Regenxbio's RGX-121 Hunter syndrome gene therapy faces second clinical hold after spinal lumps found in 5 CAMPSIITE trial patients, sending $RGNX shares down 23%.

Investigators detected masses on the spines of five patients who received its Hunter syndrome treatment, leading to the program’s second clinical hold this year.

REGENXBIO Announces Regulatory Update on RGX-121 for MPS II