Prevention of active multiple myeloma (MM) using IL-1 receptor antagonist (IL-1ra) and low-dose dexamethasone (Dex) and monitoring the high sensitivity C-reactive protein (hsCRP)

• Published in: Journal of clinical oncology Vol. 25; no. 18_suppl; p. 8105
• Main Authors: Lust, J. A., Lacy, M. Q., Zeldenrust, S. R., Dispenzieri, A., Gertz, M. A., Greipp, P. R., Witzig, T. E., Kumar, S., Geyer, S. M., Donovan, K. A.
• Format: Journal Article
• Language: English
• Published: 20.06.2007
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2007.25.18_suppl.8105

Abstract only 8105 Background: IL-6 is the central myeloma growth factor and we have shown that abnormal production of IL-1beta in the myeloma microenvironment stimulates the generation of paracrine IL-6. A Phase II trial was completed using IL-1ra, which inhibits paracrine IL-6 production, and low dose Dexamethasone (Dex), which decreases IL-1 levels through myeloma cell apoptosis, in patients with smoldering/indolent MM (SMM/IMM). These patients are at the greatest risk for progression to active MM and most likely to benefit from anti- cytokine therapy. Methods: Patients that had ≥ 10% bone marrow plasma cells and/or an IgG or IgA M-spike ≥ 3 g/dL and did not require immediate chemotherapy were eligible. A total of 47 patients received 100 mg of IL-1ra SQ qd for 6 months unless clinical progression occurred. Responding patients were allowed to continue on therapy with IL-1ra alone. Low dose Dex (20 mg qweek) was added after 6 months of IL-1ra in non-responding patients. The primary endpoint was progression-free survival (PFS). Results: The 47 patients were at high risk for progression to active MM with 98% having ≥ 10% plasma cells, 89% generating IL-1 levels consistent with myeloma (≥ 1.0), and 32% having bone lesions. All 47 patients received IL-1ra initially and 25/47 subsequently received IL-1Ra/Dex. For the group of 47 patients, the median overall progression-free survival was 37.5 months. Three patients achieved a minor response (MR) to Anakinra alone; 5 pts achieved a PR and 4 patients an MR after addition of Dex. Seven patients had a decrease in the plasma cell labeling index (PCLI; a marker of myeloma cell growth) on Anakinra alone which paralleled a decrease in the high sensitivity CRP (a marker of serum IL-6 levels). The median PFS for patients without (n=12) and with (n=35) a ≥ 15% decrease in their baseline hsCRP was 6 months and > 3 yrs, respectively (p=0.002). Conclusions: In SMM/IMM patients at high risk for progression to active myeloma, treatment with IL-1 inhibitors (IL-1ra ± Dex) results in an increased PFS in patients that demonstrate a ≥15% reduction in the baseline CRP compared to those that do not respond. No significant financial relationships to disclose.