The following potential serious adverse reactions are discussed in greater detail in other sections of the labeling:

• Splenic Rupture [see WARNINGS AND PRECAUTIONS]
• Acute Respiratory Distress Syndrome [see WARNINGS AND PRECAUTIONS]
• Serious Allergic Reactions [see WARNINGS AND PRECAUTIONS]
• Use in Patients with Sickle Cell Disorders [see WARNINGS AND PRECAUTIONS]
• Potential for Tumor Growth Stimulatory Effects on Malignant Cells [see WARNINGS AND PRECAUTIONS]

The most common treatment-emergent adverse reaction that occurred at an incidence of at least 1% or greater in patients treated with tbo-filgrastim t the recommended dose and was numerically two times more frequent than in the placebo group was bone pain.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Tbo-filgrastim clinical trials safety data are based upon the results of three randomized clinical trials in patients receiving myeloablative chemotherapy for breast cancer (N=348), lung cancer (N=240) and Non- Hodgkin's lymphoma (N=92). In the breast cancer study, 99% of patients were female, the median age was 50 years, and 86% of patients were Caucasian. In the lung cancer study, 80% of patients were male, the median age was 58 years, and 95% of patients were Caucasian. In the Non-Hodgkin's lymphoma 52% of patients were male, the median age was 55 years, and 88% of patients were Caucasian. In all three studies a placebo (Cycle 1 of the breast cancer study only) or a non-US-approved filgrastim product were used as controls. Both tbo-filgrastim and the non-US-approved filgrastim product were administered at 5 mcg/kg subcutaneously once daily beginning one day after chemotherapy for at least five days and continued to a maximum of 14 days or until an ANC of ≥ 10,000 x10⁶/L after nadir was reached.

Bone pain was the most frequent treatment-emergent adverse reaction that occurred in at least 1% or greater in patients treated with tbo-filgrastim at the recommended dose and was numerically two times more frequent than in the placebo group. The overall incidence of bone pain in Cycle 1 of treatment was 3.4% (3.4% tbo-filgrastim, 1.4% placebo, 7.5% non-US-approved filgrastim product ).

Leukocytosis

In clinical studies, leukocytosis (WBC counts > 100,000 x 10⁶/L) was observed in less than 1% patients with non-myeloid malignancies receiving tbo-filgrastim. No complications attributable to leukocytosis were reported in clinical studies.

Immunogenicity

As with all therapeutic proteins, there is a potential for immunogenicity. The incidence of antibody development in patients receiving tbo-filgrastim has not been adequately determined.

Read the Tbo-filgrastim (tbo-filgrastim injection) Side Effects Center for a complete guide to possible side effects »

No formal drug interaction studies between tbo-filgrastim and other drugs have been performed.

Drugs which may potentiate the release of neutrophils‚ such as lithium‚ should be used with caution.

Increased hematopoietic activity of the bone marrow in response to growth factor therapy has been associated with transient positive bone imaging changes. This should be considered when interpreting bone imaging results.

Last reviewed on RxList: 10/10/2012
This monograph has been modified to include the generic and brand name in many instances.