Abstract: Background Induction therapy followed by autologous stem cell transplantation (ASCT) is the standard of care for patients with symptomatic multiple myeloma less than 66 years old. The quality of response to the induction treatment is an important prognostic factor and is predictive of progression free survival (PFS) following ASCT. The triplet combinations bortezomib-thalidomide-dexamethasone (VTD) and bortezomib-cyclophosphamide-dexamethasone (VCD) have demonstrated high response rates in prospective phase 2 and phase 3 clinical trials, they are 2 of the most commonly used induction regimens prior to ASCT, and are both recommended in the International guidelines. To date, no comparative data from prospective randomized trials of the safety and efficacy of VTD vs VCD are available. This provided the rationale for the phase 3 investigation of VTD vs VCD prior to ASCT in patients with de novo MM in this randomized multicenter study (NCT01564537). Methods Patients with de novo symptomatic MM less than 66 years old were prospectively randomized to receive either 4 cycles of VTD (arm A) or 4 cycles of VCD (arm B) followed by ASCT. The VTD regimen consisted of four 21-day cycles of bortezomib 1.3 mg/m²/d, subcutaneously (SC) D1, 4, 8 and 11, Dexamethasone 40 mg/d, PO D1 to 4, D9 to 12 and Thalidomide 100 mg/d, PO D1 to D21. The VCD regimen consisted of four 21-day cycles of bortezomib 1.3 mg/m²/d, SC D1, 4, 8 and 11, Dexamethasone 40 mg/d, PO D1 to 4, D9 to 12 and Cyclophosphamide 500 mg/m²/d, PO D1, 8, 15. Patients were stratified according to ISS (1-2 versus 3) and cytogenetics (high-risk defined by 17p deletion and t(4;14) versus other).The primary endpoint was very good partial response (VGPR) rate following 4 cycles. Response was assessed in a central lab according to the IMWG criteria. Assuming a VGPR rate of 60% in the VTD arm versus 45% in the VCD arm (15% difference), the possibility to detect a statistically significant difference required the enrolment of 340 patients overall (170 per arm). Adverse events were graded using the NCI CTCAE catalogue, version 4.0. Results From 11/2013 to 02/2015, 358 patients were enrolled into the study. 18 were screening failures, and 170 were randomized each to arm A (VTD) and arm B (VCD). The median age was 60 years (range, 26-65), 62% of the patients were male, and overall, the patient characteristics were well-balanced across the 2 arms of the study. The median number of induction cycles administered in both arms was 4 (1-4). On an intent-to-treat basis, the overall response rate ( 〉 partial response [PR]) was 92.3% in arm A, including a 10.7% complete response (CR) rate and a VGPR rate of 66.7%, while in arm B the overall response rate was 84%, with a 9.5% CR and a 56.2% VGPR rate. VGPR and PR rates were significantly higher in the VTD arm with p-values of 0.04 and 0.02, respectively. Seven patients died during induction therapy (2%), 3 in arm A from infections (2) and pulmonary embolism (1), and 4 in arm B from progression to extramedullary myeloma (2) and infections (2). Grades 3 / 4 peripheral neuropathy occurred in 4% and 2.2% in Arm A and B, respectively. Grade 3/4 neutropenia was seen in 11.9% vs 22.5% in Arm A and B, respectively. Conclusion This trial is the first prospective randomized comparison of 4 cycles of VTD versus 4 cycles of VCD administered as induction therapy prior to ASCT. VTD was shown to be significantly superior to VCD in terms of VGPR and PR rates. Neuropathy rates low in both arms, while neutropenia was more frequent with VCD. Disclosures Moreau: Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: 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; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hulin:Celgene Corporation: Honoraria; Janssen: Honoraria; Bristol Myers Squibb: Honoraria; Amgen: Honoraria. MACRO:celgene: Membership on an entity's Board of Directors or advisory committees; jansen: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees. Garderet:Bristol-Myers Squibb: Consultancy. Stoppa:Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Facon:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Pierre Fabre: Membership on an entity's Board of Directors or advisory committees. Laribi:Hospira SAS: Research Funding. Avet-Loiseau:jansen: Membership on an entity's Board of Directors or advisory committees; onyx: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; jansen: Membership on an entity's Board of Directors or advisory committees; onyx: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Attal:jansen: Honoraria; celgene: Membership on an entity's Board of Directors or advisory committees.

Abstract: Serum FLC analysis is a more sensitive indicator of disease than urinalysis. Improved sensitivity of serum over urine measurements during monitoring translates into valuable prognostic information.

Abstract: The overall response rate following 4 induction cycles of VTD prior to ASCT is higher than that of 4 cycles of VCD.

Abstract: Background. Progression by serum free light chain (sFLC) test without or preceding progression with intact immunoglobulin (Ig) is called light chain escape. This event alone is not considered a progression for patients with Multiple Myeloma (MM) according to International guidelines, although it is often considered a progression in real life and by clinical trials' investigators. We therefore sought to determine whether light chain escape would be a predictor of relapse and thus question a possible need to modify the current criteria for progression according to the International Myeloma Working Group (IMWG). Material and method. We have reviewed 325 (323 for analysis) patients that presented with a progression in the IFM/DFCI2009 phase 3 study (Attal et al. NEJM 2017). Among these 323 patients, 260 had initial tumor bulk measurement with intact Ig by serum protein electrophoresis test (SPEP; Ig ≥ 10 g/L) and 63 light chain MM (Ig 〈 10 g/L) measured using urine protein electrophoresis (UPEP). All progressions were validated in the central laboratory of CHU de Nantes (Dr T. Dejoie) and followed IMWG recommendations. sFLC increase was determined by absolute increase ≥ 100 mg/L and ≥ 25% from nadir value of the difference between involved and uninvolved FLC (ΔiFLC). Light chain escape was defined as sFLC increase without progression by SPEP (Ig increase ≥ 5 g/L and ≥ 25%) or UPEP (increase ≥ 200 mg/24h and ≥ 25%). Results. Among the 260 patients with intact Ig at diagnosis, 3 (1.15%) patients presented a light chain escape: progression by sFLC test without progression by SPEP. In parallel, 228 patients (87.7%) progressed by SPEP, of whom 18/228 (6.25%) showed a sFLC increase preceding the increase of intact Ig, with a median delay of 63 days. Among the 63 light chain MM, 6 (9.5%) patients presented a light chain escape: progression by sFLC test without progression by UPEP. Interestingly, 6 other patients (9.5%) progressed by SPEP even though Ig was 〈 10 g/L at diagnosis. Of the remaining 46 patients, 38 (60.3%) showed sFLC increase before progression by UPEP. Finally, 8 patients (12.7%) progressed but with intact Ig pauci-secreting MM meeting none of the M spike based progression criteria. Median time from iFLC nadir to ΔiFLC ≥ 100 mg/L was 280 days for light chain MM, 496 days for intact Ig MM, and 651 days for light chain escape. Median time from ΔiFLC ≥ 100 mg/L to follow-up visit to assess progression was 402 days light chain MM, 536 days for intact Ig MM, and 713 days for light chain escape. Overall, 9 (3%) patients had true light chain escape with progression by sFLC test without any other progression criteria. In parallel, in 56 (17%) patients, sFLC increase preceded progression to MM by standard test (SPEP or UPEP). Still the vast majority of patients had a regular relapse using the standard markers for progression. Conclusion. Based on a large study of patients treated into a phase 3 clinical trial with centralized assessment of response and progression, we showed that 20% of patients had progression by sFLC without meeting standard progression markers, of whom 3% had true light chain escape and 17% early light chain increase. Even though true light chain escape seems to be a rare phenomenon, analysis of sFLC test could help to avoid delayed or missed diagnosis of progression in 20% of patients in this clinical trial. This data should be confirmed in another database to assess whether a modification in the progression criteria in MM International guidelines should be proposed. Disclosures Hulin: Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Roussel:Amgen: Consultancy; Celgene: Consultancy; Takeda: Consultancy. Hebraud:Amgen: Consultancy; Janssen: Consultancy, Other: Lecture fees; travel and accommodation for congress, Research Funding; Sanofi: Consultancy; Takeda: Consultancy; Celgene: Consultancy, Other: Lecture fees, Research Funding. Karlin: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, Other: travel support; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support. Belhadj:Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Decaux:Celgene: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Amgen: Honoraria. Garderet:Amgen: Consultancy; Takeda: Consultancy; Celgene: Consultancy. Facon:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Oncopeptides: Membership on an entity's Board of Directors or advisory committees. Avet-Loiseau:Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Moreau:Amgen: 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; Abbvie: 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; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Attal:Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janseen: Consultancy, Research Funding; Sanofi: Consultancy. Leleu:Karyopharm: Honoraria; Gilead: Honoraria; Incyte: Honoraria, Other: steering committee membership ; Roche: Honoraria; Sanofi: Honoraria, Other: steering committee membership steering committee membership ; Novartis: Honoraria, Other: steering committee membership ; Amgen: Honoraria, Other: steering committee membership ; Merk: Honoraria, Other: steering committee membership ; Takeda: Honoraria, Other: steering committee membership ; BMS: Honoraria, Other: steering committee membership ; Celgene: Honoraria, Other: steering committee membership ; Janssen: Honoraria, Other.

Abstract: 8029 Background: Prolonged treatments have significantly improved survival in newly diagnosed multiple myeloma (NDMM). Lenalidomide (IMiDs), is currently approved in this indication, but remains a daily treatment, although oral, and may favor side effects in the long run. Furthermore, the use of a proteasome inhibitor (PI) is warranted in certain type of MM, such as high-risk. Carfilzomib, a second generation PI, has proved active combined with an acceptable security profile but its added benefit when given continuously is unknown. We thought to study maintenance Carfilzomib for elderly NDMM (eNDMM). Methods: The IFM 2012-03 multicenter phase I KMP (Carfilzomib, Melphalan, Prednisone) weekly study for eNDMM (≥ 65 years old) determined the maximal tolerated dose of weekly Carfilzomib at 70mg/m². We focus herein on the second part of the study with IV Carfilzomib monotherapy given at 36mg/m² for 13 cycles maintenance on an every 2 weeks schedule. Results: Thirty eNDMM were recruited in IFM 2012-03. Median age is 75, with 56% R-ISS 2 or 3 and 11% high-risk cytogenetic. With K weekly from 36 to 70mg/m², OS is reported at 93.3%, including 46.7% ≥CR; median PFS is 35.8 months and median OS was not reached. Twenty-two (73%) patients started K maintenance and 16 (73%) completed it. Four patients progressed and 2 stopped for AEs (renal amylosis, sensory neuropahty) during the maintenance phase. At maintenance completion, 50% were ≥CR. From the start of maintenance, in landmark analysis, median PFS is 28.1 months and the estimated 36-months OS approximately 70%. Conclusions: Carfilzomib monotherapy can be used safely in maintenance for 1 year in eNDMM, including for patients above 75 years. K maintenance may lead to deep response rate, certainly a most relevant prognostic factor for prolonged survival. Therefore, Carfilzomib maintenance, characterized with a simple administration modality, might be considered as an alternative to Lenalidomide and integrate the armamentarium of prolonged therapy in eNDMM. Clinical trial information: NCT02302495.

Abstract: Carfilzomib is a novel generation proteasome inhibitor. The Carmysap trial demonstrated that twice-weekly KMP (carfilzomib, melphalan, prednisone) might challenge the MPV (melphalan, prednisone, bortezomib) standard. We sought to study KMP weekly, allowing to increase carfilzomib's dose with maintained efficacy and improved safety profile. Patients and Methods: IFM2012-03, a phase I multicenter study of KMP weekly in elderly patients with newly diagnosed multiple myeloma (eNDMM), aimed to determine the MTD of carfilzomib. Carfilzomib was given intravenously at 36, 45, 56, and 70 mg/m2/day on days 1, 8, 15, and 22 with melphalan and prednisone, for nine 35-day induction cycles, followed by carfilzomib maintenance for 1 year. Three dose-limiting toxicities (DLT) determined MTD at the lower dose. Results: Thirty eNDMMs were treated, 6 per cohort at 36, 45, and 56 mg/m2 and 12 at 70 mg/m². There was one DLT at 36 mg/m2 (lymphopenia), one at 45 mg/m2 (lysis syndrome), two at 56 mg/m2 (cardiac insufficiency and febrile neutropenia), and two at 70 mg/m2 (vomiting and elevated liver enzymes). The safety profile was acceptable; however, specific attention must be paid to the risk of cardiovascular events, especially for elderly patients. The overall response rate was 93.3%, with 46.6% complete response. Conclusions: The MTD dose of carfilzomib was 70 mg/m2 in this KMP weekly study in eNDMM. Response rates, and especially CR rate, were remarkable in this population, and would benefit from being assessed in a larger-scale study. The IFM2012-03 study demonstrated that the MTD of carfilzomib weekly is 70 mg/m2 in eNDMM, and 56 mg/m2 for patients older than 75 years. Carfilzomib used weekly in combination has a good efficacy and safety profile in eNDMM.

Abstract: Introduction: The rate of response (partial remission and better) to pomalidomide and low dose dexamethasone in myeloma patients who had previously received lenalidomide and bortezomib was 33% (Richardson PG, et al. Blood 2014;123:1826). In view of improving the response rate of pomalidomide based therapy, we conducted a phase II trial to evaluate the efficacy and safety of the addition of weekly oral cyclophosphamide to pomalidomide and dexamethasone (PCD) in patients in first relapse following initial treatment in the IFM 2009/DFCI trial (Attal M, et al. NEJM 2017;376:1311). Since the combination of lenalidomide, bortezomib and dexamethasone (RVD) is becoming the standard of care in the frontline setting with or without autologous stem cell transplantation (ASCT), our goal was also to find an effective salvage regimen to induce new remission in patients relapsing after exposure to lenalidomide and bortezomib so as to be able to proceed to ASCT (ClinicalTrials.gov identifier: NCT02244125). Patients / Methods: Eligible patients had relapsed myeloma after one line of treatment according to the IFM 2009/DFCI trial. All patients had received RVD as induction and consolidation therapy plus lenalidomide maintenance for 1 year (Arm A). Half of them had undergone upfront ASCT after the induction phase as part of the initial protocol (Arm B). At first relapse, all patients received oral pomalidomide 4 mg on D1-21, oral cyclophosphamide 300 mg on D1, 8, 15 and 22 and oral dexamethasone 40 mg D1-4 and D15-18 of a 28 day cycle (PCD). Four reinduction cycles were administered to all patients. Those who had not been transplanted initially (Arm A) and who were responding underwent ASCT and received two additional cycles of PCD while those who had already been transplanted (Arm B) received 5 cycles of PCD. All were subsequently treated with pomalidomide plus dexamethasone maintenance until disease progression. The primary endpoint was the rate of partial response or better after the initial 4 cycles of PCD. Responses were assessed using the IMWG criteria. Results: Between April 2014 and February 2017, 100 patients were enrolled. The cut-off date for this intermediate analysis was 4th July 2017. At inclusion in the relapse trial, the median age was 62 years (range 39-70), and 62% of the patients were male. The median time from diagnosis of myeloma to current therapy was 3.6 years (3.1-4.3, 1st and 3rd quartile) and 97% had a PS of 0 or 1. The myeloma isotype was IgG (72%), IgA (17%), light chain (9%) or IgD (2%). Five patients had a plasmacytoma and 15% high risk cytogenetics (t(4-14) and/or del 17p and/or t(14-16)). The ISS was I (78%), II (15%) or III (7%). In 90 evaluated patients after 4 cycles of PCD, objective responses were obtained in 82 (91%): CR: 2 (2.2%), VGPR: 29 (32%) and PR: 51 (57%). Stable disease was observed in 3 patients (3%) and progressive disease in 5 (5.6%). Adverse events (AE) of grade 3-4 occurred in 72 patients (72%) including hematological toxicities (61%) (53% neutropenia, 36% lymphopenia, 6% anemia, 5% thrombocytopenia), infection (8%) (63% pneumonia), asthenia (7%), hyperglycemia (6%), gastrointestinal disorders (3%), allergic skin reactions (2%) and cardiovascular disorders (3%) (1 pulmonary embolism, 1 myocardial infarction and 1 syncope). There was no grade 3 or 4 peripheral neuropathy. Six patients (6%) discontinued one of the study drugs (P, C or D). Dose reductions were recorded in 38% of the patients for pomalidomide, in 35% for cyclophosphamide and in 46% for dexamethasone, the reasons being AE/SAE (77%, 70% and 71%), omission (13%, 13% and 9%) and other (10%, 17% and 20%) (P, C and D, respectively). Four of the 50 patients in Arm A could not have the planned ASCT at relapse while 7 of the 50 in Arm B received a second ASCT. PFS (PFS1 and PFS2) and OS will be reported during the meeting. Conclusion: In this first planned relapse trial, the all oral combination of pomalidomide, cyclophosphamide and dexamethasone was very efficacious at first relapse following lenalidomide, bortezomib and dexamethasone treatment. After 4 cycles, the rate of partial response or better was 91% and 92% of the patients could proceed to ASCT. Toxicity was mostly hematological and manageable. These results should be compared to those of other pomalidomide and dexamethasone-based second line therapies. Disclosures Garderet: Amgen: Honoraria; Takeda: Honoraria. Roussel: JANSSEN: Honoraria, Research Funding. Facon: Amgen, Celgene: Speakers Bureau. Karlin: Janssen: Honoraria, Other: Travel expenses. Perrot: Sanofi: Honoraria; Amgen: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Moreau: Celgene, Janssen, Takeda, Novartis, Amgen, Roche: Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceutical: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Consultancy, Honoraria; Amgen: Honoraria; Takeda: Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Millennium: Consultancy, Honoraria. Macro: JANSSEN: Honoraria. Benboubker: Takeda, Celgene, Janssen, Amgen: Consultancy. Jourdan: NOVARTIS: Consultancy, Honoraria. Mohty: Sanofi: Honoraria, Speakers Bureau. Attal: Sanofi: Consultancy; Amgen: Consultancy, Research Funding; JANSSEN: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.

Abstract: Background: The role of maintenance lenalidomide in myeloma, following autologous stem cell transplantation (ASCT) or not, is well established. However, 29% of patients discontinue the treatment with a median duration of less than 2 years with an increased rate of secondary primary malignancies (SPM). Pomalidomide could provide alternative maintenance therapy. Methods: This was a single arm phase II study of pomalidomide/dex (PD) maintenance therapy for MM patients (pts) in first relapse after treatment in the IFM 2009 trial. At first relapse, 100 pts received pomalidomide/cyclophosphamide/dex (PCD) for 4 cycles, after which half underwent ASCT (if no first line transplant) followed by 2 cycles of PCD consolidation (Arm A), or 5 cycles of PCD (if previously transplanted) (Arm B). All pts then received maintenance therapy consisting of 28-day cycles of pomalidomide 4 mg daily on days 1-21 and dex 20 mg once a week until progression (Blood 2018). The primary objective was to establish the safety and efficacy of PD as maintenance therapy. Results: A total of 75 pts were enrolled in the maintenance phase from January 2015 to November 2017 (Table 1) and the database was locked on 07/07/2021. The median age was 60 (range 39-70); 67% (50/75) were male. 53 pts had ISS stage I, 10 stage II and 3 stage III disease (9 missing). Infectious prophylaxis was antiviral in 94%, sulfamethoxazole/trimethoprim in 76%, penicillin in 69% and fluoroquinolone in 38%. A granulocyte colony stimulating factor was administered in 15 (20%) pts and immunoglobulins in 13 (17%). One quarter had thromboprophylaxis. The median follow-up was 73 months (95% CI: 68-75). Among the 75 pts, 63 (84%) left the study, 34 (54%) due to progressive disease, 19 (30%) due to AE/SAE, 7 (11%) on investigator (PI) discretion and 3 (5%) after consent withdrawal. 12 (16%) remained on therapy in July 2021.The median duration of maintenance was 23.7 months (IQR: 14.5-44). Pts received a median of 26 cycles (range 1-80) and 17 (23%) had 50 or more cycles. The reasons for pomalidomide discontinuation were progression or death in 54%, AE/SAE in 30%, PI decisions in 11% and patient decisions in 5%. 56 (75%) pts required a reduction in the dose of pomalidomide due to AE/SAE in 50%, omission in 19%, resumption of treatment in 11%, PI decisions in 16% and patient decisions in 2.7%. The reasons for dex discontinuation were progression or death in 30%, AE/SAE in 43%, PI decisions in 22% and patient decisions in 3%. 57 (76%) pts required a reduction in the dose of dex due to AE/SAE in 54%, omission in 3.4%, resumption of treatment in 0.3%, PI decisions in 38.7% and patient decisions in 3.1%. 31 SAE were reported in 22 pts: 13 (42%) infections, 5 tumors, 1 case of thrombosis, 1 diabetic ketoacidosis and 12 others. Grade 3/4 hematologic AE included neutropenia (51%), lymphopenia (35%), anemia and thrombocytopenia (0%). G3/4 drug-related non-hematologic AE ( & gt;5%) comprised 13% infections (5% pneumonia). G1/2 AE included 69% infections (49% bronchitis), 49.3% gastrointestinal disorders (20% diarrhea, 20% constipation), 48% fatigue, 31% skin disorders, 25% muscle spasms, 24% insomnia and 14.7% eye disorders (6.7% cataracts, 4% dry eyes). Concerning peripheral neuropathy, one patient had G3/4 and 45% G1/2. Eight pts developed SPM: 4 basocellular carcinoma, 1 epidermoid carcinoma, 1 melanoma, 1 colon carcinoma and 1 non small cell bronchial carcinoma. We observed an improvement in the response from the initiation of treatment: PR: 32.4 to 17.4%, VGPR: 56.8 to 49.3%, CR: 9.5 to 28%, sCR: 0 to 5.3% (at initiation to best response, respectively). A total of 33.4% of pts improved their response. The median PFS was 33.2 months (95% CI: 25.6-53.3). 41 pts died and the median OS was not reached (95% CI: 70.7-NR). All deaths were related to myeloma progression except 2 due to pulmonary infection, 1 lung carcinoma and 1 colorectal cancer. Conclusions: In the first relapse PCD trial, 75% initiated maintenance therapy. Long term administration of pomalidomide/dexamethasone as maintenance therapy is feasible. Thirty percent stopped pomalidomide because of SAE/AE, mostly related to hematologic AE, but this could be managed with dose reductions. There was generally G1/2 neuropathy, rare SPM and no other unexpected toxicity. One third of the pts improved their depth of response. The combination is safe, feasible and well tolerated and experience to date supports its further exploration with monoclonal antibodies. Figure 1 Figure 1. Disclosures Garderet: Amgen: Consultancy; Sanofi: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Janssen: Consultancy. Roussel: Amgen: Consultancy; BMS: Honoraria; GSK: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy. Leleu: Novartis: Honoraria; Mundipharma: Honoraria; Merck: Honoraria; Karyopharm Therapeutics: Honoraria; Janssen-Cilag: Honoraria; Gilead Sciences: Honoraria; Celgene: Honoraria; Carsgen Therapeutics Ltd: Honoraria; Bristol-Myers Squibb: Honoraria; Amgen: Honoraria; AbbVie: Honoraria; Oncopeptides: Honoraria; Pierre Fabre: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Takeda: Honoraria, Other: Non-financial support. Karlin: Takeda: Honoraria, Other: member of advisory board; Amgen: Honoraria, Other: travel support and advisory board ; Sanofi: Honoraria; Abbvie: Honoraria; oncopeptide: Honoraria; GSK: Honoraria, Other: member of advisory board; Janssen: Honoraria, Other: member of advisory board, travel support; Celgene-BMS: Honoraria, Other: member of advisory board. Perrot: Abbvie: Honoraria; BMS Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Honoraria, Research Funding; GSK: 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. Moreau: Abbvie: Honoraria; Oncopeptides: Honoraria; Celgene BMS: Honoraria; Amgen: Honoraria; Sanofi: Honoraria; Janssen: Honoraria. Macro: abbvie: Honoraria; sanofi: Honoraria; celgene bms: Honoraria; takeda: Honoraria; janssen: Honoraria. Jourdan: Novartis: Consultancy; Abbvie: Consultancy; bms/celgene: Consultancy. Jaccard: Pfizer: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria. Mohty: Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Sanofi: Honoraria, Research Funding; Gilead: Honoraria; Janssen: Honoraria, Research Funding; Jazz: Honoraria, Research Funding; Takeda: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; Adaptive Biotechnologies: Honoraria. Hulin: Celgene/BMS: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; abbvie: Honoraria. OffLabel Disclosure: pomalidomide as maintenance treatment

Abstract: The Intergroupe Francophone du Myelome conducted a randomized trial to compare bortezomib-dexamethasone (VD) as induction before high-dose therapy (HDT) and autologous stem cell transplantation (ASCT) to a combination consisting of reduced doses of bortezomib and thalidomide plus dexamethasone (vtD) in patients with multiple myeloma. Overall, a total of 199 patients were centrally randomly assigned to receive VD or vtD. After 4 cycles, the complete response (CR) rate was the same in both groups (13% in the vtD arm, 12% in the VD arm, P = .74). However, the CR plus very good partial response (VGPR) rate was significantly higher in the vtD arm (49% vs 36%, P = .05). After ASCT, the CR plus VGPR rate was significantly higher in the vtD arm (74% vs 58%, P = .02). The reduced doses of bortezomib and thalidomide translated into a reduced incidence of peripheral neuropathy (PN): grade ≥ 2 PN were reported in 34% in the VD arm versus 14% in the vtD arm (P = .001). vtD, including reduced doses of bortezomib and thalidomide, yields higher VGPR rates compared with VD and can be considered a new effective triplet combination before HDT/ASCT. This study was registered with www.clinicaltrials.gov as #NCT00910897 and EudraCT as #2007-005204-40.