Efgartigimod Treatment for CIDP Leads to Increased Spending, Study Shows

A United States integrated delivery network perspective model was developed to project costs expected by introducing efgartigimod alfa (Vyvgart; Argenx), a neonatal Fc receptor antagonist, in a portion of patients with chronic inflammatory demyelinating polyneuropathy (CIDP). All told, budget estimates analyzing patients who are currently receiving subcutaneous immunoglobulin (SCIG) or intravenous immunoglobulin (IVIG) found that introducing efgartigimod alfa as a treatment option is expected to result in substantially increased spending in the treatment of CIPD.¹

Using a hypothetical 25-million-member health plan based on prevalence and immunoglobulin treatment, senior author Betsy Lahue, MPH, founder and CEO of Alkemi, and colleagues estimated an expected 708 patients with CIDP on treatment. Results indicated a budget impact of $45,996,708 (35.5% increase) for efgartigimod when assuming a 10% uptake of the treatment in year one drawing patient share proportionally from IVIG and SCIG. In an alternative scenario, a 10% uptake of efgartigimod alfa in year one drawing patient share exclusively from IVIG led to a projected budget impact of $46,079,091 (35.6% increase).

Presented at the 2025 American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) meeting, held October 29 to November 1, in San Francisco, California, cost inputs for the prospective model include pharmacy, site of care, and indirect costs, such as infusion related complications, and side effects. Pivotal studies for each product were used to inform relapse rate inputs: the PATH study provided relapse rates at 24 and 52 weeks for SCIG maintenance, while the ICE study provided relapse rates for efgartigimod alfa.

CIDP is an acquired immune-mediated inflammatory disorder of the peripheral nervous system that is mostly managed through IVIG, corticosteroids, plasma exchange, and chronic immunosuppressive agents, either alone or in combination. Just last year, the FDA approved Argenx's coformulation therapy including efgartigimod alfa and hyaluronidase-qvfc (Vyvgart Hytrulo) as a new treatment for adults with CIPD.²

This analysis is not the first time the financial burden of patients with CIDP in the United States has been studied. A retrospective cohort analysis published in Value of Health in 2024 evaluated the cost and healthcare resource utilization (HCRU) burden of adults with CIDP in the United States.³

The analysis identified 3409 patients with CIDP and determined the mean HCRU and all-cause medical costs in year 1 to be $84,684. Notably, patients labeled as a chronic IG users had an average all-cause medical cost of $206,418 and patients labeled as intermittent IG users had an average all-cause medical cost of $64,722.

The analysis determined the average cost per patient based on treatment type, distinguishing between chronic and intermittent IG users according to IG utilization. Chronic IG patients received at least 8 IG infusions no more then 5 days apart, while other patients were considered intermittent IG users.

Patients with CIDP were identified from a U.S. claims database based on specific diagnostic and enrollment criteria. Eligible patients had at least two claims with a CIDP diagnosis recorded 30 to 365 days apart, with the first diagnosis defined as the index date. To confirm diagnostic accuracy, patients were also required to have at least one nerve conduction test performed either within 90 days before the index date or between the first and subsequent CIDP diagnoses. In addition, continuous health plan enrollment for one year before and one year after the index date was necessary to ensure comprehensive data on healthcare use and costs.

REFERENCES
1. Romano J, Carlton R, Van Stiphout J, et al. Budget Impact of Subcutaneous Immunoglobulin and Efgartigimod Alfa in Patients with Chronic Inflammatory Demyelinating Polyneuropathy in the United States. Presented at the 2025 American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting, held October 29-November 1, in San Francisco, California.
2. Argenx reports positive topline data from ADHERE study of Vyvgart Hytrulo in patients with chronic inflammatory demyelinating polyneuropathy. News release. Argenx. July 17, 2023. Accessed July 19, 2024. https://www.globenewswire.com/news-release/2023/07/17/2705309/0/en/argenx-Reports-Positive-Topline-Data-from-ADHERE-Study-of-VYVGART-Hytrulo-in-Patients-with-Chronic-Inflammatory-Demyelinating-Polyneuropathy.html
3. Guptill J, Belein C, Arvin-Berod C, et al. EE18 Burden of Illness for Adults With Chronic Inflammatory Demyelinating Polyneuropathy in the United States. Value in Health. 2024:27(6):S60. doi: https://doi.org/10.1016/j.jval.2024.03.319