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Evaluation of the Efficacy, Safety, and Tolerability of Subcutaneous REGN7999 in Adults with Iron Overload Due to Non-Transfusion Dependent Beta-Thalassemia

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as non-transfusion dependent beta-thalassemia, which can lead to an excess of iron in the body, referred to as iron overload. The trial will test a new treatment called REGN7999, which is a type of protein designed to help manage iron levels in the body. REGN7999 is administered as an injection under the skin.

The purpose of the study is to evaluate how effective and safe REGN7999 is for people with iron overload due to non-transfusion dependent beta-thalassemia. Participants in the study will receive either REGN7999 or a matching placebo. The study will use MRI scans to measure the amount of iron in the liver, which is a key indicator of iron overload. The study will also monitor any side effects and how well participants tolerate the treatment.

Throughout the study, participants will receive regular injections and undergo MRI scans to track changes in their liver iron levels. The study aims to determine if REGN7999 can reduce iron levels and improve overall health outcomes for those with this condition. The trial will also assess changes in hemoglobin levels, which is an important component of red blood cells, and monitor the need for any additional blood transfusions.

The research process

The trial runs in 3 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    <b>participation</b> in the study

    After joining the study, injections are administered under the skin.

    The medication used is REGN7999, which is a powder for a solution used for injection, or a placebo, which is an inactive substance used for comparison.

  2. Step 2

    <b>monitoring</b> of iron levels

    The liver iron concentration, which is the amount of iron stored in the liver, is measured using R2* magnetic resonance imaging (MRI), a type of specialized scan.

    The goal is to observe changes in iron levels and to check the safety and tolerability of the different doses of REGN7999.

  3. Step 3

    <b>assessment</b> of blood and health

    Changes in hemoglobin, which is a protein in red blood cells that carries oxygen, are monitored over time.

    The number of red blood cell transfusions required is tracked.

    serum levels, which are the liquid part of the blood, are checked to measure the concentration of REGN7999.

    The presence of anti-drug antibodies, which are proteins the body might create in response to the medication, is monitored.

Who can join the trial?

5 criteria

  • You must have a formal medical diagnosis of non-transfusion dependent beta-thalassemia, which is a condition where your body does not produce enough healthy hemoglobin but you do not require regular blood transfusions.
  • You must have iron overload, which means there is too much iron stored in your body.
  • Your liver iron concentration (the amount of iron stored in your liver) must be 5 mg or more per gram of dry weight, as measured by a special type of scan called an R2* MRI.
  • Your serum ferritin levels, which is a protein in your blood that measures how much iron your body is storing, must be at least 300 ng/mL.
  • You must meet any other specific requirements outlined in the study rules.

Who cannot join the trial?

9 criteria

  • Having a hemoglobin level (a protein in your red blood cells that carries oxygen) that is 8 grams per deciliter or lower during the initial check.
  • Receiving a red blood cell transfusion (a medical procedure where healthy blood is put into your body) within 12 weeks of the third visit.
  • For those in Part A of the study: Using any iron chelation therapy (medicine used to remove extra iron from the body) during the 12 weeks before the initial screening.
  • For those in Part B of the study: Making any changes to the dose of iron chelation therapy during the 12 weeks before the initial screening.
  • Using the medications luspatercept or mitapivat within the 6 months before the initial screening.
  • Having any medical reason that prevents you from having an MRI (a medical imaging test that uses strong magnets to take pictures of the inside of your body).
  • Having a diagnosis of cirrhosis (severe scarring of the liver).
  • Having chronic kidney disease (long-term kidney damage) at stage 4 or higher.
  • Meeting any other specific reasons for exclusion defined in the study rules.
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Investigated drugs

REGN7999 is an experimental medication given as an injection. It is designed to help reduce the amount of iron that builds up in the body in people with a specific type of blood disorder called non-transfusion dependent beta-thalassemia.

What is already known about the treatment

  • REGN7999

    This medication is an experimental drug provided as a powder that is mixed into a liquid and given through an injection under the skin. It is currently being studied in clinical trials and is not yet widely available for general medical use. It is intended to treat iron buildup in people with a blood disorder called non-transfusion dependent beta-thalassemia. At a molecular level, this drug works by blocking a specific protein called TMPRSS6, which helps the body better regulate how much iron it absorbs and stores.

  • R7999 matching placebo

    This is an inactive substance administered through an injection under the skin to serve as a comparison for the study medication. It contains no active medicinal ingredients and is used in clinical research to help determine if the test drug actually works. It is used in this trial to provide a baseline for evaluating the safety and effectiveness of the experimental treatment.

Investigated diseases

  • Beta-thalassemia

    This condition is a genetic blood disorder that affects the production of hemoglobin, the protein in red blood cells that carries oxygen. It occurs when the body does not produce enough beta-globin chains, which are essential components of hemoglobin. As the disease progresses, red blood cells may become misshapen and break down more quickly than normal. This leads to a decrease in the total number of healthy red blood cells available in the bloodstream. Some individuals may experience varying levels of severity depending on their specific genetic makeup.

  • Iron overload

    This condition occurs when excessive amounts of iron accumulate within the body's tissues and organs. It often develops as a result of many blood transfusions or when the body absorbs too much iron from the diet. As iron levels rise, the metal can build up in vital organs like the liver and heart. This accumulation can gradually interfere with the normal functioning of these organs over time.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-508604-37-00Protocol codeR7999-BTHAL-2350Estimated enrolment95 patientsSponsorRegeneron Pharmaceuticals Inc.

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