The graft-versus-myeloma effect: chronic graft-versus-host disease but not acute graft-versus-host disease prolongs survival in patients with multiple myeloma receiving allogeneic transplantation.

We conducted a study of patients with multiple myeloma (MM) undergoing allogeneic transplantation to evaluate outcome parameters. Fifty-seven consecutive patients with MM received an allogeneic transplantation between 2004 and 2011 at our institution. Patients who had received at least 1 prior autologous transplantation were included. Twenty-six patients underwent allogeneic transplantation for consolidation after a response to their first autograft, and 30 patients received an allogeneic transplantation as salvage therapy. Donor source was evenly distributed between related and unrelated. The median follow-up was 52 months. Thirty-two (57.1%) patients achieved a complete response (CR). At 5 years, 49.2% of all patients were in CR. Sixteen patients received either donor lymphocyte infusions or immune suppression withdrawal for disease progression, with a 62.5% response rate. The 5-year overall survival (OS) for all patients was 59%. The 5-year OS for the 30 patients in the consolidation group was 82% compared with 38% for those in the salvage group. In multivariate analysis, 3 factors remained significantly associated with OS. These include being in the salvage group (hazard ratio [HR], 4.05; P = .0196), acute graft-versus-host disease (aGVHD) (HR, 2.99; P = .034), and chronic graft-versus-host disease (cGVHD), which was highly protective, with a 5-year OS of 78.8% for patients with cGVHD versus 42.6% for patients without cGVHD (HR .17, P = .008). Our data show that allogeneic transplantation for MM can lead to sustained remissions. aGVHD is significantly deleterious to OS and progression-free survival, whereas cGVHD is strongly favorable, supporting an important role for the graft-versus-myeloma effect.