Oral presentation by Dr. Meletios A. Dimopoulos
For patients with multiple myeloma being treated on a first-line basis and who have received an autologous hematopoietic stem cell transplant, the use of maintenance therapy has become a standard therapeutic approach.
The phase III Tourmaline-MM3 study evaluates the impact of the first oral proteasome inhibitor, ixazomib, versus placebo as maintenance therapy after induction and an autologous transplant with an at least partial response. Ixazomib was used at 3 mg on Day 1, 8 and 15 every 28 days, with a dose increase to 4 mg starting with the 5th cycle so long as there was no significant toxicity for a maximum of 2 years. The primary objective was progression-free survival (PFS).
Six hundred and fifty-six patients with multiple myeloma were recruited. After a median follow-up of 31 months, PFS went from 21.3 months to 26.5 months, a 39% improvement. Significantly more patients had an improved quality of response. The tolerance to treatment was particularly good, 7% of patients in the ixazomib arm discontinued maintenance treatment due to side effects versus 5% in the placebo arm. Despite the maintenance treatment, the quality of life of patients on ixazomib was preserved, similar to placebo.
In summary, this study demonstrated a 28% reduction in the risk of progression or death with the use of ixazomib compared to placebo. The magnitude of this benefit is not that of the lenalidomide used as maintenance therapy following the autologous transplant. However, this study is not a comparison of ixazomib to lenalidomide, but rather a study that mentions that ixazomib is an appropriate alternative to lenalidomide when the latter should be avoided.