UCB bets $2.2 billion that T cell engagers can reset the autoimmune immune system
UCB bets $2.2 billion that T cell engagers can reset the autoimmune immune system
UCB is making a $2.2 billion bet that the immune system can be edited, not just suppressed.
The Belgian pharma company announced Monday it will acquire Candid Therapeutics, a San Diego-based clinical-stage biotech, for $2 billion upfront and up to $200 million in milestones. The lead asset is cizutamig, a BCMA/CD3 bispecific T cell engager that has moved into five autoimmune indications: IgA nephropathy, myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis. Over 100 patients have been treated across oncology and autoimmune trials. The deal is expected to close in Q2 or Q3 2026, pending antitrust review.
The scientific bet is precise. Cizutamig directs a patient's own T cells to destroy BCMA-expressing plasma cells and B cells, the antibody-producing cells that drive a range of autoimmune diseases. The goal is not suppression but elimination: remove the pathogenic cells, and the disease cannot sustain itself. Unlike JAK inhibitors or anti-TNF biologics that must be taken indefinitely, a single course of a T cell engager could theoretically deliver durable disease control. Whether that means true immune reset, and whether that reset lasts, remains the central open question.
The mechanism is not without risk. A Nature Medicine paper published in February 2026 reported on compassionate use of two T cell engagers, blinatumomab and teclistamab, in patients with severe autoimmune connective tissue diseases. Both showed clinical benefit, including reversal of skin fibrosis and drops in autoantibody levels. Both also caused cytokine release syndrome, including Grade 3 CRS in multiple patients. The authors noted that ongoing maintenance therapy with rituximab was required to prevent redifferentiation of B cells and relapse. Candid's pipeline includes a second asset, CND261, engineered with lower CD3 affinity to reduce CRS risk — a design choice that acknowledges the toxicity problem without claiming to have solved it.
"This acquisition demonstrates our inorganic innovation strategy in action," said Jean-Christophe Tellier, UCB's CEO, calling cizutamig "potentially transformative" and "the next wave of therapies to treat immune mediated diseases."
The Candid deal is not UCB's first move in this direction. In March 2026, the company acquired rights to ATG-201 from Antengene, a CD19/CD3 TCE, in a transaction valued at roughly $1.1 billion. Together, the two acquisitions give UCB four TCE programs across multiple B cell antigens: BCMA, CD19, CD20, and combination targets. The company is building a platform while its competitors are buying individual assets.
"We're efficiently generating clinical data so as to identify where our TCEs could provide maximal clinical benefit for the broadest number of patients," said Ken Song, MD, Candid's chairman and CEO. Candid launched in late 2024 with $370 million in financing. Song has said publicly that he believes TCEs will become the largest therapeutic class in autoimmune disease, surpassing the commercial success of TNF inhibitors like Humira.
UCB is not positioning itself in isolation. Three major engineered cell therapy deals for autoimmune disease have crossed a combined $10 billion in commitments in recent weeks. Eli Lilly paid up to $2.4 billion for Orna Therapeutics in February 2026, focused on in vivo CAR-T for autoimmune disease. Eli Lilly then paid up to $7 billion for Kelonia Therapeutics in April 2026, acquiring a second in vivo CAR-T platform. UCB's back-to-back TCE acquisitions slot into that pattern: big pharma is racing to own the technology that could replace chronic immunosuppression with something more definitive.
The competitive stakes are not abstract. UCB's existing immunology portfolio includes Cimzia, a TNF inhibitor whose peak sales target is €2 billion, reached ahead of schedule. The company's broader 2025 guidance projects revenue of €6.5 to €6.7 billion. If TCEs prove durable in autoimmune disease, they do not merely represent a new product — they represent a competitor to the chronic-drug revenue model that has financed UCB's growth. The same tension applies to every large pharma company with a legacy autoimmune franchise.
The risks are real and interconnected. Cizutamig must demonstrate durable responses in autoimmune populations without the CRS that has complicated comparable agents. The Nature Medicine data suggests that even when TCEs work, maintenance therapy may be required — the reset may not be permanent. The antitrust review could delay or block the deal. And dealmakers are noticing: the pace of recent acquisitions has compressed the field of available targets with credible data, and buy-side sources describe the window for opportunistic licensing as narrowing fast.
For now, UCB is stacking deals. The next data readouts across those five autoimmune indications will begin answering whether the platform thesis holds.