Entrada Therapeutics' ENTR-601-44 showed only 2.36% dystrophin increase in phase 1/2 trial for DMD exon 44 skipping, far below expectations of double-digit levels.
Stock plunged 59% to $6.57 from $16.02 after data release.
Rival Avidity's delpacibart zotadirsen achieved 25% dystrophin increase; Avidity acquired by Novartis for $12B.
Lower plasma exposure in juvenile DMD patients (50% less than adults/NHPs) cited as cause.
Higher-dose cohort data expected Q4; plans for third dose cohort and platform adjustments.