VYVGART Sjögren’s setback sends argenx shares lower despite $1.5bn quarterly sales

argenx shares fell by double digits after the biotechnology company stopped the Phase 3 UNITY trial of efgartigimod in Sjögren’s disease for futility, removing one of the more important potential expansion markets from the rapidly growing VYVGART franchise. The setback surprised investors because UNITY was not expected to read out until 2027 and followed encouraging Phase 2 evidence that had supported a larger registrational program. The Nasdaq-listed shares were down roughly 13% during the session around $798, leaving argenx valued at about $50 billion despite the selloff. The reaction reflects how much of the company’s premium valuation depends not only on continued VYVGART growth in approved diseases but also on repeatedly expanding the FcRn therapy into new autoimmune markets.

The failure does not damage VYVGART’s established businesses in generalized myasthenia gravis and chronic inflammatory demyelinating polyneuropathy, where product sales continue to accelerate. argenx generated $1.52 billion in second-quarter VYVGART net product sales, up from $949 million a year earlier, and produced a quarterly operating profit of $494 million. The commercial engine therefore remains unusually strong for a biotechnology company, but UNITY removes another potential blockbuster label expansion and increases the importance of myositis, primary immune thrombocytopenia, Graves’ disease and argenx’s newer non-FcRn programs.

Sjögren’s failure removes a potentially large market from the VYVGART expansion strategy

UNITY was designed to test weekly subcutaneous efgartigimod in adults with moderate-to-severe Sjögren’s disease who remained symptomatic despite stable standard therapy. An independent monitoring committee recommended stopping the Phase 3 study after an interim analysis concluded that it was unlikely to meet its primary endpoint measuring systemic disease activity.

That decision means argenx will not continue spending toward the planned Week 48 analysis and effectively closes the current registrational path for efgartigimod in Sjögren’s disease. The company plans to complete the database and analyze the results to understand whether specific disease characteristics, biomarkers or patient subgroups help explain the disappointing outcome.

The commercial opportunity had been meaningful because Sjögren’s remains a large autoimmune market without an FDA-approved therapy specifically proven to alter the underlying systemic disease. BioPharma Dive reported that some Wall Street estimates had assigned as much as approximately $1.4 billion in peak annual sales to a successful VYVGART Sjögren’s indication, although several analysts excluded the indication from base-case forecasts because development risk was already considered high.

That distinction helps explain both the magnitude and limits of the stock selloff. Losing Sjögren’s removes a potentially large source of upside, but it does not eliminate revenue already being generated by VYVGART or invalidate other efgartigimod indications that rely on different disease biology and separate clinical datasets.

The UNITY failure nevertheless adds to a history showing that FcRn blockade does not succeed automatically whenever autoantibodies are involved. argenx has previously stopped efgartigimod development in other diseases after late-stage results failed to justify further investment, reinforcing the need to evaluate each autoimmune indication independently rather than assume the VYVGART mechanism will translate broadly.

Positive Phase 2 results made the late-stage failure more damaging to investor expectations

Investor disappointment was amplified by the contrast with the earlier RHO proof-of-concept study. In that 34-patient Phase 2 trial, 45.5% of patients receiving efgartigimod met the CRESS composite response criterion compared with 11.1% receiving placebo, while treatment also reduced circulating IgG and autoantibodies.

Those results provided a coherent biological argument for advancing into Phase 3. Sjögren’s frequently involves anti-Ro and other autoantibodies, and efgartigimod lowers circulating IgG by blocking the neonatal Fc receptor, creating the possibility that reducing pathogenic antibodies could improve systemic disease.

UNITY demonstrates the risk of extrapolating from a small study into a substantially broader registrational population. Sjögren’s is clinically heterogeneous, with varying combinations of glandular, musculoskeletal, neurological and systemic manifestations, making it difficult for one biological mechanism to produce a large average benefit across every patient.

The failure also arrives earlier than investors expected. argenx had previously guided to UNITY topline results in the second half of 2027, meaning the interim futility assessment pulled a negative catalyst forward by roughly a year and forced investors to remove potential Sjögren’s value immediately rather than gradually reassess the program.

The company has not disclosed the interim treatment effect, making it impossible to determine whether efgartigimod produced a small but insufficient benefit or essentially failed to separate from placebo. More detailed analyses could provide scientific lessons for future FcRn development, but they are unlikely to restore the immediate commercial opportunity without another substantial clinical program.

VYVGART’s existing $1.5 billion quarterly business limits the damage from one failed indication

The most important counterweight to UNITY is the scale VYVGART has already achieved. Second-quarter product net sales reached $1.52 billion, representing approximately 60% year-over-year growth and 17% sequential growth. First-half VYVGART sales totaled $2.81 billion compared with $1.74 billion during the same period a year earlier.

argenx is also profitable. Second-quarter operating profit reached $494 million, while net profit was $472 million compared with $245 million a year earlier. Cash flow from operations totaled approximately $700 million during the first half, giving the company internally generated resources to fund a development portfolio that would normally require repeated external financing at a smaller biotechnology company.

The balance sheet reinforces that resilience. Cash, cash equivalents and current financial assets totaled $5.2 billion at the end of June, up from $4.4 billion at year-end. That capital allows argenx to absorb a failed Phase 3 study without cutting its broader pipeline purely to preserve liquidity.

VYVGART’s core labels have also continued expanding. The FDA broadened the generalized myasthenia gravis label this year to cover all adult serotypes, while VYVGART Hytrulo remains established in chronic inflammatory demyelinating polyneuropathy. The company is also developing an autoinjector intended to simplify subcutaneous administration beginning in 2027.

Those existing franchises explain why the UNITY failure is better viewed as a reduction in future upside than a threat to argenx’s current commercial foundation. The company still has one of biotechnology’s fastest-growing product franchises and enough cash to continue investing aggressively.

Myositis becomes more important after successful Phase 3 data strengthen another rheumatology path

The loss of Sjögren’s increases the importance of argenx’s positive Phase 3 ALKIVIA results in autoimmune myositis. That trial met its primary endpoint in the combined immune-mediated necrotizing myopathy and dermatomyositis population, with efgartigimod producing a 15.4-point greater improvement in Total Improvement Score compared with placebo at Week 52.

The treatment effect appeared early and remained through a full year despite steroid tapering, while the immune-mediated necrotizing myopathy subgroup independently reached statistical significance. Dermatomyositis showed a similarly sized numerical benefit but did not achieve statistical significance within the smaller subgroup.

That dataset could support another meaningful rheumatology indication and demonstrates why UNITY should not be interpreted as a broad failure of efgartigimod outside neurology. Different autoimmune diseases have different pathogenic mechanisms and clinical endpoints, and the positive ALKIVIA trial provides direct late-stage evidence in a separate systemic disease.

argenx is also pursuing primary immune thrombocytopenia, Graves’ disease and ocular myasthenia gravis, while future FcRn molecules are being designed to improve dosing convenience. ARGX-213 is intended for monthly administration and is described by the company as Phase 3 ready, giving argenx another route to protect and extend its leadership in FcRn biology.

The strategic challenge is maintaining enough successful label expansions to support long-term growth expectations already embedded in argenx’s valuation. VYVGART is enormously successful today, but a company worth around $50 billion needs continued commercial expansion to justify premium expectations several years into the future.

Positive FB102 celiac disease data provide diversification beyond the VYVGART franchise

argenx also released positive Phase 2 results from FB102 in celiac disease, providing an important counterpoint to the UNITY disappointment. The CD122-targeting antibody met the study’s primary endpoint by significantly protecting intestinal tissue from gluten-induced damage, with a p-value of 0.0176, and argenx plans to move the program into Phase 3 development.

FB102 came into argenx through its approximately $2.2 billion acquisition of Forte Biosciences, meaning the positive readout provides early clinical validation for one of the company’s largest recent business-development investments. Unlike VYVGART, the asset does not depend on FcRn blockade, giving argenx an opportunity to build a second immunology franchise around a different biological pathway.

The market nevertheless focused much more heavily on UNITY. argenx shares remained down by double digits despite the favorable celiac result, illustrating how investors currently place greater weight on losing a late-stage expansion opportunity for an established blockbuster than on gaining encouraging Phase 2 evidence for an acquired asset.

That calculation could shift if FB102 succeeds in Phase 3. Analysts cited by BioPharma Dive have estimated potential peak celiac sales near $1 billion, although such projections remain speculative until larger studies establish efficacy, safety and commercial positioning.

The program is strategically important because argenx has repeatedly stated that it wants to become a multi-asset immunology company rather than remain dependent on one successful molecule. A positive Phase 3 celiac program could make that diversification significantly more credible.

argenx stock selloff reflects a premium valuation built on repeated pipeline expansion

argenx shares fell sharply following the UNITY announcement, with the Nasdaq-listed ADRs trading around $798 and down roughly 13% during the session. European-listed shares also declined by double digits, while argenx’s market capitalization fell toward approximately $50 billion.

The reaction is partly a consequence of expectations. VYVGART’s rapid commercial growth has transformed argenx into one of the world’s most highly valued biotechnology companies, with its market capitalization remaining above several much older companies that sell multiple approved medicines. BioPharma Dive noted that analyst estimates for eventual VYVGART sales across remaining opportunities still range from roughly $11 billion to $17 billion even without Sjögren’s disease.

A valuation based on that scale of future growth leaves less room for failed expansion programs. Investors are effectively paying not only for current VYVGART revenue but also for the expectation that argenx can repeatedly convert its immunology research into additional multibillion-dollar markets.

UNITY weakens that assumption without destroying it. The company still has positive Phase 3 myositis data, a growing gMG and CIDP franchise, additional efgartigimod studies, late-stage empasiprubart programs and the newly acquired FB102 opportunity.

The next major tests will therefore determine whether the selloff represents a temporary reset or the beginning of a broader reassessment of argenx’s growth multiple. Third-quarter financial results, expected later this month, will provide another look at VYVGART’s commercial momentum, while upcoming data from empasiprubart and other programs will help determine how quickly the company can replace the value lost from Sjögren’s disease.

Key takeaways from argenx’s UNITY failure and the VYVGART growth outlook

• argenx stopped the Phase 3 UNITY Sjögren’s trial after an interim analysis concluded it was unlikely to meet its primary endpoint.
• The setback removes a potentially large VYVGART label expansion, with some analyst estimates previously assigning more than $1 billion in peak sales to Sjögren’s disease.
• argenx shares fell roughly 13% during the session as investors reassessed the long-term growth potential of the FcRn franchise.
• The failure does not affect VYVGART’s approved businesses in generalized myasthenia gravis or chronic inflammatory demyelinating polyneuropathy.
• VYVGART generated $1.52 billion in second-quarter net product sales, rising about 60% from the prior-year period.
• argenx reported $472 million in second-quarter profit and held $5.2 billion in cash and current financial assets, limiting financial pressure from the failed trial.
• Positive Phase 3 ALKIVIA results in autoimmune myositis preserve another significant rheumatology expansion opportunity for efgartigimod.
• Positive Phase 2 FB102 data in celiac disease provide a separate growth path outside FcRn and support argenx’s $2.2 billion Forte Biosciences acquisition.
• Upcoming empasiprubart and additional efgartigimod readouts will become increasingly important as argenx works to justify its premium biotechnology valuation.