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The Sidney Kimmel Comprehensive Cancer Center

Blood and Bone Marrow Cancers Program

Paroxysmal Nocturnal Hemoglobinuria (PNH)

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder that occurs when a part of your immune system attacks your red blood cells and causes them to break apart. If left untreated, the disorder can cause problems such as exhaustion and weakness associated with anemia, chronic kidney disease, and blood clots.

PNH is generally treated with drugs that, although they do not cure the disease, control blood cell damage by inhibiting part of the immune system to stop it from attacking. Because of the advances in the treatment of PNH, bone marrow transplants, while a potential cure for PNH, are generally only recommended in severe cases with other complications. With a proper diagnosis by an experienced expert, PNH patients can have a normal lifespan.

At Johns Hopkins, our team of experts are known internationally for their expertise in PNH. We use the latest treatments and work together to give you the best care possible.

  • Our Team

    Experts at The Johns Hopkins Kimmel Cancer are nationally and internationally recognized as leaders in the research and treatment of paroxysmal nocturnal hemoglobinuria and other blood disorders.

  • Treatment Options

    At the Johns Hopkins Kimmel Cancer Center, PNH patients are managed by experts from the Bone Marrow Failures Disorders Program. The appropriate treatment for PNH depends on the severity of symptoms.

  • Clinical Trials

    Find information about open paroxysmal nocturnal hemoglobinuria studies offered at the Johns Hopkins Kimmel Cancer Center.

Our Physician Scientists

Johns Hopkins’ physician scientists conduct the cutting-edge research that determines the best, most effective treatments for PNH. Their world-class patient care is complemented by highly trained and experienced healthcare professionals offering patient support.

An Acquired Genetic Mutation

PNH develops when proteins that help  defend against infection, called the complement system, damage your red blood cells. Normally, red blood cells have a shield against the complement system, but with PNH, a gene called PIG-A mutates and stops making the shields, so the red blood cells break apart. The hemoglobin in your red blood cells, which normally helps them to carry oxygen throughout your body, is dumped into your bloodstream. The overflow of hemoglobin can damage your kidneys. Anemia happens when your body cannot make enough red blood cells to replace the broken ones.

As a result of the mutated PIG-A gene, people with PNH have an increased risk of life-threatening blood clots. This is mitigated by PNH treatment.

Clinical Trials

Clinical trials offer access to medical treatments that are being tested on PNH, which may work better for you than a standard course of treatment. Johns Hopkins is a leading research institution offering trials that test the latest therapies and technologies. Johns Hopkins may also connect you with trials being conducted by cooperating organizations. Ask your treatment team about clinical trials early on.

PNH Trials
Cancer Trials

Treatment

As of the past few years, there are multiple drugs to treat PNH. These drugs all inhibit the part of the immune system, known as the complement system, that in PNH is destroying red blood cells and raising the risk of blood clots. They don’t cure PNH, but they can prevent it from causing serious medical problems. Studies show that these drugs can allow someone with PNH to live as long as someone who doesn’t have it. The dosing, the way they are given, and how often they are given depends on the specific drug. 

The drugs affect a part of your body's natural defense (immune) system by stopping certain proteins. Some target early steps (“proximal” inhibitors), while others act later in the process (“terminal” inhibitors). Because they work in different ways, their effects and side effects can vary.

The care team at Johns Hopkins will help you decide which drug is best for you, depending on your preferences and any other medical conditions you have. We can also help with any side effects. It’s important to talk to your care team about how you’re feeling so they can help manage these effects.

These are the six approved drugs used to treat PNH.

  • Eculizumab 
  • Ravulizumab
  • Crovalimab
  • Pegcetacoplan 
  • Iptacopan
  • Danicopan (in combination with ravulizumab or eculizumab) 

Bone marrow transplantation may be recommended for PNH patients who have severe reductions in red blood cells, white blood cells, and platelets, despite medication, and significant bone marrow failure. With a transplant, healthy blood cell-producing stem cells in a donor’s bone marrow are provided to the patient after the patient’s non-functioning bone marrow is inactivated with drugs and/or radiation. Learn more about the Johns Hopkins Bone Marrow Transplant Program.

PNH Resources