The combination of ixazomib, cyclophosphamide, and dexamethasone induced high response rates with good tolerability in patients with newly-diagnosed multiple myeloma, a study presented at the 2016 American Society of Clinical Oncology (ASCO) meeting has shown.1

For this trial, investigators enrolled 10 patients with newly-diagnosed multiple myeloma to phase 1 and 41 patients to phase 2.  All patients received ixazomib 4 mg orally on days 1, 8, and 15, cyclophosphamide 300 or 400 mg/m2 on days 1, 8, 15, and 22, and dexamethasone 40 mg on days 1, 8, 15, and 22, for a dozen 28-day cycles. Patients could then continue ixazomib monotherapy.

Results showed that at a median follow-up of 8.7 months, the best confirmed response included a partial response or better in 78% of the 48 evaluable patients. The very good partial response rate was 33% and 2 patients achieved a complete response.

At the time of analysis, 19 patients continued treatment. The majority of the 29 patients who went off treatment did so for hematopoietic cell transplantation; 4 had disease progression.

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Nearly 3/4 of patients reported a grade 3 or higher adverse event possibly related to treatment. The most common adverse events were cytopenias, fatigue, and gastrointestinal toxicities. Dose modifications were mostly due to cyclophosphamide and dexamethasone.

“[This combination] offers the opportunity to utilize a completely oral regimen, which also is less expensive compared with the lenalidomide combinations,” the authors concluded. “Future studies should assess its efficacy against other proteasome inhibitor combinations.”

Reference

1. Lacy M, Bergsagel PL, LaPlant B, Halvorson A, Buadi F, Leung N, et al. Phase 1/2 trial of ixazomib, cyclophosphamide, and dexamethasone for newly diagnosed multiple myeloma (NDMM). J Clin Oncol. 2016; 34 (suppl; abstr 8002).