UCB pays up to $2.2bn for Candid Therapeutics, doubles for T-cell contributor to autoimmune disease

Belgian pharma buys two-year-old San Diego biotech for $2bn up front, TCE’s second bet in months. Thesis: B-cell killers designed for cancer could rewire how autoimmune diseases are treated.

Candid Therapeutics is two years old. It does not have an approved drug. Its lead program has been tested in nearly 100 patients across multiple early-stage trials. On Sunday, UCB, the Brussels-listed pharmaceutical company, agreed to buy it for up to $2.2bn.

That kind of price for that kind of biotech needs an explanation, and the explanation, in 2026, has a name: IT-cell engagers in autoimmune disease.

Under the deal announced on May 3, UCB will pay $2bn in cash on a first-come, first-served basis, up to $200m in milestone payments linked to development and regulatory progress.

The deal, expected to close by the end of the second quarter or the beginning of the third, is subject to antitrust approval. UCB also confirmed its financial guidance for 2026, which suggests it intends to take on the job without any expected delays.

It is the second time in months that a Belgian company has achieved the same treatment. In an earlier deal, UCB licensed ATG-201, a CD19/CD3 bispecific from China-based Antengene, in a deal worth up to $1.1bn. The discovery of Candid falls on top of that and adds a B-cell target.

What does Candid actually have?

Candid’s lead product is cizutamig, a bispecific antibody designed to block two cells: it captures the T-cell on the one hand with CD3 and the plasma cell on the other with BCMA, the B-cell maturation antigen, instructing the T-cell to destroy the plasma cell.

The device was developed for multiple myeloma, where killing the malignant plasma cells is the only treatment. The 2026 thesis states that the same engine can be used to eliminate autoreactive B-cells and plasma cells that drive autoimmune diseases such as lupus, myasthenia gravis, and a long list of infamous conditions where the immune system attacks its own tissues.

According to UCB, cizutamig has now been clinically tested in more than 100 patients combined in all myeloma and autoimmune indications, and is currently in Phase 1 studies in more than ten autoimmune diseases.

UCB describes it, in its statement, as the potential best BCMA T-cell in the most advanced immune disease, ambitious language and common in press releases of this type.

The reason consumers are willing to write nine-person checks for the Phase 1 data is that the early immune signals from this class of drugs, by and large, have been really impressive. Patients with severe disease have shown long-lasting remission after a single course of B-cell-depleting therapy, including cases where decades of small-molecule and biologic therapy have produced only partial control. None of this is clear yet.

Later cross-sectional data, larger cohorts, and longer follow-up will be needed. But the direction has been consistent enough that pharma boardrooms have begun pricing in the price as if it’s working.

Candid was founded in 2024 in San Diego, backed by Two River Group and Vida Ventures and a $370m funding round. Its chairman, chief executive and president is Dr Ken Song, who previously led RayzeBio through its $4.1bn acquisition by Bristol Myers Squibb in late 2023. Building, scaling, and selling clinical-stage oncology and immunology biotechs, in other words, is what he does.

That history is part of what UCB pays for. Buyers in this segment of the market are increasingly willing to write down the quality of management next to the quality of the molecule, especially if the sales promise of the molecule depends on the design of a disciplined trial with a large number of small indicators.

The valuation gap between the initial funding of $370m in mid-2024 and the $2bn front UCB is paying now, in cash, less than two years later, is a fair indication of what investors think he and his team have built.

It is also a sharp reversal. In March, Candid had announced a reverse merger with Rallybio, a publicly listed but small rare disease company, aiming to take Candid’s community to the backlist. That transaction, to all appearances, has now been superseded. UCB’s offer, perhaps, was better.

UCB’s purchases follow a pattern that is hard to miss. In the past nine months, every major immunology pharma company has purchased, licensed, or partnered with a T-cell-based immune disease target.

Gilead acquired Ouro Medicines for $2.18bn earlier this year, picking up gamgertamig, another BCMAxCD3 company. Sanofi has licensed a trispecific from Kali Therapeutics in a deal worth up to $1.2bn. GSK paid $300m to license Chimagen’s CMG1A46 lupus candidate. Prolium Bioscience launched in March with $50 million to develop CD20xCD3 interactions. The list is expanded almost weekly.

Two facts explain the rush. The first is that science, in the end, looks like it might be inclusive; what worked in oncology to remove malignant B-cells appears to work in autoimmune diseases to remove autoimmunity, and early human data are far better than the standard pharmacology playbook predicted.

The second is that immunology is, by some distance, the largest pharmaceutical market in the world after oncology. Drugs like AbbVie’s Humira, before the erosion of its biosimilar, and Sanofi’s Dupixent are reminders that successful autoimmune therapies are generating revenue at a level that only a few classes aspire to.

If TCEs work in this setting, the reward is equally great. If they don’t, many of these deals will look expensive in retrospect.

Where the AI ​​discussion doesn’t fit

It’s worth noting what doesn’t make a deal. Despite increasing attention on AI-discovered medicine, from Google DeepMind spinoff Isomorphic Labs entering trials this year to ByteDance’s Anew Labs launching its AI-designed treatment and Anthropic paying $400m to a 10-person biotech startup to design a protein-based drug, cizutamig itself.

It was discovered through a licensing relationship with general antibody engineering, not the protein models it produces. The molecules that drive the flow of today’s autoimmune disease are, almost without exception, products of the chemistry of the last decade.

AI’s promised acceleration in drug discovery has, so far, produced more announcements than approvals.

The Candid agreement, in that sense, is a reminder that the creation of the greatest value in pharma is happening in molecules that were already on the way before the start of the AI ​​cycle. The next set of discoveries, in two or three years, may include humans discovered by AI. This one does not need.

What UCB has now, and what it has to prove

For UCB, the strategic logic is pure. The company is mid-sized in pharma terms, with a long-standing immunology franchise and a recent track record of opening new therapeutic areas through targeted M&A.

Pairing Antengene’s CD19xCD3 candidate with Candid’s BCMAxCD3 lead product gives it two complementary ways to eliminate B cells on the market in terms of looking to reward platform breadth rather than single-molecule efficiency.

What UCB has to prove is execution. Phase 1 data in autoimmune disease are encouraging but thin. The intensity of competition is unusually high, at least with large pharma companies following similar paths in all overlapping directions. Pricing pressure, both regulatory and payer, will overtake any successful TCE as it approaches approval. And producing bispecific antibodies at scale is no small feat. None of this is fatal. They are all real.

By the time the deal closes this summer, the broader market may have adjusted its appetite for upside or downside. UCB chose to act before that change.

Whether that proves timely or costly will be seen in Phase 2 studies over the next 18 months. Now, the two-year-old company that started out as a bet on the immune system by an experienced user is valued at $2.2bn, which is money, a chemical company that is convinced that the bet was right.