A Study of Pirtobrutinib in Participants With Immune Thrombocytopenia

A Phase 1/2, Dose-finding Study Investigating the Safety and Efficacy of Pirtobrutinib in Adults With Immune Thrombocytopenia

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.

The study will last up to approximately 16 weeks for phase 1 dose-escalation and 28 weeks for phase 2 dose-optimization, excluding screening.

Study Overview

• Status: Recruiting
• Conditions: Immune Thrombocytopenia (ITP)
• Intervention / Treatment: Drug: Placebo; Drug: Pirtobrutinib

• Study Type: Interventional
• Enrollment (Estimated): 58
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or; Phone Number: 1-317-615-4559; Email: LillyTrials@Lilly.com
• Study Contact Backup: Name: Physicians interested in becoming principal investigators please contact; Email: clinical_inquiry_hub@lilly.com

Study Locations

• China
  • Guangzhou, China, 510515
    • Not yet recruiting
    • Nanfang Hospital of Southern Medical University
  • Jinan, China, 250012
    • Not yet recruiting
    • Qilu Hospital of Shandong University
  • Tianjin, China, 300020
    • Not yet recruiting
    • Hematology Hospital of the Chinese Academy of Medical Sciences
  • Wuhan, China, 430022
    • Not yet recruiting
    • Union Hospital Tongji Medical College Huazhong University of Science and Technology
• Denmark
  • Odense C, Denmark, 5000
    • Recruiting
    • OUH
• France
  • Créteil, France, 94010
    • Recruiting
    • Hôpital Henri Mondor
  • Dijon, France, 21034
    • Recruiting
    • Chu Dijon - Hopital Du Bocage
  • Pessac, France, 33604
    • Recruiting
    • CHU Bordeaux - Hôpital Haut-Lévêque
• Italy
  • Bologna, Italy, 40138
    • Recruiting
    • Azienda Ospedaliera Universitaria Policlinico Sant'Orsola Malpighi IRCCS
  • Milan, Italy, 20122
    • Recruiting
    • Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico
  • Roma, Italy, 00168
    • Recruiting
    • Fondazione Policlinico Universitario Agostino Gemelli Irccs
  • Trieste, Italy, 34129
    • Not yet recruiting
    • Azienda Sanitaria Universitaria Giuliano Isontina (ASU GI)
• Norway
  • Bergen, Norway, 5021
    • Not yet recruiting
    • Haukeland University Hospital
  • Grålum, Norway, 1714
    • Not yet recruiting
    • Sykehuset Ostfold, Kalnes
  • Trondheim, Norway, 7030
    • Not yet recruiting
    • St. Olavs Hospital Hf, Universitetssykehuset i Trondheim
• Poland
  • Katowice, Poland, 40-519
    • Recruiting
    • Pratia Onkologia Katowice
  • Krakow, Poland, 30-727
    • Recruiting
    • Pratia MCM Krakow
  • Skorzewo, Poland, 60-185
    • Recruiting
    • Aidport sp z o.o.
  • Torun, Poland, 87-100
    • Recruiting
    • MICS Centrum Medyczne Torun
  • Wroclaw, Poland, 50-367
    • Not yet recruiting
    • Uniwersytecki Szpital Kliniczny im. Jana Mikulicza-Radeckiego we Wroclawiu
• South Korea
  • Busan, South Korea, 49241
    • Recruiting
    • Pusan National University Hospital
  • Seoul, South Korea, 05505
    • Recruiting
    • Asan Medical Center
  • Seoul, South Korea, 03080
    • Recruiting
    • Seoul National University Hospital
  • Seoul, South Korea, 03722
    • Recruiting
    • Severance Hospital, Yonsei University Health System
  • Seoul, South Korea, 06591
    • Recruiting
    • The Catholic University of Korea, Seoul St. Mary's Hospital
• Spain
  • Barcelona, Spain, 08036
    • Recruiting
    • Hospital Clinic De Barcelona
  • Burgos, Spain, 09006
    • Recruiting
    • Hospital Universitario de Burgos
  • Murcia, Spain, 30008
    • Recruiting
    • Hospital General Universitario Morales Meseguer
  • Pamplona, Spain, 31008
    • Recruiting
    • Clinica Universidad de Navarra
• United Kingdom
  • Bristol, United Kingdom, BS2 8ED
    • Recruiting
    • Bristol Haematology and Oncology Centre
  • Leeds, United Kingdom, LS9 7TF
    • Recruiting
    • St James's University Hospital
  • Leicester, United Kingdom, LE1 5WW
    • Recruiting
    • Leicester Royal Infirmary
  • London, United Kingdom, W12 0HS
    • Not yet recruiting
    • Hammersmith Hospital
  • London, United Kingdom, E1 1FR
    • Not yet recruiting
    • Royal London Hospital
• United States
  • California
    • Los Angeles, California, United States, 90033
      • Recruiting
      • USC Norris Comprehensive Cancer Center
    • Stanford, California, United States, 94305-5406
      • Not yet recruiting
      • Stanford University
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20007
      • Recruiting
      • MedStar Georgetown University Hospital
  • Florida
    • Miami, Florida, United States, 33136
      • Not yet recruiting
      • University of Miami Hospital and Clinics Sylvester Comprehensive Cancer Center
  • Illinois
    • Peoria, Illinois, United States, 61614
      • Not yet recruiting
      • Bleeding and Clotting Disorders Institute
  • Louisiana
    • New Orleans, Louisiana, United States, 70121
      • Recruiting
      • Ochsner Clinic Foundation
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Not yet recruiting
      • Mayo Clinic
  • New York
    • Westbury, New York, United States, 11590
      • Recruiting
      • Clinical Research Alliance
  • Texas
    • Austin, Texas, United States, 78758
      • Not yet recruiting
      • Texas Oncology - Central South
    • Houston, Texas, United States, 77030
      • Recruiting
      • MD Anderson Cancer Center
    • The Woodlands, Texas, United States, 77380
      • Not yet recruiting
      • Texas Oncology Gulf Coast

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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
• Have a diagnosis or history of hematologic malignancy
• Have hepatitis B virus (HBV) defined as positive for antigen of hepatitis B (HBsAg) or polymerase chain reaction (PCR) positive for HBV deoxyribonucleic acid (DNA)
• Have hepatitis C virus (HCV) defined as positive for anti-HCV antibodies and PCR positive for HCV ribonucleic acid (RNA)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Pirtobrutinib Phase 1; Pirtobrutinib administered orally	Drug: Pirtobrutinib; Administered orally
Experimental: Pirtobrutinib Phase 2; Pirtobrutinib administered orally	Drug: Pirtobrutinib; Administered orally
Placebo Comparator: Placebo Phase 2; Placebo administered orally	Drug: Placebo; Administered orally

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	A summary of TEAEs and SAEs regardless of causality, will be reported in the Reported Adverse Events module	Baseline Up to Week 4
Phase 1-Dose Limiting Toxicity (DLT) of Pirtobrutinib	DLTs of Pirtobrutinib	Baseline Up to Week 4
Phase 1-Number of Participants with Treatment-Related Adverse Events as Assessed by Vital Signs: Blood Pressure, Pulse Rate, and Body Temperature	Blood Pressure, Pulse Rate, and Body Temperature	Baseline Up to Week 16
Phase 1-Number of Participants with Treatment-Related Adverse Events as Assessed by Electrocardiograms (ECGs): ECG QT Interval	ECG QT Interval	Baseline Up to Week 16
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)	Hematology, Clinical Chemistry, Urinalysis, Pregnancy, Hepatitis Serology and Cytomegalovirus (CMV)	Baseline Up to Week 16
Phase 2-Efficacy of Pirtobrutinib Versus Placebo	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	Baseline Up to Week 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Phase 1-Preliminary Efficacy of Pirtobrutinib	Platelet response rate defined as proportion of participants who achieve at least 2 consecutive platelet counts of greater than or equal to 50 k/μL and an increase from baseline of greater than or equal to 20 k/μL to any time during treatment without the use of rescue medication within 4 weeks prior to the latest elevated platelet count.	Day 1 Up to Week 12
Phase 1-Evaluate the Extent of Disease Control	Number of cumulative weeks with platelet counts greater than or equal to 50 k/μL by Week 12	Day 1 Up to Week 12
Phase 1: Pharmacokinetics (PK) of Pirtobrutinib	PK: Plasma Concentrations of Pirtobrutinib	Baseline Up to Week 16
Phase 2-Evaluate the Extent of Disease Control of Pirtobrutinib Versus Placebo	Number of cumulative weeks with platelet counts greater than or equal to 50 k/μL and greater than or equal to 100 k/μL	Baseline Up to Week 24
Phase 2-Describe the Use of Rescue Medications of Pirtobrutinib Versus Placebo	Proportion of participants requiring rescue therapy	Baseline Up to Week 24
Phase 2-Describe the PK of Pirtobrutinib	PK: Plasma Concentrations of Pirtobrutinib	Week 16 Up to Week 40
Phase 2-Assess Additional Efficacy of Pirtobrutinib Versus Placebo	Platelet response rate is defined as the proportion of participants with greater than or equal to 2 consecutive platelet counts greater than or equal to 50 k/μL and an increase of platelet count of greater than or equal to 20 k/μL from baseline to any time during treatment or follow-up without the use of rescue medication or prohibited concomitant medication that may impact efficacy within 4 weeks prior to the latest elevated platelet count	Week 14 Up to Week 24

Collaborators and Investigators

• Sponsor: Eli Lilly and Company
• Investigators: Study Director: Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 8 AM - 8 PM Eastern time (UTC/GMT - 5 hours, EST), Eli Lilly and Company

Publications and helpful links

Helpful Links

• Lilly Trials

Study record dates

Study Major Dates

• Study Start (Actual): July 30, 2025
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): February 1, 2027

Study Registration Dates

• First Submitted: December 3, 2024
• First Submitted That Met QC Criteria: December 5, 2024
• First Posted (Actual): December 6, 2024

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cytopenia; Pathologic Processes; Autoimmune Diseases; Immune System Diseases; Hemorrhage; Skin Manifestations; Hematologic Diseases; Blood Coagulation Disorders; Hemorrhagic Disorders; Blood Platelet Disorders; Thrombotic Microangiopathies; Purpura, Thrombocytopenic; Purpura; Thrombocytopenia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hemic and Lymphatic Diseases; Purpura, Thrombocytopenic, Idiopathic; Substandard Drugs; Pharmaceutical Preparations; pirtobrutinib
• Other Study ID Numbers: 27294; J2N-MC-JZNZ (Other Identifier: Eli Lilly and Company)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No