July 14 (Reuters) - Spero Therapeutics SPRO.O has licensed rights outside Greater China to develop and commercialize Innovent Biologics' 1801.HK experimental autoimmune disease treatment in a deal worth up to about $1.1 billion, the companies said on Tuesday.

• Spero will get exclusive rights to develop, manufacture and sell the treatment, IBI355, worldwide outside Greater China, while Innovent will retain rights in its home market.

• The transaction gives Spero its first immunology asset as it expands beyond its infectious disease business.

• Innovent will receive an upfront payment and is eligible for development, regulatory and commercial milestone payments, totaling about $1.1 billion, as well as royalties on sales.

• IBI355 targets CD40L, a protein involved in immune system signaling, and is being developed for autoimmune and inflammatory diseases.

• Spero plans to begin a mid-stage trial of the drug in IgG4-related disease in the second quarter of 2027, while Innovent plans a mid-stage China study in Sjögren's disease by early 2027.

• IgG4-related disease is a chronic inflammatory disorder affecting multiple organs, while Sjögren's disease is an autoimmune disease that primarily affects tear and salivary glands.

• The drug has completed early-stage testing in healthy volunteers and has also been studied in patients with Sjögren's disease, the companies said.