According to St Augustine, yes. A person may be truly regenerate and justified and yet lose the grace he has received.
If, however, being already regenerate and justified, he relapses of his own will into an evil life, assuredly he cannot say, 'I have not received,' because of his own free choice to evil he has lost the grace of God, that he had received.St Augustine of Hippo
On Rebuke and Grace, Chap. 6:9
ML 44, 921
NPNF V, 475