- Patients must have recovered from the acute toxicity of all prior chemotherapy; patients may not have received cytotoxic chemotherapy within 2 weeks of first dose of G-CSF (filgrastim) therapy, with exception of hydroxyurea, which is allowed for up to 24 hours prior to first dose of G-CSF, and intrathecal chemotherapy, which is allowed prior to, or in the 1st 72 hours after start of G-CSF therapy