Real-World Multinational Survey of Chronic Inflammatory Demyelinating Polyneuropathy: Disease Characteristics and Therapeutic Landscape

Abstract

Background and aims: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated syndrome characterized by progressive muscle weakness and sensory impairment. Clinical similarities with other neuropathies can cause misdiagnoses and delayed diagnoses. Additionally, a large proportion of patients appropriately treated according to current guidelines still show residual disability. This real-world study aimed to characterize a global cohort of patients with CIDP.

Methods: Data were drawn from the Adelphi CIDP Disease Specific Programme, a cross-sectional survey with retrospective data collection, conducted in China, France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States between September 2022 and April 2023. Neurologists and neuromuscular specialists reported on patient demographic and clinical characteristics at the time of the survey. Patients self-reported treatment satisfaction, disease control, and health-related outcome measures.

Results: Overall, 164 physicians provided data for 1056 patients, with 428 (40.5%) providing self-reported data. Patients were diagnosed with typical CIDP (69.2%) and variant CIDP (30.8%). Overall, initial misdiagnosis occurred in 37.2% of patients, with a median (interquartile range) diagnostic delay of 6.0 (3.0-12.0) months. Maintenance therapy was prescribed for 81.6% of patients, with corticosteroid use ranging from 25.7% in the United States to 80.0% in China. Some patients were dissatisfied by treatment outcomes (11.0%) and symptom control (12.2%). Overall, mean (SD) patient-reported scores were 62.1 (20.4) for I-RODS, 35.0 (11.1) for FACIT fatigue, and 0.662 (0.253) for EQ-5D-5L.

Interpretation: Diagnostic delay and misdiagnoses were common occurrences across typical CIDP and variant CIDP. Despite the use of guideline treatments, there were unmet needs and a continued disease burden for patients.

Keywords: chronic inflammatory demyelinating polyneuropathy; disease burden; healthcare resource utilization; patient reported outcomes; treatment patterns.

FIGURE 1

(a) frequency of CIDP variants within the overall patient sample; (b) distribution of INCAT scores across CIDP variants. Abbreviations: CIDP—Chronic inflammatory demyelinating polyneuropathy, INCAT—Inflammatory Neuropathy Cause and Treatment. ¹The INCAT disability score, where 0 represents no disability and 10 represents complete functional loss.

FIGURE 2

Diagnostic delay (months from symptom onset to diagnosis of CIDP) experienced by patients across CIDP variants. Abbreviations: CIDP—Chronic inflammatory demyelinating polyneuropathy. Diagnostic delay: Defined as time from symptom onset to physician‐confirmed diagnosis of CIDP.

FIGURE 3

(a) patient maintenance treatment (MT) status at the time of the survey; (b) frequency of prescribed therapies among those receiving MT; (c) mean (SD) and frequency of lines of MT received; among the overall patient sample and across regions. Abbreviations: MT—Maintenance therapy, SD—Standard deviation. Due to 1 decimal place rounding, percentages do not total exactly 100% in 3a. Other maintenance treatments included: amifampridine, amitriptyline, carbamazepine, duloxetine, gabapentin, pregabalin, venlafaxine, other.

FIGURE 4

Overall satisfaction with current drug treatment, reported by matched physician‐patient dyads and split by region/country.

FIGURE 5

Perceived level of symptom control on current drug treatment, reported by matched physician‐patient dyads and split by region/country.

FIGURE 6

Health care resource utilization, a) frequency of HCP involvement in patient management (five most frequently involved HCPs shown); b) mean (SD) total HCP types involved in patient management; c) mean (SD) total HCP consultations in the 12 months prior to survey; d) mobility aid utilization (five most frequently utilized devices shown); e) percentage of patients with one or more hospitalization in relation to CIDP in the 12 months prior to survey; f) percentage of patients with one or more ER admissions in the 12 months prior to survey. Abbreviations: ER—Emergency room, GP—General practitioner, HCP—Health care professional, PCP—Primary care physician, SD—Standard deviation. HCPs that were involved in less than 10% of all patient management included: nurse, internal medicine/internist, rehabilitation therapist, psychologist, psychiatrist, ophthalmologist, physician associate/assistant, speech and language therapist, neuropsychiatrist, and other. Mobility aids that were utilized by fewer than 2% of all patients included: Modified car (e.g., wheelchair accessible vehicle), motorized scooter, and other.

FIGURE 7

(a) Distribution of I‐RODS centile scores; (b) Distribution of FACIT‐Fatigue scores; (c) Distribution of EQ‐5D health utility values, and frequency of response levels to individual dimensions. FACIT—Functional Assessment of Chronic Illness Therapy. I‐RODS—Inflammatory Rasch‐built Overall Disability Scale. I‐RODS data has been presented as centiles, with higher centile scores indicating lower disability. For FACIT‐Fatigue, higher scores indicate lesser fatigue. The EQ‐5D‐5L health utility values can exist in the range of < 0 (worse than death), 0 (death) and 1 (perfect health).