LoigBio's shares, which have traded below $1 since February, were up 637% at $2 before the bell, close to AstraZeneca's offer price of $2.07 per share.

LogicBio is developing gene editing therapies to treat pediatric rare disease like methylmalonic acidemia, where the body cannot break down certain proteins and fats.

AstraZeneca said the deal would accelerate growth of its Alexion unit, which it acquired for $39 billion last year, in the field of genomic medicine.

(Reporting by Leroy Leo in Bengaluru; Editing by Maju Samuel)