Purpose: To determine the efficacy of bortezomib in patients with lymphoid malignancy, correlating clinical response with effect on plasma cytokines and in vitro activity in primary cultures.
Patients and methods: Patients received bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11 of a 3-week cycle. Plasma tumor necrosis factor alpha (TNF-alpha) and interleukin-6 were measured before each treatment, and bortezomib activity was examined in patient samples grown in primary culture.
Results: Fifty-one patients received a total of 193 cycles of treatment. Twenty-four patients had mantle cell lymphoma (MCL), 13 had follicular lymphoma (FL), six had lymphoplasmacytic lymphoma, six had Hodgkin's disease (HD), and one each had diffuse large B-cell lymphoma and adult T-cell leukemia/lymphoma. Patients were heavily pretreated with a median of four previous therapies. Significant grade 3 to 4 toxicities were thrombocytopenia (n = 22), fatigue (n = 10), and peripheral neuropathy (n = 3). Seven patients with MCL responded to treatment (one complete response, six partial responses [PRs]; overall response rate, 29%). Two patients with FL achieved a late PR 3 months after discontinuing therapy. Two patients with Waldenström's macroglobulinemia and one patient with HD achieved a PR. MCL primary cultures demonstrated greater sensitivity to bortezomib than FL (median 50% effective concentration for viability, 209 nmol/L v 1,311 nmol/L, respectively; P = .07), which correlated with clinical response. A median reduction in plasma TNF-alpha of 98% was observed in six patients with MCL who responded to bortezomib compared with a reduction of 38% in six nonresponders (P = .07).
Conclusion: Bortezomib demonstrates encouraging efficacy in MCL in heavily pretreated individuals. Response was associated with a reduction in plasma TNF-alpha and in vitro sensitivity in a small number of patients.