Bortezomib, Lenalidomide, and Dexamethasone (VRD) Consolidation and Lenalidomide Maintenance in Frontline Multiple Myeloma Patients: Updated Results of the IFM 2008 Phase II VRD Intensive Program

Introduction of new drugs in the intensive pathway have markedly increased survival rates for MM patients within the last 10 years. Efforts to further improve response and survival are still needed, mainly by increasing the depth of tumor reduction and the duration of response. Bortezomib (Bor), Lenalidomide (Len) and Dexamethasone (Dex) combination demonstrated substantial activity in frontline MM (Richardson P et al., Blood 2010); the IFM reported primary results of the VRD regimen as induction and consolidation therapy in the transplant setting (Roussel M et al. ASH 2010). We currently present updated data of the IFM 2008 trial.

This phase II study was conducted at 10 transplant centers in France, with enrollment between Sept. 7 and Dec. 15, 2009. Pts with symptomatic upfront MM were enrolled to receive three 21-day induction cycles of VRD= Bor 1.3 mg/m2 (D1, 4, 8, 11), Len 25 mg/day (D1–14), and Dex 40 mg/day once a week (D1, 8 and 15). Stem cell collection (STC) was planned after high dose cyclophosphamide (3g/m2). All pts then proceeded to melphalan 200 mg/m2 followed by ASCT. Two months after hematological recovery, pts received two 21-day consolidation cycles of VRD (same schedule) followed by 1 year of maintenance with Len at 15 mg/day. All pts received, unless contraindicated, anticoagulation for prevention of deep-vein thrombosis (DVT), and anti-viral therapy. Pts with grade ≥2 peripheral neuropathy (PNY) were excluded. The primary endpoint was the best response achieved after consolidation. The secondary endpoints were: response rate after 3 cycles of VRD as induction, after ASCT and after maintenance; safety profile of the program; feasibility and quality of STC; duration of response, PFS, and OS. Response was assessed according to International Uniform Response Criteria including stringent Complete Response (sCR). Flow cytometric analysis of bone marrow plasma cells for minimal residual disease (MRD) was performed before and after ASCT, after consolidation and after maintenance. Adverse events (AEs) were graded using the CTC for Adverse Events (AE) v4.

Thirty-one pts were enrolled. Baseline characteristics were: median age= 58 (range 33–65); women= 55%; 55%/32%/13% had IgG/IgA/light chain MM; ISS= 1 in 52%, 2 in 32% and 3 in 16% of pts; chromosome 17p del in 18% and t(4;14) translocation in 11% among 27 assessable pts.

All pts but 7 remain on study program at data cut-off (01/08/11). One pt discontinued treatment due to mobilization failure, 5 pts stopped maintenance because of serious AE (1 extensive DVT unless efficient anticoagulation) or AEs ( 3 grade 3/4 neutropenia and/or thrombocytopenia, 1 grade 3 hypothyroidism) and 1 pt went off study because of progressive disease. Currently, Len maintenance is on going for 6 pts and 4 pts just completed their last cycle.

Therefore, 30 pts are evaluable for response after consolidation, and 20 after maintenance. All results are summarized in table 1. In ITT analysis, the overall response rate (ORR) after consolidation is 94%, including 36% VGPR, 48% RC or better (9% CR, 39% sCR). Consolidation therapy with 2 VRD cycles upgraded response in 26% of pts but only 1 pt achieved MRD negative (among 24 assessed). At time of reporting, Len maintenance did not improve response rate but 1 pt get MRD negative. One pt progressed during maintenance phase and 2 pts turned into MRD positive again without evidence of relapse.

Considering the safety profile, 18 serious AEs were reported. There was no treatment-related mortality. The most common toxicities during consolidation therapy were: emergent PNY (23%), including 10% grade 1 and 13% grade 2; grade 3/4 neutropenia (17%), and thrombocytopenia (10%). The most common toxicities during Len maintenance were: grade 3/4 neutropenia (43%), and thrombocytopenia (10%); fatigue (13%); erythrodermia (10%); zona (10%). One extensive DVT and one pulmonary embolism were reported. There was no evidence of secondary malignancy.

VRD consolidation plus Len maintenance after VRD induction and HDT produce high quality responses with 38% of sCR and is well tolerated in de novo MM pts. Updated efficacy and safety data will be presented at the meeting.

Roussel:Janssen: Honoraria; Celgène: Honoraria. Off Label Use: bortezomib, lenalidomide and dexamethasone as induction and consolidation therapy lenalidomide maintenance. Moreau:Millennium Pharmaceuticals, Inc.: Advisory board, Honoraria; Janssen: Advisory board, Honoraria. Hulin:Celgene: Honoraria; Amgen: Honoraria; Janssen-Cilag: Honoraria. Leleu:celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Facon:celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Avet-Loiseau:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Attal:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.