Lenalidomide, Adriamycin and Dexamethasone (RAD) As An Induction Regimen In Newly Diagnosed Multiple Myeloma – Interim Results From a German Multicenter Phase II Trial

Induction triplets utilizing at least one of the “novel drugs” and steroids with or without chemotherapy are considered current standard of care in newly diagnosed, symptomatic multiple myeloma (MM). Medically fit patients (pts) remain candidates for subsequent autologous (auto) stem cell transplant (SCT) while use of allogeneic (allo) SCT remains a matter of debate. As we had previously shown the RAD regimen to be well tolerated and highly effective in relapsed and relapsed/refractory MM, we evaluated this combination in first-line treatment.

The current phase II trial (DSMM XII) was designed to include a total of 190 pts up to 65 years of age with symptomatic MM. Four 4-week cycles of RAD (lenalidomide 25 mg/day, d 1-21; adriamycin 9 mg/m² as 24-hour infusion, d1-4; oral dexamethasone 40 mg, d1-4 and 17-20; pegfilgrastim 6 mg, d 6) preceded stem cell chemomobilization. Low-molecular weight heparin for prophylaxis of venous thromboembolic events (VTE) was mandatory. Pts received either tandem auto SCT (melphalan 200 mg/m²; Mel200) or auto followed by allo SCT. Allo SCT (preparative regimen: treosulfan/fludarabine) was reserved for pts featuring at least one cytogenetic or serologic risk factor who had a matched sibling or unrelated donor available. Lenalidomide maintenance was administered for one year following both tandem auto and auto/allo SCT. This is the second pre-planned interim safety and efficacy analysis.

Eighty-nine pts with a median age of 54 (range, 30-65) years, who were recruited between August 2009 and October 2010, are evaluable. Fifty pts (56.2%) had ISS stage II/III disease and in all except three, molecular cytogenetic analysis was performed. Incidences of chromosomal abnormalities were as follows: deletion of (del) 13q, 24.7%; translocation t(4;14), 12.4%; t(14;16), 3.4%; and del 17p, 5.6%. Treatment-related mortality with RAD induction was 0% while 61.8% of pts had treatment-emergent SAEs. Seventeen pts (19%) experienced neutropenia of grades 1 to 4. Incidences of severe (grades 3/4) and febrile neutropenia were 5.6 and 1%, respectively. Seven pts each (8%) had pneumonia and VTE, respectively. Post-RAD-induction CR/sCR and at least VGPR rates were 9% and 47.2%, respectively. All 78 pts with at least stable disease successfully mobilized stem cells. Overall response rate (at least partial response, PR) following first SCT on an intention-to-treat basis was 83%. Twelve pts each (13.5%) achieved centrally confirmed complete response (CR) or stringent (s)CR, respectively, and 54 pts (60.7%) had at least very good PR (VGPR).

This interim analysis shows RAD to be very well tolerated and effective in first line treatment of symptomatic MM. Mel200 further increased rates of deep response (at least VGPR) achieved by RAD induction. We are currently comparing this regimen to bortezomib, lenalidomide and dexamethasone (VRd) in a phase III trial.

Knop:Celgene GmbH: Honoraria. Off Label Use: Lenalidomide and doxorubicin in newly diagnosed multiple myeloma. Engelhardt:MSD, Janssen-Cilag: Research Funding. Einsele:Celgene GmbH: Consultancy, Honoraria, Research Funding. Bargou:Celgene GmbH: Research Funding.