Forodesine (BCX-1777) is an orally active and potent purine nucleoside phosphorylase (PNP) inhibitor, a new purine nucleoside analog, inhibitor of human lymphocyte proliferation, induces apoptosis in leukemic cells by increasing dGTP levels, and may be useful in the study of cutaneous T-cell lymphomas.

Forodesine hydrochloride (BCX-1777 hydrochloride), a potent inhibitor of human lymphocyte proliferation, effectively induces apoptosis in leukemic cells by elevating dGTP levels. This compound is an orally active, highly potent purine nucleoside phosphorylase (PNP) inhibitor, demonstrating IC50 values between 0.48 to 1.57 nM across human, mouse, rat, monkey, and dog PNP.