Trial Information

Safety of a Maintenance Therapy With Lenalidomide After Reduced-intensity Allogeneic Stem Cell Transplantation for Chemosensitive Relapsed Multiple Myeloma

Lenalidomide has a significant clinical activity in patients with relapsed or refractory MM
and in patients relapsing after Allo-SCT. The mechanisms of action involve immunomodulation,
anti-angiogenesis activity, direct anti tumor activity and effects on microenvironment. So
far, the experience with lenalidomide after Allo-SCT has been limited to patients with
progressive disease. In such patients, some responses are observed but most of them are
transient with median progression-free survivals of less than one year. Lenalidomide used as
maintenance therapy in patients with persistent rather than progressive disease might be a
better approach.

Lenalidomide is interesting in the Allo-SCT setting also because some recent studies
focusing on its immunological properties have suggested that the molecule could stimulate
the graft versus myeloma effect. First, it has been demonstrated in vitro that lenalidomide
can inhibit the proliferation and the suppressor function of regulatory T cells. Secondly, a
clinical study using lenalidomide as salvage therapy after Allo-SCT demonstrated an increase
of activated T cells and NK cells. Finally, a case report described a patient's response to
lenalidomide associated with the development of an acute graft versus host disease.

Taken together, these data suggest that patients with MM who have a persistent disease after
a reduced-intensity Allo-SCT might benefit from a post-transplant maintenance strategy with
lenalidomide by a direct anti-tumor effect and a stimulation of the graft versus myeloma
effect. The primary objective of this study is to evaluate the safety of such a strategy.