AbbVie has announced a definitive agreement to acquire Capstan Therapeutics, a clinical-stage biotechnology company pioneering targeted in vivo cell engineering, in a deal valued at up to $2.1 billion. The acquisition includes Capstan’s lead asset, CPTX2309—an investigational therapy targeting B cell-mediated autoimmune diseases—as well as the company’s proprietary targeted lipid nanoparticle (tLNP) platform for RNA delivery.
This strategic move signals AbbVie’s growing commitment to reshaping the treatment landscape for autoimmune diseases. While AbbVie has long been a major player in immunology with blockbuster therapies like Humira and Rinvoq, the addition of Capstan’s in vivo CAR-T capabilities positions the company at the frontier of a new therapeutic modality.
CPTX2309 is an mRNA-based therapy that delivers an anti-CD19 chimeric antigen receptor (CAR) directly into CD8-expressing cytotoxic T cells via Capstan’s tLNP system. Unlike traditional ex vivo CAR-T therapies, which require harvesting and engineering a patient’s cells outside the body before reinfusion, CPTX2309 enables this transformation to happen in vivo. This significantly simplifies the treatment process by eliminating the need for lymphodepletion or complex manufacturing steps—making it potentially more scalable and accessible.
Targeting CD19, a well-validated marker expressed on B cells, CPTX2309 aims to deplete the autoreactive B cells responsible for driving autoimmune diseases such as lupus or multiple sclerosis. The goal is to eliminate the pathogenic immune cells and repopulate the system with naïve, healthy B cells—effectively resetting the immune system and halting disease progression.
AbbVie is not only acquiring a promising clinical candidate but also a platform technology with broad applications. Capstan’s proprietary CellSeeker™ tLNP platform can be adapted to deliver a variety of RNA payloads to specific cell types in vivo, opening possibilities far beyond autoimmune conditions. This could have future implications for oncology, infectious diseases, and more.
As part of the agreement, AbbVie will make a cash payment of up to $2.1 billion at closing, subject to customary regulatory and legal conditions, including the expiration of the waiting period under the Hart-Scott-Rodino Act.
This acquisition adds to AbbVie’s expanding immunology pipeline and enhances its positioning in next-generation therapeutic development. By integrating Capstan’s cutting-edge technology, AbbVie aims to develop new approaches that go beyond treating symptoms and instead target the root causes of autoimmune disorders.
The transaction is expected to close later this year. Capstan was advised by Centerview Partners LLC as financial advisor and Cooley LLP as legal counsel. AbbVie did not disclose its legal or advisory team.
This deal reflects a growing industry trend of major pharmaceutical companies investing heavily in advanced RNA delivery platforms and in vivo cell therapies—technologies seen as essential to the next wave of personalized medicine. With this acquisition, AbbVie reaffirms its commitment to driving innovation that transforms the standard of care for patients worldwide.
