IMAAVY - Use in Patients with Warm Autoimmune Hemolytic Anemia with a History of Rituximab Use

SUMMARY

• The company cannot recommend any practices, procedures, or usage of IMAAVY that deviate from the approved labeling.
• ENERGY is a 24-week, phase 2/3, multicenter, randomized, double-blind, placebo (PBO)-controlled trial in adult patients with warm autoimmune hemolytic anemia (wAIHA)¹.
  • Patients who received rituximab within 3 months prior to screening were excluded from the study.

CLINICAL DATA

ENERGY Study

Fattizzo et al (2026)¹ evaluated the efficacy and safety of IMAAVY in adults with wAIHA in a phase 2/3 multicenter, randomized, double-blind, PBO-controlled study.

Study Design/Methods

• The study included adults (≥18 years of age) diagnosed with primary or secondary wAIHA for ≥3 months, defined as having all of the following^1,2:
  • Hemoglobin (Hgb) <10 g/dL
  • Signs of hemolysis (lactic dehydrogenase [LDH] >upper limit of normal [ULN], or indirect bilirubin >ULN, or haptoglobin [Hp] <lower limit of normal [LLN])
  • Direct antiglobulin test (DAT) positive for immunoglobulin G (IgG) +/- complement component 3d (C3d)
• The study consisted of a 2-week screening phase, followed by a 24-week, double-blind, PBO-controlled treatment phase, a 144-week open-label extension (OLE) phase, and safety follow-up at 8 weeks after the last infusion.¹
• Eligible patients were randomized (1:1:1) to receive intravenous (IV) IMAAVY 30 mg/kg every 4 weeks (Q4W), IMAAVY 15 mg/kg Q2W, or matching PBO every 2 weeks (Q2W) through week 24.
• Patients who received rituximab treatment within 3 months prior to screening were excluded.

Results

• A total of 115 patients were included in the efficacy analysis population (IMAAVY 30 mg/kg Q4W, n=38; 15 mg/kg Q2W, n=38; PBO, n=39).¹
• Prior rituximab use was reported in 42.1% (16/38), 55.3% (21/38), and 48.7% (19/39) of patients in the IMAAVY 30 mg/kg Q4W, 15 mg/kg Q2W, and PBO groups, respectively.
  • Durable Hgb response among patients with and without history of rituximab use is presented in Table: Durable Hemoglobin Response by History of Rituximab Treatment.²

Safety

• Most commonly reported (≥10%) treatment-emergent adverse events (TEAEs) occurring in the IMAAVY groups were wAIHA (as reported by the investigators), diarrhea, dizziness, headache, asthenia, peripheral edema, pyrexia, fatigue, and coronavirus disease 2019 (COVID-19).¹

Literature Search

A literature search of MEDLINE^®, EMBASE^®, BIOSIS Previews^®, and DERWENT^® (and/or other resources, including internal/external databases) was conducted on 31 August 2026.