Efficacy and Safety of Stapokibart for Primary Cutaneous Amyloidosis: A Randomized, Double-blind, Placebo-controlled Study
Phase: NA
Conditions: Primary Cutaneous Amyloidosis
Sponsor: First Affiliated Hospital of Chongqing Medical University

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Efficacy and Safety of Stapokibart for Primary Cutaneous Amyloidosis: A
Randomized, Double-blind, Placebo-controlled Study
I. Background of the Study
Amyloidosis is a group of diseases characterized by the abnormal
deposition of amyloid substances in tissues and organs, which can be classified
into primary and secondary forms, or focal and systemic types. Primary
cutaneous amyloidosis (PCA) refers to a chronic metabolic skin disorder in
which amyloid proteins are deposited only in the dermis without involvement of
internal organs [1]. This condition is more common in middle-aged and elderly
individuals and generally shows no gender predilection. Skin lesions are
frequently found on the back, anterior tibia, and thighs, and may also be
distributed on the upper lip, nasolabial folds, and penis. PCA comprises three
basic types: lichen amyloidosis (LA), macular amyloidosis (MA), and nodular
amyloidosis. In addition, it includes special types such as dyschromatosis-like
amyloidosis and bullous amyloidosis. Clinically, LA and MA are the most
common types.
PCA is generally a chronic condition,with the main clinical manifestations
including
papules,macules,scales,lichenification,pigmentation,dryness
and
roughness
of
the
affected
skin,excoriations,and
in
some
cases,local
pruritus.There are currently no guidelines or expert consensus to direct the
standard treatment of PCA,and topical corticosteroid ointments are the most
commonly used empirical therapeutic means in clinical practice.In addition to

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this,depending on the clinical manifestations and therapeutic expectations of the
patients,some may be treated with oral medications such as antihistamines in
combination.Overall,the existing traditional treatment options are relatively
limited.The need to use medications daily leads to poor patient compliance,and
the therapeutic effects are often poor and prone to relapse[2].Because PCA
shares
certain
similarities
with
another
common
dermatological
condition—atopic dermatitis—in terms of clinical manifestations and traditional
treatments,there have been a few case reports in recent years on the use of novel
drugs for atopic dermatitis(biologics represented by IL-4 receptor antagonists
and small-molecule drugs represented by JAK pathway inhibitors)to treat
PCA,all of which have shown good therapeutic effects[3-4].Currently,clinical
trials of JAK pathway inhibitors for the treatment of PCA are being conducted in
China.However,there is still a lack of large-scale clinical studies exploring the
efficacy and safety of novel drugs in PCA.Therefore,this trial is planned to
investigate the efficacy and safety of Stapokibart Injection (an IL-4 receptor
antagonist
that
has
been
marketed
and
is
currently
approved
for
moderate-to-severe atopic dermatitis)in patients with PCA.
References：
[1]Guillet C, Steinmann S, Maul JT, Kolm I. Primary Localized Cutaneous Amyloidosis: A
Retrospective Study of an Uncommon Skin Disease in the Largest Tertiary Care Center in Switzerland.
Dermatology. 2022;238(3):579-586. doi: 10.1159/000518948. Epub 2021 Sep 15. PMID: 34525472;
PMCID: PMC9153345
[2] Zhang Zihui, Du Dan, Jiang Xian. Current Status and Prospects of Physical Therapy for
Primary
Cutaneous
Amyloidosis.
Journal
of
Clinical
Dermatology,
2018,
47(9):3.DOI:CNKI:SUN:LCPF.0.2018-09-024.
[3]Zhang, Y., et al. (2024). Successful treatment of primary cutaneous amyloidosis with
dupilumab: a case report. Journal of the American Academy of Dermatology.

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[4] Shahriari, N., et al. (2023). JAK inhibitors as rescue therapy in dupilumab-refractory severe
atopic dermatitis: A case series. JAAD Case Reports, 32 , 1-5.
II.Aims and Expected Outcomes of the Study
Research Objective: To clarify the efficacy and safety of the IL-4 receptor
antagonist Stapokibart in primary cutaneous amyloidosis.
Expected Outcome: Publication of 1 SCI (Science Citation Index) article.
III.Design and Methods of the Study
1. Study Period: Sep 15, 2025 – December 31, 2026
2. Randomized, Double-Blind, Placebo-Controlled Trial
3. Two Groups: Placebo group and treatment group
4. Enrollment: A total of 40 participants are planned to be enrolled, with 20
participants in each group, assigned randomly.。
Randomization
Process:This
study
employs
a
randomized
design.A
fixed
investigator(Investigator A)will use SAS software to generate the randomization tables for subjects
and study medications using a stratified block randomization method.Subjects who meet the
inclusion criteria will be stratified by baseline IGA(Investigator’s Global Assessment)score(3 or
4)and randomly assigned to either the Stapokibart group or the placebo group in a 1:1 ratio.After
successful screening of the subjects,the investigators will obtain the randomization numbers from
Investigator A.At each study visit when medications are dispensed,the investigators and their
designated personnel will obtain the drug identification numbers from Investigator A and assign the
study
medications
according
to
these
numbers.Investigator
A,who
is
responsible
for
randomization,will record the seed and other parameters used to generate the random numbers in the
blind code,which can be unblinded in case of emergency.After signing the informed consent
form,subjects will be assigned a unique enrollment number in the order of their successful
screening,and this enrollment number will serve as their randomization number.
5. For quantitative data, statistical descriptions are provided using mean, median,
standard deviation,maximum value, and minimum value. For categorical or ordinal
data, frequency and proportion are used to describe the data. Homogeneity
comparisons between groups are performed using analysis of variance (ANOVA),
chi-square (χ²) test, or rank-sum test.

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IV. Process of Study Implementation
Objective
Primary Objectives:

To evaluate the efficacy of Stapokibart in adult subjects with Primary Cutaneous
Amyloidosis (PCA).

To evaluate the safety of Stapokibart in adult subjects with Primary Cutaneous
Amyloidosis (PCA).
Evaluation
Criteria
Primary Evaluation Criteria:
a.The percentage of subjects achieving AASI-75 at Week 16 of treatment.
Secondary Evaluation Criteria:
a.The percentage of subjects with a weekly average reduction of≥4 points in PP-NRS
score at Week 16 of treatment compared to baseline.
b.The percentage of subjects achieving AASI-75 at other evaluation visits.
c.The percentage of subjects with an IGA score of 0 or 1 and a reduction of≥2 points
compared to baseline at each evaluation visit.
d.The percentage of subjects achieving AASI-50 at each evaluation visit.
e.The percentage of subjects achieving AASI-90 at each evaluation visit.
f.Changes and change rates in AASI scores from baseline at each evaluation visit.
g.The percentage of subjects with a weekly average reduction of≥3 points in PP-NRS
score compared to baseline.
h.Changes and change rates in weekly average PP-NRS scores compared to baseline.
i.Change rates in BSA involvement from baseline at each evaluation visit.
j.Changes in DLQI scores from baseline at each evaluation visit.
k.Changes in absolute eosinophil counts in complete blood counts from baseline at
each evaluation visit.
l.Changes in IgE levels in complete blood counts from baseline at each evaluation
visit.
m.Changes in histopathology of skin lesions at Week 16 of treatment compared to
baseline in some subjects.
Safety Endpoints:Including the occurrence of AEs(Adverse Events),and abnormalities
in laboratory tests,physical examinations,and vital signs.
(For detailed scoring tables,please refer to the appendix.)
Subjects
Adult subjects with Primary Cutaneous Amyloidosis
Sample size
40 cases
Trial Design
This study is a randomized,double-blind,placebo-controlled trial designed to evaluate
the efficacy and safety of Stapokibart in adult subjects with Primary Cutaneous
Amyloidosis(PCA).A total of 40 subjects are planned to be enrolled and will be
randomized in a 1:1 ratio to receive either Stapokibart Injection at a dose of 300 mg

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every two weeks(Q2W)(with an initial loading dose of 600 mg) or matching placebo.
The study will consist of a screening period of up to 4 weeks,a 16-week treatment
period,and a 12-week post-treatment follow-up period.The treatment period will begin
with drug administration on Day 1(D1)and continue with dosing every 2 weeks until
Week 16.
After providing informed consent,subjects will enter the screening period.During the
screening period,subjects will discontinue any ongoing PCA treatments according to
the inclusion criteria.For subjects who do not meet the inclusion/exclusion criteria due
to transient laboratory abnormalities or clinical conditions,up to two re-screenings are
allowed.At least 7 days before randomization,subjects must apply a moisturizing
cream once daily,and this same moisturizing cream must be continued throughout the
study period.To objectively assess skin dryness,subjects should avoid applying
moisturizing cream on non-lesional skin within 8 hours prior to visits.
Subjects who meet the inclusion criteria and do not meet the exclusion criteria will
proceed to the baseline/D1 visit.Subjects will be stratified by baseline IGA
score[3(moderate),4(severe)]and randomly assigned to either the Stapokibart group or
the placebo group in a 1:1 ratio,to receive the following treatments:
• Stapokibart group:Stapokibart Injection,300 mg,Q2W,with an initial dose of 600 mg.
• Placebo group:Matching placebo injection with the same dosage and regimen as
above.
Subjects will follow the visit schedule and receive study drug/placebo injections every
2 weeks during the study period from V2(D1)to V10(D113).
During the study,subjects will undergo the following assessments:Complete blood
counts,biochemical tests,and urinalysis will be performed at V1,V2,V10,and V12.An
electrocardiogram(ECG)and pregnancy test will be conducted at V1,and ECGs will
also be performed at V10 and V12.A subset of subjects will undergo skin biopsies for
histopathological examination at V1 and V12.(For details,see Table 1:Subject Visit
Schedule and Table 2:Laboratory Tests Checklist)
The study design is illustrated in the figure below.：

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Estimated
Target
The primary clinical question of this study is: Among PCA patients randomly enrolled
and treated with Stapokibart or placebo, regardless of whether they terminated
treatment or used prohibited medications (live attenuated vaccines) that do not affect
efficacy assessment for reasons other than disease progression or use of prohibited
medications during the study period (including within D1–D28 days or before 16
weeks of treatment), to evaluate the percentage of subjects achieving AASI-75 at
Week 16. The difference in the AASI-75 response rate between the treatment group
and the control group will be used as the effect size at the population level to assess
the efficacy of the study drug.Primary Estimation Target:• Target Population: Adult
PCA subjects randomly enrolled.• Treatment: Stapokibart Injection/Placebo 300 mg
Q2W (with an initial loading dose of 600 mg).• Target Variable: The percentage of
subjects achieving AASI-75 at Week 16.
Concomitant Events and Management Strategies：
Concomitant Events
Management
Strategies
Notes
Rescue therapy is used only during
the treatment period from Day 1 to
Day 28.
Therapeutic
Strategy
If this event occurs during th
treatment
period,
the
subjec
will still follow the planned
follow-up schedule, and actua
observed data will be used.
Discontinuation of treatment due
Composite
After the occurrence of thi

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to lack of efficacy
Variable
Strategy
event
during
the
treatmen
period, the primary endpoin
will
be
considered
as
"no
achieved."
Discontinuation of treatment for
reasons other
than
the
use
of
prohibited medications or disease
progression
Therapeutic
Strategy
If this event occurs during th
treatment
period,
the
subjec
will
continue
to
follow
th
planned
follow-up
schedule
and actual observed data will b
used.
Use of prohibited medications or
treatments that affect the efficacy
assessment during the study period
(excluding
rescue
therapy
used
from Day 1 to Day 28).
Composite
Variable
Strategy
After the occurrence of thi
event
during
the
treatmen
period, the primary endpoin
will
be
treated
as
"no
achieved."
Use of prohibited medications that
do not affect efficacy assessment
during
the
study
period
(live
attenuated vaccines).
Therapeutic
Strategy
If this event occurs during th
treatment
period,
the
subjec
will
continue
to
follow
th
planned
follow-up
schedule
and actual observed data will b
used.
Population-level Summary: The difference in the AASI-75 response rate between
the treatment group and the control group.。
Inclusion
Criteria
1) Males or females aged 18 to 75 years, with a diagnosis of PCA confirmed by skin
biopsy, and an IGA score of ≥3, a AASI score of ≥5, and a BSA involvement of ≥5%.
2) Subjects who have received at least 4 weeks of mid-to-high potency or at least 2
weeks of very high potency topical corticosteroids (TCS) or an adequate course of
systemic corticosteroids within the 6 months prior to screening, but with an
inadequate response; or subjects who are unable to receive the above treatments due to
adverse reactions or potential risks.
3) Prior to the first dose, subjects must have used a moisturizer continuously for at
least 1 week, once daily, and must continue to use it throughout the study period.
4) Able to understand and complete study-related questionnaires.
5) Able to read, understand, and are willing to sign the informed consent form.
6) Willing and able to comply with study visits and related procedures.
7) Women of childbearing potential must agree to use contraception (such as

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intrauterine devices, oral contraceptives, or condoms) during the study and for 6
months after the study ends; must have a negative serum pregnancy test within 7 days
before the first dose and must not be breastfeeding; male subjects must agree to use
contraception during the study and for 6 months after the study ends.
Exclusion
Criteria
Subjects meeting any of the following criteria will be excluded from the trial:1) Use
of any of the following treatments within 4 weeks prior to randomization:
a.
Immunosuppressants
or
immunomodulators,
such
as
systemic
corticosteroids,
cyclosporine, mycophenolate mofetil, interferon gamma
(IFN-γ), azathioprine,
methotrexate, and Janus kinase (JAK) inhibitors;
b. UV phototherapy;
c. Systemic
traditional Chinese medicine (TCM) treatment.2) Use of topical corticosteroids (TCS),
topical calcineurin inhibitors (TCI), TCM, or phosphodiesterase 4 (PDE-4) inhibitors
within 2 weeks prior to randomization.3) Receipt of anti-IL-4R monoclonal
antibodies, anti-IgE monoclonal antibodies, or other biologics within 12 weeks or 5
half-lives (whichever is longer) prior to randomization.4) Receipt of live attenuated
vaccines within 12 weeks prior to randomization or planned vaccination during the
study period.5) Use of antihistamines within 1 week prior to randomization (subjects
who have been on a stable dose of antihistamines for at least 7 days prior to
randomization and plan to continue during the study period may be included).6)
Receipt of allergen-specific immunotherapy (desensitization therapy) within 6 months
prior to randomization.7) Presence of any skin comorbidities that may interfere with
study assessments, including but not limited to scabies, cutaneous T-cell lymphoma,
psoriasis, etc.8) Previous receipt of at least 12 consecutive doses of anti-IL-4Rα or
IL-13 monoclonal antibodies with inadequate clinical response (defined as failure to
achieve AASI 50 during treatment).9) Presence of any other significant medical
history that the investigator deems would pose a risk to the subject's safety or be
poorly controlled if the subject participates in the study, in addition to PCA.10)
History of known or suspected immunosuppression (immunodeficiency), including a
history of invasive opportunistic infections (such as histoplasmosis, listeriosis,
coccidioidomycosis, pneumocystosis, and aspergillosis), even if the infection has
resolved; or unusual frequency, recurrence, or chronicity of infections (at the
investigator's discretion).11) Subjects with any type of active malignancy or a history
of malignancy (except for cervical cancer that has been cured for more than 5 years
prior to the screening period, or non-metastatic squamous cell carcinoma of the skin,
basal
cell
carcinoma,
and
papillary
thyroid
cancer).12)
Presence
of
active
Mycobacterium tuberculosis infection.13) Subjects with severe liver or kidney
function impairment during the screening period, such as aspartate aminotransferase
or alanine aminotransferase >2 times the upper limit of normal (ULN), total
bilirubin >1.5 times ULN, serum creatinine >1.2 times ULN, etc.14) Presence of
active hepatitis during the screening period, or positive for hepatitis B surface antigen
(HBsAg), or positive for hepatitis B core antibody (HBcAb) and HBV-DNA, or
positive for hepatitis C virus (HCV) antibody and HCV-RNA.15) Positive for HIV
antibody during the screening period, or history of HIV infection.16) Positive for
Treponema pallidum antibody during the screening period (subjects who have
undergone standard treatment and have a negative non-treponemal antigen serological
test may participate in the study).17) Participation in another clinical trial of a drug or

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medical device within 12 weeks prior to randomization.18) Presence of chronic active
or
acute
infection
requiring
systemic
treatment
with
antibiotics,
antivirals,
antiparasitics, antiprotozoals, or antifungals within 4 weeks prior to randomization.
After resolution of the infection, the subject may be re-screened once.19) Subjects
who plan to undergo major surgical procedures during the study period.20) Pregnant
or breastfeeding women.21) Subjects with a history of alcoholism, drug abuse, or
known drug dependence.22) History of atopic keratoconjunctivitis involving the
cornea.23) Any medical or psychiatric conditions that the investigator deems would
pose a risk to the subject, interfere with participation in the study, or confound the
interpretation of study results.
Investigationa
l
Medicinal
Product
Investigational Medicinal Product: Stapokibart Injection, Specification: 300mg (2ml)
per vial
Control Medication: Stapokibart Placebo, Specification: 0mg (2ml) per vial
Dosage
Regimen
Subjects will receive dosing starting from Day 1 (D1), once every 2 weeks, continuing
until Visit 10 (Day 113), for a total of 9 doses. The treatment period will end after
Visit 10. Any changes in the subject's condition that require communication with the
investigator or the need for rescue therapy* will necessitate an unscheduled visit. If
the trial is discontinued early, the Early Termination (ET) visit should be initiated as
soon as possible.
Safety
Evaluation
Criteria
The severity of adverse events will be assessed using the NCI-CTC AE 5.0 criteria.
During the trial, the Adverse Event Record Form should be completed accurately,
including the time of occurrence of the adverse event, its severity, its relationship to
the study treatment, its duration, measures taken, and its outcome.
Efficacy
Evaluation
Criteria
AASI score, PP-NRS score, IGA score, DLQI score, BSA score (for details, see the
appendix).
Data Analysis
and Statistical
Methods
Efficacy Analysis
The
primary
efficacy
endpoint
will
be
analyzed
using
the
Cochran-Mantel-Haenszel test, adjusted for randomization stratification, and the 95%
confidence interval for the difference in response rates (Stapokibart group - Placebo
group) will be calculated.For secondary efficacy endpoints, binary variables will be
analyzed using the same method as the primary efficacy endpoint. Continuous
variables will be analyzed using a mixed-effects model for repeated measures

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(MMRM), incorporating relevant baseline covariates into the model, and the 95%
confidence interval for the difference between the treatment group and the placebo
group will be calculated
Safety Analysis
Adverse events will be coded using MedDRA (Medical Dictionary for Regulatory
Activities). The incidence, number of cases, and rate of each type of adverse event in
the treatment group and the control group will be calculated separately. Adverse
events will be classified and summarized at two levels: System Organ Class (SOC)
and Preferred Term (PT). Safety assessments will also include vital signs, 12-lead
electrocardiograms (ECGs), and laboratory test results.
Estimated
Timeline
for
the Trial
• Complete enrollment of all subjects by December 2025.
• Complete treatment for all subjects by May 2026.
• Complete follow-up for all subjects by August 2026.
* Rescue Therapy: If the investigator determines at any visit after dosing that rescue therapy is
needed (i.e., to control intolerable PCA symptoms—persistent worsening of rash or pruritus that
affects daily life and work), they may provide treatment with medications that were otherwise
prohibited. The investigator should, whenever possible, limit the first step of rescue therapy to
topical medications. The use of topical corticosteroids (e.g., mometasone furoate cream; if not
tolerated, another non-maxipotent topical corticosteroid may be chosen) is permitted as rescue
therapy. Rescue therapy should not be initiated earlier than 4 weeks after the first dose of the study
drug, if feasible. The study drug may continue to be administered during the period of topical rescue
therapy. If, after 7 days of topical treatment, the worsening of PCA symptoms has not improved, the
investigator may consider escalating topical rescue therapy to include oral antihistamines (loratadine
and/or levocetirizine are permitted).
V.Risks and Benefits of the Study
Expected Benefits: To clarify the efficacy and safety of the IL-4 receptor
antagonist Stapokibart in primary cutaneous amyloidosis.
Study Risks: None.
VI.Costs and Compensation
The investigational medicinal product (Stapokibart) required for this study will
be provided free of charge by the project team, and subjects will not be required to

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pay for it. All examinations planned within the study protocol during the screening
and follow-up processes of this study are necessary for treatment and disease
monitoring, and the costs will be covered by the project team.If a subject is injured as
a result of participating in this study: in the event of harm related to this clinical study,
the subject will be entitled to free treatment and corresponding compensation, with
the relevant costs provided by the project team. The project team has purchased
insurance for the subjects. If a subject is randomized to the placebo group, they will
receive a subsidy of 1,000 yuan upon completion of the trial. If efficacy is not
satisfactory during the trial, the subject will receive free rescue treatment with the
investigational medicinal product during the trial period, with the relevant costs
covered by the project team.
VII. Quality Control and Quality Assurance
Investigators should establish a quality assurance system, fulfill their
responsibilities, and strictly adhere to the clinical trial protocol, employing
relevant standard operating procedures to ensure the implementation of the
quality control and quality assurance system in the clinical trial.。
7.1 Quality Assurance in the Clinical Trial Process
Prior to the initiation of the clinical trial, investigators should receive
training on the trial protocol to ensure a thorough understanding and awareness
of the protocol and its specific components. Quality control personnel should
verify the basic conditions for the clinical trial to ensure that they meet the
protocol requirements. During the trial, investigators should conduct clinical
operations in accordance with the department's SOPs and protocol requirements,

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and document all activities in a truthful, timely, complete, and standardized
manner. Quality control personnel should conduct quality checks on the trial
process and corresponding original records. After the trial concludes, the
research unit should organize the relevant project documents, which should be
reviewed by quality control personnel and then archived. The quality assurance
department of the clinical research unit should conduct feasibility audits of the
trials conducted. In the event of non-compliance, the investigators and unit heads
should be promptly notified to make corrections, and the status of these
corrections should be tracked.
7.2 Quality Assurance in the Data Transfer, Calculation, and Reporting
Process
After data entry into the Case Report Form (CRF) at the research center,
quality control personnel should verify the consistency between the CRF data
and the original records to ensure that the data are accurately entered into the
CRF. Monitors should conduct a 100% check on the completeness and accuracy
of data entry in the CRF and ensure that it is consistent with the original medical
records. For any data items that are questionable or inconsistent with the original
records, queries should be raised promptly, and the data entry personnel and
investigators should be urged to respond to the queries, verify, and correct any
inconsistencies. When data management staff conduct logical checks, they
should verify the quality of data entry and send queries to the investigators
regarding any questionable results, who will then verify and make corrections.
Quality control personnel should review data management files and database

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data. Quality assurance personnel at the research center should conduct spot
checks on data transfer files and statistical analysis reports to ensure the
accuracy of the data.
VIII. Data Management Methods
8.1 Data Entry and Verification
Data entry personnel should enter the information from the original
documents in a timely, accurate, complete, and standardized manner. Monitors
should verify the data in a timely manner based on the source documents to
ensure that the data are accurate, complete, consistent, and standardized. Data
managers should review the data according to the data verification plan to ensure
that the data are logically correct, complete, and standardized. When monitors
and data managers identify any issues, they should promptly raise queries.
Investigators or Clinical Research Coordinators (CRCs) should promptly
respond to the queries or make data corrections. After the monitors and data
managers confirm that there are no errors, the queries can be closed.。
8.2 Data Cleaning and Archiving
Investigators should confirm the queried data and either modify the data or
respond to the queries. Monitors or data managers should re-verify the modified
data. If the query is resolved, the query can be closed. If the query still exists,
monitors or data managers should raise the query again to obtain further
confirmation until the query is finally resolved. After the data verification is
completed, investigators should finally confirm the authenticity and accuracy of
the entered data, sign it, and then the data can be archived. The archived files

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include various records generated in data management, all data collected from
subjects throughout the trial process, and their audit trails. If regulatory
authorities conduct an on-site inspection, the required archived files should be
provided to the inspectors.。
IX. Source Documents and Acquisition of Source Data/Files
In accordance with relevant regulations and the requirements for the protection
of subjects' personal information by the research institution, the research center
must properly keep all treatment and research records related to this study, with
the original documents archived at the investigator's site.Data transferred from
the original documents to the Case Report Forms (CRFs) must be consistent with
the original documents, and any discrepancies must be explained. Depending on
the trial situation, the investigator may need previous medical records or referral
records, as well as current medical records. The investigator will agree to allow
inspections, audits, IRB/IEC reviews, and regulatory inspections related to the
trial, and will provide direct access to all relevant original data/documents. The
CRFs and all source documents, including copies of medical records and results
of laboratory and medical examinations, must be readily available for inspection
by health authorities.
X. Information and Confidentiality of Subjects
Personal data of subjects, including medical records and biological samples,
are confidential. Information that can identify subjects will not be disclosed to
anyone outside the research team unless permitted by the subjects. Subject files
are accessible only to the researchers. To ensure that the study is conducted as

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required, members of government regulatory authorities or ethics review
committees may, as required, review the personal data of subjects at the research
institution. When the results of this study are published, no personal information
of the subjects will be disclosed.

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Table 1: Subject Visit Schedule
Study
Procedures
Screening
Double-Blind Treatment Period
Follow-up Period
Unsch
edule
d
Visit
ET
Visit
Visit（V）
1
2
Baseline
3
4
5
6
7
8
9
10
11
12EOS
week（W）
0
2
4
6
8
10
12
14
16
20
28
day（D）
-28
至-1
1
15
29
43
57
71
85
99
113
141
197
Window Period
（d）
NA
±3
±3
±3
±3
±3
±3
±3
±3
±7
±7
Screening and Baseline
Sign
the
Informed
Consent
X
Inclusion/Exclu
sion Criteria
X
X
Demographic
Information1
X
Current
Illness
History and Past
Medical History
2
X
Randomization
X
Treatment
Administration
of
Investigational
Medicinal
Product 3
X
X
X
X
X
X
X
X
X

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Study
Procedures
Screening
Double-Blind Treatment Period
Follow-up Period
Unsch
edule
d
Visit
ET
Visit
Visit（V）
1
2
Baseline
3
4
5
6
7
8
9
10
11
12EOS
week（W）
0
2
4
6
8
10
12
14
16
20
28
day（D）
-28
至-1
1
15
29
43
57
71
85
99
113
141
197
Concomitant
Medications/Tre
atments
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Efficacy Evaluation
AASI、IGA、B
SA、DLQI4
X
X
X
X
X
X
X
X
X
X
X
X
X
X
PP-NRS5
X………………………………………………………………………………………………………………………………………………………………X
Photography 6
X
X
X
X
X
X
Safety Evaluation
Weight
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Height
X
Vital Signs 7
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Physical
Examination 8
X
X
X
X
X
X
Assessment
of
Injection
Site
Reactions 9
X
X
X
X
X
X
X
X
X
12-Lead
Electrocardiogra
m(ECG) 10
X
X*
X
X
X

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Study
Procedures
Screening
Double-Blind Treatment Period
Follow-up Period
Unsch
edule
d
Visit
ET
Visit
Visit（V）
1
2
Baseline
3
4
5
6
7
8
9
10
11
12EOS
week（W）
0
2
4
6
8
10
12
14
16
20
28
day（D）
-28
至-1
1
15
29
43
57
71
85
99
113
141
197
Monitoring and
Recording
of
Adverse Events
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Laboratory Tests
Serum
Pregnancy Test
11
X
X
X
X
X
Complete Blood
Count 12
X
X*
X
X
X
X
Biochemical
Profile 12
X
X*
X
X
X
X
Urinalysis 12
X
X*
X
X
X
X
Screening
for
Infectious
Diseases 13
X

Notes:
1. Demographic Information: Includes gender, age, weight, height, BMI, and ethnicity.
2. Current Illness History and Past Medical History: Includes medical history and family medical history, treatment history, alcohol use history, smoking

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history, past medical history, allergy history, concomitant diseases, and concomitant medications.
3. Medication Administration: All medications must be administered by research staff at the research center.
4. Assessments at Each Visit: Assessments should be conducted before dosing, in the following order: Patient-Reported Outcomes (PRO), investigator
assessments, safety and laboratory tests, and subcutaneous injection.
5. Itch Peak NRS Scale: This scale should be completed daily by the patient starting from Day -7, after training by the research staff, until the last study visit.
6. Photography: Photos are taken for documentation, quality review, and other research purposes. Photos should be taken at visits V2, V4, V6, V8, V10, and
V12, capturing the trunk, limbs, and typical lesions. For patient privacy, facial photos are generally not taken, and private and tattooed areas should be
appropriately covered.
7. Vital Signs: Includes temperature, blood pressure, pulse, and respiratory rate.
8. Physical Examination: Includes general physical condition, skin condition, head/neck, chest, abdomen, gastrointestinal system, superficial lymphatic
system, musculoskeletal system, limbs, and nervous system.
9. Injection Site Reactions (ISR): Investigators should assess the incidence, extent, and/or severity of ISR (erythema, edema, induration, tenderness, and
pruritus) before and after injection (0.5 hours after injection).
10. Electrocardiogram (ECG): ECG should be performed before blood sampling whenever possible. For each ECG, the subject should rest in a supine
position for 5 minutes before the test to ensure stability. ECG reports and tracings should be traceable, with the subject's name and examination time clearly
recorded on the thermal paper tracing, which should be copied and retained. Bedside ECG tracings are for reference only and should not be included in
statistical analysis.
11. Serum Pregnancy Test: This test is only for women of childbearing age.
12. Complete Blood Count (CBC) and Biochemical Profile: These tests should be performed after fasting (at least 10 hours).
13. Screening for Infectious Diseases: Includes:nullVirology Screening: Hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis B e
antibody (anti-HBe), hepatitis B surface antibody (HBsAb), hepatitis B core antibody (HBcAb), hepatitis C antibody (anti-HCV), HIV antibody, and syphilis
antibody testing. If HBcAb is positive, HBV DNA should be additionally tested. If anti-HCV is positive, HCV-RNA should be additionally tested. If syphilis
antibody is positive, non-treponemal antigen serological testing should be additionally performed.nullTuberculosis Infection Screening: Chest X-ray
(anteroposterior and lateral views). Additional tests related to tuberculosis screening may be added according to the research center's diagnostic routine.*If
CBC, biochemical profile, urinalysis, and 12-lead ECG are completed within 7 days before baseline, they do not need to be repeated at baseline.

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Table 2: List of Laboratory Tests
Test Items
Test Name(Standard Abbreviation)
Complete
Blood
Count
(CBC)
White Blood Cell Count(WBC),Neutrophil Percentage(NE%),Lymphocyte
Percentage(LY%),Monocyte Percentage(MO%),
Eosinophil Percentage(EO%),Basophil Percentage(BA%),
Absolute Neutrophil Count(NE#);
Absolute Lymphocyte Count(LY#),Absolute Monocyte Count(MO#),
Absolute Eosinophil Count(EO#),Absolute Basophil Count(BA#),
Red Blood Cell Count(RBC),Hemoglobin(HGB),Hematocrit(HCT),
Mean Corpuscular Volume(MCV),Mean Corpuscular Hemoglobin(MCH),
Mean Corpuscular Hemoglobin Concentration(MCHC),Platelet Count(PLT)
Urinalysis
Urine Glucose(GLU),Urine Bilirubin(BIL),Urine Occult Blood(BLD),Urine
Protein(PRO),Urine
Ketone
Bodies(KET),Urine
Nitrite(NIT),Specific
Gravity(SG),Urine pH Value,Urine Urobilinogen(UBG),Red Blood Cell
Count(RBC),White Blood Cell Count(WBC)
Biochemical
Profile
Direct Bilirubin(DBIL),Indirect Bilirubin(IBIL),Total Bilirubin(TBIL),
Urea(UREA),Blood Urea Nitrogen(BUN),Creatinine(Cr),
Aspartate Aminotransferase(AST),Alanine Aminotransferase(ALT),
Gamma-Glutamyl Transferase(GGT),Alkaline Phosphatase(ALP),
Total Protein(TP),Albumin(ALB),Fasting Blood Glucose(GLU),
Serum Amylase(AMY),Creatine Kinase(CK),Lactate Dehydrogenase(LDH),
Creatine Kinase Isoenzyme,Triglycerides(TG),Cholesterol(CHOL),
High-Density Lipoprotein,Low-Density Lipoprotein Cholesterol,
Prealbumin,Globulin,Albumin/Globulin Ratio,
Total Bile Acids,Potassium(K),
Sodium(Na),Chloride(Cl),Calcium(Ca),Inorganic Phosphate(P),Serum Uric
Acid(UA)
Pregnancy
Test
Human Chorionic Gonadotropin(HCG)
Virology
Tests
Virology Tests:
Hepatitis B Virology:Hepatitis B surface antigen(HBsAg),Hepatitis B
surface antibody(HBsAb),Hepatitis B e antigen(HBeAg),Hepatitis B e
antibody(HBeAb),Hepatitis B core antibody(HBcAb)
Hepatitis C Virology:Hepatitis C antibody(Anti-HCV)

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HIV Virology:Human Immunodeficiency Virus antibody(Anti-HIV)
Syphilis Test:Anti-Treponema pallidum antibody(TP-Ab)

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