Response-adapted lenalidomide-dexamethasone (LenDex) intensification after CyBorD induction for transplant-eligible...

Combination therapy with novel agents is the standard initial treatment for transplant-eligible patients with newly diagnosed multiple myeloma. However, the benefit of additional induction therapy for insufficient response remains unclear. This multicenter prospective study investigated response-adapted intensification with lenalidomide and dexamethasone (LenDex) after cyclophosphamide, bortezomib, and dexamethasone (CyBorD) in patients who did not achieve a very good partial response (VGPR) or better, followed by autologous stem cell transplantation (ASCT) and lenalidomide maintenance.

Sixty-three patients were enrolled at 10 centers between March 2014 and December 2017.

Of the 63 patients, 44 underwent ASCT. Six patients (9.5% [6/63; 95% confidence interval, 3.6%-19.6%]) achieved complete response (CR) or better at 100 days post-ASCT; this rate was not higher than in the previous BD-based TUBA study. Best responses following ASCT and maintenance were stringent CR in 10 patients, CR in one, VGPR in 23, and partial response in eight. Three-year overall survival (OS) and progression-free survival (PFS) from induction were 90.0% and 43.9%, respectively. Thirty-one patients received LenDex before ASCT for insufficient response to CyBorD; 17 showed improved responses. OS and PFS from ASCT were comparable between patients treated with CyBorD alone and those receiving additional LenDex.

The primary endpoint of CR or better at 100 days after ASCT was not improved compared with the historical BD-based TUBA study. However, response-adapted LenDex intensification was feasible, improved responses pre-ASCT in some patients, and resulted in post-ASCT outcomes comparable to those observed in patients who achieved sufficient responses with CyBorD alone.