Safety and Efficacy Study of QL0911 to Treat Immune Thrombocytopenia (ITP) in Pediatric Patients

A Phase III, Randomized, Double-Blind, Placebo-Controlled Study of QL0911 in Pediatric Patients With Primary Immune Thrombocytopenia.

The purpose of this study is to evaluate efficacy and of safety QL0911 in the treatment of thrombocytopenia in pediatric patients with previously treated chronic ITP.

Study Overview

• Status: Not yet recruiting
• Conditions: Thrombocytopenia, Immune
• Intervention / Treatment: Drug: QL0911; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Run hui Wu, Doctorate; Phone Number: 13370115037; Email: wurunhuigcp@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age ≥ 1 years old and < 18 years old.
2. Diagnosed primary ITP for at least 12 months;
3. Had received at least one first-line ITP treatment with no response or recurrence after treatment;
4. Had a platelet count <30×10^9/L within 48 hours before the first dose;
5. Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2;
6. Patients of child-bearing potential must agree to use effective contraception during the study and for 3 months following the last dose of study treatment.

Exclusion Criteria:

1. Had a history of bone marrow stem cell abnormalities or myelodysplastic syndrome other than ITP-specific changes.
2. Underwent splenectomy within 12 weeks before the first dose;
3. Had received ITP treatments (including rescue treatment) within 2 weeks before the first dose;
4. Had received romiplostim (Nplate®) or eltrombopag (Revolade®), rhTPO or other agents that stimulate TPO receptors (also known as c-Mpl)within 4 weeks before the first dose;
5. Had received antibody-based therapies within 14 weeks before the first dose.
6. Patients with concurrent or past malignant disease.
7. Serum creatinine or total bilirubin >1.5*ULN) alanine transaminase (ALT) or aspartate transaminase (AST) >3* ULN.
8. Had received antibody-based therapies within 14 weeks before the first dose.
9. Had prothrombin time (PT) or prothrombin time-international normalized ratio (PT-INR) or activated partial thromboplastin time (APTT) exceeded 20% of the reference range of normal values.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: QL0911; Participants received once weekly subcutaneous QL0911 at a starting dose of 1 µg/kg; weekly dose increases continued in increments of 1 µg/kg/week to a maximum dose of 10 µg/kg in an attempt to reach a target platelet count of ≥ 50 x 10^9/L.	Drug: QL0911; The starting dose of QL0911 is 1 µg/kg administered weekly by subcutaneous injection. Participants will return to the clinic weekly to provide platelet counts and undergo dose titrations under the supervision of the treating physician. Weekly dose increases will continue in increments of 1 µg/kg up to a maximum dose of 10 µg/kg in an attempt to reach a target platelet count of ≥ 50 x 10^9/L. Dose adjustment will be allowed during the treatment period to maintain a platelet count between ≥ 50 x 10^9/L and ≤ 200 x 10^9/L.
Placebo Comparator: placebo; Participants received weekly subcutaneous placebo.	Drug: Placebo; Matching placebo administered by subcutaneous injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants With a Durable Platelet Response	A participant with durable platelet response was defined as achieving at least 6 weekly platelet counts of ≥ 50 x 10^9/L from week 18 to week 25. If a platelet count from a participant was not available (missing) in a certain week, that week was imputed as non-response for that participant. Platelet counts were not deemed as a positive response for 4 weeks after the administration of rescue medication.	Week 18 to week 25

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants With an Overall Platelet Response	Overall platelet response is defined as either a durable platelet response or transient platelet response.	24 weeks
The proportion of subjects with a weekly platelet count ≥ 30 × 10^9/Land at least twice the baseline platelet count without bleeding during the double-blind period of 24 weeks.	The proportion of subjects with a weekly platelet count ≥ 30 × 10^9/Land at least twice the baseline platelet count without bleeding during the double-blind period of 24 weeks.	24 weeks
Number of Weeks With Platelet Response	Number of weeks with platelet counts ≥ 50 x 10^9/L.	24 weeks
Percentage of Participants Who Received Rescue Medication During the Treatment Period.	Rescue medication is any medication that is intended to increase platelet counts or prevent bleeding.	24 weeks
Number of Participants With Treatment-emergent Adverse Events (TEAEs)		Up to Week 38
Number of Participants With Antidrug Antibodies (ADAs) , Anti endogenous TPO antibody and Neutralizing Antibodies (Nab)；		Up to Week 38

Collaborators and Investigators

• Sponsor: Qilu Pharmaceutical Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): April 20, 2026
• Primary Completion (Estimated): December 10, 2027
• Study Completion (Estimated): March 10, 2028

Study Registration Dates

• First Submitted: March 2, 2026
• First Submitted That Met QC Criteria: March 2, 2026
• First Posted (Actual): March 6, 2026

Study Record Updates

• Last Update Posted (Actual): March 6, 2026
• Last Update Submitted That Met QC Criteria: March 2, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Immune Thrombocytopenia
• 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
• Other Study ID Numbers: QL0911-303

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No