PracticeUpdate

IV ImmuneGlobulin Improves Disability inChronic InflammatoryDemyelinating Polyneuropathy Disability improvement was seen after 10-13 weeks of treatment IV immune globulin has been shown to improve

reactions were reported in 105 individuals (44.7%), a rate of 0.144 adverse drug reactions per infusion. Dr. Merkies concluded that pooled PRIMA and PATH data showed improvement in disability with IV immune globulin in this large cohort of individuals with chronic inflammatory demyelinating polyneuropathy. Improvement was seen at up to 10 to 13 weeks, which suggested that some individuals may need multiple immune globulin doses. Re-stabilization treatment after IV immune globulin withdrawal In PATH, IV immune globulin was withdrawn before ran- domization. Individuals who did not deterioratewithin 12 weeks of withdrawal, discontinued the study because immune globulin dependency was not confirmed. On deterioration (increase in adjusted INCAT score), individuals underwent IV immune globulin re-stabili- zation. The induction dose was 2 g/kg. Maintenance doses were 1 g/kg every 3 weeks for up to 10 to 13 weeks. Of 245 individuals in whom IV immune globulin was withdrawn, 28 (11.4%) did not deteriorate within 12 weeks. Another 10 individuals withdrew for other reasons, leaving 207 in the re-stabilization phase. Of these, 91% improved in at least one efficacy measure (one point improvement in adjusted INCAT score, four points in Rasch-built overall disability score, 8 kPa in mean grip strength, or three points in Medical Research Council score) by 10 to 13 weeks. Adjusted INCAT score improved in 72.9%, with approx- imately 21% of individuals improving beyond baseline status. Improvements were seen in all secondary scores. Post-study follow-up of participants who did not improve revealed that most had improved. Dr. Merkies explained that in individuals with chronic inflammatory demyelinating polyneuropathy, it is rec- ommended that the dose or frequency of IV immune globulin administration be reduced periodically to assess the need for ongoing therapy. Little is known about the effectiveness of IV immune globulin re-sta- bilization in individuals who worsen after withdrawal of IV immune globulin. Dr. Merkies concluded that withdrawal of IV immune globulin was effective in detecting individuals who did not require IV immune globulin therapy. For individu- als dependent on IV immune globulin, re-stabilization with IV immune globulin was effective in reversing observed deteriorations within 12 weeks. www.practiceupdate.com/c/70784

disability in chronic inflammatory demyelinating polyneuropathy, and its withdrawal has been shown to detect individuals who do not need it. These outcomes from the prospective, open- label, single-arm PRivigen Impact on Mobility and Autonomy (PRIMA) and randomized, double-blind Polyneuropathy And Treatment with Hizentra (PATH) studies were reported at ICNMD 2018. Efficacy and safety Ingemar S.J. Merkies, MD, of the Maastricht University Medical Center in The Netherlands, and colleagues assessed the efficacy and safety of IV immune globulin in individuals with chronic inflammatory demyelinating polyneuropathy in the PRIMA and PATH studies. In PRIMA, 28 individuals with chronic inflammatory demyelinating polyneuropathy received induction IV immune globulin (2 g/kg of body weight) and main- tenance therapy (1 g/kg every 3 weeks for 21 weeks). This regimen was also used in 207 individuals who were pre-treated with IV immune globulin during the 10 to 13-week PATH re-stabilization period, before randomization to subcutaneous immune globulin versus placebo. Both studies investigated response (defined as a one- point decrease or greater in adjusted Inflammatory Neuropathy Cause and Treatment [INCAT] score), changes in mean grip strength, and Medical Research Council score, as well as safety. Separate and pooled results were analyzed from both studies.

INCAT response rate at last observation was 76.9% (95% CI 49.7–91.8) in IV immune globu- lin – pre-treated participants in PRIMA (60.7% in all participants in PRIMA) and 72.9% (95% CI 66.5–78.5) in individuals rand- omized to PATH. In the pooled cohort (n=235), the INCAT response rate was 71.1% (95% CI 65.0–76.5). Most responders improved by week 4. Additional responses occurred up to week 13. No clear differences in charac- teristics were noticed between early (responding before week 7) and late responders. In the pooled cohort, 271 adverse drug

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