Vyvgart Hytrulo Gets Priority Review for Chronic Inflammatory Demyelinating Polyneuropathy

The Food and Drug Administration (FDA) has accepted for Priority Review the supplemental Biologics License Application (sBLA) for the subcutaneous (SC) formulation of efgartigimod alfa plus hyaluronidase-qvfc, for the treatment of chronic inflammatory demyelinating polyneuropathy (CIDP).

The sBLA is supported by data from the ADHERE study (ClinicalTrials.gov Identifier: NCT04281472) which 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).

Results from Stage B showed that treatment with efgartigimod alfa plus hyaluronidase-qvfc met the primary endpoint reducing the risk for CIDP relapse vs placebo (P =.000039). In the open-label Stage A, 67% of patients demonstrated evidence of clinical improvement after receiving efgartigimod alfa plus hyaluronidase-qvfc. Moreover, clinically meaningful improvements were observed on I-RODS (Inflammatory Rasch-built Overall Disability Scale) and in grip strength in Stage A for the efgartigimod alfa group and maintained in Stage B.

The safety profile of efgartigimod alfa plus hyaluronidase-qvfc was well tolerated and consistent with prior clinical trials and with its known profile. The most common treatment-related adverse event reported was injection site reactions. After completing the ADHERE study, 99% of eligible patients have continued to the ADHERE+ open-label extension study (ClinicalTrials.gov Identifier: NCT04280718). 

A Prescription Drug User Fee Act target date of June 21, 2024 has been set for this application.

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