ATG and cyclosporine

Say it: A-T-G and SY-klo-SPOR-een

Antithymocyte globulin and cyclosporine, often with eltrombopag

ATG and cyclosporine calm down an overactive immune system so the bone marrow can make blood cells again in severe aplastic anemia.

Also called: ATG, horse ATG, Atgam and cyclosporine, hATG CsA, immunosuppressive therapy, IST, ATG cyclosporine eltrombopag, triple therapy for aplastic anemia

What it is

Aplastic anemia is not cancer. In most people, the immune system attacks the bone marrow by mistake, so it stops making enough red cells, white cells and platelets. ATG and cyclosporine quiet that immune attack, and eltrombopag helps the marrow make more cells. The goal is to bring blood counts back up so you no longer need transfusions; this often takes 3 to 6 months.

Often used for

• Severe aplastic anemia in people who are not getting a bone marrow transplant
• Aplastic anemia in older adults, or while a donor search is underway

ATG and cyclosporine with eltrombopag

Adding eltrombopag from the start is now the usual plan for adults and older children. It helps more people respond, and responses come sooner.

Rabbit ATG

A different ATG made in rabbits is sometimes used, for example after a reaction to horse ATG or for a second course. It works a bit less well as a first treatment.

Bone marrow transplant instead

Younger people with a matched sibling donor are often offered a transplant first, since it can cure aplastic anemia.

The medicines in this plan

Antithymocyte globulin (ATG, Atgam)

An antibody made in horses that removes the immune cells attacking your marrow. Given through a vein over several hours, once a day for 4 days, in the hospital.

Cyclosporine

An immune calming pill taken twice a day for at least 6 months, then slowly lowered. Blood levels are checked to get the dose right.

Eltrombopag

A pill that stimulates the bone marrow to make more blood cells. Taken once a day, usually for about 6 months, on an empty stomach.

How you get it

ATG is given in the hospital, usually as a 4 day course with a stay of about 1 to 2 weeks. Cyclosporine and eltrombopag are pills you continue at home. You will have frequent clinic visits for blood tests and transfusions while you wait for your counts to recover. Cyclosporine is usually continued for at least 6 months and then lowered slowly over months. Your schedule may be different.

A typical cycle

Days 1 to 4

Hospital stay. Premedicines (a steroid, an antihistamine and acetaminophen), then IV ATG over several hours each day. Cyclosporine and eltrombopag pills start.

Days 5 to 14

Steroid pills continue for a short time to prevent serum sickness, then are tapered off. You go home when stable.

Weeks 2 to 12

Clinic visits for blood counts, cyclosporine levels, kidney and liver tests, and transfusions as needed.

Months 3 to 6

Blood counts often start to rise. Response is checked around 3 and 6 months.

After 6 months

Eltrombopag usually stops, and cyclosporine is lowered slowly while counts are watched.

Common side effects and what helps

• Fever, chills, shaking or rash during the ATG infusion. Premedicines help, and nurses watch you closely.
• Serum sickness, about 1 to 2 weeks after ATG: fever, rash, joint pain or achy muscles. Steroids treat and help prevent it.
• Low blood counts for months, with a need for transfusions. Avoid injury and infection.
• High blood pressure from cyclosporine. Check it at home if your team asks.
• Kidney effects from cyclosporine. Drink fluids and keep all blood test visits.
• Gum swelling and extra hair growth from cyclosporine. Brush and floss gently every day.
• Shaky hands, tingling or headaches from cyclosporine. Tell your team if this bothers you.
• Nausea or upset stomach. Take pills with the timing your team gives you.
• Liver test changes from eltrombopag. Blood tests check this.

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• Bleeding that will not stop, black stools, blood in urine, or many new bruises or tiny red spots on the skin
• Trouble breathing, swelling of the face or throat, or a fast heartbeat during or after ATG
• A very bad headache, confusion, vision changes or a seizure
• Joint pain, rash and fever about 1 to 2 weeks after ATG
• Yellow skin or eyes, or dark urine
• Making much less urine than usual, or severe swelling

Good to know

• Aplastic anemia is not cancer. This treatment calms the immune system and is not chemotherapy.
• Because ATG is made in horses, you may get a test dose first, and you are watched closely for allergic reactions.
• Cyclosporine blood levels are checked often. Take it at the same times every day and do not eat grapefruit or drink grapefruit juice.
• Many medicines interact with cyclosporine. Check with your team or pharmacist before starting any new medicine or supplement.
• Blood products you receive are usually irradiated, and you may take medicines to prevent infections.
• Response is slow. It often takes 3 to 6 months before blood counts improve, so patience is part of the plan.

At home

• Take cyclosporine twice a day at the same times, about 12 hours apart.
• Take eltrombopag on an empty stomach, and keep it apart from dairy, calcium, iron, antacids and other minerals by several hours, as your team instructs.
• Wash hands often, avoid crowds and sick people, and do not handle pet litter or bird cages.
• Use a soft toothbrush and an electric razor to lower bleeding risk.
• Keep a log of your blood pressure, temperature and pill times.

Questions to ask

• Am I a candidate for a bone marrow transplant instead?
• How long until we know if this is working?
• How often will I need transfusions while I wait?
• What should I do if I miss a cyclosporine dose?
• Which foods, medicines and supplements should I avoid?
• What happens if my counts do not improve?

Anemia and iron deficiency

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.