and locations