UMIN-ICDS Clinical Trial

Public title

A Nationwide Multicenter Retrospective Registry Study of Chronic Eosinophilic Pneumonia

Acronym

CEP Registry

Scientific Title

A Nationwide Multicenter Retrospective Registry Study of Chronic Eosinophilic Pneumonia

Scientific Title:Acronym

CEP Registry

Region

Japan

Condition

Chronic Eosinophilic Pneumonia

Classification by specialty

Pneumology

Classification by malignancy

Others

Genomic information

YES

Narrative objectives1

The primary objective of this study is to establish a nationwide, multicenter retrospective registry based on medical record data for idiopathic chronic eosinophilic pneumonia (CEP) to systematically characterize clinical features, diagnostic findings (clinical, laboratory, and radiological), treatment strategies (including the initiation and tapering schedules of systemic corticosteroids, as well as concomitant use of biologics), and clinical outcomes.
Specifically, in addition to quantifying the real-world status of relapse-including its frequency, timing, and number of episodes - we will explore predictive factors associated with relapse using candidate variables such as comorbidities (e.g., comorbid asthma), blood and bronchoalveolar lavage (BAL) findings, CT features (scored as necessary), initial treatment intensity, and tapering speed, thereby obtaining foundational data to support relapse prediction and treatment optimization.
Furthermore, considering the pathophysiological heterogeneity (including cases with comorbid asthma), we will evaluate airway morphometric parameters on diagnostic CT scans to explore their association with relapse and treatment burden.
Additionally, clinically important outcomes - such as cumulative oral corticosteroid (OCS) dose, corticosteroid-related adverse events, hospitalization, and mortality - will be evaluated to generate hypotheses for future prospective studies, stratified treatment strategies, and the development of clinical practice algorithms.

Basic objectives2

Safety,Efficacy

Basic objectives -Others

Trial characteristics_1

Exploratory

Trial characteristics_2

Pragmatic

Developmental phase

Not applicable

Primary outcomes

The primary endpoint will be defined as the presence or absence of relapse during the observation period and the time to first relapse.
Relapse will be determined according to a definition that satisfies both of the following criteria: (1) a clinical judgment of CEP relapse leading to the resumption or dose escalation of OCS (or an equivalent intensification of treatment), and (2) the presence of new or worsening findings on imaging (chest X-ray or CT, with CT prioritized). Patients who do not experience a relapse within the observation period will be censored at their last observation point.
The primary endpoint, which can also be evaluated as a binary outcome (the presence or absence of relapse), was selected as the metric that best aligns with the core clinical challenges of this disease: the prediction and suppression of relapse.

Key secondary outcomes

Secondary endpoints are established to complement the primary endpoint and comprehensively evaluate the clinical features, treatment burden, prognosis, and impact of therapeutic strategies in CEP. Specifically, the number of relapses and relapse rate (including incidence per person-year) during the observation period, presence/achievement of remission, time to remission, respiratory-related and all-cause hospitalizations, and all-cause mortality will be evaluated.
To assess treatment burden, the cumulative oral corticosteroid (OCS) dose, rate of successful OCS discontinuation, maintenance dose, and tapering rate will be evaluated. Additionally, longitudinal trends in pulmonary function (e.g., FEV1) and peripheral blood eosinophil counts will be analyzed where data are available. For safety assessment, the incidence of corticosteroid-related adverse events, such as infections, osteoporosis, and glucose metabolism abnormalities, will be evaluated.
Furthermore, exploratory evaluations will investigate:
Associations between diagnostic chest CT findings - including infiltration scoring and airway quantitative parameters (airway wall thickness, internal lumen diameter, total airway count, etc.) - and patient outcomes.
Differences in clinical presentation, relapse risk, and treatment responsiveness based on the presence or absence of comorbid asthma.
Real-world utilization of biologics and its impact on relapse risk and steroid burden.

Study type

Observational

Basic design

Randomization

Randomization unit

Blinding

Control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

Purpose of intervention

Type of intervention

Interventions/Control_1

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

Not applicable

Age-upper limit

Not applicable

Gender

Male and Female

Key inclusion criteria

Patients diagnosed with CEP during the data collection period (January 1, 2000, to March 31, 2026), regardless of age or sex, who meet the following criteria:
1. Meet the diagnostic criteria for CEP (A-D below), including the attending physician's comprehensive clinical judgment.
2. Have key clinical parameters (symptoms, imaging findings, blood/BAL eosinophils, treatment details, and clinical outcomes) extractable from medical records.
Diagnostic Criteria for CEP (Operational Definition for This Study)
* A. Presence of subacute to chronic respiratory symptoms (e.g., cough, dyspnea, wheezing, fever).
* B. Chest X-ray or CT showing alveolar opacities such as infiltrates or ground-glass opacities (often peripherally predominant and/or migratory).
* C. Peripheral blood eosinophilia (eosinophil count >1000/uL) or BAL eosinophilia (BAL eosinophil fraction >=25%).
* D. Reasonable exclusion of other eosinophilic lung diseases or secondary causes (e.g., infections, drug-induced lung disease, parasitic infections, EGPA, ABPA/ABPM).
Note: While respecting decisions made in routine clinical practice at each institution regarding diagnostic thresholds, eligibility will be evaluated against the above criteria to the extent possible.

Key exclusion criteria

1) Patients diagnosed with acute eosinophilic pneumonia (AEP).
2) Patients with confirmed or strongly suspected eosinophilic granulomatosis with polyangiitis (EGPA) or other systemic vasculitis.
3) Patients in whom secondary eosinophilia due to hypereosinophilic syndrome (HES), hematologic malignancies, or other underlying conditions is determined to be the primary cause.
4) Patients in whom diseases primarily localized to the airways, such as allergic bronchopulmonary aspergillosis (ABPA) or allergic bronchopulmonary mycosis (ABPM), are determined to be the primary cause.
5) Patients with substantially missing medical record data during the study period, making it difficult to evaluate the primary endpoint (relapse).

Target sample size

300

Name of lead principal investigator

1st name	Jun
Middle name
Last name	Miyata

Organization

Department of Medicine, Keio University School of Medicine.

Division name

Division of Pulmonary Medicine

Zip code

160-0016

Address

Tokyo, Shinkjuku-ku, Shinanomachi, 35

TEL

03-3353-1211

Email

junmiyata.a2@keio.jp

Name of contact person

1st name	Ryojiro
Middle name
Last name	Kido

Organization

Department of Medicine, Keio University School of Medicine.

Division name

Division of Pulmonary Medicine

Zip code

160-0016

Address

Tokyo, Shinkjuku-ku, Shinanomachi, 35

TEL

03-3353-1211

Homepage URL

Email

ryo.kido.respi@keio.jp

Institute

Keio University

Institute

Department

Personal name

Organization

Japan Agency for Medical Research and Development

Organization

Division

Category of Funding Organization

Japanese Governmental office

Nationality of Funding Organization

Japan

Co-sponsor

Name of secondary funder(s)

Organization

Department of Medicine, Keio University School of Medicine.

Address

Tokyo, Shinkjuku-ku, Shinanomachi, 35

Tel

03-3353-1211

Email

med-rinri-jimu@adst.keio.ac.jp

Secondary IDs

YES

Study ID_1

20251234

Org. issuing International ID_1

Keio University School of Medicine Ethics Committee

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

慶應義塾大学病院(東京都)

Date of disclosure of the study information

2026

Year

10

Month

01

Day

URL releasing protocol

Publication of results

Unpublished

URL related to results and publications

Number of participants that the trial has enrolled

Results

Results date posted

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Participant flow

Adverse events

Outcome measures

Plan to share IPD

IPD sharing Plan description

Recruitment status

Enrolling by invitation

Date of protocol fixation

2026

Year

03

Month

31

Day

Date of IRB

2026

Year

03

Month

31

Day

Anticipated trial start date

2026

Year

03

Month

31

Day

Last follow-up date

2036

Year

03

Month

31

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

Study Overview
Study Title: A Nationwide, Multicenter Retrospective Observational Study to Establish a Registry for Chronic Eosinophilic Pneumonia
Objectives: To identify predictive factors for relapse in chronic eosinophilic pneumonia (CEP) and obtain insights that contribute to treatment optimization.
Endpoints: Primary Endpoint: Presence or absence of relapse during the observation period (based on predefined criteria).
Secondary Endpoints: Time to relapse, number of relapses, remission, hospitalization, mortality, changes in pulmonary function, cumulative OCS dose and corticosteroid-related adverse events, real-world utilization and effectiveness of anti-IL-5/IL-5R antibodies, etc. (exploratory/reference analysis).
Study Design: Multicenter, retrospective observational study (utilizing existing data from medical records, opt-out approach).
Target Population
Inclusion Criteria: Patients with CEP (including diagnosis based on the attending physician's comprehensive clinical judgment) whose key parameters (symptoms, imaging findings, blood/BAL eosinophils, treatment details, and clinical outcomes) can be extracted from medical records.
Exclusion Criteria: Patients diagnosed with other diseases such as acute eosinophilic pneumonia (AEP), or patients with substantially missing medical record data during the study period, making it difficult to evaluate the primary endpoint (relapse).
Study Methodology: Retrospective observational study.
Target Sample Size: Approximately 300 cases (to be adjusted based on the enrollment capacity of participating centers).
Study Period: From the date of institutional protocol approval to March 31, 2036.

Registered date

2026

Year

09

Month

19

Day

Last modified on

2026

Year

09

Month

08

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071911