Frontline Therapy with Bortezomib, Lenalidomide, and Dexamethasone (VRD) Induction Followed by Autologous Stem Cell Transplantation, VRD Consolidation and Lenalidomide Maintenance In Newly Diagnosed Multiple Myeloma Patients: Primary Results of the IFM 2008 Phase II Study

Autologous Stem Cell Transplantation (ASCT) is a standard of care for eligible MM patients (pts). Introduction of new drugs in this setting have markedly increased survival rates within the last 10 years. Efforts to further improve response and survival in those pts are still needed, mainly by increasing the depth of tumor reduction and the duration of response through more effective induction, consolidation and maintenance therapies. Therefore, the IFM (Intergroupe Francophone du Myélome) decided to evaluate the Bortezomib (Bor), Lenalidomide (Len) and Dexamethasone (Dex) regimen as induction and consolidation therapy followed by Len maintenance in the transplant setting for newly diagnosed pts.

This open-label phase II study was conducted at 10 IFM transplant centers, with enrollment between September and December 2009. Pts under 65 with symptomatic de novo MM were enrolled to receive three 21-day induction cycles of VRD= Bor 1.3 mg/m2 (days 1, 4, 8, 11), Len 25 mg (days 1–14), and oral Dex 40 mg (days 1, 8 and 14). Stem cell collection was planned for all pts after high dose cyclophosphamide (3g/m2). All pts then proceeded to intensification prepared with melphalan 200 mg/m2 followed by ASCT. Two months after hematological recovery, pts could receive two 21-day consolidation cycles of VRD (same schedule) followed by 1 year of maintenance with Len at 10–15 mg/day. All patients received, unless contraindicated, aspirin prophylaxis or alternative anticoagulation for prevention of deep-vein thrombosis (DVT), anti-viral therapy (valacyclovir) for herpes zoster prevention. Pts with ≥ grade 2 peripheral neuropathy (PNY) were excluded. The primary endpoint was the best response achieved 1 month after consolidation. The secondary endpoints were the response rate after 3 cycles of VRD, after ASCT and after consolidation; the safety profile of the program, the feasibility and quality of stem cell collection and dthe uration of response (DOR), PFS, OS. Response was assessed according to International Uniform Response Criteria including stringent Complete Response (sCR). Flow cytometric analysis of bone marrow plasma cells was performed before and after ASCT, and after consolidation. Toxicities were graded using the CTCAEv4.

Thirty-one pts with symptomatic MM were enrolled. Baseline characteristics of the pts were: median age = 58 (range 33–65); 55% were women; 55%/32%/13% had IgG/IgA/light chain MM; ISS= 1 in 52%, 2 in 32% and 3 in 16% of pts; chromosome 13q deletion in 41% over 27 assessable pts; chromosome 17p del in 18% and t(4;14) translocation in 11%.

All pts but one remain on study program at data cut-off (01/08/10). The one pt had discontinued treatment at time of ASCT due to mobilization failure. Therefore, 31 pts are evaluable for response rates after induction therapy, 30 after ASCT and 13 after consolidation. All results are summarized in table 1. In Intent To Treat analysis, the overall response rate (ORR) after ASCT was 94%, including 32% VGPR, 13% CR and 23% sCR. Nine serious AEs were reported. There was no treatment-related mortality. The most common toxicities were: sensory PNY (45%), including 29% grade 1 and 16% grade 2; neuropathic pain (13%); GI tract symptoms (42%) including diarrhea (16%) and constipation (10%); fatigue (10%) and erythrodermia (9%). There was no grade 3/4 PNY. Grade 3/4 hematological toxicities included neutropenia (26%), and thrombocytopenia (6%). No DVT or pulmonary embolism was reported.Six of 31 pts (19%) have had difficulty with mobilization but only 1 pt did not undergo ASCT. Stem cell collection with plerixafor was successful in 4 pts. Median stem cell collection was 7.7 × 10⁶ CD34+ cells/kg.

VRD induction followed by ASCT and VRD consolidation produce high quality responses and is well tolerated in newly diagnosed MM pts under 65. Updated efficacy and safety data will be presented at the meeting.

Roussel:Janssen: Consultancy, Research Funding, orator; Celgene: Consultancy, Orator, Research Funding. Off Label Use: bortezomib, lenalidomide as induction and consolidation therapies in frontline MM pts. Leleu:Celgene: Consultancy, Research Funding; Janssen Cilag: Consultancy, Research Funding; Leo Pharma: Consultancy; Amgen: Consultancy; Chugai: Research Funding; Roche: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Facon:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Attal:celgene: Consultancy, Research Funding; johnson and johnson: Consultancy, Research Funding.