China-based Zai Lab Ltd (NASDAQ: ZLAB; HKG: 9688) and its Netherlands-based partner argenx SE (NASDAQ: ARGX) have announced preliminary positive results from the ADHERE study. The study assessed the effects of Vyvgart Hytrulo (efgartigimod alfa and hyaluronidase) in adults with chronic inflammatory demyelinating polyneuropathy (CIDP). The ADHERE trial is the largest clinical study conducted for CIDP patients to date, encompassing both treatment-naïve patients and those currently undergoing immunoglobulin therapy or corticosteroid treatment.
Study Design and Positive Outcomes
The trial design included a run-in period where pre-existing treatments were halted, followed by an open-label Stage A. Responders to Vyvgart Hytrulo then progressed to a randomized, placebo-controlled Stage B. Out of 322 patients in Stage A, 67% (214/322) exhibited clinical improvement (ECI). Sensitivity analysis of patients who received at least four injections showed an 78% (214/275) ECI rate, indicating the full IgG-lowering effect of Vyvgart Hytrulo. Response rates were consistent across all prior CIDP medication subgroups, with reliable efficacy observed on INCAT, I-RODS, and grip strength tests. A total of 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’s Mechanism and Market Potential
Vyvgart Hytrulo is a subcutaneous combination therapy consisting of efgartigimod alfa, a human IgG1 antibody fragment, and recombinant human hyaluronidase PH20 (rHuPH20), utilizing Halozyme’s ENHANZE drug delivery technology for subcutaneous injection of biologics. By binding to the neonatal Fc receptor (FcRn), Vyvgart Hytrulo reduces circulating IgG levels and is the first-and-only approved FcRn blocker for subcutaneous administration. Zai Lab secured licensing deals with argenx for development and commercialization rights in Greater China, initiating the ADHERE study in November 2021.
Understanding CIDP and Its Impact
Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare and severe autoimmune disease affecting the peripheral nervous system, characterized by fatigue, muscle weakness, and sensory loss in the limbs. These symptoms can severely impede daily functioning, with one-third of untreated CIDP patients requiring wheelchair assistance. There is a growing body of evidence suggesting that IgG antibodies play a pivotal role in peripheral nerve damage, making the positive outcomes of the ADHERE study particularly significant for CIDP treatment.-Fineline Info & Tech
