US pharmaceutical company AbbVie (NYSE ABBV) and Capstan Therapeutics Inc, a clinical-stage biotechnology company involved in advancing in vivo engineering of cells through RNA delivery using tLNPs, announced on Monday a definitive agreement under which AbbVie will acquire Capstan.

The deal includes CPTX2309, a potential first-in-class in vivo tLNP anti-CD19 CAR-T therapy candidate, currently in Phase 1, in development for the treatment of B cell-mediated autoimmune diseases.

Additionally, AbbVie will acquire Capstan's proprietary tLNP platform technology designed to deliver RNA payloads, such as mRNA, capable of engineering specific cell types in vivo.

Under the terms of the agreement, AbbVie will pay up to USD2.1bn in cash at closing to acquire Capstan, subject to certain customary adjustments. The transaction is subject to the satisfaction of customary closing conditions, including expiration of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act.