ADHERE data show VYVGART®Hytrulo has potential to be first advancement for CIDP patients in 30 years

Real-world data demonstrate gMG patients able to significantly reduce steroid use over first six months of initiating VYVGART®treatment

April 16, 2024 – 7:00am CET

Amsterdam, the Netherlands – argenx SE (Euronext & Nasdaq: ARGX), a global immunology company committed to improving the lives of people suffering from severe autoimmune diseases, today announced that data from its Phase 3 ADHERE trial evaluating VYVGART Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) were presented for the first time to the medical community during the Clinical Trials Plenary Session at the American Academy of Neurology (AAN) Annual Meeting in Denver, CO.

argenx also highlighted clinical trial and real-world data across seven posters and presentations that continue to reinforce VYVGART and VYVGART Hytrulo as a transformative treatment option for gMG patients.

“Our innovative approach to autoimmunity research is changing expectations for the global immunology community,” said Luc Truyen, M.D., Ph.D., Chief Medical Officer, argenx. “The gMG and CIDP data presented at AAN reinforce that our pioneering approach to transforming autoimmunity is redefining what is possible for patients and their communities.”

“Patients with CIDP face a number of diagnostic and treatment challenges” said Jeffrey Allen, M.D., Professor, Department of Neurology, University of Minnesota and Principal Investigator in the ADHERE trial. “The results of the ADHERE trial show that VYVGART Hytrulo reduces the risk of clinical deterioration in patients with CIDP while minimizing side effects and reducing the treatment burden. These findings enhance our understanding of the role that IgG autoantibodies are likely to play in the disease, and open the door to new safe, effective and well-tolerated treatments that eliminate pathogenic IgGs.”

ADHERE Plenary Session (PL5)Highlights Rapid, Deep and Clinically Meaningful, and DurableFunctional Improvementsin CIDP

In the ADHERE study, a majority of patients treated with VYVGART Hytrulo, regardless of prior treatment, demonstrated evidence of rapid clinical improvement, and a reduced risk of relapse compared to those treated with placebo. As previously reported, ADHERE met its primary endpoint (p=0.000039) demonstrating a 61% reduction (HR: 0.39 95% CI: 0.25; 0.61) in the risk of relapse versus placebo. VYVGART Hytrulo was well-tolerated, and the observed safety and tolerability profile was consistent with previous clinical trials.

• Evidence of rapid onset and maintenance of clinical response: In the open-label Stage A of the ADHERE study, 67% of patients treated with VYVGART Hytrulo demonstrated evidence of clinical improvement (ECI), including 40% who had achieved ECI by the earliest possible measure at week 4. In Stage B, VYVGART Hytrulo-treated patients maintained a clinical response to treatment longer than those on placebo as evidenced by a statistically significant and clinically relevant reduction in risk of relapse. Results across both Stage A and B indicate IgG autoantibodies play a significant role in mediating the underlying biology of CIDP.
• Deep and clinically meaningful functional improvements: 81% of VYVGART Hytrulo-treated patients demonstrated ≥1 point improvement on the aINCAT as compared to baseline Stage A scores in ADHERE, which includes 42% of patients with ≥2 point improvement, 28% with ≥3 point improvement, and 12% with ≥4 point improvement.
• Clinical benefit demonstrated regardless of prior CIDP treatment: Clinical benefit was seen across all patient subtypes, including those who had previously received corticosteroids, intravenous or subcutaneous immunoglobulin, or were on no treatment prior to study entry.
• High rate of treatment continuation: 99% of eligible patients continued to the ADHERE-Plus open-label extension study.
• FDA decision on CIDP sBLA expected by June 21, 2024: Data from the ADHERE trial were submitted to the U.S. Food and Drug Administration (FDA) as part of a supplemental Biologics License Application (sBLA) for VYVGART Hytrulo for the treatment of CIDP. The application was accepted for Priority Review in February 2024 and has been granted a PDUFA target action date of June 21, 2024.

AAN presentations highlight rapid, deep, and sustained improvements in gMG with ability to reduce steroid burden

Clinical trial data and real-world evidence presented during AAN continue to highlight the differentiated efficacy and safety profile of VYVGART and VYVGART Hytrulo, driving rapid, deep, and sustained improvement across disease scales and with different dosing schedules, including the ability for patients to achieve minimal symptom expression (MSE).

• MSE results in ADAPT/ADAPT+: Poster Session 10
• ADAPT-SC+ interim results: Poster Session 10
• ADAPT-NXT interim results: Poster Session 10
• Cost-benefit analysis of efgartigimod to IVIG in Canada: Poster Session 4

Side effects from long-term steroid use continue to be a significant burden associated with autoimmune disease, reinforcing the importance of the favorable safety profile of VYVGART. New data presented in an oral presentation (Scientific Platform Session 38) during AAN characterize how VVYGART treatment can significantly reduce concomitant steroid use.

• A substantial proportion of gMG patients (46%) were able to reduce steroid use over the first six months of initiating VYVGART treatment, including 34% of patients who tapered to