UCB buys Candid Therapeutics for up to US$2.2bn to deepen autoimmune T-cell engager push

The transaction, announced on 3 May, gives UCB a portfolio of bispecific antibodies designed to redirect T cells against disease-driving B cells and plasma cells. UCB will pay US$2.0bn upfront, with a further US$200m tied to milestones.

The size of the cheque is notable because Candid is still young. The company launched in September 2024 with a US$370m Series A and an unusually engineered formation: a financing round combined with the acquisition of two biotechs, Vignette Bio and TRC 2004, and the licensing of their lead assets.

That strategy has now produced a rapid exit. Candid’s CEO Ken Song previously led RayzeBio, the radiopharmaceutical company acquired by Bristol Myers Squibb for around US$4.1bn in February 2024. Song’s Candid playbook was again built around fast company formation, clinical-stage assets and a large syndicate of specialist investors.

For UCB, the deal is not a one-off excursion into a fashionable field. In March, the Brussels-based company licensed ATG-201, a CD19/CD3 bispecific T-cell engager from Antengene, gaining worldwide rights to develop and commercialise the candidate for B-cell-related autoimmune diseases. UCB and Antengene described that agreement as giving UCB access to a next-generation biologics platform and a T-cell engager designed for B-cell depletion.

The Candid acquisition therefore looks less like opportunistic M&A than a deliberate attempt to assemble a portfolio before the autoimmune T-cell engager field becomes crowded with late-stage data.

From lupus CAR-T excitement to bispecific competition

The scientific rationale behind the deal has been building for several years. Autoimmune drug development has been energised by academic and early clinical work suggesting that deep B-cell depletion, including with CAR-T therapies, could produce profound responses in diseases such as systemic lupus erythematosus.

But pharma companies are now looking beyond autologous cell therapy. Kyverna’s lupus programme, one of the closely watched CAR-T efforts in autoimmune disease, saw investor enthusiasm hit by a relapse in a lupus nephritis patient who had initially responded. Kyverna’s stock fell by about 34% after the news, while the company’s data also showed cytokine release syndrome in 26 of the first 30 patients treated, although none of the ICANS cases were severe.

That does not invalidate autoimmune CAR-T, but it does explain the industry’s interest in redosable, off-the-shelf alternatives. T-cell engagers aim to borrow the immune-cell redirection logic of oncology bispecifics, but without the manufacturing complexity of autologous CAR-T.

And the pharma industry noticed the change. GSK paid US$300m upfront to test Chimagen Biosciences’ CD19/CD20 dual-targeted T-cell engager in lupus and potentially other B-cell-driven autoimmune diseases, and companies like Takeda, Nkarta, Sana Biotechnology and IGM Biosciences have also shifted oncology cell therapy or T-cell engager programmes toward autoimmune disease. Seen against that backdrop, UCB’s Candid acquisition is part of a wider migration of oncology technologies into immunology.

Why Candid was attractive

Candid’s two initial T-cell engager assets were developed in China for cancer, had completed Phase I trials, and were being repositioned for autoimmune disease. One targeted BCMA and the other CD20, with both also binding CD3 on T cells.

The structure is becoming familiar in biotech dealmaking: assets generated or first tested in China, financed and packaged by US venture investors, then acquired or licensed by global pharma companies seeking differentiated clinical-stage programmes.

UCB has now used both routes in quick succession. The Antengene licensing deal gave it a CD19/CD3 programme and platform access. The Candid acquisition adds a broader company and a clinical-stage portfolio, including cizutamig, Candid’s BCMA/CD3 bispecific. The common thread is B-cell depletion, but across different targets and constructs.

A European buyer in a US-led financing story

For Europe’s biotech sector, the deal is interesting because the buyer is European even though the company creation story is largely American. Candid was launched in San Diego, backed by US venture investors, and led by a management team already associated with a major US pharma exit. Its Series A was co-led by Venrock Healthcare Capital Partners, Fairmount, TCGX and venBio Partners, with Foresite Capital and Third Rock Ventures also participating.

That fits a broader pattern in which European mid-to-large biopharma companies are increasingly using business development to compete in high-risk modality shifts rather than relying only on internal R&D. In UCB’s case, the company had already built commercial momentum in immunology through Bimzelx, its dual IL-17A/IL-17F inhibitor. Bimzelx had secured five approvals in two years and become an immunology blockbuster.

The Candid deal therefore extends UCB’s immunology ambitions. It also puts UCB into more direct competition with companies trying to define whether the future of severe autoimmune disease belongs to CAR-T, bispecific antibodies, multispecific antibodies, or some combination of all three.