Lenalidomide maintenance for high-risk multiple myeloma after allogeneic hematopoietic cell transplantation.

Allogeneic hematopoietic cell transplantation (alloHCT) with reduced-intensity conditioning is an appealing option for patients with high-risk multiple myeloma (MM). However, progression after alloHCT remains a challenge. Maintenance therapy after alloHCT may offer additional disease control and allow time for a graft-versus-myeloma effect. The primary objective of this clinical trial was to determine the tolerability and safety profile of maintenance lenalidomide (LEN) given on days 1 to 21 of 28 days cycles, with intrapatient dose escalation during 12 months/cycles after alloHCT. Thirty alloHCT recipients (median age, 54 years) with high-risk MM were enrolled at 8 centers between 2009 and 2012. The median time from alloHCT to LEN initiation was 96 days (range, 66 to 171 days). Eleven patients (37%) completed maintenance and 10 mg daily was the most commonly delivered dose (44%). Most common reasons for discontinuation were acute graft-versus-host disease (GVHD) (37%) and disease progression (37%). Cumulative incidence of grades III to IV acute GVHD from time of initiation of LEN was 17%. Outcomes at 18 months after initiation of maintenance were MM progression, 28%; transplantation-related mortality, 11%; and progression-free and overall survival, 63% and 78%, respectively. The use of LEN after alloHCT is feasible at lower doses, although it is associated with a 38% incidence of acute GVHD. Survival outcomes observed in this high-risk MM population warrant further study of this approach.