Phase 1/2 study of forodesine in patients with relapsed peripheral t-cell lymphoma (PTCL).

7542Background: Forodesine, a potent purine nucleoside phosphorylase inhibitor, induces apoptosis mainly in T cells. Forodesine at relatively low dose was feasible but the response rate was not sufficient in early trials for PTCL and cutaneous T-cell lymphomas. A pivotal single-arm phase 1/2 study of forodesine at relatively high dose was conducted in patients with relapsed PTCL. Methods: Eligible patients, who had relapsed PTCL, confirmed by central pathology review according to the WHO classification 2008, and without major organ dysfunction, received forodesine 300 mg twice a day (BID) continuously. Tumor response was assessed with CT and PET by independent imaging review using IWC 2007 criteria. The primary endpoint was the overall response rate (ORR), and the secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. Results: In the phase 1 part (n = 4), no DLTs were observed at 300 mg BID, determined as the recommended phase 2 dose. In the phase 2 part, 44 pat...