Abstract: Introduction High-dose chemotherapy and stem cell transplant (SCT) remains a standard of care in medically fit patients (pts) with newly diagnosed (ND) MM. Induction triplets with at least one of the newer compounds are recommended. Bortezomib (V), lenalidomide (R) and dexamethasone (D; VRD) ranks among the most effective regimens and VRD/SCT was superior to VRD alone in an RCT. In a phase 2 study, we demonstrated RAD induction (lenalidomide 25 mg d1-21; Adriamycin 9 mg/m2 iv d1-4; dexamethasone 40 mg d 1-4 and 17-20 every 4 weeks) followed by SCT to be safe and effective (Knop et al., Leukemia 2017). Therefore, we decided to compare RAD versus (vs) VRD (lenalidomide 25 mg, d1-14; subcutaneous bortezomib 1.3 mg/m2 d 1, 4, 8, 11; dexamethasone 20 mg d 1+2, 4+5, 8+9, 11+12 every 3 weeks) induction (3 cycles each) in an RCT. MethodsThe current study was set up according to a double 2x2-factorial design to enrol transplant-eligible pts up to 65 years. The post-induction (PI) complete response (CR) rate as per IMWG criteria was the efficacy co-primary endpoint. We hypothesized the CR rate following RAD to be non-inferior to VRD which was estimated to be 20%. The study was powered to confirm non-inferiority of RAD at a margin of 10% with a one-sided alpha level of .05. Cytogenetic characterization was performed by fluorescence in situ hybridization (FISH) from CD138-enriched plasma cells. Minimal residual disease (MRD) was assessed by second-generation eight-color flow cytometry (FC; EuroFlow protocol). Bone marrow (BM) samples from baseline and defined restaging time points were analyzed for an acquisition of ⩾107cells/sample. In a subgroup of 103 pts, we evaluated the applicability of comprehensive immunoglobulin (Ig) amplicon next generation sequencing (NGS) to detect molecular MRD markers and to compare the results with FC. NGS-based marker screening was performed in baseline BM. Sequencing libraries were prepared using 2-step PCR employing multiplex primer sets for IGH V-D-J (FR1, FR2 and FR3), IGH D-J and IGK loci (V-J and KDe). For MRD detection, we used 1-step library preparation with the same primer sets. Results476 pts with a median age of 55 (range, 32-65) years were randomized between 05/2012 and 06/2016 and 469 received at least one dose of study drug. High-risk (HR) FISH abnormalities comprised del17p (11.3% of pts); t(4;14) (11.7%); and t(14;16) (4.5%). 232 pts were randomized to receive RAD, and 237 to VRD, respectively. 90.5% of RAD vs 93.7% of VRD pts completed all 3 cycles. PI CR rate was 13.5% (95% CI, 9.4%-18.7%) with RAD vs 13.4% (95% CI, 9.3-18.5) with VRD, (P=.971). Rates of ≥VGPR were 40.6% (50% CI, 34.2%-47.3%) with RAD vs 48.9% (95% CI, 42.3-55.6%) with VRD (P=.076). In pts with HR cytogenetics, rates of ≥VGPR were 43.3% (RAD) vs. 59.3% (VRD; P=.096). From 317 pts with paired samples, 33/151 (21.9%) of RAD vs 45/166 (27.1%) of VRD pts were FC MRD negative (P=.169) following induction at a median sensitivity level of 6.73x10-6. 197/239 positive pts (82.4%%) had MRD levels above 0.01%, and 42 (17.6%), between 0.0001 and 0.01%. Flow MRD negativity as per IMWG MRD criteria (Kumar et al, Lancet Oncol 2016) was seen in 8/151 (5.2%) pts with RAD vs 6/166 (3.6%) with VRD (P=.27). The remainder of pts did not (yet) fulfil IMWG CR for various reasons. NGS marker screening identified at least 1 Ig marker in 98/103 evaluable patients. To date, 47/98 pts were analyzed for NGS MRD following induction. Four out of 47 (8.5%) subjects were sequencing negative (3/4 post-VRD) with all of them also being IMWG FC MRD negative. One VRD patient died during induction for a mortality rate of 0.2 %. 62.1% of RAD vs 55.3% of VRD pts experienced at least one serious adverse event (SAE; p=.16). SAEs with relationship to study drugs of at least °3 severity occurred in 26.3% (RAD) vs 23.6% (VRD) pts (p=.523). ConclusionsTo the best of our knowledge, this is the first RCT to compare two R-based triplets in SCT-eligible pts. The co-primary efficacy endpoint was met with identical PI CR rates of around 13% for RAD and VRD, respectively. However, a trend emerges to favor VRD over RAD in terms of at least VGPR including HR FISH subjects. Analysis of MRD by multicolor FC showed 5% of pts to be already IMWG flow MRD-negative. Results for all 98 pts evaluable for NGS MRD will be presented. As of yet, too few progression events have occurred to estimate the second co-primary endpoint, 3-year progression-free survival. Longitudinal response and MRD analysis are ongoing. Disclosures Langer: Celgene: Consultancy. Mügge:Celgene: Honoraria, Research Funding; Janssen: Honoraria; Novartis: Honoraria; Bristol Myers Squibb: Honoraria; Amgen: Honoraria. Blau:Amgen: Other: Advisory board; BMS: Other: Advisory board; Novartis: Other: Advisory boards; Takeda: Other: Advisory board; Janssen: Other: Advisory board, Research Funding; Celgene: Other: Advisory board, Research Funding. Rollig:Janssen: Research Funding; Bayer: Research Funding. Dechow:AMGEN: Consultancy; Celgene: Honoraria. Gramatzki:Affimed: Research Funding. Brümmendorf:Merck: Consultancy; Janssen: Consultancy; Takeda: Consultancy; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Schmidt:Gilead: Honoraria, Other: Travel Grants; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grants; Celgene: Honoraria. Knop:Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding.

Abstract: Introduction: Cancer pts present with a highly heterogeneous health status and treatment choices are often numerous. Therefore, careful assessment of individuals' condition is highly relevant. In order to define best possible and tolerable treatment options, novel parameters and metrics for non-disease variables are needed. Albeit impairment in the Karnofsky Performance Status (KPS), Activities of Daily Living (IADL or ADL) and quality of life (QoL) are predictive for outcome in cancer and MM pts, the prognostic variables within a defined and prospectively assessed battery of established functional tests have rarely been delineated nor have their combination with disease-related risk factors or molecular markers been meticulously assessed. Their prognostic value for functional decline and overall survival (OS) has also not been tested and validated prospectively. Methods: We performed this comorbidity and functional geriatric assessment (CF-GA) in consecutive MM pts treated at our center according to our institutional Comprehensive Cancer Center pathway. The GA was prospectively obtained prior to initiation of anti-myeloma treatment and reflected pts' baseline health status rather than being confounded by toxicities induced by therapy. This CF-GA included the IADL, ADL, Timed Up and Go-Test, malnutrition, pain, rating of fitness, SF12-QoL and geriatric depression scale. Moreover, established comorbidity (CM) scores: ß2MG/eGFR (Eur J Haematol. 2009;83:519-27), Kaplan Feinstein (KF), Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI), Charlson Comorbidity Index (CCI) and initial Freiburg Comorbidity Index (iFCI) vs. revised FCI (rFCI) were assessed. This CF-GA was performed as one screening tool to assess pt fitness as well as to predict survival and toxicities in elderly myeloma pts. Results: Characteristics of 131 pts, currently included in this CF-GA, were typical for tertiary centers with a median age of 63 years (40-83), all with symptomatic disease. Their median hemoglobin was 10.8g/dl (7.6-14.7), the eGFR 68ml/min/1.73qm (7-136), the ß2-MG 4.4mg/l (0.8-38.4) and BM infiltration 40% (3-90). The baseline frailty assessment revealed a median KPS of 80% (40-100). The fitness score scaled both by physicians and patients was 4 vs. 3 (1-6), demonstrating that physicians overestimate pts' performance status and objective tests to verify this are essential. Median functional results for the IADL were 5 (1-8), for the ADL 4 (2-6), for pain 2 (0-10), for malnutrition 4 (0-14) and for cognitive deficiency via Mini Mental State Examination 28 (16-30). The median geriatric depression scale was 3 (0-13) and Timed Up and Go-Test 10 (4-30). Median CM scores were substantially different with an iFCI of 0 (0-3), ß2MG/eGFR of 1 (0-2), KF of 1 (0-3), HCT-CI of 2 (0-8), rFCI of 4 (0-9) and CCI of 7 (0-12). Highly valuable CF-GA-tools seem currently the IADL, Timed Up and Go-Test and rFCI. Since CF-GA is a time and man-power consuming procedure, we have presently completed a web account that allows the straightforward assessment of the rFCI for MM pts (https://rfci-score.org). This permits to perform this score in only 1-2 minutes. Moreover, we continue to perform this prospective assessment in more MM pts at our center and within a multicentre approach within the German Study Group Multiple Myeloma(DSMM) and will thereby also assess whether these function deficits and tests change over time. Prior scores to define fit, intermediate and frail pts (Blood. 2015;125:2068-74) will be compared with our risk group definitions and their predictive power for progression free survival, overall survival, side effects, therapy termination/discontinuation and early mortality will be evaluated. Adverse risk groups will allow to test and validate the most significant predictors of survival outcomes. Conclusions: Our CF-GA and rFCI contain easily assessable and reliable tests, which are of value to further test for their discriminative character in MM pts. Moreover, most predictive CF-CA tools need to be determined in prospective multicentre cohorts and need to be included in future clinical trials. We advocate our CF-GA and rFCI to foresee treatment toxicity, facilitate treatment decisions and guide personalized therapies. Timely identification and management of risk factors in MM pts are important considerations in the daily care of older and frail cancer pts, specifically those with MM. Disclosures Zober: Deutsche Krebshilfe: Other: grant. Knop:Celgene Corporation: Consultancy. Einsele:Amgen/Onyx: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Engelhardt:Deutsch Krebshilfe: Other: grant.

Abstract: Abstract 4900 Introduction: Clinical studies have shown that Rituximab plus Bendamustin (R-B) in indolent lymphoma results in favourable responses, progression free survival (PFS) and lower toxicity as compared to R-CHOP. The aim of this analysis was to characterize response and tolerability of R-B in patients with LBCL, who were not qualifying for R-CHOP due to age, comorbidity and/or prior pretreatment (including anthracyclines). Methods: We retrospectively identified consecutive patients with LBCL receiving at least two cycles of R-B in our department between 2003 and 2010 using our electronic tumor documentation system. Patient characteristics, response to R-B, and toxicity were assessed. Results: We identified 9 caucasian patients (5 females, 4 males) with LBCL; their median age was 71 years (range; 51–82). Two presented with stage I/II, seven with stage III/IV disease at initial diagnosis and before R-B. Six patients had a low or intermediate IPI and three were high risk. Four patients received R-B as first-line therapy, and five were treated for relapsed or refractory disease. Main determinants for the R-B-selection were contraindications for anthracyclines in five patients and advanced age and/or poor performance status in four patients. A median of four R-B-cycles were applied (range; 2–6). Response with achievement of CR and PR was observed in 6/9 (CR: 2, PR: 4), two achieved SD. Only one pt showed PD after four R-B cycles. The response of R-B in first-line vs. relapsed appeared similar. Of note, one female patient with secondary LCBL, after initial Hodgkin's lymphoma and C-MOPP chemotherapy (CTx) and mediastinal irradiation - with excellent response to R-B- failed to successfully mobilize PBSC thereafter. However, she was effectively mobilized with R-Ara-C-thiotepa (peripheral blood CD34+ cells were 5.82 vs. 54/μl, obtaining no vs. 6.72 × 106 CD34+ cells/kg KG via leukapheresis, respectively). Clinical tolerance of R-B in all patients was excellent in a total of 31 R-B-cycles, only two major CTC-events occurred: one infection (CTC grade III) and one thromboembolism (grade IV). Median PFS and overall Survival (OS) were 16 (7- not reached) and 20 (11-21) months. Conclusions: If standard R-CHOP cannot be given due to age, comorbidity or CTx-contraindications (e.g. anthracyclines), R-B may represent an effective treatment in LBCL. Larger cohorts and prospective clinical trials are needed to confirm these promising results. Currently, patients with grade III/IV follicular lymphoma are additionally evaluated for response and tolerability under R-B, also being presented at the meeting. Disclosures: No relevant conflicts of interest to declare.

Abstract: Multiple myeloma (MM) remains an incurable disease, with significant variation in the response and survival even with current treatment modalities, such as high-dose chemotherapy (CTx) and autologous stem cell transplantation (auto-SCT), novel drugs and intensive supportives. Hence, prognostic parameters that help to predict the benefit of different therapeutics are of utmost importance to be defined further. The objective of this analysis was to determine whether treatment selection and response are markedly influenced by specific clinico-pathological parameters and how these effect overall survival (OS). Of 143 consecutive MM patients (pts) receiving either standard therapy (Std-CTx, group A, n=79) or auto-SCT (group B, n=64) at our center between 1997–2003, gender, age, MM-type, -stage, number of CTx lines, LDH,β 2-MG and bone marrow (BM) infiltration were evaluated on response and survival in uni- and multivariate analyses and hazard ratios (HR) were determined. To further pay tribute to pts’ average age, as MM is primarily a disease of the elderly, special attention was paid to the influence of the performance status (Karnofsky Index=KI) and number of concurrent diagnoses (CD). Pts in groups A and B were comparable in terms of gender distribution, MM type, CD and LDH-level. However, group A as compared to B pts were older (65 vs. 56 yrs), had received more radiation (26 vs. 19%) and showed higher β2-MG (5 vs. 2.3g/L; respectively). Moreover, pts in group B as compared to A had more advanced disease (Durie and Salmon [D & S] stage II/III: 92 vs. 65%), a higher BM-infiltration (40 vs. 30%), and were treated later in their disease course. In group A pts, HR were increased for β2-MG 〉 3, D & S stage II/III, stage B disease, CD 〉 1, LDH 〉 200U/L and age 〉 60y, and HR decreased for females and KI 〉 80%, reaching significance for β2-MG, D & S stage II/III, stage B disease, CD and KI. Although these HR were also observed for group B pts, none of these prognostic factors reached statistical significance. Multivariate analysis on all pts identified β2-MG 〉 3mg/L and age 〉 60y as independent prognostic factors, with HRs of 3.6 (95% CI 1.6–8.1) and 2.1 (CI 0.9–5.0), respectively. Of note, current CR/PR rates for group A and B pts are 4 vs. 20%, and at last follow-up (6/2006) median OS from treatment initiation is 49.5% vs. 61.4%, respectively. Our data show that an elevated β2-MG, D & S stage II/III, stage B disease, more than 1 CD and reduced performance status before therapy, negatively influence response and OS in Std-group pts, whereas these do not significantly impact HR in auto-SCT pts. We conclude that MM pts benefit from auto-SCT independently of prognostic factors which, however, do impact outcome with Std-CTx alone. Since randomized trials have repetitively shown response and survival with auto-SCT to be superior to Std-CTx, we propose that pts with the above prognostic factors should be carefully evaluated for intensive therapies, as this analysis accentuates that auto-SCT is the treatment of choice for eligible MM pts.

Abstract: Introduction: Novel substances such as the next generation IMiD pomalidomide or the recently approved next generation proteasome inhibitor carfilzomib (Cfz) have considerably expanded our treatment options in MM, both of them influencing multiple myeloma (MM) interaction with bone marrow stroma cells (BMSCs), that provides an interesting target for anti MM therapy. More compounds directed at this disease critical crosstalk are currently under investigation, however the development of novel drugs remains inefficient, displayed by a substantial drop out rate of the 376 preclinical single agents tested since 1961 (Rongvaux, Annu Rev Immunol. 2013; Schüler, Expert Opin Biol Ther. 2013; Kortüm, CLML 2014). Our focus in the projected presented here was to develop a novel bone-derived in vitro 3D co-culture model specifically adapted to mimic the BM niche to more closely study the role of bone and BM bystander cells and to perform more reliable ex vivo compound screening in MM. Methods: Previous 2D models were compared to a novel 3D co-culture model (agarose matrix interlayer, 100 microwells/cm², 1.5mm in depth, permeable for oxygen+cytokines, but not for BMSCs utilizing U266, RPMI-8226, OPM-2 and primary BM patient (pt) cells, with and without HS-5 vs. M210B4 stroma support (Fig. A + Fig. B.a. for pt characteristics). Analyses covered Trypan Blue, Annexin/PI, MTT, FACS, cell cycle analyses and H2B-mCherry/cytochrome c-GFP assays (Udi, Br J Hematol. 2013). In a next step, primary bone-derived stroma cells were acquired from bones of C57BL/6 J mice. Bones were flushed, digested and FACS sorted in order to acquire single BM and bone bystander cell subtypes (MSPCs [mesenchymal stem and progenitor cells], endothelial cells, osteoblasts, PAS [PDFGRalphaSca1] and CaRs [CXCL12-abundant reticular cells]) which were then compared to HS-5 and M210B4 with regard to growth support, cytokine secretion and protection from anti-MM substances. Results: MMCLs and pt specimens were cultured at different concentrations (10 vs. 100 cells per microwell) with and without M210B4 demonstrating a growth advantage with vs. without M210B4 (Fig. B.b). Liquid overlay technique allowed cluster formation of pt specimens leading to more reliable propagation of pt material for up to 20d of culture. Apoptotic changes were assessed by confocal microscopy of RPMI8226 co-expressing fluorescently labelled histone 2B-mCherry (red) and cytochrome c-GFP (green) as indicators of late and early apoptosis. Comparing BMSCLs with regard to their MM growth support capacities, human HS-5 proved even more beneficent than M210B4 stroma (Fig. B.b). Phenotypic analyses of pt specimens showed decreased CXCR4 expression with vs. without BMSCs suggesting a dynamic regulation of homing molecules. The model was then used as an ex-vivo platform allowing both cytotoxicity and cell cycle analyses for the combination of bortezomib (Btz) vs. Cfz with ARRY-520 (kinesin spindle protein inhibitor). Btz (10nM) and Cfz (20nM) proved significantly cytotoxic compared to the control (U266 and pt specimens, respectively) after 48h of single agent treatment Fig.B.c). Compared to Btz (10nM, B10) and Cfz (20nM, C20) as single agents, the additional combination with ARRY-520 showed stronger additive cytotoxicity for Btz (A5+B10, median: 37.5% vs. 13.1%) than for Cfz (A5+C20, 38.6% vs. 34.1%). To note, the model could also be utilized for more profound analyses as depicted for G2/M cell cycle studies in Fig.B.d. 5nM ARRY-520 (A5) led to significant accumulation of OPM-2 cells in G2/M arrest after 48h of treatment confirming prior analyses (Hernández-Garcia Blood Suppl 4710,2014; Fig. B.d). Co-culture studies with different subsets of BM and bone-derived bystander cells are currently ongoing and will be presented at the meeting (Fig. B.e). Conclusions: More complex, 3D bone-derived high-throughput in vitro models are urgently needed to better predict the potency of preclinically tested agents and to better estimate the likelihood of their later clinical adoption into phase I-II trials. With this work, we provide an innovative model which reflects the BM microenvironment as a crucial predictor for in-vivo sensitivity as shown for ARRY-5200. This ex-vivo approach helps to better incorporate MM growth support by bone and BM-derived bystander cells and thus depicts a valid tool to better characterize the role of the BM niche in myeloma. Figure 1. Figure 1. Disclosures Engelhardt: Deutsch Krebshilfe: Other: grant. Wäsch:German Cancer Aid: Research Funding; Comprehensiv Cancer Center Freiburg: Research Funding; Janssen-Cilag: Research Funding; MSD: Research Funding.

Abstract: Abstract 4922 Introduction Thalidomide and lenalidomide possess antiangiogenic, antiproliferative, proapoptotic and immunomodulatory effects. The proteasome inhibitor bortezomib induces cell death in MMCLs and has demonstrated synergism on various tumor cell lines, when combined with the multikinase inhibitor sorafenib. Sorafenib targets various kinases involved in tumor growth and angiogenesis, which plays a governing role in numerous cancers, including MM. EGCG, the most active catechin in green tea, has been described to induce anti-MM- and anti-amyloid-, but recently also to prevent bortezomib-induced-effects. We therefore tested these compounds individually and in combinations on 3 MMCLs in order to assess their cytotoxicity, cell growth inhibition and phenotype changes. Material and Methods RPMI8226, U266 and L363 were cultured at 1×105 cells/ml, with RPMI1640, 10% FCS and 0.2% pen/strep. On day (d) 0, increasing concentrations of bortezomib, sorafenib, thalidomide, lenalidomide and EGCG were added. On d3 and d6, we determined cytotoxicity and cell viability via trypan blue dye exclusion assay and propidium iodide (PI) staining by flow-cytometry (FACS). Additionally, we analyzed phenotype changes by means of CD138-expression (FACS). To evaluate CD138-expression as well as morphologic changes after sorafenib treatment, we also performed confocal microscopy analyses. Results 100nM bortezomib showed pronounced cytotoxicity on all 3 MMCLs: mean PI-positivity in L363 was 83.9% on d3, remained stable on d6 and was significantly increased as compared to control-L363-cells (p 〈 0.01). In U266, mean PI-positivity on d3 and d6 was 37.5% and 25.2%, respectively, again being significantly higher than in control-U266-cells (p 〈 0.0001). In RPMI, PI-positivity was similarly increased on d3 and d6 with 94.5% and 91.3%, respectively, again substantially higher than in control-RPMI-cells (p 〈 0.001). With 10 and 100μM sorafenib in L363, we observed mean PI+ cells on d3 as high as 61.6% and 94.3% and on d6 of 80.8% and 91.8%, respectively (p 〈 0.0001). A statistically significant dose-dependent decrease in viable cells and CD138-expression with 10 and 100μM sorafenib as compared to L363-control-cells could also be detected. By confocal microscopy, CD138-downregulation was prominent, besides manifest morphologic changes. In U266, mean PI+ cells were 33.1% with 10μM and 78.3% with 100μM, again significantly higher than in control-U266-cells (p 〈 0.001), not substantially increasing on d6. Sorafenib's cytotoxicity was likewise evident in RPMI: PI+ cells on d3 with 10 and 100μM were 89.8% and 95.2% (p 〈 0.001), respectively. In contrast, even with 100μg/ml thalidomide, cytotoxicity in L363 cells was subtle, with mean PI+ cells of 10.0% on d3 and 21.6% on d6 (n.s.), with cell viability only slightly decreasing. Thalidomide did not significantly affect U266 cell growth either. Lenalidomide did not increase PI+ cells in L363 on d3, but induced a noticeable PI+-rise on d6 of 19.2% with 10μM (p 〈 0.01) and 15% with 100μM (p 〈 0.001) as compared to control-L363-cells. No statistically significant decrease in viable cells and CD138-expression was observed. With 10 and 100μM lenalidomide in U266, PI+ cells on d6 were higher with 19.9% and 29.6% (p 〈 0.001), respectively, as compared to control-U266-cells. Exposure of all MMCLs to EGCG, with concentrations ranging from 1 to 500μM, showed potent cytotoxic effects, most evident with concentrations of 250μM or higher in L363 (p 〈 0.01). Conclusions Bortezomib and sorafenib showed impressive cytotoxic effects as single agents and ongoing experiments suggest additive effects between both compounds, which is currently being investigated, both in vitro and in our in vivo NOD/SCID-IL2-receptor-gamma-chain−/− (NSG)-mouse-model. Further investigations will also validate the recently suggested inhibitory effects of EGCG on bortezomib-induced cytotoxicity. Thalidomide and lenalidomide moderately reduced viable cell numbers, confirming that other mechanisms, such as anti-angiogenesis and immunomodulation are of greater relevance on MM cells. In line with earlier work, EGCG induced a pronounced cytotoxic effect and inhibition of proliferation. Our results demonstrate that our in vivo model is valuable for the thorough analysis and discovery of innovative targeted anti-MM-agents. Disclosures No relevant conflicts of interest to declare.

Abstract: Lenalidomide (Len), an immunomodulatory drug, in combination with dexamethasone (Dex) is a new treatment option for patients (pts) with relapsed or refractory multiple myeloma (MM). Reimbursement and drug laws in Germany allow treatment before marketing authorization of a given drug, if no alternatives are available for life-threatening diseases. AIM: To evaluate efficacy and tolerability of MM pts treated with Len/Dex in the German named patient (pt) program. PATIENT AND METHODS: A comprehensive, previously tested, questionnaire was used to document data from consecutive pt series in five large and specialized university treatment centres. Response was assessed using the EBMT criteria. RESULTS: 55 pts were documented so far (median age, 63 yrs; 92% stage III Durie & Salmon). Pts were heavily pretreated: 30% had up to 2 previous therapy lines, 35% had three, 13% four and 21% more than four; the median no. was 3 (interquartile range, IQR 2–4). Pts had received a median of 16 (IQR 10–22) previous courses of chemotherapy. Forty-nine patients (89%) had previously received a stem cell transplant (SCT): 41 an autologous and an additional eight allogeneic SCT. That correlates with a 2-fold higher proportion of pts with prior SCT compared to the Len registration trial. Furthermore, the proportion of pts treated with the new drugs thalidomide or bortezomib was even 7–10-fold higher than in the registration trial. Best response could be assessed in 49 pts.: 4% CR, 32% PR, 19% MR, thereby showing an overall reponse rate of 55%. Four patients (8%) progressed during therapy and two (4%) died before response evaluation. The table shows response in different subgroups according to previous therapies. Response (CR/PR/MR) ranged from 88% (7/8) with only 1 previous treatment line shown in the table to 52% (16/31) with 2–3 and 43% (6/14) with 4–5. The most common adverse event III°/IV° was infection occurring in 21/55 (38%) patients. Thrombo-embolic events were observed in three patients (5%). Haematological toxicity grade IV° was seen in 11/46 (24%) patients, most common in course 1 of therapy. Five patients (9%) died during treatment, four due to infection (one in neutropenia) and one patient due to cerebral bleeding. 70% of patients were alive at last follow-up. CONCLUSION: In this pt cohort Len/Dex induced considerable antineoplastic activity despite extensive pretreatment. Toxicity was moderate and as expected for this risk-cohort. Nevertheless pts with more than 3 prior treatment lines should receive close clinical monitoring in order to prevent life-threatening infection. Response in different subgroups Over all response Prev. alloSCT Prev. ASCT Prev. thalidomide Prev. bortezomib 3 prev. treatment lines 〉 〉 n 49 8 40 30 39 19 CR/PR/MR 55% 50% 53% 50% 54% 42%

Abstract: Patients (pts) suffering from mature (peripheral) T-cell lymphoma are known to have a poor outcome compared to pts with aggressive B-cell lymphoma when receiving conventional therapies. However, case reports and single centre experiences show promising results of allogeneic stem cell transplantation (allo SCT) for these pts. We here present a retrospective analysis of 103 pts with mature T-cell lymphoma who received an HLA-identical allo SCT in EBMT centres between 2000 and 2005. Histological subtypes of the patients were anaplastic large cell lymphoma (n=25; 4 anaplastic lymphoma kinase [ALK] positive, 11 ALK negative, 10 ALK unknown), peripheral T-cell lymphoma unspecified (n=51), angioimmunoblastic T-cell lymphoma (n=18) and aggressive T-cell lymphoma unspecified (n=9). Patients with primary cutaneous T-cell lymphoma or T-lymphoblastic lymphoma were excluded. Median follow up for surviving patients was 40 months (6–98), median age at allo SCT 42 years (18–68) and median time to allo SCT 17 months (3–233). 39 pts had failed a prior autologous SCT; 68 pts had chemosensitive disease at allo SCT (of these 15 in CR1) and 30 pts had chemorefractory or untested relapsed or progressive disease. Donors were HLA identical siblings for 73 and matched unrelated donors for 30 pts; 82 pts received peripheral blood stem cells. 54 pts were treated with reduced intensity conditioning before SCT. The cumulative incidence (CI) of acute graft versus host disease (GvHD) 100 days after SCT was 52% and had no effect on non-relapse mortality (NRM) or relapse rate (RR). 34 of 74 evaluable pts experienced chronic GvHD (14 limited, 20 extensive), CI 46% at 2 years. Introducing chronic GvHD as a time dependent covariate, this factor was associated with a higher NRM (p 〈 0.001) and a lower RR (statistically not significant), resulting in a lower progression free survival (PFS) (p=0.001). For all patients CI of NRM and RR at 3 years were 36.7% and 24.9%, respectively, resulting in 41.4% PFS and 46.9% OS. Median time to relapse / progression was 4 (1–18) months. In multivariate COX analysis for PFS refractory disease (relative risk 3.4, p=0.001), prior failed auto SCT (relative risk 2.6, p=0.001) and poor performance status at SCT (relative risk 2.5, p=0.04) were significant adverse factors. Additionally, there were trends for T-cell depleted grafts (p=0.1), CMV status other than negative-negative (p=0.1) and reduced intensity conditioning (p=0.2) to be adverse factors. A subgroup of 39 good risk pts (good performance status, chemosensitive disease, no prior autologous SCT) had a PFS of 59%. This retrospective analysis on allo SCT in peripheral T-cell lymphoma shows an encouraging low RR but efforts have to be made to reduce NRM. Prospective studies are warranted to further define pts who will profit from an early allo SCT.

Abstract: Abstract 4912 Since novel treatment options are needed in multiple myeloma (MM), novel anti-MM agents and combinations are eagerly pursued to further improve the prognosis for MM patients. For potentially novel therapeutic agents, functional in vivo models are highly valuable. We have established a cell line-based, disseminated MM model in NOD/SCID-IL2-receptor-gamma-chain−/− (NSG) mice. In our current analysis, the multikinase inhibitor sorafenib was validated alone and in combination with the well-established anti-MM agent bortezomib in 6 independent experiments. Optimized dose and schedule were determined as follows: 1. sorafenib (100mg/kg/d; d0-11) alone, 2. bortezomib (0.7mg/kg/day (d); d0,4,11) alone, 3. both in combination with the respective doses and schedules compared to 4. a control group. L363 cells were injected intratibialy into NSG mice and respective therapies were started 7 days after L363-injection (d0). Tumor growth was monitored with daily monitoring of MM-symptoms, flow-cytometry (FACS) and fluorescence-based in vivo imaging (FI). Tumor inhibition was calculated as the proportional reduction of mean MM-cell-infiltration at the respective compartment of the test- compared to the control-group (optimal T/C in %). Furthermore, hollow bones of the injected mice were retrieved when mice were sacrificed, cells flushed out and MM cells purified by MACS microbeads. Total RNA was isolated from these cells and gene expression profiles analyzed using the HG-U133 Plus 2.0 array (Affymetrix) and the Expressionist software (Genedata AG, Basel). L363 engrafted reliably (take rate=100%) at the injection site and in distant organs, such as bone marrow (BM; 100%), spleen (38%) and rarely liver (8%); in the latter organs as previously reported. Control mice developed MM symptoms, such as hind limb pareses, weight loss and osteolyses. At the respective doses and schedules, the examined compounds were well tolerated in tumor-bearing mice. No acute toxicity could be observed and maximal body weight loss was 4% with mono- and 11% with combined therapy. Primary tumor development was markedly reduced by sorafenib (optimal T/C of 11% on d11), as well as with bortezomib, albeit to a lesser extend (optimal T/C: 22% on d5). BM metastases were also significantly reduced by sorafenib with an optimal T/C value of 21% on d11. Bortezomib reduced BM infiltration to an optimal T/C value of 46% on d5 as compared to the control. Combined therapy of sorafenib and bortezomib showed most pronounced anti-tumor and anti-metastatic effects, inducing T/C values of 17% (primary tumor) and 7% (BM) on day 11, respectively. Table 1. Antitumor effect of Sorafenib and Bortezomib in mono- and combined therapy in the L363-xenograft model Compound Side effects Primary tumor Bone marrow Dose Mortality Max. median bwc1 FI2 tumor inhibition FI2 tumor inhibition [mg/kg/d] [n] [%] [%] [%] Sorafenib 100 0 / 5 96 11 21 Bortezomib 0.7 0 / 5 97 22 46 Soraf. / Bortez. 100 / 0.7 0 / 5 89 17 7 1 bwc=body weight changes 2 Tumor inhibition was calculated as the median % of MM cells determined by FI at respective compartments of the test vs. control group multiplied by 100 (optimal test/control (T/C) in %) L363 engraftment into NSG is a valuable in vivo MM model which exhibits high reproducibility, take- and metastases-rates and closely mimics the clinical situation. Collection of whole-body FI data proved to be a time- and animal-saving analysis that allows to closely monitor MM growth. Sorafenib showed promising results in our MM model, in particular in combination with bortezomib. Amongst others, a detailed characterization of the anti-tumor activity of both compounds will be provided by gene expression analysis of L363 cells isolated from untreated vs. treated mice. Further investigations to validate other innovative anti-MM agents as well as their combinations are currently also pursued. Disclosures No relevant conflicts of interest to declare.

Abstract: Introduction: Multiple myeloma (MM) relapse is common and may eventually lead to highly refractory/relapsed MM (RRMM). Therefore, novel treatment combinations are crucially needed for this highly challenging subgroup of patients (pts). The aim of the here presented phase I/II IIT was to test the tolerability and activity of a novel, so-called VBDD schedule within an outpatient regimen for extensively pretreated RRMM pts. In addition to Bortezomib, Doxorubicin and Dexamethason, which are all active and approved drugs in RRMM, Vorinostat has shown promising anti-tumor effects as a histone deacetylase inhibitor (HDACi). It inhibits the enzyme activity of HDAC 1, 2, 3 and 6, thereby allowing the activation of tumor suppressor genes. MM cells have been shown to escape from bortezomib treatment by formation of aggrosomes which desensitize cells to proteasome inhibitors and by microtubule mediated protein shuttling to lysosomes, where proteins are degradaded in order to prevent cytotoxic stress and ultimately escape from apoptosis (Fig.A). Albeit vorinostat has shown moderate activity when given alone, it has promising additive effects when combined with other antimyeloma agents, and was therefore used as an add-on agent within this RRMM regimen as it blocks microtubule coppling and aggrosome building and thereby may antagonize escape mechanisms in bortezomib-refractory pts. Methods: Vorinostat was escalated from 100mg (dose level 0), to 200mg (+1) and 300mg (+2). Primary objectives (MTD; 3+3 dose escalation), secondary objectives (safety, IMWG responses, PFS, OS) and supplementary endpoints (organ function, prognostic factors, QoL, comorbidity and HDAC-activity in PBMCs/BM) were assessed throughout the trial. Dose limiting toxicities (DLTs) were defined as any possibly drug-related adverse event (AEs) ≥grade 3 (CTCAE) during the 1st cycle. After completing 6 cycles, patients could receive either a bortezomib maintenance therapy or next-line treatment (e.g. 2nd ASCT). Results: 34 pts with RRMM with a median age of 63 years (47-78) and KPS of 90% (70-100%) have been enrolled, of which 33 received therapy according to the study protocol (1 pt deceased prior to study start due to aggressive MM progression and was therefore not included in the evaluation). The number of prior therapy lines was substantial with a median of 3 (1-8; with prior bortezomib, SCT and IMiDs in 88%, 94% and 42%, respectively). 3 pts each were treated in dose levels 0 and +1, and the remaining 27 pts in dose level +2. No DLTs were observed. In our current analysis, SAEs amounted to 15 and occurred in 9/33 pts (27%): Amongst them, 2 nonfatal SAEs were judged to be related to the investigational therapy (1 bacteraemia, 1 herpes zoster), for the others, no causal relationship to VBDD was found. The response according to IMWG criteria was rewarding with best ORR ( 〉 PR) and clinical benefit rate (CBR; 〉 SD) of 42% and 94% (Fig. B), and end of treatment (EoT) ORREoT and CBREoT of 36% and 88%, respectively (Fig.C). Our data also revealed that the response was independent of the presence or absence of unfavorable cytogenetics. Comorbidity assessments assured no decline in pts' mental or physical condition and pts reported preserved or improved QoL with this well-tolerated 4-agent treatment regimen. Pharmacodynamic analyses in peripheral blood (PB) MCs showed substantial and early HDAC downregulation between VBDD cycles 1 and 2 in 11/16 pts (69%): median HDAC activity decreased to 52% of pre-treatment levels. Thereby, we were able to distinguish 3 groups of pts with substantial, more subtle or no PB HDAC decreases in 8, 3 and 5 pts, respectively. Of note, these HDAC changes correlated well with pts' serological and clinical responses, except in 2 pts. These intriguing results are currently further assessed and will be presented at the meeting. Conclusions: VBDD demonstrated to be an effective and well-tolerated outpatient regimen with promising response rates in heavily pretreated RRMM pts. The employed VBDD regimen, with a continuous, rather than pulsed vorinostat-schedule, constitutes a promising treatment option, expands current standard therapies and, similarly to other HDACi (i.e. panobinostat), suggests HDACi as a valuable add-on within this combination schedule in order to stabilize the disease and/or bridge RRMM patients to next-line treatments (i.e. autologous/allogenic stem cell transplantation) or novel clinical trial drugs. *AK and JW contributed equally Figure 1. Figure 1. Disclosures Off Label Use: We report on results of an Phase I/II IIT, in which the HDACi Vorinostat is used to treat relapsed or refractory Multiple Myeloma pts . Engelhardt:MSD: Research Funding; Janssen-Cilag: Research Funding; Comprehensive Cancer Center Freiburg: Research Funding; German Cancer Aid: Research Funding. Wäsch:German Cancer Aid: Research Funding; Janssen-Cilag: Research Funding; Comprehensiv Cancer Center Freiburg: Research Funding; MSD: Research Funding.