argenx SE 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. 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.

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). 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. The ADHERE trial was a multicenter, randomized, double-blind, placebo-controlled trial evaluating VYVGART® Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) for the treatment of chronic inflammatory demyelinating polyneuropathy (CIDP).

ADHERE enrolled 322 adult patients with CIDP who were treatment naïve (not on active treatment within the past six months or newly diagnosed) or being treated with immunoglobulin therapy or corticosteroids. The trial consisted of an open-label Stage A followed by a randomized, placebo-controlled Stage B. In order to be eligible for the trial, the diagnosis of CIDP was confirmed by an independent panel of experts. Patients entered a run-in stage, where any ongoing CIDP treatment was stopped and in order to be eligible for Stage A had to demonstrate active disease, with clinically meaningful worsening on at least one CIDP clinical assessment tool, including INCAT, I-RODS, or mean grip strength.

Treatment naïve patients were able to skip the run-in period with proof of recent worsening. To advance to Stage B, patients needed to demonstrate evidence of clinical improvement (ECI) with VYVGART Hytrulo. ECI was achieved through improvement of the INCAT score, or improvement on I-RODS or mean grip strength if those scales had demonstrated worsening during the run-in period.

In Stage B, patients were randomized to either VYVGART Hytrulo or placebo for up to 48 weeks. The primary endpoint was measured once 88 total relapses or events were achieved in Stage B and was based on the hazard ratio for the time to first adjusted INCAT deterioration (i.e. relapse). After Stage B, all patients had the option to roll-over to an open-label extension study to receive VYVGART Hytrulo.

VYVGART and VYVGART HYTRULO are both prescription medicines, each used to treat a condition called generalized myasthenia gravis, which causes muscles to tire and weaken easily throughout the body, in adults who are positive for antibodies directed toward a protein called acetylcholine receptor (anti-AChR antibody positive). Do not use VYVGART if have a serious allergy to efgartigimod alfa or any of the other ingredients in VYVGART. Do not use VYVGART HYTRULO if have a serious allergy to efgartigimod alfa, hyaluronidase, or any of the other ingredients in VYVGART HYTRULO.

VYVGART and VYVGART HYTRULO can cause serious allergic reactions and a decrease in blood pressure leading to fainting. Infection: VYVGART and VYVGART HYTRULO may increase the risk of infection. The most frequent symptoms and signs reported with efgartigimod alfa-fcab were high blood pressure, chills, shivering, and chest, abdominal, and back pain.

The most common side effects in efgartigimod-alfa-fcab-treated patients were respiratory tract infection, headache, and urinary tract infection. Additional common side effects with VYVGART HYTRULO are injection site reactions, including rash, redness of the skin, itching sensation, bruising, pain, and hives.