A 20-mer antisense oligodeoxynucleotide (ODN) against the proto-oncogene Akt with potential antineoplastic activity. Akt-1 antisense oligonucleotide RX-0201 binds to Akt-1 mRNA, inhibiting translation of the transcript; suppression of Akt-1 expression may result in the inhibition of cellular proliferation and the induction of apoptosis in tumor cells that overexpress Akt-1. Akt-1 is a serine-threonine protein kinase that stimulates proliferation and inhibits apoptosis of tumor cells.