Bortezomib-Based Triplet Therapy Shows No Benefit Over Doublet for MM With Acute Kidney Injury

A randomized trial comparing a bortezomib-based triplet therapy regimen to a bortezomib doublet regimen showed no benefit in adding cyclophosphamide to bortezomib plus dexamethasone (C-BD) over bortezomib plus dexamethasone (BD) for renal recovery in patients with multiple myeloma (MM) and acute kidney injury (J Clin Oncol. 2020;38[23]:2647-2657).

“We report a multicenter controlled trial comparing renal recovery and tolerance profile of doublet versus triplet bortezomib-based regimens in patients with initial myeloma cast nephropathy and acute kidney injury without need for dialysis,” wrote Frank Bridoux, MD, PhD, Centre Hospitalier Universitaire de Poitiers, France, and colleagues.

A total of 184 patients were enrolled in the trial, with patients being split into 2 groups (n = 92 each). Both groups had similar characteristics, with the median age being 68 years and a serum creatinine level of 305.5 µmol/L in the BD group and 273.5 µmol/L in C-BD group.

After 3 cycles, patients with <50% reduction of serum-free light chains (sFLCs) received chemotherapy with cyclophosphamide (BD group) or thalidomide (C-BD group).

After 3 months of therapy, there was no significant difference in renal response rate from either group, with 41 versus 47 responders in the BD and C-BD groups, respectively (relative risk, 0.87; P = .46). In the BD arm, 36 patients achieved a very good partial response (FLC reduction ≥90%) compared with 47 in the C-BD arm (relative risk, 0.76; P = .10).

After 1 cycle of chemotherapy, 69 patients in the BD group had achieved sFLC level ≤500 mg/L, and 30 had serious adverse events versus 67 in the C-BD arm and 40 reporting serious adverse events.

At 12-months, 19 patients had died (9 in the BD group, 10 in the C-BD group), including 10 who passed from myeloma progression (6 BD, 4 C-BD), and 3 in the C-BD group who died from infection.

During the median 27-month follow-up period, 50 patients died and 43 and 42 patients in the BD and C-BD groups, respectively, switched to a new therapy.

“This randomized study did not show any benefit of C-BD compared with BD on renal recovery of patients with initial CN not requiring dialysis. Adding cyclophosphamide did not sufficiently improve the efficacy-toxicity balance,” concluded Dr Bridoux et al.—Alexandra Graziano