The clinical and economic implications of an individualised intravenous immunoglobulin (IVIg) protocol for chronic inflammatory demyelinating polyneuropathy (CIDP) are unknown.
We retrospectively studied 47 IVIg-treated subjects with CIDP over four years with an individualised, outcomemeasured, dose-modifying protocol. We compared clinical benefits and costs with those reported with standard dosing at 1gram/kg every 3 weeks.
The IVIg-responder rate was 83% and the 4-year remission rate was 25.6%. Mean IVIg dose requirements were 22.06 grams/week (S.D.:15.29) in patients on ongoing therapy. Dose range was wide (5.83-80 grams/week). Mean infusion frequency was every 4.34 weeks (S.D.:1.70) and infusion duration of 2.79 days (S.D.:1.15). Mean modified-INCAT (Inflammatory Neuropathy Cause and Treatment) score improvement was similar (p=0.47) and mean MRC sum score improvement greater (p<0.001) in our cohort, compared to the IVIg-treated arm of the ICE Study. Mean drug costs were GBP 37,660/patient/year (€ 43,309) and mean infusion-related costs of GBP 17,115/patient/year (€ 19,682), totalling GBP 54,775/patient/year (€ 62,991). Compared to standard dosing using recorded weight, mean savings were of GBP 13,506/patient/year (€ 15,532). Compared to standard dosing using dosing weight, savings were of GBP 6,506/patient/year (€ 7,482).
This study is the first to compare clinical and economic aspects with different IVIg treatment strategies for CIDP. Clinical equivalence as well as cost savings were demonstrated with our individualised protocol in comparison to standard dosing regimens at 1 g/kg/3 weeks.
An individualised IVIg treatment protocol is clinically non-inferior and 10-25% more costeffective than standard dosing in CIDP.