My son was dx'ed w/ SAA in 2004. He underwent one round of ATG/CsA. He was weaned and was off all meds for about one year when his numbers began to drop. Cyclosporine was restarted, but at a pretty high dose (400mg) 2X daily to stop the downward spiral. Once a trough level was established and his counts stabilized, they started a very slow wean once again. This up and down pattern has been pretty much the norm since then.
He has never been off CsA since then...