RESUMEN
Objective The efficacy of maintenance intravenous immunoglobulin (IVIg) therapy has been established to prevent relapse in chronic inflammatory demyelinating polyneuropathy (CIDP). This prospective post-marketing surveillance study evaluated the treatment duration, efficacy, and safety of maintenance IVIg therapy in Japanese patients with CIDP. Methods Patients were registered between June 2017 and December 2018. After induction of IVIg therapy (0.4 g/kg/day for 5 consecutive days), patients received maintenance IVIg (1.0 g/kg every 3 weeks). The observation period was 18 months. Efficacy in preventing relapse was assessed using the Inflammatory Neuropathy Cause and Treatment (INCAT) disability score. Relapse was defined as a worsening of the INCAT score by ≥1 from baseline. Patients The efficacy population comprised 103 patients (80 with typical CIDP and 23 with CIDP variants). Results During the observation period, 86 (83%) patients were scheduled to continue maintenance IVIg therapy during the observation period, and the relapse rate was 24% (21/86). In the remaining 17 patients who showed continuous remission, maintenance IVIg therapy was stopped (mean, 136 days after the start), and the relapse rate was 24% (4/17). One serious adverse drug reaction of cardiac failure was reported. Conclusion In this post-marketing surveillance, most (83%) patients with CIDP were scheduled to continue maintenance IVIg for 18 months, with a relapse rate of 24%, indicating long-term efficacy. Maintenance IVIg therapy was rarely withdrawn, and the relapse rate after withdrawal was 24%. Further studies are required to determine the optimal maintenance IVIg dose and duration.
RESUMEN
OBJECTIVES: To investigate potential knowledge gaps between neurologists and non-specialists and identify challenges in the current management of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), with a focus on 'early diagnosis' and 'appropriate treatment' for CIDP. DESIGN: A non-interventional, cross-sectional, web-based quantitative survey of physicians working in healthcare clinics or hospitals in Japan. SETTING: Participants were recruited from the Nikkei Business Publications panel from 18 August to 14 September 2022. PARTICIPANTS: Responses from 360 physicians (120 each of internists, orthopaedists and neurologists) were collected. OUTCOME MEASURES: Responses relating to a CIDP hypothetical case and current understanding were assessed to determine awareness, collaboration preferences and diagnosis and treatment decisions. RESULTS: Understanding of CIDP was 90.8% among neurologists, 10.8% among orthopaedists and 13.3% among internists; >80% of orthopaedists and internists answered that neurologists are preferable for treatment. Diagnostic assessment using a hypothetical case showed 95.0% of neurologists, 74.2% of orthopaedists and 72.5% of internists suspected CIDP. Among orthopaedists and internists suspecting CIDP, >70% considered referring to neurology, while ~10% considered continuing treatment without a referral. Among neurologists, 69.4% chose intravenous immunoglobulin (IVIg) as first-line treatment and determined effectiveness to be ≤3 months. CONCLUSIONS: Orthopaedists and internists had lower CIDP awareness compared with neurologists, which may lead to inadequate referrals to neurology. Evaluation of IVIg effectiveness for maintenance therapy occurred earlier than the guideline recommendations (6-12 months), risking premature discontinuation. Improving CIDP knowledge among orthopaedists and internists is critical for better diagnosis and collaboration with neurologists. Neurologists should consider slow and careful evaluation of IVIg maintenance therapy. TRIAL REGISTRATION NUMBER: UMIN000048516.