UCB, the Brussels-based drugmaker, signed a definitive agreement on 4 May 2026 to acquire Candid Therapeutics, a privately held San Diego biotech that develops T-cell engagers for autoimmune and inflammatory diseases. UCB agreed to pay $2 billion upfront and up to $200 million more in future milestone payments, putting the total value at up to $2.2 billion.
Candid was founded in 2024. Its lead drug, cizutamig, is an antibody that directs the body's T cells to kill the plasma cells and B cells that drive many autoimmune conditions. It has been given to more than 100 patients and is being tested in more than 10 autoimmune indications.
The deal needed antitrust clearance and was expected to close by the end of the second quarter or early in the third. UCB announced on 17 June that it had completed the acquisition. It did not say how it financed the purchase.
What Candid built
Cizutamig is a bispecific antibody: one arm binds BCMA, a protein on plasma cells, and the other binds CD3 on T cells, so that T cells attack the targeted cells. Candid designed it to keep that killing effect while limiting cytokine release, a common safety concern with this class of drug. The drug has not been approved by the FDA or any other regulator.
According to GEN, cizutamig was licensed from Shanghai-based EpimAb Biotherapeutics. Of the more than 100 patients treated, 40 had multiple myeloma and 68 had autoimmune diseases, in studies in China and Europe. BioPharma Dive reported in March that Candid planned Phase 2 trials in myasthenia gravis and interstitial lung disease later in 2026.
Candid is developing a second lead B-cell depleting T-cell engager, CND261, which targets CD20 and CD3 and was licensed from Genor Biopharma, GEN reported. It completed a 93-patient Phase 1 study in non-Hodgkin's lymphoma. Two trispecific antibodies, CND319 and CND460, are in preclinical work; CND319 was licensed from WuXi Biologics in a deal worth up to $925 million.
“We started Candid with the goal to redefine the standard of care for immune-mediated diseases. We purposefully built a broad portfolio of TCE assets against a number of clinical indications.”
Why UCB is buying
UCB, which employs more than 9,000 people in about 40 countries, is building a set of T-cell engagers aimed at so-called immune reset in diseases driven by B cells. About two months before the Candid deal it licensed ATG-201, a CD19 and CD3 bispecific, from Hong Kong-based Antengene for $80 million in upfront and near-term payments and up to about $1.1 billion in milestones, GEN reported.
Chief executive Jean-Christophe Tellier called cizutamig a potentially transformative asset that complements UCB's existing programmes. UCB said the financial impact would be manageable and left its 2026 guidance unchanged. Its shares fell 0.65% on the day of the announcement, according to GEN.
The founders and the funding
Candid launched in September 2024 with $370 million in a Series A co-led by Venrock Healthcare Capital Partners, Fairmount, TCGX and venBio Partners, with Foresite Capital and Third Rock Ventures taking part, Pharmaceutical Technology reported. The company was formed by merging two biotechs, Vignette Bio and TRC 2004, which brought in the first BCMA and CD20 programmes.
Chairman and chief executive Ken Song previously ran RayzeBio, which he sold to Bristol Myers Squibb for about $4.1 billion in 2024.
A listing that never happened
Two months before the UCB deal, Candid had chosen a different route. In early March 2026 it agreed to merge with Nasdaq-listed Rallybio, a deal that would have taken Candid public under the ticker CDRX, alongside a private financing of more than $505 million from investors including Venrock, RA Capital Management and Janus Henderson Investors, BioPharma Dive reported.
Candid terminated that merger agreement on 3 May, the same day it entered the agreement with UCB. Rallybio's quarterly filing shows it was paid a $50 million termination fee on 4 May, plus $0.4 million in expenses.
Lazard and Covington & Burling advised UCB. Jefferies and Goldman Sachs were Candid's joint lead financial advisers, with BofA Securities also advising and Cooley as legal counsel.
