argenx has agreed to acquire Forte Biosciences for approximately $2.2 billion in cash, moving to secure an experimental autoimmune-disease therapy that could become a new multi-indication growth platform alongside the company’s established antibody portfolio.

Under the definitive merger agreement announced Monday, a wholly owned argenx subsidiary will launch a tender offer for all outstanding Forte shares at $77 each. The consideration is payable in cash, without interest and subject to applicable withholding taxes. Following completion of the tender offer, the acquisition subsidiary will merge into Forte, with untendered shares generally converted into the right to receive the same cash price.

The offer represents a premium of approximately 86% to Forte’s volume-weighted average share price since July 9, when the Dallas-based biotechnology company reported positive Phase 1b results for its lead candidate, FB102, in patients with vitiligo. The $77 price also represents a premium of roughly 41% to Forte’s closing share price immediately before the agreement was announced.

The size of the premium reflects argenx’s assessment that the early clinical data have reduced some of the biological risk surrounding FB102, even though the drug remains years away from potential commercialization. Forte is substantially centered on the candidate, making the transaction effectively a multibillion-dollar purchase of one mechanism with the potential to be developed across multiple autoimmune diseases.

FB102 is a monoclonal antibody targeting CD122, the beta subunit shared by the receptors for the immune signaling proteins interleukin-2 and interleukin-15. Forte designed the antibody to modulate IL-2- and IL-15-dependent pathogenic T-cell activity and natural killer-cell activity while preserving regulatory T cells that help restrain excessive immune responses.

That mechanism gives argenx exposure to a different part of autoimmune biology than its best-known product, VYVGART, which reduces circulating immunoglobulin G autoantibodies by blocking the neonatal Fc receptor. FB102 could therefore expand the company’s ability to pursue disorders driven by pathogenic immune cells rather than primarily by disease-causing antibodies.

argenx described FB102 as a potential “pipeline-in-a-product,” meaning one molecule could support development programs in several diseases. Current and potential indications include vitiligo, celiac disease, alopecia areata and other autoimmune or autoimmune-related conditions. The acquisition adds FB102 to a portfolio that includes efgartigimod, marketed as VYVGART, as well as empasiprubart, adimanebart, ARGX-121 and earlier-stage programs.

The latest clinical catalyst came from Forte’s randomized, double-blind and placebo-controlled Phase 1b vitiligo study. The trial enrolled 43 participants, with 32 receiving FB102 and 11 receiving placebo. Forte reported that treated participants achieved a 29.6% mean improvement from baseline in the Facial Vitiligo Area Scoring Index at week 24, a result that reached statistical significance.

Among participants who began the study with greater facial disease involvement, the mean improvement was 43.2% at week 24. Forte also reported that 84% of FB102-treated participants improved from baseline and none worsened, while three of the 11 placebo recipients worsened during the observation period. Adverse events in the treatment group were described as mild or moderate.

The results were notable because improvement continued after the 12-week treatment period ended, supporting Forte’s hypothesis that the therapy may produce sustained modulation of pathogenic immune-cell activity. However, the trial was small and designed primarily to establish early evidence of biological activity and tolerability. Larger and longer studies will be required to determine whether the magnitude and durability of the effect can be reproduced across broader patient populations.

FB102 had previously generated positive Phase 1b data in celiac disease. That study enrolled 32 participants who underwent a controlled gluten challenge, with 24 receiving FB102 and eight receiving placebo. Forte reported statistically significant benefits on a composite histological endpoint and on measurements of intestinal T-cell infiltration. Participants receiving FB102 also experienced fewer gastrointestinal symptom events during the challenge period than those receiving placebo.

A Phase 2 celiac disease study is underway, with topline results expected in the second half of 2026. That readout will be an important test of the valuation underpinning the acquisition because it will provide a larger and more advanced assessment of whether FB102 can protect patients from the inflammatory consequences of gluten exposure. Forte has also been advancing clinical work in alopecia areata, another immune-mediated condition linked to the biological pathways targeted by the antibody.

argenx said the vitiligo and celiac disease results were central to its decision to move from investor to full owner. The company had made a strategic investment in Forte earlier in 2026, giving it a closer view of the program before committing to the acquisition. The progression from minority investment to takeover reflects a staged approach frequently used by larger drug developers seeking access to external innovation without assuming the full risk before initial human data become available.

The transaction also follows a period of strong commercial and financial performance for argenx. The company reported $1.52 billion in product net sales for the second quarter of 2026, up approximately 60% from the year-earlier period, as adoption of VYVGART and VYVGART Hytrulo continued to expand. Six-month product sales reached approximately $2.81 billion.

argenx reported $472 million in quarterly profit and generated approximately $700 million of operating cash flow during the first half of the year. As of June 30, the company held $3.6 billion in cash and cash equivalents and $1.6 billion in current financial assets, giving it total reported liquidity of approximately $5.2 billion.

The Forte acquisition will be funded entirely from cash on hand and is not contingent on argenx obtaining outside financing. On the basis of its June liquidity position, the stated equity purchase price would consume a little more than two-fifths of the company’s cash, cash equivalents and current financial assets before transaction costs and any changes in working capital.

Using existing funds avoids equity dilution and financing uncertainty, but the acquisition will meaningfully reduce the liquidity available for other business-development transactions, clinical programs and commercialization investments. The financial return will depend on argenx’s ability to advance FB102 through substantially larger trials, obtain regulatory approvals and establish reimbursement and commercial demand in competitive autoimmune markets.

The deal supports argenx’s Vision 2030 strategy, under which the company aims to treat 50,000 patients globally, secure 10 labeled indications and move five pipeline candidates into registrational development by the end of the decade. VYVGART remains the primary commercial engine, with approvals spanning generalized myasthenia gravis and chronic inflammatory demyelinating polyneuropathy in key markets. Management has also been pursuing label expansions and advancing additional antibody candidates intended to create new growth sources.

Adding FB102 could reduce long-term concentration around FcRn biology by introducing a program directed at pathogenic T cells and natural killer cells. It may also allow argenx to apply its clinical-development infrastructure, regulatory expertise and global commercial organization to diseases outside the initial focus of Forte, which has operated as a smaller clinical-stage company with limited resources.

The transaction is structured as a two-step acquisition under Delaware law. The argenx subsidiary is required to commence the tender offer within 10 business days after execution of the merger agreement, and the offer must initially remain open for at least 15 business days. Completion requires the valid tender of enough shares to represent more than 50% of Forte’s outstanding stock when combined with shares owned by the buyer and its affiliates.

The acquisition is also subject to the expiration or early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act and other customary closing conditions. Given Forte’s clinical-stage status and the absence of a marketed product, conventional product-overlap concerns may be limited, although the transaction remains subject to regulatory review.

Both companies’ boards unanimously approved the agreement. Forte’s board has recommended that shareholders accept the offer and tender their shares. Directors and executive officers who hold Forte stock entered into support agreements covering approximately 1% of the outstanding shares as of July 26.

The merger agreement includes customary restrictions on Forte soliciting competing proposals, while allowing the board to consider a superior offer under specified circumstances consistent with its fiduciary duties. Forte may be required to pay argenx a $65 million termination fee if the agreement ends under certain conditions, including a decision to accept a superior transaction. The agreement also provides for termination if the tender offer has not been completed by late November, subject to its detailed terms.

The parties expect the acquisition to close in the third quarter of 2026. Goldman Sachs International is serving as exclusive financial adviser to argenx, with Freshfields acting as legal adviser. Guggenheim Securities is Forte’s exclusive financial adviser, while Wilson Sonsini Goodrich & Rosati is providing legal counsel.

For Forte shareholders, the transaction converts exposure to an uncertain clinical-development program into a fixed cash payment at a substantial premium. For argenx investors, the offer transfers the development risk directly to a company with greater financial, regulatory and commercial resources, but at a valuation that already assumes FB102 can progress beyond encouraging early-stage data.

The central question is whether FB102’s initial signals in two distinct autoimmune diseases translate into reliable efficacy in larger trials. Phase 1b studies can establish proof of concept, but small patient numbers, limited treatment duration and selected trial populations can produce results that are not replicated in later development. Safety must also be evaluated over longer periods because therapies that alter T-cell and natural killer-cell signaling can have broad immunological effects.

If subsequent trials confirm the early data, argenx could gain a differentiated antibody with applications across several disorders lacking convenient or consistently effective treatments. Failure in the Phase 2 celiac study or later vitiligo development, by contrast, would impair much of the strategic value attached to the purchase because Forte’s pipeline is heavily concentrated around FB102.

The acquisition therefore combines the features driving renewed biotechnology dealmaking: a cash-rich commercial buyer, a smaller target built around a clinically validated mechanism and an opportunity to obtain full control before pivotal development substantially increases either the asset’s value or its cost. argenx is paying heavily for that opportunity, betting that its development platform can turn Forte’s early evidence into a broader autoimmune franchise.