What are Neupogen and Neulasta?

Neupogen is the brand name for filgrastim or G-CSF. Neulasta is the brand name for pegfilgrastim or pegylated G-CSF. G-CSF stands for granulocyte colony stimulating factor. Pegylation is a change made to a drug to make it work better inside your body. 

Neupogen and Neulasta are blood stem cell growth factors. You may have this type of treatment after chemotherapy. It stimulates your bone marrow to make more white blood cells. You need more white blood cells to replace those killed off by your chemotherapy.

G-CSF is a natural substance made by the body. It is now possible to make G-CSF in the laboratory, so it is now available as a drug. Generally you have G-CSF every day as an injection. The exception to this is pegylated G-CSF, where the drug is surrounded by a fatty capsule. This means it is released into the body more slowly, so you can have it as a single injection.

Having G-CSF means that your white blood cell counts go back to normal more quickly. So you are at risk of infection for a shorter time. This is very important if you are having quite a strong chemotherapy regime. Or if your white counts are a little slow to recover on their own.

Doctors use G-CSF as part of high dose chemotherapy in people who are at high risk of their cancer or leukaemia coming back. You may also have this treatment if you have had regular and serious infections during a course of chemotherapy. But it isn't used routinely during most chemotherapy courses because we don't know for sure that it is helpful.

There is more about how chemotherapy affects your blood and bone marrow in CancerHelp UK.