Treatment Impact of Efgartigimod PH20 SC on I-RODS Daily Activity Assessment in Patients with Chronic Inflammatory Demyelinating Polyneuropathy: Post Hoc Analysis of the Registrational ADHERE Study
Jeffrey Allen1, Jie Lin2, Mark Stettner3, Ingemar Merkies4, Jeffrey Guptill5, Kelly Gwathmey6, Geoffrey Istas7, Arne De Roeck7, Satoshi Kuwabara8, Giuseppe Lauria9, Luis Querol10, Niraja Suresh11, Chafic Karam12, Thomas Skripuletz13, Simon Rinaldi14, Andoni Echaniz-Laguna15, Benjamin Van Hoorick7, Ryo Yamasaki16, Pieter Van Doorn17, Richard Lewis18
1UMN, 2Fudan University, 3University Medicine Essen, 4Curacao Medical Center, 5Duke University, 6VCU Neuroscience, Orthopedic, and Wellness, 7argenx, 8Chiba University, 9Istituto Neurologico Carlo Besta, 10Hospital de la Santa Creu i Sant Pau, 11Lakeland Regional Medical Center, 12University of Pennsylvania, 13Hannover Medical School, 14University of Oxford, 15Bicetre University Hospital, 16Kyushu University Hospital, 17Erasmus University Medical Center, 18Cedars-Sinai Medical Center
Objective:

Assess the effect on functionality of subcutaneous (SC) efgartigimod PH20 (co-formulated with recombinant human hyaluronidase PH20) in chronic inflammatory demyelinating polyneuropathy (CIDP).

Background:

CIDP is a rare, progressive, immune-mediated polyneuropathy characterized by proximal and distal weakness, and sensory disturbance that can lead to irreversible disability. Efgartigimod, a human IgG1 antibody Fc fragment, blocks the neonatal Fc receptor, decreases immunoglobulin G (IgG) recycling, and reduces IgGs.

Design/Methods:

ADHERE (NCT04281472), a multistage, multicenter, randomized, double-blinded, placebo-controlled trial, enrolled participants with CIDP (off treatment or on standard treatments withdrawn during ≤12-week run-in). Participants with active disease received open-label, weekly efgartigimod PH20 SC 1000 mg (stage-A). Responders were randomized (1:1) to weekly efgartigimod PH20 SC 1000 mg or placebo for ≤48 weeks (stage-B). We report a post hoc analysis of changes from run-in baseline (study enrollment) to stage-B last assessment in centile metric total (all participants) and individual items of the Inflammatory Rasch-built Overall Disability Scale (I-RODS) (participants with improvements of 1–2 points on individual I-RODS items of clinical interest from run-in baseline).

Results:

322 participants entered stage-A; 221 were randomized and treated in stage-B (111 efgartigimod, 110 placebo). 191/221 participants had run-in baseline and post–stage-B timepoints. Mean (SE) I-RODS change at stage-B last assessment vs run-in baseline was 5.7 (1.88) and −4.9 (1.82) in participants randomized to efgartigimod PH20 SC and placebo, respectively. 37/97 (38.1%) and 24/92 (26.1%) participants randomized to efgartigimod PH20 SC and placebo, respectively, experienced ≥4-point improvements in I-RODS score. Efgartigimod-treated participants improved ≥1 point in I-RODS items of Dress Upper Body (24/57, 42.1%), Wash Upper Body (19/54, 35.2%), Walk Outdoors (27/83, 32.5%), Walk One Flight of Stairs (25/83, 30.1%), Walk Avoiding Obstacles (19/72, 26.4%), and Wash Lower Body (17/69, 24.6%).

Conclusions:

Participants who received efgartigimod PH20 SC in stage-B experienced improvements in I-RODS score from study enrollment to stage-B last assessment.

10.1212/WNL.0000000000211994
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