Johnson & Johnson’s IMAAVY shows rapid, durable hemoglobin gains in Phase 2/3 wAIHA trial

Study design and primary endpoint

ENERGY is a multicenter, randomized, double‑blind, placebo‑controlled Phase 2/3 study that randomized 115 adults approximately 1:1:1 to two nipocalimab dose schedules or placebo. The primary endpoint—durable hemoglobin (Hgb) response—was prespecified as Hgb ≥10 g/dL plus an increase ≥2 g/dL from baseline for at least 28 days (met starting by Week 16), without rescue therapy or changes to background wAIHA medications. The dose submitted to the FDA was 30 mg/kg IV every four weeks.

Efficacy results

In the 30 mg/kg group, mean Hgb rose by about 1 g/dL by Week 1 versus no change on placebo. By Week 24, roughly three times more patients on 30 mg/kg met the durable Hgb response compared with placebo, and nearly two‑thirds achieved both Hgb ≥10 g/dL and a ≥2 g/dL increase. Patient‑reported fatigue improved as early as Week 2 and was sustained through Week 24 (mean FACIT‑Fatigue benefit 3.51 points over placebo).

Safety and secondary outcomes

Safety was described as consistent with the established profile of IMAAVY in generalized myasthenia gravis; the most common adverse reactions (≥10%) were peripheral edema, diarrhea and fever. Participants who met the durable Hgb response were required to taper corticosteroids; mean steroid dose reduction at Week 24 was 15% for nipocalimab versus 4% for placebo.

Regulatory context

Johnson & Johnson reported these results to support a supplemental BLA; the submission has been granted U.S. FDA Priority Review. There are currently no FDA‑approved therapies specifically for warm autoimmune hemolytic anemia (wAIHA).