Combo Therapy Cuts Relapse Risk in Chronic Inflammatory Demyelinating Polyneuropathy Trial

Treatment with the subcutaneous (SC) formulation of efgartigimod alfa plus hyaluronidase-qvfc led to a significantly lower risk of relapse in adults with chronic inflammatory demyelinating polyneuropathy (CIDP), according to findings from the phase 2 ADHERE study.

The ADHERE study (ClinicalTrials.gov Identifier: NCT04281472) evaluated the efficacy and safety of the SC formulation in 322 adults with CIDP. The study consisted of an open-label portion (Stage A) in which patients received efgartigimod alfa, a neonatal Fc receptor blocker, plus hyaluronidase-qvfc, an endoglycosidase, for up to 12 weeks. Responders from Stage A were then randomly assigned to receive either efgartigimod alfa plus hyaluronidase-qvfc or placebo for up to 48 weeks (Stage B).

Findings from Stage A showed that 67% (n=214/322) of patients in the efgartigimod alfa treatment arm met the primary endpoint demonstrating evidence of clinical improvement after a run-in withdrawal period. Among the 221 responders who entered Stage B, treatment with efgartigimod alfa plus hyaluronidase-qvfc reduced the risk for CIDP relapse (primary endpoint) by 61% at week 48 compared with placebo, based on time to the first adjusted INCAT (Inflammatory Neuropathy Cause and Treatment) deterioration of at least 1 point (hazard ratio, 0.39 [95% CI, 0.25-0.61]; P =.000039).

Results also showed a lower relapse rate with efgartigimod alfa plus hyaluronidase-qvfc vs placebo at week 24 (26% vs 54%) and week 48 (34% vs 60%). Clinically meaningful improvements on I-RODS (Inflammatory Rasch-built Overall Disability Scale) and in grip strength were observed in Stage A in the efgartigimod alfa group and maintained in Stage B. The most common treatment-related adverse event reported was injection site reactions.

The SC formulation of efgartigimod alfa plus hyaluronidase-qvfc is currently marketed under the brand name Vyvgart Hytrulo for the treatment of generalized myasthenia gravis in adults who are anti-acetylcholine receptor (AChR) antibody positive.

“With these positive ADHERE data, we have generated strong clinical evidence that CIDP has a significant IgG-driven pathogenesis component and that Vyvgart Hytrulo can meaningfully improve and stabilize disease symptoms with a favorable safety profile and a simple route of administration,” said Luc Truyen, MD, PhD, Chief Medical Officer of argenx.