Pilot study of recombinant human soluble tumor necrosis factor (TNF) receptor (p75) fusion protein (TNFR:Fc; Enbrel) in patients with refractory multiple myeloma: increase in plasma TNF alpha levels during treatment.

Elevated tumor necrosis factor (TNF)-alpha levels are associated with poor prognosis in patients with multiple myeloma (MM). Enbrel is a TNF antagonist fusion protein consisting of the extracellular, ligand-binding domain of the human p75 TNF receptor linked to the Fc portion of human IgG1. Ten patients with refractory MM were treated with Enbrel 25mg s.c twice weekly for a minimum of eight median age was 63 years (range, 43-76). The total number of Enbrel doses was 191 (median 16; range, 3-55). TNF alpha plasma levels increased significantly during treatment with Enbrel. No objective response occurred. Acceleration of disease occurred in four patients. While well-tolerated, Enbrel did not have anti-myeloma activity as administered on this study.