Comparative effectiveness of filgrastim, pegfilgrastim, and sargramostim as prophylaxis against hospitalization for neutropenic complications in patients with cancer receiving chemotherapy.

BACKGROUND

Comparative effectiveness of filgrastim, pegfilgrastim, and sargramostim in preventing hospitalization for febrile neutropenia (FN) during myelosuppressive chemotherapy has not been well characterized and is an important clinical question in oncology.

METHODS

This study used a retrospective cohort design and US healthcare claims data. Source population included patients with solid tumors receiving filgrastim, pegfilgrastim, or sargramostim during their first observed course of chemotherapy between July 2001 and June 2007. For each patient, every unique chemotherapy cycle during the course was identified, along with each cycle in which filgrastim, pegfilgrastim, or sargramostim was administered by the fifth day of the cycle (ie, as prophylaxis). Risks of hospitalization for neutropenic complications (broad definition: admission with a diagnosis of neutropenia, fever, or infection; narrow definition: admission with a diagnosis of neutropenia) and for any reason were examined on a cycle-specific basis during all the cycles in which colony-stimulating factor prophylaxis was administered. Unadjusted and adjusted odds ratios (ORs) for hospitalization were estimated.

RESULTS

Risk (unadjusted) of hospitalization for neutropenic complications (narrow definition) was 2.1% for filgrastim prophylaxis (n=8286), 1.1% for pegfilgrastim prophylaxis (n=67,247), and 2.5% for sargramostim prophylaxis (n=1736). Corresponding risks of hospitalization based on the broad definition were 4.0%, 2.6%, and 5.1%. Risks of all-cause hospitalization were 7.9%, 5.3%, and 9.6%, respectively. Adjusted odds of hospitalization were significantly higher for filgrastim [OR (range across the 3 alternative measures of hospitalization): 1.58-1.79; P<0.001] and sargramostim (OR: 1.89-2.68; P<0.001) versus pegfilgrastim.

CONCLUSIONS

Risk of hospitalization for neutropenic complications during cancer chemotherapy is lower with pegfilgrastim prophylaxis than with filgrastim or sargramostim prophylaxis.