Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 10/21/2021
Rethymic Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Rethymic?

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

What Are Side Effects of Rethymic?

Side effects of Rethymic include:

Dosage for Rethymic

Rethymic is administered by a surgical procedure. The recommended dose range is 5,000 to 22,000 mm2 of Rethymic/m2 recipient body surface area (BSA). 

Rethymic In Children

The efficacy and safety of Rethymic have been established in pediatric patients with congenital athymia. 

What Drugs, Substances, or Supplements Interact with Rethymic?

Rethymic may interact with other medicines such as:

Tell your doctor all medications and supplements you use and vaccines you recently received or plan to get.

Rethymic During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before using Rethymic; it is unknown how it might affect a fetus. It is unknown if the cellular components of Rethymic pass into breast milk or if it could affect a nursing infant. Consult your doctor before breastfeeding. 

Additional Information

Our Rethymic (allogeneic processed thymus tissue–agdc) for Surgical Implantation Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. 

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Rethymic Professional Information


The most common adverse reactions (incidence in at least 10% of patients) reported following administration of RETHYMIC were 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.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety data described in this section are derived from 10 prospective, single-center, open-label studies, and include 105 patients who were treated with RETHYMIC in these studies and who had at least one year of follow-up. Table 1 lists the adverse reactions occurring in 105 patients who were treated with RETHYMIC in these studies.

Table 1: Adverse Reactions Occurring in at least 5% of Patients Treated with RETHYMIC During Clinical Studies

System Organ Class
Preferred Term
n (%)
Number of Patients with Adverse Reactions1 80 (76)
Hypertension (high blood pressure) 20 (19)
Cytokine release syndrome2 19 (18)
Hypomagnesemia (low magnesium) 17 (16)
Rash3 16 (15)
Renal impairment / failure4 (decrease of kidney function) 13 (12)
Thrombocytopenia5 (low platelets) 13 (12)
Graft versus host disease6 11 (10)
Hemolytic anemia7 (low red bloods cells) 9 (9)
Neutropenia (low white blood cells) 9 (9)
Respiratory distress8 (difficulty breathing) 8 (8)
Proteinuria (protein in urine) 7 (7)
Pyrexia (fever) 6 (6)
Acidosis9 6 (6)
Diarrhea10 5 (5)
Seizure11 5 (5)
1 Reactions which occurred in the 2 years after treatment.
2 All events (19/19) of cytokine release syndrome occurred in association with ATG-R treatment.
3 Rash includes rash, granuloma skin, rash popular, urticaria.
4 Renal impairment / failure includes renal failure and acute kidney injury, proteinuria and blood creatinine increased.
5 Thrombocytopenia includes thrombocytopenia and Immune thrombocytopenic purpura.
6 GVHD includes GVHD, GVHD-gut, GVHD-skin, Omenn syndrome.
7 Hemolytic anemia includes autoimmune hemolytic anemia, Coombs-positive hemolytic anemia, hemolysis, hemolytic anemia.
8 Respiratory distress includes respiratory distress, hypoxia, respiratory failure.
9 Acidosis includes acidosis, renal tubular acidosis and blood bicarbonate decreased.
10 Diarrhea includes diarrhea and hemorrhagic diarrhea.
11 Seizures include infantile spasms, seizures and febrile convulsion.

Of the 105 patients, 29 patients died after receiving RETHYMIC, including 23 deaths in the first year (<365 days) after treatment with RETHYMIC. Causes of death in the first year included 13 deaths due to infection or complications due to infection, 5 deaths due to respiratory failure / hypoxia, 3 deaths due to hemorrhage-related events, and 2 deaths due to cardiorespiratory arrest. Of the 6 patients who died more than 1 year after treatment with RETHYMIC, the deaths were considered unrelated to study treatment: 2 died due to respiratory failure and 1 died due to each of the following: cardiopulmonary arrest, intracranial hemorrhage, infection, and unknown cause.

Severe Combined Immunodeficiency (SCID) Patients

Two patients with SCID were treated in the RETHYMIC clinical program. One patient died two years after receiving RETHYMIC, and the other patient died three years after receiving RETHYMIC.

Patients With Prior Hematopoietic Cell Transplant

Six patients with a prior hematopoietic cell transplant (HCT) were treated in the RETHYMIC clinical program. Two patients died within the first 2 years after receiving RETHYMIC.


No drug interaction studies have been conducted with RETHYMIC. If possible, prolonged use of immunosuppressive therapies, including high-dose corticosteroids, should be avoided.

Read the entire FDA prescribing information for Rethymic (Allogeneic Processed Thymus Tissue-agdc)

© Rethymic Patient Information is supplied by Cerner Multum, Inc. and Rethymic Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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