A long-term study to assess the safety and efficacy of efgartigimod in adult patients with primary immune thrombocytopenia (an autoimmune disorder that destructs platelets, blood cells that help with clotting, and can lead to easy or excessive bruising and bleeding)

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Argenx

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Immune System Diseases [C20]

Trial duration

15 Dec 2020 → 11 Mar 2026

Decision date (initial)

2024-05-07

Transition trial

Yes

Low-intervention

No

Rare-disease indication

No

Vulnerable population

Yes

Funding sources

argenx BV

External identifiers

EU CT number

2024-511504-17-00

EudraCT number

2019-002101-21

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Pharmacodynamic, Others, Pharmacokinetic, Efficacy, Safety

To evaluate the long-term safety of efgartigimod in adult patients with primary immune thrombocytopenia (ITP)

Secondary objectives 8

1. First 52-week treatment period only: To evaluate the long-term efficacy of efgartigimod on overall platelet count response.
2. First 52-week treatment period only:To explore the potential for reduction in concurrent ITP therapy.
3. First 52-week treatment period only: To evaluate the effects of efgartigimod treatment on quality-of-life (QoL) measures and patient-reported outcomes (PRO).
4. First 52-week treatment period only:To evaluate the incidence and severity of bleeding events while receiving treatment with efgartigimod.
5. First 52-week treatment period only:To evaluate the use of rescue treatment while receiving treatment with efgartigimod
6. First 52-week treatment period only:To assess the pharmacodynamic (PD) effects of efgartigimod.
7. First 52-week treatment period only:To evaluate the pharmacokinetics (PK) of efgartigimod
8. First 52-week treatment period and additional 52-week treatment periods: To assess the immunogenicity of efgartigimod.

Conditions and MedDRA coding

Primary immune thrombocytopenia

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 6

1. Ability to understand the requirements of the trial, to provide written informed consent (including consent for the use and disclosure of research-related health information), and to comply with the trial protocol procedures (including required trial visits).
2. Patients enrolled in the ARGX-113-1801 trial who completed the 24- week trial period.
3. Women of childbearing potential must have a negative urine pregnancy test at baseline before trial medication (infusion) can be administered. Women are considered of childbearing potential unless they are post-menopausal (defined by continuous amenorrhea) for at least 1 year with a FSH of >40 IU/L or are surgically sterilized (ie, women who had a hysterectomy, a bilateral salpingectomy, both ovaries surgically removed, or have a documented permanent female sterilization procedure including tubal ligation). Follicle-stimulating hormone can be used to confirm post-menopausal status in amenorrheic patients not on hormonal replacement therapy.
4. Women of childbearing potential should use a highly effective or acceptable method of contraception during the trial and for 90 days after the last administration of the IMP. They must be on a stable regimen, for at least 1 month: • combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation - oral - intravaginal - transdermal • progestogen-only hormonal contraception associated with inhibition of ovulation: - oral - injectable - implantable • intrauterine device (IUD) • intrauterine hormone-releasing system • bilateral tubal occlusion • vasectomized partner(provided that the partner is the sole sexual partner of the trial participant and that aspermia was documented postprocedure) • continuous abstinence from heterosexual sexual contact. Sexual abstinence is only allowable if it is the preferred and usual lifestyle of the patient. Periodic abstinence (calendar, symptothermal, postovulation methods) is not acceptable • male or female condom with or without spermicide • cap, diaphragm, or sponge with spermicide. In addition to the above criteria, for patients who want to continue receiving efgartigimod during an additional 52-week treatment period (only applicable in case efgartigimod is not yet commercially available for patients with primary ITP, or becomes available through another patient program for patients with primary ITP):Ability to understand the requirements of the additional 52-week treatment period of the trial, to provide written informed consent (including consent for the use and disclosure of research- related health information), and to comply with the trial protocol procedures (including required trial visits).
5. Ability to understand the requirements of the additional 52-week treatment period of the trial, to provide written informed consent (including consent for the use and disclosure of research- related health information), and to comply with the trial protocol procedures (including required trial visits).
6. Patient has completed a 52-week treatment period.

Exclusion criteria 4

1. Introduction or continuation of non-permitted medications during the ARGX-113-1801 trial (such as anti-CD20 therapy, romiplostim, monoclonal antibodies, Fc fusion proteins or live/live-attenuated vaccines).
2. Pregnant or lactating women, and those intending to become pregnant during the trial or within 90 days after the last dosing.
3. Patients with known medical history of hypersensitivity to any of the ingredients of efgartigimod.
4. Use of any other investigational drug or participation in any other investigational trial.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Frequency and severity of AEs, vital signs, and laboratory assessments.

Secondary endpoints 15

1. First 52-week treatment period only: 1. Extent of disease control defined as the percentage of weeks in the trial with platelet counts of ≥50×10^9/L.
2. First 52-week treatment period only: Percentage of patients with overall platelet count response defined as achieving a platelet count of ≥50×10^9/L on at least 4 occasions at any time during the 52-week treatment period.
3. First 52-week treatment period only: Mean change from baseline in platelet count at each visit.
4. First 52-week treatment period only: For patients rolling-over from the ARGX-113-1801 trial with a platelet count of <30×10^9/L: time to response is defined as the time to achieve 2 consecutive platelet counts of ≥50×10^9/L.
5. First 52-week treatment period only: The percentage of weeks in the trial with platelet counts of ≥ 30×10^9/L and at least 20×10^9/L above baseline.
6. First 52-week treatment period only: In patients with baseline platelet count of <15×10^9/L in the current trial (ARGX-113-1803), the percentage of weeks in the trial with platelet counts of ≥30×10^9/L and at least 20×10^9/L above baseline.
7. First 52-week treatment period only: In patients with first exposure to efgartigimod: proportion of patients who achieve a sustained platelet response defined as achieving platelet counts of at least 50×10^9/L for at least 4 of the 6 visits between week 19 and 24 of the trial.
8. First 52-week treatment period only: In patients with first exposure to efgartigimod: proportion of patients in the overall population achieving platelet counts of at least 50×10^9/L for at least 6 of the 8 visits between week 17 and 24 of the trial.
9. First 52-week treatment period only: Rate of receipt of rescue therapy (rescue per patient per month).
10. First 52-week treatment period only: Reduction in concurrent ITP therapy.
11. First 52-week treatment period only: Incidence and severity of the WHO-classified bleeding events.
12. First 52-week treatment period only: Change from baseline in PRO (FACIT-Fatigue, Fact-Th6) and QoL (SF- 36) at planned visits.
13. First 52-week treatment period only: Pharmacokinetic parameter of efgartigimod: serum concentration observed predose (Ctrough).
14. First 52-week treatment period only: Pharmacodynamics markers: total IgG.
15. First 52-week treatment period and additional 52-week treatment periods: Incidence of anti-drug antibodies (ADA) to efgartigimod.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Argenx

Sponsor organisation

Argenx

Address

Industriepark-Zwijnaarde 7

City

Gent

Postcode

9052

Country

Belgium

Scientific contact point

Organisation

Argenx

Contact name

Regulatory

Public contact point

Organisation

Argenx

Contact name

Regulatory

Third parties 7

Locations

4 EU/EEA countries · 8 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 3 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

5 submissions — initial application plus substantial / non-substantial modifications