Biomodulatory therapy approach with lenalidomide in combination with pioglitazone, dexamethasone, and metronomic low-dose chemotherapy with treosulfan in patients with relapsed/refractory multiple myeloma > second-line.

Abstract

8037 Background: Nowadays, therapy for relapsed or refractory multiple myeloma (rrMM) usually consists of multi-targeted combination regimens for achieving complete remission. In this context, resistance resembles a therapeutic challenge that may be overcome by novel biomodulatory therapies communicatively reprogramming dysregulated cellular and intercellular homeostasis in neoplasia. Methods: The present, prospective phase II, one-arm, one-stage multi-center, open label trial, following phase I, focused on reprogramming myeloma and adjacent stroma cells in order to control rrMM beyond > 2nd-line treatment and following lenalidomide resistance in prior line. Adults with rrMM were eligible for receiving continuously, oral, daily dexamethasone 1mg, pioglitazone 45mg, low-dose treosulfan as metronomic chemotherapy ( 250mg bid) and lenalidomide 15mg, respectively, until disease progression. Results: Thirty-nine patients (mean time since diagnosis, 5.7 years; 66.7% with age > 60 years) had received a median of 5.5 (range 2 to 10) prior treatments. 89.5% of the patients were refractory to last therapy (all IMiD resistant), and 48.7% had received autologous stem-cell transplants. The overall response rate (CR, VGPR) was 17.9%. Eighteen patients (46.2%) had partial response or better; ten patients (25.6%) had stable disease. The disease control rate (DCR) was 71.8%. Time-to-progression was not significantly different between IMiD refractory patients and those relapsing following prior IMiD therapy or between high-risk versus non-high-risk cytogenetics. The median progression-free survival (PFS) and overall survival was 5.6 months (95% confidence interval [CI], 3.8 to 8.5) and 17.6 months (95% [CI], 14.9 to 39.2), respectively. The major AE (NCI-CTCAE grade) with grade ≥ 3 and relation to study drugs was hematologic toxicity (N = 31, 67.4%). Due to scheduled dose reductions, this was associated with only 7 (15.2%) grade ≥ 3 infections. Conclusions: The favorable safety profile, encouraging efficacy and equivalent median PFS between biomodulatory and modern targeted therapy in a historic comparison reveal a proof of concept of combined biomodulatory therapy in patients with heavily pretreated and IMiD-resistant rrMM, which should be further evaluated. Clinical trial information: NCT001010243.