CIDP is a rare, progressive autoimmune disease causing peripheral nervous system dysfunction. Guidelines recommend immunoglobulin (IG) therapy as an immunomodulatory agent in CIDP i.e., subcutaneous IG (SCIG) or intravenous IG (IVIG). Efgartigimod alfa, a novel Fc receptor antagonist, is expected to become available as an additional option for CIDP patients.

A model was developed to project, from a US integrated delivery network perspective, the costs expected with introducing efgartigimod alfa for CIDP. Cost inputs included pharmacy costs, administration costs by site of care, infusion-related complications, side effects, and indirect costs.  Pharmacy costs were based on a payment mix of ASP (73%), WAC (2%), and AWP (25%). The PATH clinical study of SCIG maintenance was the basis for input on relapse rates at initial assessment (24 weeks) and at 52 weeks for SCIG.  The ICE clinical study of IVIG maintenance therapy was the basis for input relapse rates for IVIG.  The ADHERE clinical study was used to obtain relapse rates of efgartigimod alfa. 

For a hypothetical 25-million-member health plan, the analysis estimated, based on prevalence of disease and IG treatment, an expected 708 CIDP patients treated with IG. Assuming a 10% uptake of efgartigimod alfa in year 1 drawing patient share proportionally from IVIG and SCIG yielded a total projected budget impact of $45,996,708, a 35.5% increase. In an alternative scenario, assuming a 10% uptake of efgartigimod alfa in year 1 drawing patient share exclusively from IVIG led to a projected total budget impact of $46,079,091, a 35.6% increase. 

This analysis suggests that the introduction of efgartigimod alfa is expected to result in substantially increased spending in the treatment of CIDP.