LONDON, Feb 15 (Reuters) - GSK said on Thursday it had completed the acquisition of Aiolos Bio, a clinical-stage biopharmaceutical company focused on respiratory and inflammatory conditions.

GSK will pay $1 billion upfront and up to $400 million in success-based milestone payments.

"In addition, GSK will also be responsible for success-based milestone payments as well as tiered royalties owed to Jiangsu Hengrui Pharmaceuticals Co, Ltd," the group said.

(Reporting by Pablo Mayo Cerqueiro; editing by Jason Neely)