Granulocyte-colony stimulating factor for mobilizing bone marrow stem cells in subacute stroke: the stem cell trial of recovery enhancement after stroke 2 randomized controlled trial

Abstract

Background and purpose: Granulocyte-colony stimulating factor (G-CSF) is neuroprotective in experimental stroke and mobilizes CD34(+) peripheral blood stem cells into the circulation. We assessed the safety of G-CSF in recent stroke in a phase IIb single-center randomized, controlled trial.

Methods: G-CSF (10 μg/kg) or placebo (ratio 2:1) was given SC for 5 days to 60 patients 3 to 30 days after ischemic or hemorrhagic stroke. The primary outcome was the frequency of serious adverse events. Peripheral blood counts, CD34(+) count, and functional outcome were measured. MRI assessed lesion volume, atrophy, and the presence of iron-labeled CD34(+) cells reinjected on day 6.

Results: Sixty patients were recruited at mean of 8 days (SD ± 5) post ictus, with mean age 71 years (± 12 years) and 53% men. The groups were well matched for baseline minimization/prognostic factors. There were no significant differences between groups in the number of participants with serious adverse events: G-CSF 15 (37.5%) of 40 versus placebo 7 (35%) of 20, death or dependency (modified Rankin Score: G-CSF 3.3 ± 1.3, placebo 3.0 ± 1.3) at 90 days, or the number of injections received. G-CSF increased CD34(+) and total white cell counts of 9.5- and 4.2-fold, respectively. There was a trend toward reduction in MRI ischemic lesion volume with respect to change from baseline in G-CSF-treated patients (P=0.06). In 1 participant, there was suggestion that labeled CD34(+) cells had migrated to the ischemic lesion.

Conclusions: This randomized, double-blind, placebo-controlled trial suggests that G-CSF is safe when administered subacutely. It is feasible to label and readminister iron-labeled CD34(+) cells in patients with ischemic stroke.

Clinical trial registration: URL: www.controlled-trials.com. Unique identifier: ISRCTN63336619.