Bortezomib, Thalidomide, and Dexamethasone (VTD) Versus VTD Plus Cyclophosphamide as Induction Therapy in Previously Untreated Multiple Myeloma Patients Eligible for HDT-ASCT: A Randomized Phase 2 Trial.
Authors: Ludwig Heinz , Viterbo Luisa , Greil Richard , Masszi Tamas , Spicka Ivan , Shpilberg Ofer , Hajek Roman , Dmoszynska Anna , Cakana Andrew , Enny Christopher , Feng Huaibao , van de Velde Helgi , Harousseau Jean-Luc 
Published: October 2019

Abstract 2312

Poster Board II-289

Bortezomib (Velcade®) has shown substantial activity and manageable toxicity in newly diagnosed multiple myeloma (MM) in combination with thalidomide (Thalomid®) and dexamethasone (VTD) in a phase 3 study (Cavo et al, ASH 2008), and with cyclophosphamide and dexamethasone (VCD) in a phase 2 study (Knop et al, ASCO 2009). Four-drug combinations may be more effective than 3-drug regimens, but may also be associated with increased toxicity. This randomized, non-comparative, open-label, multicenter, phase 2 study was designed to evaluate the efficacy and safety of VTD and VTD plus cyclophosphamide (VTDC) as induction therapy prior to high-dose therapy plus autologous stem cell transplant (HDT-ASCT). A total of 98 previously untreated MM patients with measurable disease who were candidates for HDT-ASCT were enrolled. Additional eligibility criteria included: age 18–70 years, Karnofsky Performance Status (KPS) ≥60%, adequate hematologic, hepatic, and renal function, and no grade ≥2 peripheral neuropathy (PN)/neuropathic pain. Patients were randomized (1:1), stratified by International Staging System (ISS) disease stage (I / II / III), to receive four 21-day cycles of bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11, thalidomide 100 mg daily, and dexamethasone 40 mg on days 1–4 and 9–12 (VTD), or VTD plus cyclophosphamide 400 mg/m2 IV on days 1 and 8, as induction therapy prior to HDT-ASCT. All patients received antithrombotic prophylaxis. Patients who became ineligible for HDT-ASCT or had a complete response (CR) after induction therapy could receive an additional 4 cycles of treatment. Responses were categorized using modified IMWG Uniform Response Criteria (stringent CR [sCR] were unconfirmed by immunohistochemistry) through blinded review by the principal investigator and medical monitor, using central laboratory M-protein data and local bone marrow data. The primary efficacy endpoint was combined CR rate (sCR + CR + near-CR) following induction therapy. Secondary objectives included combined CR rate post-HDT-ASCT, overall response rate (ORR: ≥partial response) post-induction and post-HDT-ASCT, time to progression (TTP), overall survival (OS), and safety. Adverse events (AEs) were graded using NCI CTCAE v3.0. Forty nine patients were randomized to each arm; median age was 57 and 58 years in the VTD and VTDC arms, respectively, 53% and 51% of patients were male, 49% and 43% had KPS ≤80%, and 24 / 45 / 31% and 18 / 47 / 35% had ISS stage I / II / III MM. All but 7 patients completed induction; these patients discontinued due to AEs (3 [6%] each arm) and disease progression (1 [2%] VTDC). Four VTDC patients received additional cycles of treatment. One patient (VTDC arm) was not evaluable for response. Response rates following induction are shown in the table. Median CD34+ stem cell yields were 8.16 (VTD; n=48) and 8.13 (VTDC; n=40) x 106/kg. At data cut-off (April 10, 2009), 47 VTD and 35 VTDC patients had undergone HDT-ASCT; response rates post-HDT-ASCT in 38 and 27 evaluable patients are shown in the table. Time-to-event data are not mature (median follow-up: 9.8 months). The 1-year survival rate was estimated to be 94% in each arm. At least one AE was reported in 98% and 96% of patients on the VTD and VTDC arms, with at least one grade ≥3 AE reported in 47% and 59%, respectively. The most common non-hematologic grade 3/4 AEs included fatigue (2% and 8%) and constipation (6% and 2%); analyses of hematology laboratory values indicated grade 3/4 AEs of lymphopenia (39% and 77%), anemia (8% and 18%), neutropenia (14% and 18%), and thrombocytopenia (6% each). PN was reported in 35% (VTD) and 29% (VTDC) of patients, including 8% grade 3 in each arm and 2% grade 4 in the VTD arm. Two patients (1 [2%] each arm) had deep vein thrombosis; one (VTDC arm) was a grade 3 SAE. At least one serious AE (SAE) was reported in 22% (VTD) and 41% (VTDC) of patients, including 6% and 14% with SAEs of infections (MedDRA SOC), and 2% and 14% with musculoskeletal-related pain. In conclusion, both VTD and VTDC are highly active induction regimens, with CR rates and ORRs among the highest reported; the efficacy profiles were similar between the arms, but there were higher rates of toxicity in the VTDC arm compared with the VTD arm.

Table. Response rates following induction and post-HDT-ASCT. Post-induction n=49 n=48 Combined CR*, % 51 44 sCR†, % 27 27 ORR, % 100 96 Post-HDT-ASCT n=38 n=27 Combined CR*, % 76 78 sCR, % 39 33 ORR, % 100 100 * sCR + CR + near-CR † unconfirmed

Disclosures:

Ludwig: Celgene: Honoraria; Mundipharma: Honoraria; AMGEN: Honoraria; Ortho-Biotech : Honoraria; Janssen-Cilag: Research Funding; Roche: Honoraria. Masszi:Janssen Cilag: Membership on an entity's Board of Directors or advisory committees. Shpilberg:Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees. Hajek:Janssen-Cilag: Honoraria. Dmoszynska:Milllennium: Research Funding. Cakana:Janssen Cilag: Employment, Equity Ownership. Enny:Johnson & Johnson: Employment, Equity Ownership. Feng:Johnson & Johnson: Employment. van de Velde:Johnson & Johnson: Employment, Equity Ownership.