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NCT Number: NCT06503731

A Study to Evaluate the Safety and Tolerability of Efgartigimod PH20 SC Given by Prefilled Syringe in Kidney Transplant Recipients With Antibody-Mediated Rejection (AMR)

The purpose of this study is to assess the safety, tolerability, and efficacy of efgartigimod PH20 SC given by a prefilled syringe in participants with Antibody-Mediated Rejection (AMR) after kidney transplantation.

After a screening period of up to 6 weeks, eligible participants will be randomized in a 1:1:1 ratio. The study drug will be administered subcutaneously while patients remain on their standard background immunosuppression therapy (tacrolimus, mycophenolate mofetil, steroids) during the treatment period (48 weeks). At the end of the treatment period, the participants will enter an observational/follow-up period (approximately 24 weeks). The participants will be in the study for up to 78 weeks.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Antibody-mediated Rejection

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Allgemeines Krankenhaus der Stadt Wien (AKH Wien) - Medizinischer Universitätscampus, Vienna, Austria

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • The participant is within the ages of 18 and 80 years old
  • The participant had a kidney transplant (living or deceased donor) at least 6 months before the study
  • The participant has received a diagnosis of active or chronic active antibody-mediated rejection (AMR) with detectable donor-specific antibodies at time of the study
  • A participant may be allowed into the study if they receive the following medications:
  • Received mycophenolate mofetil for at least 20 weeks before the study
  • Has remained on a stable dose of mycophenolate mofetil and tacrolimus for at least 4 weeks before being allowed to participate in the study
  • Has remained on tacrolimus doses between 5 to 10 ng/mL at least 4 weeks before being allowed to participate in the study
  • Steroid dose was between 0 to 10 mg per day of prednisone (or dose equivalent) for at least 4 weeks before being allowed to participate in the study

Exclusion criteria

  • Confirmed T-cell or mixed rejection at time of the study
  • Recent change in immunosuppressive therapy agents
  • Any other medical condition that, in the investigator's opinion, would interfere with the results of the study or put the participant at undue risk
  • Pregnant or lactating state or intention to become pregnant during the study

The complete list of criteria can be found in the protocol

Treatment and study plan

Efgartigimod PH20 SC - prefilled syringe

Combination Product

Subcutaneous efgartigimod PH20 SC given by prefilled syringe

Placebo PH20 SC - prefilled syringe

Other

Subcutaneous placebo PH20 SC given by prefilled syringe

Primary outcomes

  1. Incidence of Adverse Events (AEs)

    Time frame: Up to 78 weeks

  2. Percentage of participants with permanent treatment discontinuation due to adverse events (AEs)

    Time frame: Up to 48 weeks

Secondary outcomes

  1. Changes from baseline (slope) of the estimated glomerular filtration rate (eGFR)

    Time frame: Up to 72 weeks

  2. Histological changes in kidney biopsy

    Time frame: Up to 72 weeks

  3. Urine protein creatinine ratio (UPCR)

    Time frame: Up to 72 weeks

  4. Graft and participant survival

    Time frame: Up to 72 weeks

  5. Proportion of participants with biopsy-proven histologic resolution (BPHR) over time

    Time frame: Up to 72 weeks

  6. Changes from baseline in AMR/MVI index score over time

    Time frame: Up to 72 weeks

    MVI: microvascular inflammation. AMR/MVI score is a continuous index derived from Banff histological lesions (g, ptc, cg, and C4d positivity) and used to quantify the intensity of microvascular inflammation linked to AMR. It aims to describe where a biopsy lies along the spectrum from no rejection to probable AMR to complete AMR/MVI, providing a more granular measure of disease severity than dichotomous Banff categories.

  7. Percentage change from baseline in total IgG levels in serum over time

    Time frame: Up to 60 weeks

  8. Efgartigimod serum concentration-time profile and PK parameter Ctrough

    Time frame: Up to 48 weeks

  9. Incidence of antidrug antibodies (ADA) against efgartigimod in serum over time

    Time frame: Up to 72 weeks

  10. Incidence of antibodies against rHuPH20 in plasma over time

    Time frame: Up to 72 weeks

Sponsors and collaborators

Lead sponsor

argenx

Industry

Registry information

Official study title

A Global, Multicenter, Randomized, Double-Blinded, Placebo-Controlled, Phase 2 Study to Evaluate the Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC Administered by a Prefilled Syringe in Kidney Transplant Recipients With Antibody-Mediated Rejection

Acronym: Shamrock

Important dates

Study start
2024
Primary completion
2027
Study completion
2027
First posted
Jul 16, 2024
Registry last updated
Jul 2, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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