Efficacy and Safety Study of Narsoplimab in Pediatric Patients With High-Risk Hematopoietic Stem Cell Transplant TMA

NCT05855083 | Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: OMS721-HCT-002
• Study Type: interventional
• Target: 18
• Locations: 5 countries
• Sites: 16

Brief Summary

The purpose of this study is to evaluate the safety and efficacy of narsoplimab in pediatric patients with thrombotic microangiopathies (TMA) following hematopoietic stem cell transplant (HSCT).

Conditions

Thrombotic Microangiopathies; Hematopoietic Stem Cell Transplantation

Keywords

TMA; HSCT; Pediatric; BMT; OMS721; Narsoplimab

Outcome Measures

Primary Outcomes (1)

• 100-day survival rate following high-risk HSCT-TMA diagnosis.

  Percentage of patients alive at 100 days following the diagnosis of high-risk HSCT-TMA

  100 days

Secondary Outcomes (6)

• Number of participants with treatment-emergent adverse events assessed by CTCAE v5.0

  52 weeks

• Percentage of patients meeting protocol definition of clinical response

  52 weeks

• 52 week survival rate following high-risk HSCT-TMA diagnosis

  52 weeks

• Overall survival following the diagnosis of high-risk HSCT-TMA

  52 weeks

• Pharmacokinetics (PK) of multiple-dose administration of OMS721

  52 weeks

Study Arms (1)

Narsoplimab single arm-treatment

EXPERIMENTAL

Narsoplimab 4 mg/kg

Drug: Biological: narsoplimab

Interventions

Biological: narsoplimab DRUG

Treatment with narsoplimab 4 mg/kg will be administered

Also known as: Narsoplimab

Narsoplimab single arm-treatment

Eligibility Criteria

• Age: 28 Days - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Age at least 28 days and less than 18 years prior to informed consent (Visit 0).
• Have informed consent from at least one parent or legal guardian as required by local law and regulation. Patient informed consent will be required if the patient has reached the local legal age of majority.
• Assent from patients as required by local law and regulation.
• Have received an allogeneic hematopoietic stem cell transplant for the treatment of benign or malignant disease.
• Have a diagnosis of HSCT-TMA defined as meeting both of the following criteria:
• Platelet count \< 50,000/mL or a decrease in platelet count \> 50% from the highest value obtained following transplant.
• Evidence of microangiopathic hemolysis (presence of schistocytes, serum lactate dehydrogenase \[LDH\] \> upper limit of normal (\[ULN\], or haptoglobin \< lower limit of normal \[LLN\])
• Have at least one of the following HSCT-TMA high-risk criteria:
• HSCT-TMA persistence \> 2 weeks following modification of calcineurin inhibitors or sirolimus OR
• Have evidence of high-risk HSCT-TMA defined as at least one of the following:
• Spot protein/creatinine ratio \> 2 mg/mg
• Serum creatinine \> 1.5 x the creatinine level prior to TMA development
• Biopsy-proven gastrointestinal TMA
• TMA-related neurological abnormality
• Pericardial or pleural effusion without alternative explanation

You may not qualify if:

• All treatments for HSCT-TMA are allowed except eculizumab, ravulizumab, and defibrotide within 3 months prior to informed consent, unless failure of therapy can be documented.
• a. Patients may not be on eculizumab, ravulizumab, or defibrotide for any indication at screening.
• Have Shiga toxin-producing Escherichia coli haemolytic uraemic syndrome (STEC-HUS). Test results obtained within 28 days prior to informed consent may be used.
• Have ADAMTS13 activity \< 10%. Test results obtained within 28 days prior to informed consent may be used.
• Have a severe, uncontrolled systemic bacterial or fungal infection requiring antimicrobial therapy, or a severe uncontrolled viral infection (as determined by the investigator); prophylactic antimicrobial therapy administered as standard of care is allowed.
• Have malignant hypertension (blood pressure \[BP\] \> 99th percentile plus 5 mmHg with bilateral hemorrhages or "cotton-wool" exudates on fundoscopic examination).
• Due to conditions other than HSCT-TMA, have a poor prognosis with a life expectancy of less than 3 months in the opinion of the Investigator.
• If pregnant or lactating.
• Have received treatment with an investigational drug or device within 4 weeks of entering study.
• Have abnormal liver function tests defined as alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \> 5 times ULN within 28 days prior to informed consent.
• Have a positive test by antigen or polymerase chain reaction (PCR) for human immunodeficiency virus (HIV), if negative within 28 days prior to informed consent, the test does not need to be repeated.
• Patient or one or more of the patient's parents or legal guardians are is an employee or an immediate family member of Omeros, the Clinical Research Organization (CRO), an Investigator, or a study staff member.
• Have a known hypersensitivity to any constituent of the product.
• Presence of any condition that the Investigator believes would put the patient at risk.

Sponsors & Collaborators

• Omeros Corporation: lead

Study Sites (16)

Omeros Investigational Site

San Diego, California, 92024, United States

RECRUITING

Omeros Investigational Site

Gainesville, Florida, 32608, United States

NOT YET RECRUITING

Omeros Investigational Site

Boston, Massachusetts, 02215, United States

NOT YET RECRUITING

Omeros Investigational Site

St Louis, Missouri, 63104, United States

RECRUITING

Omeros Investigational Site

New York, New York, 10065, United States

NOT YET RECRUITING

Omeros Investigational Site

Valhalla, New York, 10595, United States

RECRUITING

Omeros Investigational Site

Houston, Texas, 77030, United States

NOT YET RECRUITING

Omeros Investigational Site

Seattle, Washington, 98105, United States

NOT YET RECRUITING

Omeros Investigational Site

Halle, Germany

NOT YET RECRUITING

Omeros Investigational Site

Hanover, Germany

NOT YET RECRUITING

Omeros Investigational Site

Haifa, Israel

NOT YET RECRUITING

Omeros Investigational Site

Jerusalem, Israel

NOT YET RECRUITING

Omeros Investigational Site

Ramat Gan, Israel

NOT YET RECRUITING

Omeros Investigational Site

Tel Aviv, Israel

NOT YET RECRUITING

Omeros Investigational Site

Utrecht, Netherlands

NOT YET RECRUITING

Omeros Investigational Site

Pamplona, Spain

RECRUITING

MeSH Terms

Conditions

Thrombotic Microangiopathies

Interventions

narsoplimab

Condition Hierarchy (Ancestors)

Thrombocytopenia; Blood Platelet Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Cytopenia

Central Study Contacts

Omeros Clinical Trial Information

CONTACT

206-676-5000; ctinfo@omeros.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR
• Expanded Access: Yes

Study Record Dates

• First Submitted: April 6, 2023
• First Posted: May 11, 2023
• Study Start: May 1, 2023
• Primary Completion: December 1, 2025
• Study Completion: December 1, 2025
• Last Updated: March 25, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1); DE (2); US (8); IL (4); NL (1)