Risk Factors Related to the Development and Clinical Testing of argenx’s Products and Product Candidates

Failure to successfully identify, select and develop VYVGART in other indications, or additional products or product candidates could impair our ability to grow.

Our long-term growth strategy entails developing and marketing additional products and product candidates, including VYVGART in new indications, which requires substantial resources, whether or not any product candidates or new indications are ultimately identified. The success of this strategy depends partly upon our ability to identify, select, develop, and ultimately, commercialize promising product candidates. We are heavily dependent on precise, accurate and reliable scientific data to identify, select and develop promising product candidates and products. Our business decisions may therefore be adversely influenced by inaccurate, improper or fraudulent scientific data, including data sourced from third parties. Any irregularities in the scientific data used by us to determine our focus in research and development of product and product candidates, could impair our ability to grow. Even with accurate scientific data, our technology platforms may fail to discover and to generate additional products and products candidates, that are suitable for further development.

Even if we identify additional product candidates, they may not be suitable for clinical development as a result of harmful side effects, limited efficacy or other characteristics that indicate that it is unlikely to be a product that will receive approval by the Relevant Regulatory Authorities and other comparable regulatory authorities or achieve market acceptance. For example, in November 2023, we announced that our ADVANCE-SC clinical trial evaluating VYVGART HYTRULO in adults with ITP did not meet the primary endpoint of a sustained platelet count response in chronic ITP patients. Secondary endpoints were also not met. In December 2023, we announced that topline data from the Phase 3 ADDRESS clinical trial evaluating SC efgartigimod in adults with PV and PF showed that the proportion of PV patients achieving the primary endpoint of complete remission on CRmin was not significantly different between SC efgartigimod and placebo. We consequently decided not to pursue additional development in pemphigus and plan to prioritize clinical development of efgartigimod in its ongoing severe autoimmune indications. If we do not successfully identify, develop and commercialize product candidates and VYVGART in new indications based upon our technological approach, we may not be able to obtain product or collaboration revenues in future periods.

VYVGART has obtained regulatory approval in the VYVGART Approved Countries for the treatment of gMG. Our other products and product candidates – including additional indications or methods of use for efgartigimod, empasiprubart and ARGX-119 – are either in preclinical or clinical development or are pending marketing approval.

To obtain the requisite regulatory approvals to market and sell any of our products and product candidates, we or our collaborators for such candidates must successfully demonstrate that our products are safe and effective in humans. Clinical trials are expensive and can take many years to complete, and their outcome is inherently uncertain. Further, success in early clinical trials or in one indication does not guarantee success in later clinical trials or in other indications.

The time required to obtain approval by the Relevant Regulatory Authorities is unpredictable but typically takes many years, if obtained at all, following the commencement of clinical trials and depends upon numerous factors, including the substantial discretion or interpretation of the regulatory authorities. This lengthy approval process as well as the unpredictability of future clinical trial results may result in our failing to obtain regulatory approval to market any of our product candidates, including for new indications. We may experience delays in our ongoing or planned clinical trials, for a large variety of reasons outside our control in complying with regulatory approvals which can adversely affect the timing of trials, including as described in the section 2.4.2 “All aspects of our business ranging from preclinical, clinical trials, marketing and commercialization are highly regulated and any delay by relevant regulatory authorities could jeopardize our development and approval process or result in other suspensions, refusals or withdrawal of approvals.”

If we are unable to obtain regulatory approval of our products and product candidates on a timely basis or at all, our business may be impacted.

Our clinical trials have, and may in the future, fail, and even if they succeed, we may not obtain regulatory approval for our products and product candidates or regulatory approval may be delayed.

Even if clinical trials are initiated, our development efforts may not be successful. Many of our clinical trials are blinded, which may cause us to incur significant expenses without any visibility as to the likelihood of successful results. Even if we obtain positive results from preclinical trials or initial clinical trials, we may not achieve the same success in future clinical trials.

Regulatory approval of our products or product candidates may be delayed or refused for many reasons, including:

• the Relevant Regulatory Authorities may disagree with the design or implementation of our clinical trials;
• we may be unable to demonstrate, to the satisfaction of the FDA or comparable foreign regulatory authorities, that our product candidates are safe, pure, potent and effective for any of their proposed indications;
• we may be unable to demonstrate our product candidates’ clinical and other benefits outweigh their safety risks;
• the FDA may determine that clinical trial results are not generalizable to the U.S. population and/or U.S. medical practice based on the proportion and results of subjects outside of the U.S. where differences in patient management might affect the treatment response. Comparable foreign regulatory authorities may take a similar approach;
• the results of clinical trials may not meet the level of statistical significance required by the FDA or comparable foreign regulatory authorities for approval;
• the chemistry, manufacturing and controls information submitted in a marketing application is insufficient; and
• the facilities of third-party manufacturers with which we contract for the manufacture of our product candidates are not adequate to support approval of our product candidates.

Any of these occurrences may harm our business, results of operations and financial condition significantly.

We could also experience operational challenges as we undertake an increasing number of clinical trials, including those conducted in countries outside the EU, UK and the U.S. that may subject us to further delays and expenses as a result of increased shipment costs, additional regulatory requirements and the engagement of non-EU, non-UK and non-U.S. contract research organizations (CROs), as well as expose us to risks associated with clinical investigators who are unknown to the Relevant Regulatory Authorities, and apply different standards of diagnosis, screening and medical care.

If we experience delays in the completion of, or termination of, any clinical trial of our products or product candidates, our commercial prospects may be harmed. Any delays in completing our clinical trials may increase our costs, slow down our product candidate development and approval process and jeopardize our ability to commence product sales and generate revenues. Many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates or result in the development of our product candidates being stopped early. Significant clinical trial delays could also allow our competitors to bring products to market before we do or shorten any periods during which we have the exclusive right to commercialize our products and product candidates.

If we decide to pursue accelerated approval for any of our product candidates, it may not lead to a faster development or regulatory review or approval process and does not increase the likelihood that our product candidates will receive marketing approval. If we are unable to obtain approval under an accelerated pathway, we may be required to conduct additional clinical trials beyond those that we contemplate, which could increase the expense of obtaining, reduce the likelihood of obtaining, and/or delay the timing of obtaining, necessary marketing approvals.

In the future, we may decide to pursue accelerated approval for one or more of our product candidates. For example, under the FDA’s accelerated approval program, the FDA may approve a drug or biological product for a serious or life-threatening disease or condition that provides a meaningful advantage over available therapies based upon a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit. For products granted accelerated approval, post-marketing confirmatory clinical trials are required to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. These confirmatory clinical trials must be completed with due diligence, and the FDA may require that the clinical trial be designed, initiated, and/or fully enrolled prior to approval. If we were to pursue accelerated approval for a product candidate for a disease or condition, we would do so on the basis that there is no available therapy for that disease or condition. If standard of care were to evolve or if any of our competitors were to receive full approval on the basis of a confirmatory clinical trial for a drug or biological product for a disease or condition for which we are seeking accelerated approval before we receive accelerated approval, the disease or condition may no longer qualify as one for which there is no available therapy, and accelerated approval of our product candidate may not occur.

Moreover, the FDA may withdraw approval of any product candidate approved under the accelerated approval pathway if, for example:

• the clinical trial or clinical trials required to verify the predicted clinical benefit of our product candidate fail to verify such benefit or do not demonstrate sufficient clinical benefit to justify the risks associated with such product;
• other evidence demonstrates that our product candidate is not shown to be safe or effective under the conditions of use;
• we fail to conduct any required post-approval trial of our product candidate with due diligence; or
• we disseminate false or misleading promotional materials relating to the relevant product candidate.

Recently, the accelerated approval pathway has come under scrutiny within the FDA and by Congress. The FDA has put increased focus on ensuring that confirmatory studies are conducted with diligence and, ultimately, that such studies confirm the benefit. The recently enacted FDORA legislation includes provisions related to the accelerated approval pathway. Pursuant to FDORA, the FDA is authorized to require a post-approval clinical trial to be underway prior to approval or within a specified time period following approval. FDORA also requires the FDA to specify conditions of any required post-approval clinical trial and requires sponsors to submit progress reports for required post-approval studies. In addition, FDORA enables the FDA to initiate enforcement action for the failure to conduct with due diligence a required post-approval clinical trial, including a failure to meet any required conditions specified by the FDA or to submit timely reports.

Failure to obtain accelerated approval for our product candidates could result in a longer time period to commercialization of such product candidate, if any, and could increase the cost of development of such product candidate and harm our competitive position in the marketplace.

Our products and product candidates may have serious adverse, undesirable or unacceptable side effects or even cause death, and we or others may identify undesirable or unacceptable side effects caused by VYVGART or any of our products or product candidates after they have received marketing approval.

Undesirable side effects that may be caused by our product candidates, or by the combination of our product candidates with other medical products, could cause us or regulatory authorities to interrupt, delay or halt clinical trials and could result in more restrictive labeling or the delay or denial of regulatory approval by the Relevant Regulatory Authorities. While our preclinical trials and clinical trials for our product candidates to date show that our product candidates have generally been well tolerated from a risk-benefit perspective, we have observed adverse events and treatment emergent adverse events (TEAEs) in our clinical trials to date, and we may see additional adverse events and TEAEs in our ongoing and future clinical trials. Such side effects may be more serious than those observed to date, and as a result, our ongoing and future clinical trials may be negatively impacted. Moreover, as we seek to develop product candidates, including products in new indications, patients may experience new or more serious effects. Drug-related side effects could affect patient recruitment, the ability of enrolled patients to complete the clinical trial, result in potential product liability claims, damage sales of our existing products, result in significant reputational damage for us and our product development, and other issues including the delay of other programs.

Additionally, if we or others identify undesirable or unacceptable side effects caused by VYVGART or any of our other product candidates after they receive marketing approval, a number of potentially significant negative consequences could arise, including:

• regulatory authorities may withdraw approvals or revoke licenses of such products and require us to take such products off the market;
• regulatory authorities may require the addition of labeling statements, specific warnings, or a contraindication or request the issuance of field alerts to physicians and pharmacies;
• regulatory authorities may require a medication guide outlining the risks of such side effects for distribution to patients, or a REMS plan to ensure that the benefits of the product outweigh its risks;
• we may be required to change the way the product is administered, conduct additional clinical trials or change the labeling of the product;
• we may be subject to limitations on how we may promote the product;
• sales of the product may decrease significantly;
• we may be subject to litigation, product liability claims, or criminal prosecution; and
• our reputation may suffer.

Any of these events could negatively impact us, our collaborators or our potential future partners. Further, the Relevant Regulatory Authorities could require a change of label or even revoke the license, which could harm our reputation and have a material adverse effect on our ability to commercialize VYVGART.

If our target patient population is smaller than expected, we are unable to successfully enroll and retain patients in our clinical trials, or experience significant delays in doing so, we may not realize the full commercial potential of any products or product candidates.

Currently, we mainly develop products or product candidates for the treatment of rare diseases for which the target patient population can be small. If the actual number of patients with these disorders is smaller than we expected, we may encounter difficulties in enrolling sufficient patients in our clinical trials, thereby delaying or preventing development and approval of our products or product candidates. Physicians, who are an important source of referral of patients for clinical trials, may also be less familiar with these rare diseases and may therefore fail to identify these conditions in their patients and therefore may not refer them to our clinical trials.

Patient enrollment, a significant factor in the timing of clinical trials, depends on many factors, including the size and nature of the patient population, eligibility criteria for the clinical trial, the proximity of patients to clinical sites, competition for patient recruitment from competing clinical trials, the design of the clinical protocol, the eligibility criteria for the clinical trials, the availability of alternate approved therapies for the indication the clinical trial is investigating, and clinicians’ and patients’ perceptions as to the potential advantages of the drug being studied in relation to other available therapies. We compete with other companies to enroll target patient populations, as set forth in the risk factor section 2.3.3 “We face significant competition for our drug discovery and development efforts.” Even if product candidates obtain significant market share for their approved indications, because certain potential target populations are small, we may never recoup our investment in such product candidate without obtaining regulatory approval for additional indications for such product candidates.

Even once enrolled, we may be unable to retain a sufficient number of patients to complete any of our clinical trials. In addition, any negative results we may report in clinical trials of our drug candidates may make it difficult or impossible to recruit and retain patients in other clinical trials of that same drug candidate. Delays in the completion of any clinical trial of our product candidates will increase our costs, slow down our product candidate development and approval process and delay or potentially jeopardize our ability to commence product sales and generate revenue. In addition, some of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates.

In addition, certain of patients enrolled in our clinical trials are located in areas subject to conflict, hostilities or war, or other disruptive events outside of our control. See section 2.9.2 “Global geo- and socio-political threats and macro-economic uncertainty and other unforeseen political crises could materially and adversely affect our business and financial performance.” and “We face risks related to natural disasters and public health issues, that could negatively affect our business and financial condition”.