FCR

Say it: F C R

Fludarabine, cyclophosphamide and rituximab

FCR is a 6 month chemotherapy and antibody plan for chronic lymphocytic leukemia (CLL), now used mostly for a select group of younger, fit patients.

Also called: R-FC, FC-R, fludarabine cyclophosphamide rituximab, FC plus rituximab, FCR chemoimmunotherapy

What it is

Fludarabine and cyclophosphamide are chemotherapy medicines that kill CLL cells. Rituximab helps the immune system find and destroy them. For some people with a favorable gene pattern, FCR can lead to very long remissions after a fixed time of treatment. Today, many people with CLL get targeted pills or other plans instead.

Often used for

• chronic lymphocytic leukemia (CLL) in younger, fit people, most often with a favorable gene pattern (mutated IGHV)

The medicines in this plan

Fludarabine

Chemotherapy given through a vein over about 30 minutes on days 1 to 3.

Cyclophosphamide

Chemotherapy given through a vein on days 1 to 3.

Rituximab

Antibody given through a vein on day 1 of each cycle. The first dose is given slowly over several hours.

How you get it

FCR is given in the clinic through a vein. Each cycle is 28 days, with 3 treatment days in a row. Most people get up to 6 cycles, about 6 months total. Your schedule may be different.

A typical cycle

Day 1

Blood tests, then rituximab, fludarabine and cyclophosphamide. The first visit can take most of the day.

Days 2 and 3

Fludarabine and cyclophosphamide through the IV.

Days 4 to 28

Rest and recovery. Counts are lowest around days 10 to 14. Blood tests check recovery.

Common side effects and what helps

• Low blood counts that can last for weeks or months. Wash your hands often and stay away from people who are sick.
• Infections, including pneumonia and cold sores or shingles coming back. Medicines to prevent infection are common.
• Fever, chills or rash during the first rituximab infusion. Medicines are given beforehand to help.
• Nausea. Take anti-nausea medicine as directed.
• Tiredness. Rest and short walks can help.
• Hair thinning (usually mild).

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• A cough with fever or shortness of breath
• Bleeding that will not stop, blood in your urine or stool, or many new bruises
• Painful skin rash with blisters, which can be shingles
• Yellow skin or eyes, or dark urine
• Burning, painful or bloody urine
• New confusion, a very bad headache, trouble speaking, or weakness on one side of the body

Good to know

• You will usually take medicines to prevent pneumonia (Pneumocystis) and viral infections such as shingles, often for months after treatment.
• Your team will check for hepatitis B before rituximab, because it can wake up an old infection.
• After fludarabine, any blood you receive should be irradiated (treated with radiation) to prevent a rare but serious problem. Tell any hospital you have had fludarabine.
• Your team watches for tumor lysis (fast breakdown of CLL cells) in the first cycle and may give fluids and medicines to protect your kidneys.
• FCR slightly raises the chance of later blood cancers, such as myelodysplastic syndrome. Your team will keep checking your blood after treatment.

At home

• Take your infection prevention medicines every day as prescribed, even after treatment ends.
• Drink plenty of fluids around treatment days.
• Check your temperature if you feel unwell.
• Ask your team which vaccines are safe. Avoid live vaccines.
• Wash your hands often and stay away from people who are sick.

Questions to ask

• Is FCR the best choice for my type of CLL, or would targeted pills be better?
• Do I have a favorable gene pattern (mutated IGHV) and no TP53 or 17p change?
• How many cycles will I get?
• How long will I need infection prevention medicines?
• How will we check whether the CLL is gone after treatment?

Leukemia

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.