Rallybio (RLYB) said Tuesday it will discontinue development of RLYB212 after the drug failed to reach expected concentration levels in a phase 2 trial.

The company said that RLYB212 did not meet the predicted or minimum drug concentration needed for effectiveness in its phase 2 study for the prevention of fetal and neonatal alloimmune thrombocytopenia, a rare immune disorder.

Rallybio said no further enrollment will occur, and the program will be discontinued.

Rallybio said it will now focus on RLYB116, with a confirmatory pharmacokinetic/pharmacodynamic study set to begin in Q2. Data from the first two cohorts is expected in H2, the company said.

Rallybio shares fell by more than 32% in early trading on Tuesday.