UCB is adding a big piece to its immunology pipeline with a multi-billion dollar deal to buy Candid Therapeutics, a clinical-stage biotech company developing therapies in a promising but competitive new area of drug research aiming to treat autoimmune disorders by resetting the immune system.
According to financial terms announced Sunday, UCB will pay Candid shareholders $2 billion up front. The Belgian pharmaceutical company could shell out up to $200 million more if Candid’s therapies achieve milestones. With the acquisition, Candid is dropping a prior merger deal it had struck as a way to join the public markets.
Candid’s R&D focuses on developing drugs in the class of medicines called T cell engagers (TCEs). These therapies are bispecific antibodies designed to bind to a target on a T cell and a target on a disease-driving cell, directing the immune cell to kill the pathogenic one. While this type of therapy first reached patients as cancer treatments, a growing number of companies are developing TCEs for autoimmune disorders.
Many of the TCEs that have reached clinical development are intended to deplete the body of disease-driving B cells. It’s hoped the immune cells that replace the depleted ones do not target healthy tissue, amounting to a reset of the immune system. Such therapies could be long lasting, though efficacy and durability still needs to be assessed in clinical trials.
Lead Candid program cizutamig is a TCE designed to target the protein BCMA expressed by B cells that drive autoimmune disorders. Following positive Phase 1 results showing favorable safety and tolerability, Candid has said it plans to advance this program to Phase 2 testing in myasthenia gravis and interstitial lung disease. Candid’s next program addresses a different B cell target called CD19. This TCE, bearing the code name CND261, is in early clinical testing with initial data expected in the first half of this year. The Candid pipeline also includes TCEs in preclinical development.
The application of TCEs to immunology has become a hot area for research and dealmaking. In March, Gilead Sciences agreed to pay nearly $1.7 billion up front to acquire Ouro Medicines, a startup whose lead TCE therapeutic candidate is in early clinical development for two rare autoimmune disorders. Cullinan Therapeutics expanded beyond its previous cancer focus to include the development of TCEs for autoimmune disorders. CLN-978, a Cullinan TCE in development for rheumatoid arthritis and systemic lupus erythematosus development, is expected to post preliminary Phase 1 data in the current quarter. Large pharmaceutical companies are also in this space. GSK and Merck have bolstered their pipelines by acquiring rights to bispecific antibodies with potential applications in immunology.
UCB’s main therapeutic areas are neurology and immunology. Its top-selling product is Bimzelx, a chronically dosed antibody drug approved for treating plaque psoriasis and four other immunological disorders. For 2025, Bimzelx accounted for €2.2 billion (about $2.5 billion) of UCB’s nearly €7.4 billion (about $8.6 billion) in net sales.
UCB said Candid complements a recent deal it struck securing exclusive rights to a bispecific T cell engager that Antengene developed for B cell-related autoimmune diseases. Antengene remains responsible for Phase 1 testing in China and Australia, then UCB will take over development. UCB committed $80 million, comprised of an upfront payment and near-term milestone payments; additional milestone payments could reach $1.1 billion.
UCB said the Candid and Antengene deals reflect its platform-driven strategy for developing next-generation immunology drugs, giving the company broad reach across multiple B cell targets and disease mechanisms. The strategy is also about diversification, enabling UCB to avoid reliance on a single asset. In the Candid acquisition announcement, UCB CEO Jean-Christophe Tellier said this deal marks “a pivotal moment for UCB” as the company aims to achieve immune reset.
“We consider cizutamig as a potential transformative asset, that complements our existing programs, and is poised to redefine treatment expectations for severe, underserved immune-mediated diseases, offering the potential to deliver meaningful improvements in patient outcomes and quality of life,” he said.
UCB’s Candid acquisition still needs to pass regulatory muster, but the companies expect to close the transaction late in the second quarter of this year or early in the third quarter. First, UCB and Candid need to cough up additional cash. In March, Candid agreed to combine with publicly traded Rallybio in a reverse merger that would take Candid public. Per terms of the acquisition agreement, Candid may terminate the deal to accept a superior offer. In a Monday regulatory filing, Rallybio confirmed Candid terminated the merger in order to enter an agreement with UCB. That action triggered a $50 million termination fee payable on the first business day following the termination.
Photo: Emile Windal/Belga Mag/ Belga/AFP, via Getty Images
