What are the common side effects of C10403 (CALGB 10403)?

Low blood counts, which raise the risk of infection, bleeding and tiredness. Allergic reactions to pegaspargase, such as hives, itching or trouble breathing. Pancreas swelling (pancreatitis) from pegaspargase, which causes belly pain that may go to the back. Blood clots from pegaspargase, including clots in the legs, lungs or brain. Liver strain and high blood sugar, mostly from pegaspargase and steroids. Tingling, numbness, constipation or jaw pain from vincristine. Mood changes, trouble sleeping and bigger appetite from steroids. Mouth sores and nausea. Headache or back pain after a spinal tap.

When should I call my care team during C10403 (CALGB 10403)?

A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills; Bad belly pain that may spread to your back, with or without throwing up; Hives, swelling of the face or lips, or trouble breathing during or after a pegaspargase dose; Swelling, pain or warmth in one leg or arm, or sudden shortness of breath (signs of a blood clot); New confusion, a very bad headache, trouble speaking, or weakness on one side of the body; Bleeding that will not stop, blood in your urine or stool, or many new bruises; Yellow skin or eyes, or very dark urine; Very bad constipation, with no bowel movement for 3 days.

C10403 (CALGB 10403)

Say it: C ten four oh three

A pediatric style plan for acute lymphoblastic leukemia that uses many medicines, including vincristine, a steroid (prednisone or dexamethasone), daunorubicin, doxorubicin, pegaspargase, methotrexate, cytarabine, mercaptopurine and cyclophosphamide

C10403 is a long, step by step treatment plan for teens and young adults with acute lymphoblastic leukemia (ALL), borrowed from the way children with ALL are treated.

Also called: CALGB 10403, CALGB-10403, C-10403, pediatric inspired ALL regimen, AYA ALL protocol, pediatric style ALL treatment

What it is

Teens and young adults with ALL do better when they are treated the way children are treated. C10403 is named after the study that tested this idea in young adults. It uses many medicines in five phases, plus medicine put into the fluid around the spine to protect the brain. The goal is cure.

Often used for

acute lymphoblastic leukemia (ALL) in teens and young adults, usually about ages 17 to 39

Induction: About 4 weeks. Vincristine, prednisone, daunorubicin and pegaspargase, plus spinal taps. The goal is to clear leukemia from the bone marrow (remission).
Consolidation: About 4 weeks, sometimes longer. Cyclophosphamide, cytarabine, mercaptopurine, vincristine and pegaspargase, plus spinal taps, to kill leftover leukemia cells.
Interim maintenance: About 8 weeks. Methotrexate through a vein in slowly rising amounts, with vincristine, pegaspargase and spinal taps.
Delayed intensification: About 8 weeks. A second strong round with vincristine, dexamethasone, doxorubicin, pegaspargase, cyclophosphamide, cytarabine, thioguanine and spinal taps.
Maintenance: The longest phase. Mostly pills at home (daily mercaptopurine and weekly methotrexate) with vincristine, short steroid bursts and spinal taps every few months. It lasts until about 2 years (women) or 3 years (men) from the start of interim maintenance.

The medicines in this plan

Vincristine: Chemotherapy given through a vein. It is used in almost every phase of the plan.
Prednisone: Steroid pills that kill leukemia cells. Taken by mouth during induction and in short bursts during maintenance.
Dexamethasone: Steroid pills used during delayed intensification in place of prednisone.
Daunorubicin: Anthracycline chemotherapy given through a vein during induction.
Doxorubicin: Anthracycline chemotherapy given through a vein during delayed intensification.
Pegaspargase: A form of asparaginase, an enzyme that starves leukemia cells of a building block they need. Given through a vein or as a shot several times during the plan.
Methotrexate: Chemotherapy given into the spinal fluid (spinal tap), through a vein in rising amounts during interim maintenance, and as weekly pills during maintenance.
Cytarabine: Chemotherapy given as a shot under the skin or through a vein during consolidation and delayed intensification. Also given into the spinal fluid at the start.
Mercaptopurine: Chemotherapy pills taken daily during consolidation and maintenance.
Cyclophosphamide: Chemotherapy given through a vein during consolidation and delayed intensification.
Thioguanine: Chemotherapy pills taken for about 2 weeks during delayed intensification.

How you get it

Most of the plan is given in the clinic, with some hospital stays, especially at the start. You will need a port or other long term IV line. The first four phases take about 6 to 8 months. Maintenance is mostly pills at home with regular clinic visits, and the whole plan lasts about 2 to 3 years. Your schedule may be different.

A typical cycle

Induction (about 4 weeks): Often starts in the hospital. IV medicines, steroid pills, pegaspargase and spinal taps. A bone marrow test at the end checks for remission.
Consolidation (about 4 weeks or more): Clinic visits for IV and under the skin chemotherapy, daily pills and spinal taps.
Interim maintenance (about 8 weeks): Clinic visits about every 10 days for IV methotrexate, vincristine and spinal taps, plus pegaspargase.
Delayed intensification (about 8 weeks): A second strong round of medicines, similar to induction and consolidation. Counts drop and infection risk is high.
Maintenance (until about 2 to 3 years total): Daily and weekly pills at home, monthly to every 3 month clinic visits, steroid bursts and spinal taps every 3 months.

Common side effects and what helps

Low blood counts, which raise the risk of infection, bleeding and tiredness. Wash your hands often and stay away from people who are sick.
Allergic reactions to pegaspargase, such as hives, itching or trouble breathing. You will be watched after each dose.
Pancreas swelling (pancreatitis) from pegaspargase, which causes belly pain that may go to the back. Avoid alcohol.
Blood clots from pegaspargase, including clots in the legs, lungs or brain. Report new swelling, pain or headache.
Liver strain and high blood sugar, mostly from pegaspargase and steroids. Your team checks blood tests often.
Tingling, numbness, constipation or jaw pain from vincristine. Drink fluids and ask about a stool softener.
Mood changes, trouble sleeping and bigger appetite from steroids. Take steroid pills in the morning with food.
Mouth sores and nausea. Rinse with salt and baking soda water and use your anti-nausea medicines.
Headache or back pain after a spinal tap. Lie flat for a while and drink fluids.

Call your care team right away if you have

A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
Bad belly pain that may spread to your back, with or without throwing up
Hives, swelling of the face or lips, or trouble breathing during or after a pegaspargase dose
Swelling, pain or warmth in one leg or arm, or sudden shortness of breath (signs of a blood clot)
New confusion, a very bad headache, trouble speaking, or weakness on one side of the body
Bleeding that will not stop, blood in your urine or stool, or many new bruises
Yellow skin or eyes, or very dark urine
Very bad constipation, with no bowel movement for 3 days

Good to know

Spinal taps (lumbar punctures) put chemotherapy into the fluid around the brain and spine (intrathecal chemotherapy). This protects the brain, where leukemia can hide.
Asparaginase (pegaspargase) can cause allergy, pancreas swelling, blood clots and liver problems. Your team checks blood tests and may check asparaginase levels.
Doxorubicin and daunorubicin can affect the heart. You may have a heart test (echocardiogram) before starting.
This plan is long. Taking maintenance pills every day as directed is an important part of staying in remission.
Bone marrow tests and blood tests help your team check how well the leukemia is responding.
Some people with high risk features may be offered a stem cell transplant or other medicines instead.

At home

Take mercaptopurine and methotrexate pills exactly as your team tells you. Use a pill box or phone alarm.
Check your temperature if you feel unwell or have chills.
Avoid alcohol, which adds strain on the liver and pancreas.
Keep a list of all your medicines and bring it to every visit. Ask before taking any new medicine or supplement.
Drink plenty of fluids and use stool softeners if your team suggests them.

Questions to ask

Which phase am I in now, and how long will it last?
When will I need a spinal tap?
Do I need to stay in the hospital for any part of this plan?
What should I watch for after pegaspargase?
How will we know if the leukemia is gone (measurable residual disease testing)?
Can I keep working or going to school during treatment?

Leukemia

Sources

Quick answers

What is C10403 (CALGB 10403)?: C10403 is a long, step by step treatment plan for teens and young adults with acute lymphoblastic leukemia (ALL), borrowed from the way children with ALL are treated. A pediatric style plan for acute lymphoblastic leukemia that uses many medicines, including vincristine, a steroid (prednisone or dexamethasone), daunorubicin, doxorubicin, pegaspargase, methotrexate, cytarabine, mercaptopurine and cyclophosphamide.
How is C10403 (CALGB 10403) given?: Most of the plan is given in the clinic, with some hospital stays, especially at the start. You will need a port or other long term IV line. The first four phases take about 6 to 8 months. Maintenance is mostly pills at home with regular clinic visits, and the whole plan lasts about 2 to 3 years. Your schedule may be different.
What are the common side effects of C10403 (CALGB 10403)?: Low blood counts, which raise the risk of infection, bleeding and tiredness. Allergic reactions to pegaspargase, such as hives, itching or trouble breathing. Pancreas swelling (pancreatitis) from pegaspargase, which causes belly pain that may go to the back. Blood clots from pegaspargase, including clots in the legs, lungs or brain. Liver strain and high blood sugar, mostly from pegaspargase and steroids. Tingling, numbness, constipation or jaw pain from vincristine. Mood changes, trouble sleeping and bigger appetite from steroids. Mouth sores and nausea. Headache or back pain after a spinal tap.
When should I call my care team during C10403 (CALGB 10403)?: A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills; Bad belly pain that may spread to your back, with or without throwing up; Hives, swelling of the face or lips, or trouble breathing during or after a pegaspargase dose; Swelling, pain or warmth in one leg or arm, or sudden shortness of breath (signs of a blood clot); New confusion, a very bad headache, trouble speaking, or weakness on one side of the body; Bleeding that will not stop, blood in your urine or stool, or many new bruises; Yellow skin or eyes, or very dark urine; Very bad constipation, with no bowel movement for 3 days.

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.