Belgian pharmaceutical company UCB is making a substantial move to expand its immunology pipeline, entering into a multi-billion dollar agreement to acquire Candid Therapeutics a clinical-stage biotechnology company working on therapies designed to treat autoimmune disorders by resetting the immune system. The UCB Candid Therapeutics deal involves an upfront payment of $2 billion to Candid’s shareholders, with an additional $200 million potentially payable upon the achievement of specific development milestones.
As a direct result of the UCB acquisition, Candid Therapeutics is withdrawing from a previously announced reverse merger with publicly traded Rallybio, a transaction that had been structured as a pathway for Candid to enter the public markets. In a regulatory filing made the following Monday, Rallybio confirmed that Candid had terminated the merger agreement in order to proceed with the UCB deal. Per the terms of the prior merger agreement, Candid’s withdrawal triggered a $50 million termination fee, payable on the first business day following the termination.
The Science Behind Candid’s Pipeline
Candid Therapeutics focuses its research and development on a class of medicines known as T cell engagers, or TCEs. These are bispecific antibodies engineered to simultaneously bind to a target on a T cell and a target on a disease-driving cell, effectively directing the immune cell to destroy the pathogenic one. Although TCE therapies were initially developed and deployed as cancer treatments, a growing number of pharmaceutical and biotech companies are now advancing these therapies into the field of autoimmune disorders.
Many of the TCEs currently in clinical development are designed to deplete the body of disease-driving B cells, with the hope that the immune cells that replenish them will not attack healthy tissue effectively resulting in a reset of the immune system. The potential for long-lasting efficacy exists, though durability and overall effectiveness continue to be evaluated through ongoing clinical trials.
Cizutamig: Candid’s Lead Program
Candid’s lead asset, cizutamig, is a T cell engager developed to target the protein BCMA, which is expressed by B cells that drive autoimmune disorders. Following positive Phase 1 results that demonstrated favorable safety and tolerability, Candid has outlined plans to advance cizutamig into Phase 2 testing in myasthenia gravis and interstitial lung disease.
CND261 and Additional Pipeline Assets
Candid’s second program targets a different B cell marker known as CD19. This TCE, identified by the code name CND261, is currently in early-stage clinical testing, with initial data expected during the first half of this year. The company’s pipeline also includes additional T cell engager candidates in preclinical development.
A Competitive and Fast-Moving Space
The application of T cell engagers in immunology has rapidly emerged as one of the most active areas in biopharmaceutical research and dealmaking. In March, Gilead Sciences agreed to pay nearly $1.7 billion upfront to acquire Ouro Medicines, a startup whose lead TCE therapeutic candidate is in early clinical development for two rare autoimmune disorders. Cullinan Therapeutics has also expanded beyond its earlier cancer focus to include TCEs for autoimmune conditions, with its asset CLN-978 in development for rheumatoid arthritis and systemic lupus erythematosus expected to post preliminary Phase 1 data in the current quarter.
Large pharmaceutical companies have similarly been active. GSK and Merck have both strengthened their pipelines by acquiring rights to bispecific antibodies with potential applications in immunology.
UCB’s Strategic Context
UCB’s core therapeutic areas are neurology and immunology. Its top-selling product is Bimzelx, a chronically administered antibody drug approved for plaque psoriasis and four other immunological disorders. For 2025, Bimzelx contributed €2.2 billion (approximately $2.5 billion) of UCB’s nearly €7.4 billion (approximately $8.6 billion) in net sales.
The UCB Candid Therapeutics deal complements an earlier agreement UCB secured granting it exclusive rights to a bispecific T cell engager developed by Antengene for B cell-related autoimmune diseases. Under that arrangement, Antengene remains responsible for Phase 1 testing in China and Australia, after which UCB will take over development. UCB committed $80 million in upfront and near-term milestone payments for that deal, with additional milestone payments potentially reaching $1.1 billion.
UCB has stated that both the Candid and Antengene agreements reflect its platform-driven strategy for developing next-generation immunology drugs, providing the company with broad reach across multiple B cell targets and disease mechanisms. The approach is also intended to support diversification, reducing reliance on any single asset.
Executive Statement and Deal Timeline
In announcing the UCB acquisition of Candid Therapeutics, UCB Chief Executive Officer Jean-Christophe Tellier described 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.”
The transaction remains subject to regulatory review, with both companies anticipating deal closure in either the late second quarter or early third quarter of this year.
