Zai Lab, Argenx announce ADHERE study met primary endpoint

Zai Lab (ZLAB) and Argenx (ARGX) announced topline results from the ADHERE study evaluating Vyvgart in adults with chronic inflammatory demyelinating polyneuropathy, or CIDP. The study met its primary endpoint, demonstrating a significantly lower risk of relapse with Vyvgart Hytrulo compared to placebo. Detailed data from ADHERE will be presented at an upcoming medical meeting. ADHERE is the largest clinical trial of CIDP patients to date, enrolling adults who were treatment naive or currently on immunoglobulin therapy or corticosteroids. The trial consisted of a run-in period where current treatment was stopped followed by an open-label Stage A, after which responders to VYVGART Hytrulo advanced to a randomized, placebo-controlled Stage B. Overall, 322 patients enrolled in Stage A and received treatment with Vyvgart Hytrulo. In total, 67% demonstrated evidence of clinical improvement after a run-in withdrawal period based on the Inflammatory Neuropathy Cause and Treatment Disability Score, the Inflammatory Rasch-built Overall Disability Scale or grip strength; 70% demonstrated ECI excluding patients ongoing in Stage A at the time of the 88th event who did not have the full opportunity to achieve a response; 78% demonstrated ECI in a sensitivity analysis of patients who received at least four injections to reach the full IgG-lowering effect of Vyvgart Hytrulo. Response rates similar across all prior CIDP medication subgroups with consistent efficacy on INCAT, I-RODS and grip strength 221 responders from Stage A entered Stage B, where the primary endpoint was the relative risk of relapse based on time to relapse on the INCAT Disability Score. Vyvgart Hytrulo significantly reduced the risk of CIDP relapse compared to placebo Primary endpoint was met; Vyvgart Hytrulo demonstrated a 61% reduction in the risk of relapse compared to placebo based on time to the first adjusted INCAT deterioration of greater than or equal to1 point. Vyvgart Hytrulo patients had a lower relapse rate compared to placebo at Week 24 (26% versus 54%) and Week 48. Vyvgart Hytrulo patients experienced longer time to relapse compared to those on placebo with a rapid separation of the Kaplan-Meier curves beginning at Week 4 and sustained through Week 48. Vyvgart Hytrulo patients demonstrated a clinically meaningful mean improvement of 7.7 points on I-RODS and 12.3kPa on grip strength in Stage A. This clinically meaningful benefit was maintained in Stage B by treated patients and lost in placebo patients. Clinical benefit observed across all efficacy scales and patient subgroups, regardless of prior therapy. Vyvgart Hytrulo was well-tolerated with a safety profile that is consistent with prior clinical trials and the known profile of Vyvgart. The most frequent treatment-related adverse event was injection site reactions, which occurred in a lower percentage of patients than previous Vyvgart Hytrulo trials. All ISRs were mild to moderate and resolved over time. Zai Lab has an exclusive license agreement with argenx for the development and commercialization of Vyvgart and Vyvgart Hytrulo in Greater China. Through this agreement, Zai Lab dosed the first patient in the Greater China portion of the global registrational ADHERE trial in November 2021, and contributed a significant number of patients into this trial.