Phase II Study of Proteasome Inhibitor Bortezomib (Velcade®) in Patients with Relapsed/Refractory T-Cell Lymphoma: Preliminary Results.

The mechanisms by which Bortezomib elicits its antitumor activity may vary among tumor types, and the extent to which each affected pathway is critical to the inhibition of tumor growth could also differ. The aim of this study was to determine the efficacy and toxicity of Bortezomib in previously pretreated patients with peripheral T-cell lymphoma unspecified (PTCLU) with only skin involvement and cutaneous T-cell lymphomas (CTCL). Eligibility criteria included PTCLU or CTCL (according to REAL/WHO classification) with measurable disease; any stage, any IPI, any bone marrow status; second or more relapse or refractory disease; age ≥18; ECOG performance status ≤ 2; Hb ≥10 g/dL, ANC ≥ 1.5x109/L and platelets ≥ 100 × 10⁹/L; normal hepatic, renal and cardiac functions; and voluntary written informed consent. Bortezomib was given at 1.3 mg/m² IV push on days 1, 4, 8 and 11 every 21 days. Restaging was done every 2 cycles. Patients were treated for up to a total of 6 cycles unless removed from study for failure to respond or toxicity. The response criteria were those recommended by NCI sponsored Working Group. At data reporting for this abstract, 15 patients were enrolled and 12 were evaluable for response. Of these 12 patients, 10 had CTCL and 2 PTCL; 11 were male and 1 female; 6 were aged >60 years (range 48–80). Overall response rate was 67% (2 CR + 6 PR) and the remaining 4 patients had PD. Histologically the responder patients were 7 CTCL and 1 PTCL. Time to event analyses, including TTP and duration of response are pending further follow-up. Treatment was well tolerated; grade ≥ 3 AEs were seen in 5 patients. The most common grade ≥ 3 AEs were neutropenia, thrombocytopenia and peripheral neuropathy. These preliminary data indicate that Bortezomib is active as a single agent for patients with relapsed/refractory CTCL and PTCL with skin involvement. Final efficacy and safety data will be presented.