Safety and Efficacy Study of OMS721 in Patients With Atypical Hemolytic Uremic Syndrome

NCT03205995 | Terminated Phase 3 Results DMC FDA Drug

• 1 other identifier: OMS721-HUS-002
• Study Type: interventional
• Target: 6
• Locations: 4 countries
• Sites: 4

Brief Summary

The purpose of this study is to evaluate the platelet count change from baseline and safety of OMS721 (narsoplimab) in adults and adolescents with atypical hemolytic uremic syndrome (aHUS). The study will also evaluate pharmacokinetics (PK), pharmacodynamics (PD), and anti-drug antibody response (ADA).

Conditions

Thrombotic Microangiopathies; Atypical Hemolytic Uremic Syndrome

Keywords

TMA; aHUS

Outcome Measures

Primary Outcomes (1)

• Platelet Count (10^9 Platelets/L) Change From Baseline at Week 26

  The primary outcome to be measured is platelet count change from baseline.

  Week 26

Secondary Outcomes (15)

• Safety as Measured by Incidences of Adverse Events, Vital Signs, ECG, and Clinical Laboratory Tests

  Pre-dose and up to 771 days post-dose

• Thrombotic Microangiopathies (TMA) Response

  26 weeks

• TMA Event-free Status

  26 weeks

• Increase in Estimated Glomerular Filtration Rate (eGFR)

  26 weeks

• Hematological Normalization

  26 weeks

Study Arms (1)

OMS721 (narsoplimab)

EXPERIMENTAL

Administration of OMS721 (narsoplimab)

Biological: OMS721 (narsoplimab)

Interventions

OMS721 (narsoplimab) BIOLOGICAL

Intravenous loading dose followed by daily subcutaneous injections

Also known as: narsoplimab

OMS721 (narsoplimab)

Eligibility Criteria

• Age: 12 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Are age \>= 12 years old at screening (Visit 1).
• Have a primary aHUS, diagnosed clinically, and have ADAMTS13 activity \> 5% in plasma. Participants are eligible with or without a documented complement mutation or anti-CFH antibody. Participants are categorized according to their response to plasma therapy (plasma exchange or plasma infusion):
• Plasma therapy-resistant aHUS participants must have all of the following:
• Screening platelet count \< 150,000/μL despite at least four plasma therapy treatments in a 7-day period prior to screening
• Evidence of microangiopathic hemolysis (at least one of:
• presence of schistocytes,
• serum LDH \> 1.5 times upper limit of normal (ULN), and
• haptoglobin \< LLN)
• Serum creatinine \> ULN
• Plasma therapy-responsive aHUS participants must have all of the following:
• Have a documented history of requiring plasma therapy to prevent aHUS exacerbation defined as all of the following:
• decrease in platelet count \> 25% when plasma therapy frequency has been decreased (including discontinuation of plasma therapy)
• LDH \> 1.5 times ULN when plasma therapy frequency has been decreased (including discontinuation of plasma therapy)
• Have received plasma therapy at least once every 2 weeks at an unchanged frequency for at least 8 weeks before first dose of OMS721
• If sexually active and of childbearing potential, must agree to practice a highly effective method of birth control until the end of the study, defined as one that results in a low failure rate (i.e., less than 1% per year) when used consistently and correctly, such as implants, injectables, combined oral contraceptives, some intrauterine devices, sexual abstinence or vasectomized partner.

You may not qualify if:

• Have STEC-HUS.
• Have a positive direct Coombs test.
• Have a history of hematopoietic stem cell transplant.
• Have HUS from an identified drug.
• History of vitamin B12 deficiency-related HUS.
• History of Systemic Lupus Erythematosus.
• History of antiphospholipid syndrome.
• Active cancer or history of cancer (except non-melanoma skin cancers) within 5 years of screening.
• Have been on hemodialysis or peritoneal dialysis for ≥ 12 weeks.
• Have an active systemic bacterial or fungal infection requiring systemic antimicrobial therapy (prophylactic antimicrobial therapy administered as standard of care is allowed).
• Baseline resting heart rate \< 45 beats per minute or \> 115 beats per minute.
• Baseline QTcF \> 470 milliseconds.
• Have malignant hypertension (diastolic blood pressure \[BP\] \> 120 mm Hg with bilateral hemorrhages or "cotton-wool" exudates on funduscopic examination).
• Have a poor prognosis with a life expectancy of less than three months in the opinion of the Investigator.
• Are pregnant or lactating.

Sponsors & Collaborators

• Omeros Corporation: lead

Study Sites (4)

Omeros Investigational Site

Chicago, Illinois, 60643, United States

Location

Omeros Investigational Site

Vilnius, Lithuania

Location

Omeros Investigational Site

Lodz, Poland

Location

Omeros Investigational Site

New Taipei City, Taiwan

Location

Related Publications (1)

• Pugh D, O'Sullivan ED, Duthie FA, Masson P, Kavanagh D. Interventions for atypical haemolytic uraemic syndrome. Cochrane Database Syst Rev. 2021 Mar 23;3(3):CD012862. doi: 10.1002/14651858.CD012862.pub2.

  PMID: 33783815 DERIVED

MeSH Terms

Conditions

Thrombotic Microangiopathies; Atypical Hemolytic Uremic Syndrome

Interventions

narsoplimab

Condition Hierarchy (Ancestors)

Thrombocytopenia; Blood Platelet Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Cytopenia; Hemolytic-Uremic Syndrome; Uremia; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Anemia, Hemolytic; Anemia

Results Point of Contact

• Title: Dr. Andreas Grauer
• Organization: Omeros Corporation

ctinfo@omeros.com

206-676-5000

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 3
• 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 17, 2017
• First Posted: July 2, 2017
• Study Start: May 2, 2018
• Primary Completion: February 2, 2021
• Study Completion: February 2, 2021
• Last Updated: December 10, 2025
• Results First Posted: December 10, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1); LI (1); TW (1); PL (1)