AbbVie is making a full strength play for the in vivo CAR-T market, snapping up Capstan Therapeutics for $2.1 billion to add an early-phase autoimmune drug candidate to its pipeline.
Capstan is part of a band of biotechs trying to clear barriers to CAR-T uptake by reprogramming cells inside—rather than outside—the body. Manufacturing and scalability challenges, plus the need for patients to receive lymphodepleting chemotherapy, could prevent widespread use of traditional CAR-T cell therapies. In theory, in vivo CAR-T therapies could allow more people to receive powerful therapies.
AbbVie is on board with the idea. The Big Pharma will pay up to $2.1 billion in cash at closing to acquire Capstan. In return, AbbVie will take ownership of the phase 1 in vivo anti-CD19 CAR-T therapy candidate CPTX2309 plus preclinical programs and the technology for generating more prospects.
A phase 1 study of CPTX2309 in healthy volunteers got underway in Australia in April. Capstan is running the trial to find a pharmacologically active dose to take into phase 2 studies in patients with autoimmune disease.
Rival in vivo CAR-T biotechs Interius BioTherapeutics and Umoja Biopharma beat Capstan in the race to the clinic. However, the rival biotechs are both initially targeting cancers, not autoimmune diseases, and use different technology than Capstan. Interius’ INT2104 and Umoja’s UB-VV111 use lentiviral vectors to generate CAR cells in vivo. Capstan is using mRNA to trigger CAR T-cell production.
CPTX2309 consists of an anti-CD19 CAR mRNA payload inside a lipid nanoparticle (LNP). The LNP has a targeting antibody to enable the delivery of the payload to CD8-positive T cells. In preclinical studies, the candidate selectively engineered human CD8-positive T cells into functional CAR-T cells.
In theory, the candidate could replicate the striking efficacy seen in autoimmune studies of conventional CD19 CAR-T therapies without facing the challenges that could limit ex vivo treatments to particularly sick patients. The potential puts CPTX2309 in the wheelhouse of AbbVie, a drugmaker that brushed off the loss of company-defining autoimmune drug Humira by rolling out Skyrizi and Rinvoq as successors.
Buying Capstan could unlock opportunities in other therapeutic areas. The biotech’s preclinical pipeline includes a BCMA program, which has applications in oncology and autoimmune disease, and a fibroblast target that could extend its reach into fibrotic disorders. A who’s who of top pharma companies took a look at the pipeline, helping Capstan raise more than $300 million, before AbbVie bagged the buyout.