Rallybio Halts Development of Lead FNAIT Program Following Phase 2 Failure

Program Discontinuation:
Rallybio ceased development of its lead monoclonal antibody therapy, RLYB212, targeting fetal and neonatal alloimmune thrombocytopenia (FNAIT), a rare maternal immune disorder, after failing to meet efficacy benchmarks in Phase 2 trials3 6.

Trial Results:
The Phase 2 trial data revealed that RLYB212 could not achieve the predicted pharmacokinetic target concentrations necessary for efficacy (minimum target of 3 ng/mL, ideal range of 6-10 ng/mL)3 6.

Condition Overview:
FNAIT is a condition where a mother’s immune system destroys fetal platelets due to incompatibility, potentially causing severe bleeding or neurological damage in the fetus or newborn1 4.

Pipeline Shift:
Rallybio is now focusing on RLYB116, a complement pathway inhibitor for rare autoimmune disorders, as well as earlier-stage programs targeting conditions such as hypophosphatasia and iron overload3 6.

Market Context:
The failure of RLYB212 leaves a gap in the development of therapies for FNAIT, for which no approved preventive treatments currently exist7.

Financial Impact:
This decision comes at a time when Rallybio is under financial strain, including a potential Nasdaq delisting, with its stock trading at $0.25 per share6.