## Protocol Section
### Identification Module
**NCT ID:** NCT06436742

**Brief Title:** A Phase 1b Study to Investigate Safety and Tolerability of ARGX-119 in Adult Participants With DOK7-Congenital Myasthenic Syndromes (CMS)

**Official Title:** A Phase 1b, Double-Blinded, Randomized, Placebo-Controlled Study to Assess the Safety, Tolerability, Pharmacokinetics, Immunogenicity, and Efficacy of ARGX-119 in Adult Participants With DOK7-Congenital Myasthenic Syndromes

#### Organization Study ID Info
**ID:** ARGX-119-2302
#### Organization
**Class:** INDUSTRY
**Full Name:** argenx
#### Secondary ID Infos
**ID:** 2023-509872-41-00
**Type:** CTIS
### Status Module
#### Completion Date
**Date:** 2025-10

**Type:** ESTIMATED

#### Expanded Access Info
#### Last Update Post Date
**Date:** 2024-05-31

**Type:** ESTIMATED

**Last Update Submit Date:** 2024-05-24

**Overall Status:** NOT_YET_RECRUITING

#### Primary Completion Date
**Date:** 2025-10

**Type:** ESTIMATED

#### Start Date
**Date:** 2024-06

**Type:** ESTIMATED

**Status Verified Date:** 2024-05

#### Study First Post Date
**Date:** 2024-05-31
**Type:** ESTIMATED
**Study First Submit Date:** 2024-05-21
**Study First Submit QC Date:** 2024-05-24
### Sponsor Collaborators Module

#### Lead Sponsor

**Class:** INDUSTRY

**Name:** argenx

#### Responsible Party

**Type:** SPONSOR

### Oversight Module

**Is FDA Regulated Device:** False

**Is FDA Regulated Drug:** True

### Description Module

**Brief Summary:** The purpose of this study is to assess the safety and tolerability of ARGX-119 in adult participants with DOK7- Congenital Myasthenic Syndromes. The study will also assess how ARGX-119 is processed by the body (pharmacokinetics), how the immune system reacts to it (immunogenicity), and how it may improve the way patients feel and function.

After the screening period, eligible participants will be randomized in a 4:1 ratio to receive intravenous infusions of ARGX-119 or placebo during the treatment period. Participants will then enter the follow-up period. The full duration of the study is approximately 11 months.

### Conditions Module

**Conditions:**

- Congenital Myasthenic Syndrome

### Design Module

#### Design Info

**Allocation:** RANDOMIZED

**Intervention Model:** PARALLEL

##### Masking Info

**Masking:** QUADRUPLE

**Who Masked:**

- PARTICIPANT

- CARE_PROVIDER

- INVESTIGATOR

- OUTCOMES_ASSESSOR

**Primary Purpose:** TREATMENT

#### Enrollment Info

**Count:** 15

**Type:** ESTIMATED

**Phases:**

- PHASE1

**Study Type:** INTERVENTIONAL

### Arms Interventions Module

#### Arm Group 1

**Description:** Participants receiving intravenous infusion of ARGX-119 once every other week

**Intervention Names:**

- Biological: ARGX-119

**Label:** ARGX-119

**Type:** EXPERIMENTAL

#### Arm Group 2

**Description:** Participants receiving intravenous infusion of placebo once every other week

**Intervention Names:**

- Other: Placebo

**Label:** Placebo

**Type:** PLACEBO_COMPARATOR

### Interventions

#### Intervention 1

**Arm Group Labels:**

- ARGX-119

**Description:** Intravenous infusion of ARGX-119

**Name:** ARGX-119

**Type:** BIOLOGICAL

#### Intervention 2

**Arm Group Labels:**

- Placebo

**Description:** Intravenous infusion of placebo

**Name:** Placebo

**Type:** OTHER

### Outcomes Module

#### Primary Outcomes

**Measure:** Assessment of adverse events (AEs)

**Time Frame:** Up to week 42

#### Secondary Outcomes

**Measure:** Maximum observed serum concentration (Cmax) of ARGX-119

**Time Frame:** Up to week 42

**Measure:** Incidence of anti-drug antibodies (ADA) against ARGX-119

**Time Frame:** Up to week 42

**Measure:** Prevalence of anti-drug antibodies (ADA) against ARGX-119

**Time Frame:** Up to week 42

**Description:** Minimum value: 0 (no disease severity); Maximum value: 39 (highest disease severity)

**Measure:** Change from baseline over time for key components of the Quantitative Myasthenia Gravis (QMG) scale

**Time Frame:** Up to week 42

**Description:** Minimum value: 0 (normal symptoms); Maximum value: 24 (most severe symptoms)

**Measure:** Change from baseline over time for Myasthenia Gravis Activities of Daily Living (MG-ADL)

**Time Frame:** Up to week 42

**Description:** The participant records their response to each question on a 5-point Likert scale, with lower scores indicating poorer health (Minimum value: 0, Maximum value: 20)

**Measure:** Change from baseline over time for Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) scale

**Time Frame:** Up to week 42

### Eligibility Module

**Eligibility Criteria:** Inclusion Criteria:

* At least 18 years of age.
* Has genetically confirmed congenital myasthenic syndromes due to mutation of downstream of kinase 7 (DOK7-CMS).
* Participants taking oral beta agonists (eg, albuterol, salbutamol, ephedrine) must have been receiving the medication for more than 3 months and agree to remain on a same stable dosing regimen of the same medication until the end of the study.

Exclusion Criteria:

* Diagnosis of CMS due to mutation of any gene other than DOK7.
* Known medical condition that would interfere with an accurate assessment of CMS, confound the results of the study, or put the patient at undue risk, as assessed by the investigator.
* History of malignancy, cancer, unless considered cured by adequate treatment with no evidence of recurrence for more than 5 years. Adequately treated participants with the following cancers can be included at any time: Basal cell or squamous cell skin cancer, Carcinoma in situ of the cervix, Carcinoma in situ of the breast, Incidental histological findings of prostate cancer.
* Different study drug received in another clinical study within 12 weeks or 5 half-lives before screening.
* Current participation in another interventional clinical study or prior participation in any gene therapy or cell therapy study.
* Pregnant or lactating state or intention to become pregnant during the study.

The complete list of exclusion criteria can be found in the protocol.

**Minimum Age:** 18 Years

**Sex:** ALL

**Standard Ages:**

- ADULT

- OLDER_ADULT

### Contacts Locations Module

#### Central Contacts

**Contact 1:**

**Email:** clinicaltrials@argenx.com

**Name:** Sabine Coppieters, MD

**Phone:** 857-350-4834

**Role:** CONTACT

### IPD Sharing Statement Module

**IPD Sharing:** NO

## Derived Section

### Condition Browse Module - Ancestors

- ID: D000004194

- Term: Disease

- ID: D000010335

- Term: Pathologic Processes

- ID: D000009157

- Term: Myasthenia Gravis

- ID: D000020361

- Term: Paraneoplastic Syndromes, Nervous System

- ID: D000009423

- Term: Nervous System Neoplasms

- ID: D000009371

- Term: Neoplasms by Site

- ID: D000009369

- Term: Neoplasms

- ID: D000010257

- Term: Paraneoplastic Syndromes

- ID: D000020274

- Term: Autoimmune Diseases of the Nervous System

- ID: D000009422

- Term: Nervous System Diseases

- ID: D000019636

- Term: Neurodegenerative Diseases

- ID: D000020511

- Term: Neuromuscular Junction Diseases

- ID: D000009468

- Term: Neuromuscular Diseases

- ID: D000001327

- Term: Autoimmune Diseases

- ID: D000007154

- Term: Immune System Diseases

- ID: D000030342

- Term: Genetic Diseases, Inborn

### Condition Browse Module - Browse Branches

- Abbrev: BC23

- Name: Symptoms and General Pathology

- Abbrev: All

- Name: All Conditions

- Abbrev: BC04

- Name: Neoplasms

- Abbrev: BC10

- Name: Nervous System Diseases

- Abbrev: BC20

- Name: Immune System Diseases

- Abbrev: BC16

- Name: Diseases and Abnormalities at or Before Birth

- Abbrev: Rare

- Name: Rare Diseases

### Condition Browse Module - Browse Leaves

- ID: M16355

- Name: Syndrome

- Relevance: HIGH

- As Found: Syndrome

- ID: M18224

- Name: Lambert-Eaton Myasthenic Syndrome

- Relevance: HIGH

- As Found: Myasthenic Syndrome

- ID: M22107

- Name: Myasthenic Syndromes, Congenital

- Relevance: HIGH

- As Found: Congenital Myasthenic Syndrome

- ID: M12112

- Name: Myasthenia Gravis

- Relevance: LOW

- As Found: Unknown

- ID: M13170

- Name: Paraneoplastic Syndromes

- Relevance: LOW

- As Found: Unknown

- ID: M22160

- Name: Paraneoplastic Syndromes, Nervous System

- Relevance: LOW

- As Found: Unknown

- ID: M12367

- Name: Nervous System Neoplasms

- Relevance: LOW

- As Found: Unknown

- ID: M4629

- Name: Autoimmune Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M22094

- Name: Autoimmune Diseases of the Nervous System

- Relevance: LOW

- As Found: Unknown

- ID: M21558

- Name: Neurodegenerative Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M22297

- Name: Neuromuscular Junction Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M12411

- Name: Neuromuscular Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M10200

- Name: Immune System Diseases

- Relevance: LOW

- As Found: Unknown

- ID: M23686

- Name: Genetic Diseases, Inborn

- Relevance: LOW

- As Found: Unknown

- ID: T3299

- Name: Lambert Eaton Myasthenic Syndrome

- Relevance: HIGH

- As Found: Myasthenic Syndrome

- ID: T1538

- Name: Congenital Myasthenic Syndromes

- Relevance: HIGH

- As Found: Congenital Myasthenic Syndrome

- ID: T3973

- Name: Myasthenia Gravis

- Relevance: LOW

- As Found: Unknown

### Condition Browse Module - Meshes

- ID: D000015624

- Term: Lambert-Eaton Myasthenic Syndrome

- ID: D000020294

- Term: Myasthenic Syndromes, Congenital

- ID: D000013577

- Term: Syndrome

### Intervention Browse Module - Browse Branches

- Abbrev: Gast

- Name: Gastrointestinal Agents

- Abbrev: All

- Name: All Drugs and Chemicals

### Intervention Browse Module - Browse Leaves

- ID: M229482

- Name: Bismuth subsalicylate

- Relevance: LOW

- As Found: Unknown

### Misc Info Module

- Version Holder: 2024-05-31
