argenx will acquire Forte Biosciences for $2.2 billion, which will add first-in-class anti-CD122 antibody, FB102, to its immunology pipeline.
argenx and Forte Biosciences have entered a definitive agreement under which argenx
"Our Vision 2030 strategy is well-defined and on track, and our discovery, development and commercialization engines are delivering real value for patients," said
The deal follows a prior strategic investment argenx made in Forte Biosciences and will proceed as a cash tender offer, representing a premium of approximately 86% to Forte's volume-weighted average price since the company reported positive phase 1b vitiligo data on July 9, 2026.1,2 The transaction, funded entirely from cash on hand, is subject to customary closing conditions including majority share tender and Hart-Scott-Rodino antitrust clearance, with completion expected in the third quarter of 2026.1
In Forte's 43-patient, double-blind, placebo-controlled phase 1b vitiligo trial, FB102 produced a mean 29.6% improvement from baseline in the Facial Vitiligo Area Scoring Index at week 24, compared with 7.9% for placebo (p = .020). In patients with more extensive baseline disease, improvement reached 43.2% versus 0.5% for placebo (p = .006).2 Benefit emerged by day 64, continued after the 12-week treatment period ended, and 84% of FB102-treated patients improved through week 24 with none worsening, compared with 27% of placebo patients who worsened.2
Positive phase 1b data in celiac disease were shared last year, and a phase 2 celiac trial is underway with topline results expected in the second half of 2026.1 Forte has described celiac disease as debilitating for many patients even with trace gluten exposure, underscoring the unmet need the phase 2 trial aims to address.3 Beyond vitiligo and celiac disease, the companies said FB102 has potential in alopecia areata and additional autoimmune diseases, describing it as a possible pipeline-in-a-product opportunity.1
FB102 blocks CD122, the shared beta subunit of the interleukin-2 (IL-2) and IL-15 receptors expressed on natural killer cells and a subset of T cells; in preclinical models, CD122 blockade has been shown to selectively deplete pathogenic natural killer cells and memory-phenotype T cells while largely sparing regulatory T cells, providing mechanistic rationale for a pathogenic-cell-selective effect.4 FB102 joins argenx's existing antibody portfolio, including efgartigimod, empasiprubart, adimanebart, and ARGX-121, adding a mechanism the company said broadens its ability to pursue diseases driven by different dimensions of the immune system.1
"We are incredibly proud of what we have achieved in advancing FB102 through clinical development and firmly believe that argenx is the ideal strategic partner to unlock the full potential of this novel anti-CD122 antibody across a broad range of autoimmune diseases," said
The tender offer has not yet commenced, and completion remains subject to shareholder tender thresholds and antitrust clearance. FB102's phase 1b results have not yet been replicated in larger controlled trials, and its potential in alopecia areata and other indications beyond vitiligo and celiac disease remains unstudied in humans.
