Hans Katzberg, MD, Assistant Professor of Neurology at the University of Toronto and Neurologist at Toronto General Hospital, discusses post hoc analyses from the ADHERE clinical trial in chronic inflammatory demyelinating polyneuropathy (CIDP).
CIDP is a neurological disorder that causes progressive weakness and impaired sensory function in the legs and arms. Symptoms often include tingling or numbness, weakness of the arms and legs, loss of deep tendon reflexes, fatigue, and abnormal sensations. Other symptoms may include pain, dysphagia, and double vision. CIDP is thought to be caused by the immune system mistakenly attacking and damaging the myelin sheath of the peripheral nerves. CIDP is closely related to Guillain-Barre syndrome.
At the 2026 American Academy of Neurology Annual Meeting (ANN 2026), post hoc analyses of the ADHERE (NCT04281472) and open-label extension ADHERE+ (NCT04280718) clinical trials evaluating the impact of subcutaneous efgartigimod PH20 on treatment-naïve patients with CIDP was presented. Efgartigimod is a human immunoglobulin (Ig) G1 antibody Fc fragment that blocks the neonatal Fc receptor, thus decreasing IgG recycling and reducing IgGs.
Patients with active CIDP received weekly efgartigimod PH20 subcutaneous 1000 mg (stage-A) for 12 or fewer weeks. Those with confirmed evidence of clinical improvement entered stage-B and were randomized to weekly efgartigimod PH20 or placebo for 48 or fewer weeks. Participants with clinical deterioration in stage-B or who completed ADHERE could enter ADHERE+. The primary endpoint of ADHERE stage-A was the percentage of participants with evidence of clinical improvement. Changes from stage-A baseline to stage-A last assessment in adjusted Inflammatory Neuropathy Cause and Treatment (aINCAT), Inflammatory Rasch-built Overall Disability Scale (I-RODS), and grip strength scores were assessed.
Of the 322 participants enrolled in ADHERE, 24 were treatment-naïve. During stage-A (week 12 or before), 87.5% of treatment-naïve participants had confirmed evidence of clinical improvement, compared with 64.8% across the remaining study population. Time to initial confirmed evidence of clinical improvement among treatment-naïve participants was 39.5 days. Improvements exceeding the minimal clinically important difference were reported from stage-A baseline to stage-A last assessment across mean aINCAT, I-RODS, and dominant hand grip strength scores in treatment-naïve participants.
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To learn more about CIDP and other rare neurological conditions, visit https://checkrare.com/diseases/neurology-nervous-system-diseases/
