supportive care

Protecting a child with congenital athymia from infection requires constant care and attention

Children with congenital athymia need special care to minimize the risk of life-threatening infections. One of the most important things that your child’s healthcare provider will discuss with you is isolation—both in the hospital and in the home.1

Always talk to your child’s healthcare provider to create a plan that is right for you and your family. Some steps they may recommend are1:

Limiting or restricting visitors in the home1

Showering and changing clothes any time you leave and return home1

Frequent handwashing1

Working with healthcare providers to prevent exposure to sick people at medical appointments2

Obtaining protective supplies like masks, gloves, and gowns1

If possible, homeschooling other children in your family and/or working from home3

Wiping down any items, such as groceries, brought into the home

It may not be possible for every family member to isolate.

Talk to your child’s immunologist about recommended practices to minimize the risk of infection outside the home. These may include:

Having a “sick plan” in place for when a member of your household feels ill. Make sure they have a place to go (such as staying with a friend or relative) until they are no longer contagious. Work with your child’s healthcare provider to come up with a plan if the primary caregiver becomes sick.

Educating everyone you know about congenital athymia. Make sure they understand the severity of the diagnosis and that special precautions and isolation are needed to protect your child.1

A child with congenital athymia may be cared for by a team of healthcare providers

Your child’s team of pediatric clinicians and specialists may include but are not limited to2,3:

  • Immunologists (for immune system disorders)
  • Endocrinologists (for thyroid and parathyroid functions)
  • Cardiologists (for heart conditions)
  • Otolaryngologists (for ear, nose, and throat conditions)
  • Geneticists (for genetic screenings)
  • Infectious disease specialists (for infections)

RETHYMIC is the first and only FDA-approved tissue-based treatment for congenital athymia engineered to help children develop an immune system sufficient to fight infections.4,5


Find out how your child’s healthcare provider can begin the referral process.


Enzyvant CONNECT provides support and resources to children with congenital athymia and their caregivers.

Indication and Important Safety Information
Important Safety Information

Infection Control: Immune reconstitution sufficient to protect from infection is unlikely to develop prior to 6-12 months after treatment with RETHYMIC. Immune reconstitution is needed for the body to produce cells in the immune system to fight infection. Your child’s doctor should advise you of infection control measures which should be followed immediately after treatment and until the immune system starts working at a sufficient level. Monitor your child closely for signs of infection, including fever. Your child should be maintained on immunoglobulin replacement and prophylactic antimicrobials until certain criteria are met as determined by your doctor.

Graft versus Host Disease (GVHD): RETHYMIC may cause or make pre-existing GVHD worse. Your child will be monitored for GVHD and treated if needed. Symptoms of GVHD may include fever, rash, enlarged lymph nodes, inflammation of the gastrointestinal system and/or diarrhea.

Autoimmune Disorders: Autoimmune-related adverse events occurred in patients treated with RETHYMIC. These events included: low platelets, low white blood cells, protein in urine, low red blood cells, hair loss, poor thyroid function, inflammation of liver, inflammation of the joints, inflammation of the spinal cord, loss of pigment in the skin, eyes and hair, overactive thyroid function, and loss of function of the ovaries. Your doctor will monitor your child regularly including performing blood tests.

Kidney Disease: Treatment with RETHYMIC is a risk factor for death in patients with pre-existing kidney disease.

Cytomegalovirus (CMV) Infection: In clinical studies with RETHYMIC, 4 out of 4 patients with pre-existing CMV infection prior to the implantation with RETHYMIC died. Talk to your doctor about the benefits/risks of treatment if your child has pre-existing CMV infection.

Cancer: Due to your child’s weakened immune system, there is increased risk of developing certain cancers. Your child’s doctor will monitor your child through testing for Epstein-Barr virus (EBV) and cytomegalovirus (CMV), which are two viruses that can cause cancer.

Transmission of Serious Infections: Because RETHYMIC is made from human tissue, and animal products are used in the manufacturing process, transmission of infectious diseases may occur.

Vaccinations: Your child should not receive any vaccinations until he or she has met certain requirements set by your doctor. Talk to your child’s doctor prior to any vaccinations.

Anti-HLA Antibodies: Prior to receiving RETHYMIC your child will be tested for HLA antibodies, which are proteins that may be present in your child’s blood. If your child has these antibodies, he/she will need to receive RETHYMIC from a donor that does not express those HLA proteins.

HLA Typing: If your child has received a hematopoietic cell transplantation (HCT) or a solid organ transplant, they will have a test to look for specific antibodies that could interfere with the effect of RETHYMIC. If they are present, then it will be necessary to receive RETHYMIC from a certain group of donors that do not have these proteins.

Deaths: 105 children participated in the clinical studies of RETHYMIC. 29 of the patients died, including 23 in the first year after implantation of RETHYMIC.

What are the most common side effects with RETHYMIC?

The most common side effects with RETHYMIC are hypertension (high blood pressure), cytokine release syndrome, rash, hypomagnesemia (low magnesium), renal impairment / failure (decrease of kidney function), thrombocytopenia (low platelets), and graft versus host disease.

These are not all of the possible side effects of RETHYMIC. Talk to your child’s doctor about any side effect that bothers your child or does not go away.

You are encouraged to report side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/safety/medwatch.


RETHYMIC® (allogeneic processed thymus tissue–agdc) is indicated for immune reconstitution in pediatric patients with congenital athymia.

RETHYMIC is not for use in patients who have been diagnosed with severe combined immunodeficiency (SCID).

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Sumitomo Pharma is a trademark of Sumitomo Pharma Co., Ltd., used under license. SUMITOMO PHARMA is a trademark of Sumitomo Pharma Co., Ltd., used under license. SUMITOMO is a registered trademark of Sumitomo Chemical Co., Ltd., used under license. Sumitomo Pharma America, Inc. is a U.S. subsidiary of Sumitomo Pharma Co. Ltd. ENZYVANT CONNECT®, RETHYMIC®, and their logos are registered trademarks of Enzyvant Therapeutics GmbH. © 2023 Enzyvant Therapeutics GmbH. All rights reserved. US—2300142 11/2023