A Study to Assess the Long-term Safety and Efficacy of a Subcutaneous Formulation of Efgartigimod in Adults With Chronic Inflammatory Demyelinating Polyneuropathy (CIDP, an Autoimmune Disorder That Affects the Peripheral Nerves)

Lead Sponsor: argenx

This is the open-label extension study of phase II ARGX-113-1802 to evaluate the long-term safety and efficacy of the subcutaneous formulation of efgartigimod in adults with CIDP.

• Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Intervention Type: Biological

Intervention Name: Efgartigimod PH20 SC

Description: Subcutaneous administration of efgartigimod

Arm Group Label: efgartigimod PH20 SC

Other Name: ARGX-113

Criteria:

Inclusion Criteria: 1. Ability to understand the requirements of the trial, provide written informed consent (including consent for the use and disclosure of research-related health information), willingness and ability to comply with the trial protocol procedures (including required trial visits) of this trial. 2. Male or female patient with one of the following options: - Have completed the Week-48 visit of Stage B of the ARGX-113-1802 trial and are considered to be eligible for treatment with efgartigimod PH20 SC; or - Have deteriorated during Stage B of the ARGX-113-1802 trial and are considered to be eligible for treatment with efgartigimod PH20 SC, or - Have been offered the participation in the OLE trial due to early termination of the ARGX-113-1802 trial (because sufficient events for the primary endpoint analysis of the that trial have been reached and it is stopped) and are considered to be eligible for treatment with efgartigimod PH20 SC treatment; or - Have completed the Week-48 visit of the previous cycle of the OLE trial and are considered to be eligible to continue with efgartigimod PH20 SC treatment. 3. Women of childbearing potential who have a negative urine pregnancy test at baseline before IMP administration. 4. Women of childbearing potential must use a highly effective method of contraception (failure rate of less than 1% per year) from baseline to 90 days after the last administration of IMP 5. Non-sterilized male patients who are sexually active with a female partner of childbearing potential must use a condom and his partner must use a highly effective method of contraception (failure rate of less than 1% per year) from baseline to 90 days after the last administration of IMP. Male patients practicing true sexual abstinence (when this is in line with the preferred and usual life style of the participant) can be included. Sterilized male patients who have had vasectomy with documented aspermia post-procedure can be included. In addition, male patients are not allowed to donate sperm from baseline to 90 days after the last administration of IMP. Exclusion Criteria: 1. Week-48/ED visit in the ARGX-113-1802 trial or the Week-48 visit of the previous OLE participation occurred more than 14 days prior to SD1 of the OLE trial or the start of a new treatment cycle in the OLE trial and more than 21 days since the last dose of IMP. 2. Pregnant and lactating women and those intending to become pregnant during the trial or within 90 days after last IMP administration. 3. Patients with clinical evidence of other significant serious disease or patients who underwent a recent or have a planned major surgery, or any other reason which could confound the results of the trial or put the patient at undue risk.

Gender: All

Minimum Age: 18 Years

Maximum Age: N/A

Healthy Volunteers: No

Last Name: Antonio Guglietta

Phone: +1 857-350-4834

Email: [email protected]

Georgia

October 2020

Type: Sponsor

• Polyneuropathies
• Polyradiculoneuropathy, Chronic Inflammatory Demyelinating

Label: efgartigimod PH20 SC

Type: Experimental

Description: Patients treated with efgartigimod PH20 SC

Allocation: N/A

Intervention Model: Single Group Assignment

Primary Purpose: Treatment

Masking: None (Open Label)