ALBERT

Description: Introduction: The role of autologous stem cell transplantation (ASCT) as first line treatment for newly diagnosed patients with myeloma is currently under evaluation given the high response rates to novel induction treatment. The outcomes for patients that do not proceed to ASCT following induction remain unclear and are likely to be determined by genetic risk and response to therapy. In order to evaluate this further, this single arm phase 2 clinical trial conducted at 13 sites in the UK was designed to determine the 2 year progression free survival for patients that achieved ≥ very good partial response (VGPR) following induction therapy without ASCT. Those achieving partial response (PR) were consolidated with ASCT according to routine practice. In this first analysis we report secondary endpoints: disease response and regimen-related toxicity in patients completing induction, including minimal residual disease (MRD) negativity by multiparameter flow cytometry. Methods: Patients with newly diagnosed myeloma eligible for ASCT received PAD (bortezomib 1.3mg/m2 days 1, 4, 8, 11; doxorubicin 9mg/m2 days 1-4 and dexamethasone 40mg days 1-4 (and days 8-11 and 15-18 for the first cycle only)) for up to 6 cycles (minimum of 4). Bortezomib was initially given intravenously (IV), but once approved this was switched to sub-cutaneous (SC). Those failing to achieve PR were offered salvage therapy off protocol. All others had peripheral blood stem cell (PBSC) mobilisation using cyclophosphamide + GCSF, followed by MRD assessment on bone marrow aspirates using multi-parameter flow cytometry. Depending on disease response, patients were then stratified to ASCT (PR) or no further treatment (≥VGPR). Responses were assessed using International uniform response criteria (Durie 2006) by intent-to-treat and toxicity scored according to CTCAE version 4.0. High risk disease was defined by the presence of one or more adverse FISH lesions (t(4;14), t(14;16), t(14;20), del(17p13), +1q21) as described in the MRC Myeloma IX trial. Results: Between March 2011 and January 2014, 153 patients were enrolled (median age of 55, range 28-71 years). 139 (91%) received between 4-6 cycles of PAD. The majority (135, 88%) received SC only bortezomib and 18 (12%) received at least 1 cycle IV. The overall response rate to PAD was 81% with 46% achieving ≥VGPR (sCR: 6 (4%), CR: 13 (8%), VGPR: 51 (33%), PR: 54 (35%)). FISH data was available for 122 patients, 91 (75%) patients were standard risk and 31 (25%) were adverse. Responses were similar irrespective of ISS or genetic risk (standard, ≥VGPR 44%, PR 34%; adverse, ≥VGPR 55%, PR 29%). MRD results are currently available in 70 of the 124 patients achieving PR post PBSC harvest. Of this group 41 achieved ≥VGPR post-harvest (22 MRD+ and 19 MRD-) and hence did not proceed to ASCT, 13 patients achieved CR of which 8 were MRD negative. Toxicity was as expected for PAD and predominantly haematological. Notably the incidence of neuropathy was lower than that previously reported with IV bortezomib. Grade 3-4 events were: neutropenia: 18%; thrombocytopenia 7%. Grade 2-4 peripheral neuropathy was reported in 27% compared to 40% in the HOVON-65/ GMMG-HD4 Trial using IV bortezomib. Grade 1-2 neuropathy was similar for patients who received IV (55.6%) or SC (60%) bortezomib; however only 7% of patients receiving SC bortezomib developed grade 3 neuropathy compared to 28% with the IV route. Conclusions: SC PAD is a highly effective induction regimen for patients with newly diagnosed myeloma achieving a ≥VGPR of 46%. Of the 41 patients achieving ≥VGPR post-harvest with MRD result available, 46% were MRD negative. Response rates were similar across ISS and with adverse FISH. The use of SC bortezomib improved tolerability and substantially reduced neurotoxicity. ISRCTN no: 03381785. Disclosures Popat: Janssen: Honoraria. Cavenagh:Janssen: Honoraria. Schey:Janssen: Consultancy, Honoraria. Cook:Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau. Cook:Janssen: Honoraria, Research Funding. Yong:Janssen: Honoraria.

Description: Improving outcomes in multiple myeloma will involve not only development of new therapies but also better use of existing treatments. We performed RNA sequencing on samples from newly diagnosed patients enrolled in the phase 2 PADIMAC (Bortezomib, Adriamycin, and Dexamethasone Therapy for Previously Untreated Patients with Multiple Myeloma: Impact of Minimal Residual Disease in Patients with Deferred ASCT) study. Using synthetic annealing and the large margin nearest neighbor algorithm, we developed and trained a 7-gene signature to predict treatment outcome. We tested the signature in independent cohorts treated with bortezomib- and lenalidomide-based therapies. The signature was capable of distinguishing which patients would respond better to which regimen. In the CoMMpass data set, patients who were treated correctly according to the signature had a better progression-free survival (median, 20.1 months vs not reached; hazard ratio [HR], 0.40; confidence interval [CI], 0.23-0.72; P = .0012) and overall survival (median, 30.7 months vs not reached; HR, 0.41; CI, 0.21-0.80; P = .0049) than those who were not. Indeed, the outcome for these correctly treated patients was noninferior to that for those treated with combined bortezomib, lenalidomide, and dexamethasone, arguably the standard of care in the United States but not widely available elsewhere. The small size of the signature will facilitate clinical translation, thus enabling more targeted drug regimens to be delivered in myeloma.

Description: Abstract 3878 Poster Board III-814 Introduction Despite recent therapeutic improvements in the management of myeloma it remains an incurable disease. New therapies are therefore required. Pomalidomide (POM, Celgene) is a thalidomide derived immunomodulatory agent with similar preclinical spectrum of activity as lenalidomide. In Phase 1 studies we have previously demonstrated that POM monotherapy is well tolerated by patients with relapsed myeloma determining a maximum tolerated dose of 2mg od or 5mg on alternate days (Schey et al. JCO 2004; Streetly et al. BJHaem 2008). The toxicity profile was acceptable and overall response rates of 54 and 50% were observed with daily and alternate day dosing respectively. The current study examines long term responses, progression and survival outcomes. Patients were entered into the POM daily dosing or alternate day dosing Phase 1 studies between March 2001 and September 2003 and continued to receive treatment with POM until progressive disease (PD) or Grade 3 or greater non-haematological toxicity. Patients with PD were eligible to receive dexamethasone in addition to POM. POM became unavailable in May 2005 and patients still receiving drug were switched to receive lenalidomide. All patients gave informed consent. Results 44 patients received treatment with POM at a dose of 1mg alternate days – 10mg od. A median of 3 (range 1 – 8) prior lines of therapy had been received. POM was received for a median of 9.3 months (1 – 53). Following POM withdrawal 8/44 patients who had not developed PD subsequently received lenalidomide from a median of 30 months after starting POM. Overall responses by IMWG criteria to POM monotherapy were: CR 13.6%, VGPR 4.5%, PR 34%, MR 9%, SD 29.5% and PD 7% giving an overall response rate (〉PR) of 52%. Dexamethasone was introduced for PD for 10 patients and prolonged SD for 1 patient. 5/10 of these patients had 〉MR response to the addition of dexamethasone. With a median follow-up of 28 months the median PFS was 13.7 months and median OS was 28 months. Patients who had a PR response or better received POM for a median of 17.5 months and had improved PFS (median 19.8 months) and OS (median 42 months). 8/44 patients subsequently received lenalidomide. 7/8 of these patients have now developed PD at a median 26 months from commencing lenalidomide and 74 months from starting POM. Conclusions POM is a very well tolerated drug with excellent long term responses observed in this Phase 1/2 setting predominantly as monotherapy. Phase 2 studies are ongoing and results of these are awaited with interest. Disclosures: Streetly: Celgene: Honoraria. Schey:Celgene: Honoraria.

Description: Introduction: VTD is an effective regimen for patients with multiple myeloma and forms a backbone for the addition of novel agents. The MUK-six trial aimed to improve the efficacy by adding Panobinostat, a now FDA approved pan-histone deacetylase inhibitor that demonstrated synergy with proteasome inhibition and immunomodulatory agents in pre-clinical models. We have previously reported the phase 1 dose finding part which determined the MTD of panobinostat with VTD to be 20mg. Here we present the efficacy results from the recommended dose (RD) expansion phase (primary end point) and safety, tolerability data for all patients during the induction phase of the study. Methods: MUK-six was a multi-centre UK Phase I/IIa trial for patients with relapsed and relapsed/ refractory myeloma who had received between 1 and 4 prior lines of therapy. Subjects received VTD-P (bortezomib 1.3mg/2sc days 1 and 8, thalidomide 100mg daily (50mg if pre-existing neuropathy), dexamethasone 20mg days 1, 2, 8, 9 and panobinostat 20mg days 1, 3, 5, 8, 10, 12) every 3 weeks for up to 16 cycles (induction) followed by 1 year of panobinostat maintenance. Those planned for autologous stem cell transplantation (ASCT) received a minimum of 6 cycles of VTD-P. All patients treated with VTD-P received venous thrombosis prophylaxis as per institutional practice. Responses were assessed using modified IWG uniform response criteria and toxicity graded by CTCAE V4.0. Results: 46 patients were treated at the RD and were of a median age of 60 years (41-76). 80.4% had received one prior line of therapy (range 1-4), 71.7% had prior bortezomib and 39.2% prior thalidomide. Most patients were ISS 1 (60.9%), 45.7% had adverse FISH lesions at baseline, 8.7% had 17p deletion. 6 patients remain on treatment at the time of this abstract. 51.3% of patients came off study to proceed to ASCT. The overall response rate (≥PR) for patients receiving at least one dose of panobinostat was 91.3%, ≥VGPR 45.7% (CR 6.5%, VGPR 39.1%, PR 45.7%). The ≥VGPR rate for those with standard FISH was 52.1% vs 42.9% for adverse FISH. Those treated at first relapse had higher overall responses to those treated later in their disease course (≥PR 94.6% vs 77.8%). Responses were independent of prior bortezomib exposure (≥PR 90.9%, ≥VGPR 45.5% vs PR≥92.3%, ≥VGPR 46.2%). Treatment was generally well tolerated, with a mean panobinostat dose of 17.4mg (86.8% of the RD) delivered across all cycles. 32.1% of those starting at 50mg thalidomide stopped the drug due to toxicity, and 52.6% of those starting at 100mg required dose reductions/stopping. 46 serious adverse events were reported in 27 patients which were mainly infections (17/46, 37.0%). The commonest grade 3-4 toxicities reported for all 57 patients were: neutropenia (14, 24.6%), hypophosphatemia (11, 19.3%), thrombocytopenia (8, 14.1%) and diarrhoea (6, 10.5%). Of note there were no reports of ≥ grade 3 neuropathy. The most frequent grade 1-2 toxicities were fatigue (50, 87.7%), neuropathy (43, 75.5%), constipation (35, 61.4%), diarrhoea (35, 61.4%), bone pain (33, 57.9%), and nausea (27, 47.4%). 2 patients withdrew consent due to toxicity. Conclusions: This study demonstrated that panobinostat can be safely given in combination with VTD and appears highly effective with a response rate of 91.3%, ≥VGPR 45.6% despite 72% having previous bortezomib. This regimen was well tolerated, in particular the incidence of diarrhoea, neuropathy and asthenia/fatigue appeared lower than that observed in the PANORAMA 2 trial (San Miguel et al., 2014). It is possible that the incorporation of a low intensity subcutaneous bortezomib schedule (2 doses every 3 weeks) contributed to the lesser toxicity. Acknowledgments: This trial was part of the Myeloma UK Clinical Trial Network, ISRCTN: 59395590. Disclosures Popat: Janssen: Honoraria. Off Label Use: Panobinostat: use outside of FDA licence, not yet EU approved. Kishore:Celgene: Other: Conference Sponsorship; Jazz pharma: Other: Conference Sponsorship. Oakervee:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Yong:Janssen: Honoraria; Autolous: Consultancy; Amgen: Honoraria; BMS: Honoraria; Takeda: Honoraria; Novartis: Consultancy. Cook:Sanofi: Consultancy, Honoraria, Speakers Bureau; Jazz Pharma: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Chugai: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Cavenagh:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: Conventional techniques for assessing drug response and apoptosis induction rely on static assessment of cellular changes at predetermined time points (e.g. detection of exposed membrane phospholipids by Annexin V). The Kinetics of Optical Response assay (KOR) is a new technique that detects induction of apoptosis dynamically. It employs a spectrophotometric methodology to detect changes in optical density associated with membrane blebbing related to growth and death, allowing detection of apoptosis in real time. The KOR assay has already predicted the response to cytotoxic agents of AML cell lines and primary samples. This study uses the KOR assay in lymphoid malignancy and shows sensitivity to apoptosis induction by conventional and novel agents including bortezomib. The lymphoma cell line DOHH2 (t(14;18)), U266 (myeloma), K562 (CML) and primary CLL cells were used in this study with HL60 (AML) as a control. Cells were seeded in 96 well plates and treated with a variety of drugs alone or in combination (cytarabine, fludarabine, doxorubicin, daunorubicin, etoposide, melphalan, bortezomib) at multiple concentrations. Measurements were made at 5 min. intervals for up to 48 hrs and analysed using KORSoft™ software to generate apoptotic response curves. To validate this approach conventional techniques were used for comparison (Alamar Blue for cytotoxicity and flow cytometric analysis of cell cycle and apoptosis using propidium iodide and Annexin V staining respectively). The KOR assay can show changes in growth characteristics, induction of apoptosis and necrosis in response to drugs permitting a continuous analysis for maximum sensitivity (Smax). DOHH2 was found to be dose responsive to four of the drugs used, with the Smax for 10μM daunorubicin at 6 hours (48%), 1μM doxorubicin at 8 hours (38%), 100μM etoposide at 8 hours (52%), and minimally to 100μM cytarabine at 16 hours (21%). There was no effect from fludarabine. The addition of bortezomib increased Smax to 89% with etoposide and to a lesser degree with the other cytotoxic drugs. U266 showed a similar spectrum of results with greatest Smax with 100μM melphalan at 9 hours (57%) enhanced to 78% with the addition of bortezomib. There was minimal response to cytarabine and fludarabine. Parallel flow cytometric analysis using Annexin V and PI showed similar results to those from the KOR assay confirming the assessment of apoptosis to be valid. Cell cycle analysis showed an increased sub-G1 peak in keeping with apoptosis at times of Smax assessed by the KOR assay. The Alamar Blue cytotoxicity assay showed a dose dependent decrease in cell proliferation in response to increasing drug dose again paralleling other apoptosis measurements implying an apoptotic effect due to drug action and correlate well with those from the KOR assay. Primary CLL samples following CD19 selection were cultured with and without IL4 and exposed to the KOR assay with cytotoxics and bortezomib. Culture with IL4 alone gave good growth characteristics and revealed the combination of etoposide and bortezomib to provide the best induction of apoptosis (Smax 82%) compared to etoposide (26%) or bortezomib (32%) alone. The KOR assay is a microtitre approach to the assessment in real time of apoptosis. This study suggests the combination of bortezomib and etoposide is effective for lymphoma. Such approaches can accelerate the development of effective clinical trials.

Description: The marrow stromal cells in multiple myeloma activate multiple signalling pathways via stimulation by the cytokines they secrete. This leads to upregulation of anti-apoptosis, drug resistance, cell cycle and metabolic pathways. Disruption of these signalling networks can lead to myeloma cell death and make them attractive targets for novel therapies. In addition, Bcl-2 family proteins, mcl-1 and bcl-xL are important for the survival of myeloma cells. The modified citrus pectin, GCS-100 has been used safely in Phase I studies for solid tumors, can induce cell death in lymphoma via blocking galectin-3 / Bcl-2 dimerisation and in myeloma cells by mechanisms not fully understood. GCS-100 as well as pro-apoptotic effects, also demonstrates anti-proliferative and anti-angiogenic properties, all of which may be useful in the therapy of myeloma. This study was aimed at elucidating the mechanism of action of this novel agent so as to apply it most effectively to myeloma therapy. Myeloma cell lines RPMI8226 and U266 treated with GCS-100 show induction of apoptosis in a dose and time dependent manner with a loss of cells in the G1 and S phase of cell cycle and a significant increase in G0 / sub-G1 cells. Treatment of RPMI8226 led to a marked reduction of mcl-1 and bcl-xL after 24 hours of treatment. There was no change observed in protein levels of bcl-2 or galectin-3. Activation of NFκB in myeloma cells is associated with proliferation and adhesion molecule upregulation. GCS-100 treatment led to a time dependent reduction in activated IκBα and p65NFκB. Furthermore pre-treatment of myeloma cells with GCS-100 prior to stimulation with TNFα, a known activator of IκBα, inhibited this activation. Similarly, treatment with GCS-100 led to a reduction in the amount of activated Akt (a regulator of cell cycle) and inhibited IGF-1 associated activation of Akt. The effect of GCS-100 on cell cycle regulatory proteins revealed downregulation of cyclin D1, p16INK4A and CDK6 at 24hrs, however, there was no change in expression of CDK4 and p15INK4B. The p21CIP1 was upregulated with a corresponding decrease in protein levels of cyclin E2 and CDK2 but there was no change in p27KIP1. GCS-100 clearly inhibits progression through G1 / S phase of cell cycle. Studies are currently ongoing for primary cells. In conclusion GCS-100 is a novel complex carbohydrate that is effective for the induction of myeloma cell death. It has multi faceted effects in reducing proliferation and induces apoptosis by down regulating crucial anti-apoptotic proteins, cell cycle regulators and signalling proteins and may also act by interfering with the myeloma cell microenvironment. Phase I studies in myeloma have been commenced.

Description: Abstract 3040 The Polyomavirus hominis 1 BK virus (BKV) is a non-encapsulated DNA virus, which infects up to 90% of the world's population, and may reactivate at times of severe immunosuppression, including post haematopoietic stem cell transplantation (HSCT). The significance of BK virus reactivation post Haematopoietic Stem Cell Transplant (HSCT) remains unclear. We collected retrospective data on viruria, viraemia, haemorrhagic cystitis (HC) and acute/chronic graft versus host disease (a/cGVHD) in patients at our institution over the period 2006 to 2011. We compared with a multivariate matched control group of 38, who did not reactivate BK. The groups were matched for age, sex, donor source and conditioning regimen including use of Alemtuzumab. Global BK reactivation incidence was 32% (38/118) of allogeneic HSCT during this period. 73% (28/38) of those who reactivated received volunteer unrelated donor (VUD) grafts, and 50% (18/38) received Alemtuzumab. Patients were sub-divided into those with high grade viraemia (HGV, VL 〉104 copies/ml), 47% (18/38) or low grade viraemia (LGV, VL

Description: Background: RI occurs in ≈ 20%-30% of newly diagnosed MM pts and is associated with poor prognosis (Knudsen et al. Eur J Haematol. 2000; Kyle et al. Mayo Clin Proc. 2003). Data from 2 pivotal trials (MM-002, MM-003) suggested comparable efficacy and tolerability of POM + LoDEX in pts with or without moderate RI (Siegel ASH 2012; Weisel ASCO 2013). However, these trials excluded pts with severe RI. MM-013 (NCT02045017) is a European multicenter, open-label phase 2 study designed to assess the efficacy, safety, and pharmacokinetics of POM + LoDEX in RRMM pts with moderate or severe RI, including those on dialysis. Methods: The trial is enrolling RRMM pts (N = 80) across 3 cohorts: cohort A (moderate RI, estimated glomerular filtration rate [eGFR] ≥ 30 to 〈 45 mL/min/1.73 m2, n = 33), cohort B (severe RI without dialysis, eGFR 〈 30 mL/min/1.73 m2, n = 33), and cohort C (severe RI requiring dialysis, n = 14). Pts must have MM-related RI and have received ≥ 1 prior Tx (including lenalidomide). POM 4 mg is administered on days 1-21 of a 28-day cycle and LoDEX 40 mg/day (20 mg for pts aged 〉 75 yrs) on days 1, 8, 15, and 22 until progressive disease (PD) or unacceptable toxicity. At the time of submission of this abstract, 17 pts terminated Tx; this abstract focuses on tolerability in these pts. Results: This trial is still recruiting; at the time of data cutoff for this abstract, 39 pts were enrolled. Data are included for 17 pts who discontinued Tx. Of all 39 pts, 12 were assigned to cohort A, 18 to cohort B, and 9 to cohort C. The median age of the total population was 72 yrs (range, 52-86 yrs), with 67.7% being male. The median number of prior lines of therapy was 4.0 (3.5 in cohort A, 5.0 in cohort B, and 3.0 in cohort C). This distribution was similar in the 17 pts who discontinued Tx so far (4, 7, and 6 in cohorts A, B, and C, respectively), with a median age of 72 yrs and 58.8% being male. Reasons for discontinuation of Tx were PD (7 pts), adverse events (AEs; 3 pts), death (5 pts: 2 pts due to PD, 2 pts due to infections, 1 pt due to hyperkalemia), and other reasons (2 pts: 1 pt aged 86 yrs with general health problems, 1 pt with increasing RI). Median Tx duration in these pts was 6.9 weeks in cohort A, 12.6 weeks in cohort B, and 12.9 weeks in cohort C. The dosage of POM was reduced to 3 mg in 3 pts (1 patient in each cohort), in all cases due to an AE (thrombocytopenia in 2 pts, pneumonia in 1 pt). However, no further Tx reductions occurred. The most frequent toxicity of any grade in the pts who discontinued was hematologic (82.4% [14 pts]), notably neutropenia in 58.8% (50% in cohort A, 42.9% in cohort B, 83.3% in cohort C), anemia in 52.9% (50% in cohort A, 28.6% in cohort B, 83.3% in cohort C), and thrombocytopenia in 52.9% (75% in cohort A, 14.3% in cohort B, 83.3% in cohort C). Grade 3/4 neutropenia occurred in 47.1%; grade 3/4 thrombocytopenia occurred in 35.3%. Notably, febrile neutropenia was reported in only 1 pt in cohort A. Granulocyte colony-stimulating factor was used in 52.9% of pts. Non-hematologic AEs were less frequent. Infections occurred in 7 pts (41.2%), all of which were pulmonary infections, with the exception of 1 case of nasopharyngitis. Asthenia (23.5%) and fatigue (23.5%) occurred predominantly in cohort C. No thromboembolic events or secondary primary malignancies have been reported to date. Conclusions: These data suggest that the combination of POM and LoDEX can be safely administered in pts with RI. A starting dose of POM 4 mg can be used throughout all stages of RI, and the side effects seen in this population have been previously reported with POM use (ie, mainly hematologic events and infections). Rates of neutropenia and thrombocytopenia are similar to reports in a non-RI population. Dose modifications should be considered in pts who develop neutropenia and thrombocytopenia; in pts showing signs of infections, dose interruptions may be considered. Disclosures Off Label Use: Pomalidomide in MM patients with renal insufficiency.. Dimopoulos:Janssen: Honoraria; Celgene: Honoraria; Janssen-Cilag: Honoraria; Genesis: Honoraria; Onyx: Honoraria; Novartis: Honoraria; Amgen: Honoraria. van de Donk:Janssen Pharmaceuticals: Research Funding; Amgen: Research Funding; Celgene: Research Funding. Gamberi:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Kueenburg:Celgene Corporation: Consultancy, Honoraria. Rosettani:Celgene Corporation: Employment. Collins:Celgene Corporation: Employment. Lersch:Celgene Corporation: Employment. Bacon:Celgene Corporation: Employment, Equity Ownership. Weisel:Noxxon: Consultancy; Celgene: Consultancy, Honoraria, Other: Travel Support, Research Funding; BMS: Consultancy, Honoraria, Other: Travel Support; Novartis: Other: Travel Support; Janssen Pharmaceuticals: Consultancy, Honoraria, Other: Travel Support, Research Funding; Onyx: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel Support. Sonneveld:Amgen: Honoraria, Research Funding; Karyopharm: Research Funding; SkylineDx: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding.

Description: Introduction. The outlook for myeloma patients who relapse after or become refractory to bortezomib and IMiDs is poor, with limited therapeutic options and a median survival (OS) of 9 months. In the phase 3 MM-003 study, pomalidomide plus low-dose dexamethasone resulted in a significant PFS (median 4 vs 1.9 months) and OS (median 13.1 vs 8.1 months) benefit, compared to high-dose dexamethasone. Information on real-world outcomes of pomalidomide therapy is limited. We carried out a retrospective analysis of patients receiving pomalidomide in the UK, to compare outcomes and tolerability with published clinical trial data, and focus on high risk subgroups. Methods. All patients treated with pomalidomide at 5 major UK centres between August 2013 and March 2016 were identified from chemotherapy records, and clinical data including toxicity and survival from patient records. Disease response and adverse FISH were defined as per IMWG. Survival was estimated using Kaplan-Meier, and correlations made using log-rank methods. Key subgroups: eGFR 4 months, PFS was 11 months and OS 23 months. In contrast, in patients whose DoR was 〈 4 months or who did not respond, OS was 9 months. Conclusions. Our real-world data on the characteristics and outcomes of patients receiving pomalidomide for relapsed/refractory myeloma in the UK reflect results of published clinical trials. The ORR of 52.9% in our cohort is higher than in MM-003 and MM-010, but PFS (5 months) and OS (13 months) were remarkably similar. Rates of haematological toxicity and infections are low, confirming the good tolerability of pomalidomide in this patient group. Depth and sustainability of response were important predictors of survival: achievement of PR was associated with improved PFS and OS, while patients who achieved SD still derived a survival benefit. Patients who maintained a response for at least 4 months had an estimated survival of nearly 2 years. No difference in response, survival or tolerability was seen in key subgroups, including those with moderate renal impairment, adverse cytogenetics and older age. Our findings confirm the efficacy of pomalidomide in these heavily pre-treated patients and add to the evidence for the benefit of pomalidomide in high risk patient groups. Table Patient characteristics and comparison with MM003 trial Table. Patient characteristics and comparison with MM003 trial Figure 1 PFS and OS for the edited group of 70 patients Figure 1. PFS and OS for the edited group of 70 patients Disclosures Maciocia: Autolus: Equity Ownership, Patents & Royalties: TRBC1 and 2 Targeting for the Diagnosis and Treatment of T-cell Malignancies. Ramasamy:Celgene: Honoraria, Research Funding. Jenner:Novartis: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other: Travel support; Amgen: Consultancy, Honoraria, Other: Travel support; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel support, Research Funding. Schey:Celgene, Takeda: Honoraria; Celgene, Johnson & Johnson: Speakers Bureau; Celgene: Consultancy. Yong:Autolus Ltd: Equity Ownership, Patents & Royalties: APRIL based chimeric antigen receptor; Janssen: Research Funding.

Description: Introduction: Autologous anti-BCMA CAR-T cells have been successfully used in clinical trials for the treatment of relapsed refractory Multiple Myeloma (rrMM), achieving high initial response rates (〉80%). However, in some patients these therapeutic responses were not sustained long-term and patients relapsed within 12-18 months1,2. Poor T cell fitness leading to early CAR-T cell exhaustion as well as BCMA negative tumour escape are thought to be factors contributing to treatment failure. In this study we describe for the first time the activity of an allogeneic anti-BCMA CAR-T cell product derived from young healthy donors (HD) against primary MM cells using patient bone marrow (BM) biopsies. In addition, we compare the performance of HD and MM patient-derived anti-BCMA CAR-T cells. Results: We have developed a clinically relevant model to test the efficacy of allogeneic anti-BCMA CAR-T cells against primary MM cells. This ex vivo platform uses bulk BM biopsies from MM patients to represent the heterogeneity seen in MM tumours in vivo, including their complex genomic background and unique immunosuppressive microenvironment. Newly diagnosed patients and rrMM patients with high risk genetics are included in the cohort. Using this model we show that allogeneic anti-BCMA CAR-T cells efficiently eliminate primary MM cells after 4 hours of co-culture, in a dose-dependent manner (n=9). These allogeneic anti-BCMA CAR-T cells specifically target BCMA-expressing primary MM cells (including samples with low BCMA levels and high risk genomic abnormalities, with specific anti-BCMA CAR-T cell killing of 13-73%), whilst not affecting non-tumour cells in the BM microenvironment. Moreover, we show that anti-BCMA CAR-T cells become significantly activated after exposure to CD138+ MM cells (〉50% CD25+ T cells versus