RVD Induction Followed by Consolidation with ASCT in Patients with Newly Diagnosed Multiple Myeloma,

Lenalidomide, bortezomib, and dexamethasone (RVD) is an active and well tolerated induction regimen in newly diagnosed multiple myeloma (MM). Clinical trials show this regimen to have an overall response rate (ORR) of 95–100%. Appropriately selected patients who receive RVD induction may proceed to consolidation with high-dose therapy and autologous stem cell transplantation (ASCT). In this retrospective study we characterize the experience of patients at our center who received RVD induction followed by ASCT.

Demographic and outcome data were collected retrospectively among patients with MM who underwent ASCT between January 1, 2005 and December 31, 2010 (n=482) and received at least 2 cycles of RVD induction (n=82). Data collected include demographics, disease sub-type and International Staging System (ISS) stage, cytogenetics, treatment summary, treatment-related peripheral neuropathy and venous thromboembolism (VTE), CD34+ stem cell yield, time to hematopoietic recovery post-ASCT, disease response to induction and ASCT, and time to progression after ASCT. Response was based on M-protein or serum free light chain (FLC) response and bone marrow findings.

The cohort was 63% male with median age at induction of 57.5 years (range 24 to 71). By ISS stage, 51, 32, 12, and 5% had stage I, II, III, and unknown disease, respectively. Based on cytogenetic findings, 56, 33, and 12% had standard, high, and unknown-risk disease, respectively. IgG was the most common subtype (48% IgG, 24% IgA, and 26% light chain disease).

Patients received a median of 5 cycles (range 2 to 16) of RVD induction. 50% of patients reported any-grade peripheral neuropathy. Two patients developed VTE. In 8 (10%) patients, bortezomib or lenalidomide was discontinued due to drug toxicity. In 5 (6%) patients, omission of lenalidomide in the final cycle prior to stem cell collection was planned. Partial response (PR) or better M-protein (or FLC) response was observed in 96% (95% CI: [88%, 99%]) with 44% complete response (CR), 26% very good partial response (VGPR), 26% PR, 4% stable disease (SD) pre-ASCT. 50% of patients who achieved a CR by M-protein response had no evidence of clonal plasma cells in their bone marrow.

Sixty-three (77%) patients proceeded directly to ASCT after RVD induction with median time to ASCT 187 days (range 119 to 510). Nineteen (23%) patients received further therapy prior to ASCT: 8 patients to either deepen treatment response prior to ASCT (n=6) or for progressive disease (PD) after a transient response to RVD (n=2), while 11 were either observed (n=7) or received maintenance therapy (n=4) after induction with further therapy for PD or for cytoreduction prior to ASCT. Among patients who received additional therapy, 16% improved their response with median time to ASCT 394 days (range 155 to 975).

Median CD34+ stem cell collection was 10.0 × 10^6 (range 2.0 × 10^6 to 75.4 × 10^6). More than 4 × 10^6 stem cells were collected in 95% of patients. Median time to neutrophil and platelet engraftment was 11 (range 6 to 19) and 19 (range 10 to 92) days, respectively.

At 100 days post-ASCT, 33% showed improvement in disease response, 59% showed the same response, no one had PD, and 7% had unknown response due to no assessment ≤ 150 days post-ASCT. Lenalidomide maintenance was given to 71% of patients after day 100 post-ASCT. At median follow-up of 12.1 months, 12 subjects progressed and one patient died of angioimmunoblastic lymphoma on day 289 post-ASCT without myeloma progression (3 subjects had no follow-up data). No other second new primary malignancies were reported. The Kaplan-Meier estimate of progression-free survival (PFS) at 12 months post-ASCT is 85% (95% CI:[72;92]). Similar results were observed among the 63 patients who proceeded directly to ASCT.

RVD is a well tolerated, highly active induction regimen for patients with newly diagnosed MM. The ORR of 96% and CR rate of 44% to RVD induction prior to ASCT in our study are consistent with previous results. Stem cell collection following RVD induction was successful in all patients and post-ASCT engraftment was rapid. ASCT improved disease response and these responses appear durable at median 12 month follow-up. Data from on-going phase III trials will provide insight in a prospective manner on outcomes after RVD induction followed by ASCT (either early or late) for MM patients.

Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees. Koreth:Millennium Pharmaceuticals Inc: Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghobrial:Bristol-Myers Squibb: Research Funding; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Noxxon: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Munshi:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees. Anderson:Onyx: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Millennium: Consultancy; Novartis: Consultancy; Merck: Consultancy; Acetylon: Founder.