Neulasta (pegfilgrastim) is used to treat neutropenia. Neulasta is also available as a biosimilar. Biosimilars are biologic drugs that are similar to the original medication with no meaningful differences in effectiveness or safety. Neulasta may be covered by your Medicare or insurance plan, but some pharmacy coupons or cash prices could help offset the cost. With the Patient Assistance Program from Amgen, you can receive your medication free of charge for up to one year.