AbbVie to Acquire Capstan Therapeutics, Further Strengthening Commitment to Transforming Patient Care in Immunology

• Capstan's lead asset, CPTX2309, is a targeted lipid nanoparticle (tLNP) that delivers an mRNA encoding an anti-CD19 chimeric antigen receptor (CAR) to CD8-expressing cytotoxic T cells in vivo, and is a potential first-in-class product for treating B cell-mediated autoimmune diseases
• Proposed acquisition strengthens AbbVie's commitment to transforming the future of patient care with Capstan's innovative tLNP platform technology

NORTH CHICAGO, Ill. and SAN DIEGO, June 30, 2025 /PRNewswire/ -- AbbVie (NYSE: ABBV) and Capstan Therapeutics, Inc. ("Capstan"), a clinical-stage biotechnology company dedicated to advancing in vivo engineering of cells through RNA delivery using tLNPs, today announced a definitive agreement under which AbbVie will acquire Capstan, including 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.

"Scientific innovation is required to address not just the symptoms of autoimmune diseases, but also to resolve and potentially cure the underlying disease," said Roopal Thakkar, M.D., executive vice president, research and development and chief scientific officer, AbbVie. "By advancing CPTX2309 and utilizing Capstan's novel platform technology, AbbVie and Capstan aim to transform the care of those living with autoimmune diseases by developing treatments that have the potential to reset the immune system."

"In vivo CAR-T represents a potential new treatment modality in medicine – embodying the transformative power of cell therapy with the accessibility and scalability of an off-the-shelf biologic. This technology has the potential to become a first-in-class platform to treat a wide range of autoimmune diseases," said Laura Shawver, Ph.D., president and chief executive officer, Capstan. "Through AbbVie's world-leading expertise in immunology research, clinical development, and its commercialization capabilities, we believe that this transaction moves us closer to delivering on our shared mission to bring these innovative therapies to patients in need."

B cells contribute to the pathogenesis of autoimmune diseases. CD19 is a cell surface receptor expressed on B cells and is a clinically validated target for B cell depletion using ex vivo CAR-T cell therapy in autoimmune diseases. CPTX2309, a product of Capstan's proprietary technology platform that includes hepatic de-targeting, delivers an mRNA payload encoding an anti-CD19 CAR preferentially to reprogram CD8-expressing cytotoxic T cells. This process is achieved in vivo, without the need for lymphodepletion preconditioning and complex ex vivo manufacturing. The in vivo-modified CD8-expressing T cells will transiently express the CD19 CAR and deplete B cells in the periphery and tissues. Depletion of autoreactive antibody-producing pathogenic memory B cells and repopulation with naïve B cells, resulting in immune reset, has the potential to prevent disease progression and induce clinical remission.

Under the terms of the agreement, AbbVie will pay up to $2.1 billion 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.

Advisors

Capstan's exclusive financial advisor was Centerview Partners LLC and Cooley LLP served as legal advisor.

About AbbVie

AbbVie's mission is to discover and deliver innovative medicines and solutions that solve serious health issues today and address the medical challenges of tomorrow. We strive to have a remarkable impact on people's lives across several key therapeutic areas including immunology, oncology, neuroscience and eye care – and products and services in our Allergan Aesthetics portfolio. For more information about AbbVie, please visit us at www.abbvie.com. Follow @abbvie on LinkedIn, Facebook, Instagram, X (formerly Twitter) and YouTube.

About Capstan Therapeutics, Inc. 

Capstan is a clinical-stage biotechnology company with a mission to multiply the therapeutic possibilities for patients by developing targeted in vivo RNA technologies. Our proprietary CellSeeker™ tLNP platform technology is composed of novel LNPs conjugated with a recombinant protein binder, such as a monoclonal antibody, that deliver an RNA payload capable of engineering cells in vivo. Capstan's initial focus is on developing in vivo CAR-T therapies designed to combine the potency of CAR-T therapy with the convenience of an off-the-shelf product for the treatment of autoimmune diseases.  For more information, please visit www.capstantx.com and follow us on LinkedIn.

No Offer or Solicitation

This press release is for information purposes only and is not intended to and does not constitute, or form part of, an offer, invitation or the solicitation of an offer or invitation to purchase, otherwise acquire, subscribe for, sell or otherwise dispose of any securities, or the solicitation of any vote or approval in any jurisdiction, pursuant to the proposed transaction or otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law.

Forward-Looking Statements 

Some statements in this news release are, or may be considered, forward-looking statements for purposes of the Private Securities Litigation Reform Act of 1995. The words "believe," "expect," "anticipate," "project" and similar expressions and uses of future or conditional verbs, generally identify forward-looking statements. AbbVie cautions that these forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially from those expressed or implied in the forward-looking statements. Such risks and uncertainties include, but are not limited to, challenges to intellectual property, competition from other products, difficulties inherent in the research and development process, adverse litigation or government action, changes to laws and regulations applicable to our industry, the impact of global macroeconomic factors, such as economic downturns or uncertainty, international conflict, trade disputes and tariffs, and other uncertainties and risks associated with global business operations. Additional information about the economic, competitive, governmental, technological and other factors that may affect AbbVie's operations is set forth in Item 1A, "Risk Factors," of AbbVie's 2024 Annual Report on Form 10-K, which has been filed with the Securities and Exchange Commission, as updated by its Quarterly Reports on Form 10-Q and in other documents that AbbVie subsequently files with the Securities and Exchange Commission that update, supplement or supersede such information. AbbVie undertakes no obligation, and specifically declines, to release publicly any revisions to forward-looking statements as a result of subsequent events or developments, except as required by law.

SOURCE AbbVie