A possible mechanism of increase in serum alkaline phosphatase activity in rats given granulocyte colony-stimulating factor

Safety and Biosimilarity of ior®LeukoCIM Compared to Neupogen® Based on Toxicity, Pharmacodynamic, and Pharmacokinetic Studies in the Sprague-Dawley Rat

This study examined the safety, pharmacodynamic and pharmacokinetic similarity of the human recombinant filgrastim products ior^®LeukoCIM and Neupogen^® following a 28-day repeated subcutaneous dose administration in male and female Sprague-Dawley rats with a 14-day recovery period. Safety profiling was based on clinical observations, clinical pathology, and pathology findings for control rats dosed with vehicle and rats dosed either with 15, 75, and 150 μg/kg of ior^®LeukoCIM or with 150 μg/kg of Neupogen^®. The major adverse treatment-related clinical finding was mild to severe swelling of the hock-joint (tarsal joint) and hind limb, alone or accompanied with lameness which was more prominent in males and which had a similar frequency of occurrence for both ior^®LeukoCIM and Neupogen^®. All adverse findings were fully reversible. As expected, ior^®LeukoCIM and Neupogen^® both increased white blood cell and neutrophil levels in rats and to a similar extent for high-dose ior^®LeukoCIM and Neupogen^®. The pharmacokinetics of filgrastim following dosing with ior^®LeukoCIM were well behaved and comparable for high-dose ior^®LeukoCIM and Neupogen^®. The results of this study imply that ior^®LeukoCIM and Neupogen^® had similar safety profiles, pharmacodynamic responses, and pharmacokinetic profiles that suggest they are biosimilar.

Spleen enlargement in healthy donors during G-CSF mobilization of PBPCs

BACKGROUND

Recombinant human G-CSF is widely used to mobilize PBPCs in healthy donors for allogeneic transplantation. There have been concerns about donor safety because of splenic ruptures during G-CSF application. To address this problem, changes in splenic size in 91 healthy donors during G-CSF mobilization of allogeneic PBPCs were investigated.

STUDY DESIGN AND METHODS

For mobilization, G-CSF in a dosage of 7.5 microg per kg per day was administered for 5 days and PBPC collection started Day 5. Splenic size was determined by ultrasound before G-CSF application was started and on the day of the first apheresis.

RESULTS

The mean increase in splenic length was 11 mm (range, 0-28 mm; p<0.0001), whereas a mean increase of 5 mm in width (range, 0-14 mm; p<0.0001) was measured. No major side effects could be observed. There was no significant correlation between the increase in splenic size and the hematologic values, or the age and body-mass index. In a multivariant analysis, no independent risk factor for the development of a spleen enlargement over 19 mm in length and 9 mm in thickness was found in 20 percent of investigated donors.

CONCLUSION

In this prospective trial, a significant spleen enlargement was observed in healthy donors during G-CSF mobilization of allogeneic PBPCs. Further investigations are needed to define the degree of spleen enlargement with higher G-CSF dosages to improve donor safety.