For Medical Professionals

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Welcome to the UNITY Study

Protocol MOM-M281-003 (

A Multicenter, Open-Label Study to Evaluate the Safety, Efficacy, Pharmacokinetics, and Pharmacodynamics of M281 Administered to Pregnant Women at High Risk for Early Onset Severe Hemolytic Disease of the Fetus and Newborn (HDFN).

About M281

M281 is a fully human, anti-FcRn, glycosylated IgG1 monoclonal antibody. It is engineered to bind to FcRn with high affinity and block FcRn. M281 is intended to reduce the risk and severity of fetal anemia and the resulting morbidities by blocking FcRn-mediated IgG recycling, thereby reducing the pathogenic alloantibodies in maternal circulation; and by blocking the placental transfer of maternal IgG, including pathogenic alloantibodies, to the fetus. The investigational drug is not approved by the FDA or any other regulatory agency. It is not known if the investigational drug works or is safe.

UNITY Study Summary

Protocol MOM-M281-003 ( )
Phase 2
Patient Population Females 18 years of age or older; 8 to 13 weeks pregnant
Medical History History of previous pregnancy that included at least one of the following:
  • Severe fetal anemia
  • Fetal hydrops
  • Stillbirth indicative of HDFN
Open-Label Drug All study participants will receive the investigational drug
Method of Administration Weekly intravenous infusions (approximately two hours per infusion) until birth
Primary Objectives To evaluate the safety in mother and neonate/infant of M281 administered to pregnant women at high risk for early onset severe HDFN (EOS-HDFN).
To evaluate the efficacy of M281 as measured by the proportion of patients with live birth at or after gestational age (GA) Week 32 and without an intrauterine transfusion (IUT) throughout the entire pregnancy.
Length of Study Participation Approximately four months
  • Screening Period (Up to 6 weeks)
  • Study Treatment Period (Approximately 20 weeks)
  • Post-natal Follow-up Period (Approximately 24 weeks)
  • Infant Follow-up Period (Approximately 96 weeks)
Reimbursement and Travel Assistance All eligible study participants will be reimbursed for reasonable study-related expenses. In addition, travel assistance and living accommodations (for those not located near a participating study location) may be provided to study participants and a family member or caregiver at no cost.

Patients who do not qualify to participate in the UNITY Study may still be eligible to participate in the CLARITY Study – our non-interventional HDFN Natural History Study. Please consider this information when deciding whether to refer a patient.