ALBERT

Description: Abstract 3472 Allo-SCT procedures are currently undergoing a profound evolution. The spectra of patients and diseases for which this approach is now considered have increased considerably over the past years. This is mainly due to the introduction in routine practice of the so-called nonmyeloablative or RIC regimens. While it is well established that fludarabine is the backbone drug to secure engraftment, there is a wide variability in the degree of myeloablation between the different RIC protocols, and the toxicity profile might vary significantly from one protocol to another. The combination of fludarabine and Busulfan (usually 8 mg/Kg total dose) with or without ATG, is among the most widely used RIC protocols worldwide. In an attempt to further decrease the toxicity of the transplant procedure, we hypothesized that further reduction (50%) of the Busulfan dose can allow improving transplant outcome for lymphoid neoplasms. With this background, this retrospective analysis was performed to assess whether a RIC regimen including fludarabine (120 mg/m2), low dose busulfan (4 mg/Kg total dose administered orally over a single day) and ATG (Thymoglobuline®, 2.5 mg/Kg/d for 2 days; FB1A protocol, n=44), is a valid alternative to the classical RIC regimen including fludarabine (90 mg/m2) and TBI (2 Gy.) (FTBI, n=27) prior to allo-SCT. The cohort included 37 males (52%) and 34 females (48%) treated consecutively in a single centre, with a median age at time of allo-SCT of 53 (range, 15–66) y. Diagnoses included 39 NHL (55%), 17 Hodgkin lymphomas (24%), 12 CLL (17%) and 3 myeloma (4%). PBSCs were used as stem cell source in 42 patients (91%), while 4 patients (9%) received classical bone marrow. A matched-related donor was used in 18 cases (39%) and an unrelated donor in 28 cases (61%). With a median follow-up of 43 (range, 3.7–85) months after allo-SCT, all patients, but one (from the FTBI group) engrafted. In the FB1A group, the acute grade 3–4 GVHD rate was 20.5% (n=9), the chronic GVHD rate was 32% (n=14), the relapse rate was 23% (n=10) and the TRM rate was 25% (n=11). In the FTBI group, the rate of grade 3–4 acute GVHD rate was 44% (n=12; P=0.03 in comparison to the FB1A group), the chronic GVHD rate was 52% (n=14; P=0.09), the relapse rate was 15% (n=4; P=NS) and the TRM rate was 37.0% (n=10; P=NS). At 2 years, overall survival was 66% (95%CI, 51–78%) in the FB1A group versus 55% (95%CI, 36–73%) in the FTBI group (P=NS). Disease-free survival (DFS) was also comparable between both groups (at 2 years, 59% in the FB1A group, vs. 48% in the FTBI group, P=NS). In a Cox multivariate analysis for OS or DFS, the type of RIC regimen was not significantly associated with outcome. In all, these results suggest that in patients with lymphoid malignancies, a RIC regimen including Fludarabine, ATG and low dose busulfan (4 mg/Kg total dose) is a valid alternative to the classical Fludarabine and low dose TBI-based RIC regimen with a favorable toxicity profile and efficient disease control. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2044 Poster Board II-21 Very high risk AML can be categorized into three groups: i) group I: AML in second relapse or refractory after 2 induction regimens and AML in relapse after stem cell transplantation in patients aged 60 years or secondary AML with unfavourable karyotype, iii) group III: AML in patients aged 〉70 years with either unfavourable karyotype or secondary AML. In this subgroup of very high risk AML, results of conventional chemotherapy are very poor and overall survival (OS) does not exceed a few weeks. Recently, an ever-growing body of evidence suggested that 5-AZA, a hypomethylating agent approved in high risk myelodysplastic syndromes, might also have some potent anti-leukemic activity. The aim of this pilot study was to assess the feasibility and efficacy of 5-AZA in a single centre cohort of 58 patients with very high risk relapsed or refractory AML. Between 2006 and 2009, 58 consecutive patients received 5-AZA subcutaneously (75 mg/m2/d) for 7 days every 4 weeks (one cycle= 7 days of treatment). Response after 3 cycles was assessed by marrow examination according to the IWG criteria. 5-AZA was continued after 3 cycles, if patients were at least in stable disease and/or until progression. In this series, the median age was 66 years (range, 28-80; 32 males and 26 females). AML features were: favourable and intermediate karyotype, 59% (n=34); unfavourable karyotype, 38% (n=22); secondary AML, 57% (n=33). Distribution according to AML risk groups were: group I, 26% (n=15); group II, 50% (n=29); group III, 24% (n=14). Of note, 16% of patients (n=9) from the entire cohort had received and failed a previous stem cell transplant. In all, a mean of 4.5 cycles (range, 1-14) of 5-AZA could be administered. 48% of patients (n=28) could achieve an overall response (OR) including CR, complete remission with incomplete blood recovery (CRi), partial remission (PR) and stable disease (SD). The “CR+CRi” rate was 19% (n=11). Interestingly, 13 patients (22%) were not able to receive the full first 3 cycles of 5-AZA, with 8 early deaths and 5 treatment discontinuation before evaluation. The main causes of early death and treatment discontinuation were severe infections and/or haemorrhage. In univariate analysis, age, AML risk group, karyotype, secondary AML feature, did not prove to be significantly associated with the rate of OR. With a median follow-up of 10,5 (range, 0,6-36) months, the Kaplan-Meier estimate of OS was 13% (95%CI, 3.4-30%) at 24 months. The median OS was 13.5 (95%CI, 11-not reached) months for patients achieving at least a stable disease after 3 cycles of 5-AZA versus 4 (95% CI, 3.29-5.44) months (p

Description: Abstract 3341 Poster Board III-229 Allo-SCT procedures are currently undergoing a profound evolution. The spectra of patients and diseases for which this approach is now considered have increased considerably over the past years. This is mainly due to the introduction in routine practice of the so-called nonmyeloablative or RIC regimens. While it is well established that fludarabine is the backbone drug to secure engraftment, there is a wide variability in the degree of myeloablation between the different RIC protocols, and the toxicity profile might vary significantly from one protocol to another. The combination of fludarabine and Busulfan (usually 8 mg/Kg total dose) with or without ATG, is among the most widely used RIC protocols worldwide. In an attempt to further decrease the toxicity of the transplant procedure, we hypothesized that further reduction (50%) of the Busulfan dose can allow improving transplant outcome. With this background, this pilot study tested the combination of Fludarabine (120 mg/m2), Busulfan (4 mg/Kg total dose administered orally over a single day) and ATG (Thymoglobuline®, 2.5 mg/Kg/d for 2 days) as a RIC regimen prior to allo-SCT in a single centre series of 46 patients. The cohort included 27 males (59%) and 19 females (41%) with a median age at time of allo-SCT of 57 (range, 12-64) y. Diagnoses included 21 cases of AML (46%), 12 NHL (26%), 6 Hodgkin diseases (13%), 3 ALL (6.5%), 2 myeloproliferative syndromes (4%), 1 MDS (2%) and 1 CLL (2%). Before allo-SCT, 23 patients (50%) underwent and failed previous stem cell transplantation (auto or allo). PBSCs were used as stem cell source in 42 patients (91%), while 4 patients (9%) received classical bone marrow. A matched-related donor was used in 18 cases (39%) and an unrelated donor in 28 cases (61%). With a median follow-up of 30.4 (range, 23.7-50.8) months, the median peripheral blood chimerism of donor origin at day 30 after allo-SCT was 99%. 20 patients (43.5%) experienced grade 2-4 acute GVHD, including 13 cases (28.3%) of grade 3-4 acute GVHD. Nine patients (19.6%) experienced some form of chronic GVHD (5 extensive and 4 limited). At time of last follow-up, 26 patients (56.5%) were still alive. Relapse or disease progression occurred in 13 patients at a median of 3.5 (range, 0.6-18) months after allo-SCT. Disease progression accounted for 7 deaths, while transplant-related causes (acute GVHD, n=5; MOF, n=3; infections, n=2; other causes, n=3) were observed in 13 cases, for a TRM rate of 28.3%. The KM estimates of disease-free survival (DFS) and overall survival (OS) at 3 years after allo-SCT were 46.9% and 56.5% respectively. Interestingly, OS was lower in the AML subgroup (n=21) as compared to the remaining 25 patients with other diagnoses (42.9% vs. 68%, p=0.09). We conclude that low dose Busulfan (4 mg/kg total dose) combined with fludarabine and ATG is a feasible RIC regimen that can allow engraftment after allo-SCT in heavily pre-treated patients. The toxicity profile of this regimen is acceptable. However, in the setting of AML, disease control may be a matter of concern, especially in the early period after allo-SCT, suggesting that this type of RIC should be reserved for patients with lymphoid or indolent malignancies. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 3655 Obinutuzumab (GA101) is a type II glycoengineered, humanized anti-CD20 monoclonal antibody that has increased antibody-dependent cellular cytotoxicity and direct cell death activity but lower complement-dependent cytotoxicity compared with type I anti-CD20 antibodies such as rituximab and ofatumumab. GA101 is in clinical development for the treatment of lymphoma and chronic lymphocytic leukemia. The Phase I/II study BO20999 has evaluated the efficacy and safety of GA101 monotherapy in patients with relapsed/refractory aggressive non-Hodgkin's lymphoma (aNHL). Here, we report updated Phase II results including progression-free survival (PFS) and best overall response (BOR). Patients (n = 40) were randomized to receive GA101 (D1, D8 and D22, then 3-weekly for total of 9 infusions) at either a high dose (1,600 mg on D1 and D8, then 800 mg thereafter; 1,600/800 mg cohort; n = 19), or a flat low dose of 400 mg (400/400 mg cohort; n = 21). Baseline patient characteristics were similar for both cohorts (Table 1). The median observation time for all patients was 9.5 months (0.3–26.1 months). BOR rates are given in Table 2, with 8/25 diffuse large B-cell lymphoma (DLBCL) patients (32%) and 4/15 mantle cell lymphoma (MCL) patients (27%) responding to GA101. Among the patients with rituximab-refractory disease, a response was observed in 1/13 patients (7.7%) and 4/12 patients (33.3%) treated in the 400/400 mg and 1,600/800 mg cohorts, respectively. Of these, 4 patients (1,600/800 mg cohort) had a response duration 〉 6 months, with 2 patients having an ongoing response (response duration: 9.8, 16.5+, 19.5 and 20.0+ months). Median PFS for patients with DLBCL (Figure 1) was 1.9 months (range: 0.3–15.7 months) for the 400/400 mg cohort and 2.7 months (range: 0.2–22.3) months) for the 1,600/800 mg cohort (hazard ratio: 0.70; 95% CI: 0.30–1.66). For the DLBCL subgroup, response duration was 3.1, 3.1+, 5.8, 16.5+ and 19.5 months for the 5 responders in the 1,600/800 mg cohort, compared with 6.3, 8.6 and 9.8 months for the 3 responders in the 400/400 mg cohort. Individual response data indicated that 2 MCL patients had an ongoing response for ≥ 20 months (20.0 and 20.4 months). GA101 was well tolerated in both cohorts. Infusion-related reactions (IRRs; all grades) were the most common adverse event (AE), occurring in 81% of patients in the 400/400 mg cohort and 68% of patients in the 1600/800 mg cohort. Grade 3/4 AEs occurring in 〉5% of patients across both cohorts included IRRs (10%), tumor lysis syndrome (10%), cardiac failure (not treatment-related; 10%), anemia (14%) and thrombocytopenia (14%) in the 400/400 mg cohort and IRRs (5%) and anemia (5%) in the 1,600/800 mg cohort.Table 1.Baseline patient characteristicsCharacteristic400/400 mg (n = 21)1,600/800 mg (n = 19)All (n = 40)Median age, years (range)70 (43–80)72 (22–85)71 (22–85)Histology, nDLBCL101525MCL11415Median number of prior treatments, n (range)4 (1–17)3 (1–6)3 (1–17)Previous rituximab, n211940Rituximab refractory*, n131225Prior stem cell transplant, n268DLBCL, diffuse large B-cell lymphoma; MCL, mantle cell lymphoma.*Rituximab refractory defined as patients who had a response of 〈 6 months or who failed to respond to a rituximab-containing regimen (rituximab monotherapy or in combination with chemotherapy) at any point during their treatment history.Table 2.Best overall response according to diagnosis and cohortDLBCLMCLResponse, n (%)400/400 mg (n = 10)1,600/800 mg (n = 15)400/400 mg (n = 11)1,600/800 mg (n = 4)Complete response (CR)0 (0.0)3 (20.0)2 (18.2)0 (0.0)CR unconfirmed1 (10.0)0 (0.0)0 (0.0)0 (0.0)Partial response2 (20.0)2 (13.3)0 (0.0)2 (50.0)Stable disease1 (10.0)1 (6.7)3 (27.3)0 (0.0)Progressive disease5 (50.0)9 (60.0)6 (54.5)2 (50.0)No response assessment1 (10.0)0 (0.0)0 (0.0)0 (0.0)DLBCL, diffuse large B-cell lymphoma; MCL, mantle cell lymphoma.Figure 1.Progression-free survival for patients with diffuse large B-cell lymphomaFigure 1. Progression-free survival for patients with diffuse large B-cell lymphoma In conclusion, GA101 shows encouraging single-agent efficacy in these heavily pretreated patients with relapsed/refractory aNHL (DLBCL or MCL). A Phase III trial of rituximab plus CHOP vs GA101 plus CHOP in first-line DLBCL has recently started. Disclosures: Morschhauser: Roche: Honoraria; Celgene: Consultancy, Honoraria. Cartron:Roche: Consultancy, Honoraria; GSK: Honoraria; LFB: Honoraria. Milpied:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Wenger:Roche: Employment. Wassner-Fritsch:Roche: Employment. Asikanius:Roche: Employment. Salles:Roche: Consultancy, Honoraria.

Description: Abstract 4565 Background: The outcome of patients with relapsed or refractory non-Hodgkin's lymphoma (NHL) is very poor despite aggressive treatments or novel therapeutic agents. Allogenic STC (allo-STC) remains the only curative approach with an interesting reduced treatment-related-mortality (TRM) commonly associated with reduced intensity conditioning regimens (RIC). Radio immunotherapy (RIT) as part of conditioning regimen for autologous stem cell transplantion (ASCT) as well as for allo-SCT has demonstrated its safety and many studies are now suggesting an improved outcome. This phase II study (ClinicalTrials.gov: NCT 00607854) evaluated the safety and efficacy of Yttrium-90 ((90)-Y)-ibritumomab tiuxetan in combination with a fludarabine-based RIC followed by allo-SCT in patients with relapsed or chemorefractory CD 20 positive non-Hodgkin's lymphoma. Patients and Method: Patients with relapsed or refractory CD 20 positive NHL where eligible for the study if they had a sensitive disease (at least partial response) to the last salvage regimen and a suitable donor: related (RD) or unrelated donor (MUD or with a C or DQ mismatch). Each patient received a single dose of ((90)-Y)-ibritumomab tiuxetan (0,4 mci/Kg on day -14) followed from day -6 by a combination of fludarabine (30 mg/m2 d -6 to d -2), busilvex ((3,2 mg/Kg d -5 and d -4) and antithymocyte globulin (2,5 mg/Kg d -1). GVH prophylaxis was based on cyclosporine (CsA) alone or in combination with methotrexate (Mtx) in case of mismatched unrelated donor. The trial was designed to enroll 30 evaluable pts and the study started on January 2008. At time of this writing, 27 pts have been included and we report the preliminary results of the first 14 consecutive pts. The primary objective (PO) of the study was to evaluate the day 100 TRM. Secondary objectives were response (CR, PR) and event-free survival at 1 year. RESULTS: Fourteen pts are evaluable for the PO. The median age was 55 years (35-60), and the sex ratio (M/F) 10/4. Prior disease was DLBCL (5), MCL (4), FL (5). Pts received a median number of 2 previous treatment regimens and all pts had undergone ASCT before. Median time between diagnosis and allo-SCT and between ASCT and allo-SCT were 39 mo (range 8 – 106) and 14, 5 mo (range 3–52) respectively. At time of transplant 10 pts were in CR and 4 in PR. There were 10 RD and 4 MUD transplants. All pts received peripheral blood stem cells transplantation and GVH prophylaxis with CsA alone. Two pts died from a-GVH at day 40 and 117 post-transplant respectively with a TRM at day 100 of 7%. Both were in CR. The median time to ANC engraftment (ANC 〉 500/mm3) was 17 days (range 12 – 22) and time to platelets engraftment (Plt 〉 20.000/mm3) was 11 days (range 0–16). Acute GVH occurred in 7 pts with only 3 pts with grade ≥ 2. At day 100 after transplantation, 8 out of the 10 (80%) evaluable pts achieved a complete T-cell donor chimerism. With a median follow-up of 10 month (range 6 – 26), 12 pts are alive and in CR. The estimated event-free survival at 1year is 86% (CI 78% - 94%). CONCLUSION: ((90)-Y)-ibritumomab tiuxetan is safe and well tolerated when used in combination with a fludarabine-based RIC regime. Preliminary data suggest that the TRM is not increased by adding RIT in this conditioning regimen. Disclosures: Bouabdallah: Bayer Healthcare: The Trial has been partially sponsored by Bayer Healthcare. Off Label Use: Zevalin is off-label use in conditioning regimen in France.

Description: Abstract 2334 Umbilical cord blood has been increasingly used as an alternative stem cell source for allogeneic hematopoietic stem cell transplantation (allo-HSCT). RIC regimens have been increasingly used prior to allo-HSCT with the aim to decrease transplant-related mortality (TRM) in patients ineligible for standard conditioning. Because of the slow kinetics of immune reconstitution after UCBT, previous studies showed that EBV reactivation and EBV induced lymphoprolipherative disease (LPD) may be of matter of concern, particularly in the reduced intensity setting. The aim of this analysis was to investigate the features of EBV reactivation in 33 patients who underwent RIC UCBT between January 2005 and June 2009. In our series, 30 patients (91%) received a double UCBT and 3 patients (9%) received a single UCBT, with a median of 4.0×107/Kg (range, 2.2–5.8) total nucleated cells. Donors and recipients were mismatched with one mismatch in 14 (43%) of cases and 2 mismatches in 19 (57%) of cases. A RIC including fludarabine, cyclophosphamide and low dose TBI was used in 29 cases (88%), while 8 patients (24%), who were not heavily pretreated before UCBT, received ATG. EBV reactivation was defined as any EBV PCR load above 1000 copies of EBV DNA /105 cells. EBV LPD was defined as biopsy or autopsy proven post-transplantation lymphoma, or reactivation along with computerized tomography nodal or soft-tissue abnormalities consistent with LPD. Patients with EBV viral load 〉1000 copies/105 cells on at least two consecutive occasions were treated with rituximab at a dose of 375 mg/m2 weekly until clearance of EBV viremia. Engraftment occurred in 25 patients (76%) at a median time of 12 days after UCBT (range, 8–60). Clinically significant grade II to IV acute GVHD occurred in 5 of cases (15%). The cumulative incidence of EBV reactivation at 6 months and three years after allo-HSCT was 13% and 17%. EBV reactivation was observed at a median of 132 (range 85–438) days after allo-HSCT, with 3 (60%) reactivations occurring during the first 6 months. In 28 patients (85%), the EBV load remained less than 1000 EBV copies/105 cells at all time, and none of these patients experienced any sign or symptom of LPD. The remaining 5 patients (15%) experienced at least one EBV reactivation episode. Among the 5 patients experiencing EBV reactivation, 2 patients received ATG as part of their RIC. Among these 5 patients, 1 patient experienced an EBV load superior to 1000/105 cells at a single time point after allo-HSCT. In this patient, there were no concomitant clinical symptoms and the EBV load normalized spontaneously. Only this patient had a normal T-lymphocyte count at the time of reactivation. Four patients who had EBV DNA levels exceeding 1000 copies/105 cells on 2 or more occasions were treated with a median of 3 (range, 1–8) rituximab infusions. Two patients responded to rituximab, but 2 patients developed LPD (cumulative incidence of 6 % at three years). Both of our patients were severely immunosupressed with high dose corticosteroid therapy at the time of the occurrence of EBV LPD. One of these 2 patients died before receiving any other anti-EBV therapy. In the other patient, LPD could be controlled after additional chemotherapy, radiotherapy and 2 infusions of EBV specific Cytotoxic T-cell Lines (CTLs). Three of five patients (60%) who experienced EBV reactivation had Human Herpes Virus 6 (HHV 6) detected in the same blood sample by PCR. With a median follow-up of 468 (range, 92–1277) days post allo-HSCT among surviving patients, 21 patients (64%) were still alive and the overall survival (OS) was 62% at 3 years. 5 patients died of disease progression and 7 patients died of transplant-related complications. One patient died of LPD. There was no statistically significant difference in terms of OS or TRM between those patients who experienced an EBV reactivation after UCBT and those who did not (OS: log rank test, p=0.33, TRM: Gray test, p= 0.82). Univariate analysis did not find any risk factors significantly different between subgroups with and without EBV reactivation. Overall, this study shows the rate of EBV reactivation after RIC UCBT to be comparable to the incidence expected with RIC mismatched unrelated bone marrow or peripheral blood HSCT. Despite small numbers, our observations support close EBV monitoring and the use of pre-emptive rituximab treatment since some cases may progress to LPD requiring additional interventions such as EBV-specific CTLs. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 3563 Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin's lymphoma (NHL) characterized by overexpression of cyclin D1 as a result of the t(11;14)(q13;q32). MCL is considered among the most aggressive NHLs entity with a median overall survival (OS) of approximately 6 years. It has been showed that intensive chemotherapy followed by autologous stem cell transplantation (ASCT) upfront provides a high complete remission rate. Furthermore, Dreyling et al. demonstrated that ASCT upfront is superior to conventional chemotherapy alone (Dreyling et al; Blood 2005). However, the question of the best conditioning regimen prior autologous stem cell reinjection is still pending. One major issue is the use of a total body irradiation (TBI). To answer this question, the outcome of all MCL patients (pts) (n=73) who underwent ASCT in our institution (Hematology Department of Nantes Medical University, Nantes; France) between 1990 to December 2008 were retrospectively analyzed in regard of the use or not of TBI as part of the conditioning regimen. In all cases, local pathologic experts confirmed the initial diagnosis. There were 50 males and median age at diagnosis was 54 years (34-69). All pts at diagnosis presented with stage III-IV. The most frequent extra-nodal involved sites were bone marrow (71%), digestive track (26%) and spleen (13%). MCL international prognostic index (MIPI) was lower or equal to intermediate risk in 51 cases and higher or equal to intermediate risk in 22 cases (data missing in 9 cases). Nineteen percent of the pts presented with a blastoid feature. Sixty-seven pts received ASCT upfront while 4 underwent ASCT at first relapse and 2 at second relapse. Prior ASCT, pts received (R)-CHOP/(R)-CHOP-like (n=36), (R)-DHAP (n=22) alone or (R)-DHAP plus (R)-CHOP (n=12) (data missing in 3 cases). Disease status at the time of transplantation were a partial response (PR) in 52 cases and a complete remission (CR) in 20 cases (data missing in 1 case). A TBI-based conditioning regimen was given to 44 pts (TBI group): TBI/melphalan in 5 cases or TBI/cyclophosphamide in 39 cases. In contrast, 28 pts received BEAM but one patient who received melphalan alone (non-TBI group). According to sex, age, Ann Arbor stage, extra-nodal involvement, MIPI and blastoid feature and the number of lines of chemotherapy prior ASCT, there was no statistical difference between the two groups (TBI vs non-TBI group). After ASCT, 63 pts reached CR (37 in the TBI group compared to 26 in the non-TBI group) and 5 PR (3 in the TBI group compared to 2 in the non-TBI group). For all pts, the median follow up (FU) calculated from time of diagnosis is 3,2 years (range: 0.75–13.3) and 2.5 years from time of ASCT (range: 0.22–12.9). After ASCT, the 1- and 3-year OS rates are 90 and 70% and the event free survival (EFS) rates are 84 and 58%, respectively. In bivariate analysis, the 1- and 3-year OS rates are similar in the non-TBI vs the TBI group: 89% vs 90% and 71% vs 70% (p= 0.82), respectively. The comparison between the 2 groups shows also no difference in term of 1- and 3-year EFS rates (85% vs 83% and 55% vs 58%; p= 0.89). In multivariate analysis only the MIPI and blastoid feature have an impact for both EFS and OS. CONCLUSION: The present analysis shows no advantage for the use of TBI/cyclophosphamide (or melphalan) as compared to BEAM for the conditioning regimen. The present analysis also confirms the interest of the MIPI to predict transplanted MCL patient outcomes. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 1259 Following allogeneic hematopoietic stem cell transplantation (allo-HSCT), EBV reactivation and EBV lymphoprolipherative disease (LPD) are well recognized complications. To date, few data has been reported regarding the features of EBV LPD following RIC allo-HSCT. The aim of this study was to define the incidence and risk factors of EBV reactivation in 175 consecutive adult patients undergoing RIC allo-HSCT between January 2005 and June 2009 in our institution and to assess its impact on clinical outcome. In this series, the median age of recipients was 56 (range 18–71) years. In all, 85 patients (49%) had a myeloid malignancy, whereas 86 (49%) patients were diagnosed with lymphoid malignancies. The remaining 4 patients (2%) were treated for severe aplastic anemia. In total, 165 patients (94%) received peripheral blood stem cells (PBSC) whereas 10 patients (6%) received a bone marrow (BM) graft. 84 grafts (48%) were obtained from HLA identical sibling donors, 80 (46%) from HLA matched unrelated donors and 11 (6%) from 1 Ag HLA mismatched unrelated donors. The conditioning regimen associated fludarabine, busulfan, and ATG in 107 cases (61%), while 37 patients (21%) received fludarabine and low-dose TBI. The remaining 31 patient (18%) received different chemotherapy-based RIC regimens. EBV reactivation was defined as any EBV PCR load above 1000 copies of EBV DNA /105 cells. EBV LPD was defined as biopsy or autopsy proven post-transplantation lymphoma, or reactivation along with computerized tomography nodal or soft tissue abnormalities consistent with LPD. Patients with EBV viral load 〉1000 copies/105 cells on at least two consecutive occasions were treated with rituximab at a dose of 375 mg/m2 weekly until clearance of viremia. In our series, the median time to neutrophil recovery (absolute neutrophil count 〉0.5×109/L) was 17 (range, 6–48) days. Clinically significant grade II to IV acute GVHD occurred in 61 of cases (35%) and severe grade III to IV acute GVHD occurred in 37 of cases (21%). The cumulative incidence of EBV reactivation at 6 months after allo-HSCT was 15% (95% CI, 10–21%). EBV reactivation was observed at a median of 58 (range 0–930) days after allo-HSCT, with 27 (79%) of reactivations occurring during the first 6 months. In 141 patients (81%), the EBV load remained less than 1000 EBV copies/105 cells at all time. The remaining 34 patients (19%) experienced at least one EBV reactivation episode. Among these 34 patients, 17 patients had an EBV load superior to 1000/105 cells at a single time point after allo-HSCT. In these 17 cases, there were no concomitant clinical symptoms and the EBV load normalized spontaneously. The 17 patients who had EBV DNA levels exceeding 1000 copies/105 cells on 2 or more occasions were pre-emptively treated with a median number of 3 (range, 1–4) rituximab infusions which resulted in complete clearance of EBV viremia in all, but one patient (97%). This patient was severely immunosupressed, receiving three different immunosupressive agents and experienced both EBV and adenovirus (ADV) infection. This patient had symptoms mainly related to ADV infection, and died of multiorgan failure. Most importantly, none of the patients from this series developed EBV induced LPD. With a median follow-up of 655 (range, 92–1542) days post allo-HSCT among surviving patients, 104 patients (59%) were still alive and the overall survival (OS) was 47% at 4 years. There was no statistically significant difference in terms of OS or transplant related mortality (TRM) between patients who experienced an EBV reactivation and patients who did not (OS: log rank test, p=0.62; TRM: Gray test, p=0.99). In univariate analysis for risk factors associated with EBV reactivation only the use of ATG as part of the RIC regimen prior to allo-HSCT was significantly different between subgroups with and without EBV reactivation (Fisher's exact test, p=0.006). In the multivariate analysis, the use of ATG remained the only independent risk factor associated with EBV reactivation (Fine and Gray test; RR=4.9; 95%CI, 1.1–21.0; p=0.03). In all, we conclude that patients undergoing RIC allo-HSCT using ATG as part of the preparative regimen are at higher risk for EBV reactivation. However, this did not translate into a significant impact on outcome since monitoring of EBV viral load with quantitative PCR and early systematic pre-emptive rituximab therapy allowed for significantly reducing the risk of EBV-related LPD. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 1848 Patients with a p53 deletion or mutation are resistant to the current therapeutic arsenal. There is an obvious need to find drugs able to kill p53 abnormal myeloma cells. RITA (reactivating tumor apoptosis) is a good candidate because it kills tumor cells expressing a wild type or a mutated p53. RITA binds to p53 and allows mutated p53 to recover a functional transcriptional conformation, activating thus target genes of the p53 pathway, including pro-apoptotic molecules such as Noxa and Puma. We have assessed RITA efficiency on 31 myeloma cell lines (HMCLs), 9 expressing a wt p53 and 22 expressing no p53 or an abnormal p53 (punctual mutation, exon deletion, intron insertion). The efficiency of RITA was compared with that of Nutlin3a, a MDM2 inhibitor activating the p53 pathway through a non-genotoxic stress. Nutlin3a kills all p53Wt HMCLs with a lethal dose 50 between 3,000 and 10,000nM (median value 8,000 nM) but none p53Abn HMCLs (p20,000) HMCLs without significant difference (p=0.24). CCND1+ cell lines, t(11;14)+, were more sensitive to RITA (median value 600; range 10-〉20,000, n=10) than t(11;14)- cell lines, (median value 6,500; range 40-〉20,000, n=21), (p=0.0235). Among the 9 p53Wt HMCLs, only 2 (22%) had a LD50 inferior to 1,000 nM (40nM and 90nM), all the others having a LD50 value superior to 2,000 nM (median value 3,000 nM; range 2,000-〉20,000 nM). Among the 22 p53Abn HMCLs, 5 (23%) had a LD50 inferior to 1,000 nM (median value 100nM; range 10–400nM), all the others having a LD50 value superior to 1,000 nM (median value 7,000 nM; range 1,000-〉20,000 nM). These results showed that the killing induced by RITA was not significantly related to p53 status. Indeed, silencing of p53 in two RITA sensitive p53Abn HMCLs did not prevent RITA killing, confirming the lack of p53 involvement. Moreover, in contrast to Nutlin3a, RITA did not commonly induce an increase of expression of the p53 targets (p21, Noxa and Puma) in the sensitive HMCLs. Killing by RITA was associated to the activation of caspases, the appearance of a subG1 peak and a cell cycle arrest in G2M phase, suggesting a mitotic catastrophe. Ongoing works aim at demonstrating the involvement of mitotic catastrophe in both p53Wt and p53Abn HMCLs and at identifying the molecular target(s) of RITA, especially in t(11;14)+ cell lines. While Nutlin3a appears efficient only for cells expressing a normal p53, RITA is efficient for 23% of myeloma cell lines irrespectively of p53 status. Because patients with del17p or expressing an abnormal p53 are resistant to current therapies, RITA could be of interest for them. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 3027 Patients (pts) with advanced/aggressive NHL who relapse after autologous stem cell transplantation (auto-sct) or who fail to respond to front-line chemotherapy have a very bad prognosis with a poor survival. We performed a prospective and multicentre study (Clinical Trials.gov, NCT 00607854) to evaluate the tolerability and the benefit of Zevalin added to a fludarabine-based RIC followed by allogenic stem cell transplantation (allo-sct) in pts with a poor prognosis lymphoma. Between January 2008 and October 2010, 30 pts under 65 years old with NHL in relapse after at least 2 previous regimen with or without auto-sct underwent an allo-sct with this preparative regimen. The underlying disease was DLBCL (10 pts), MCL (9 pts) and low grade lymphoma (FL=9 and MZL=2). Patients had to be in CR or PR after the last salvage regimen (Cheson criteria) and to have a HLA-compatible (10/10) match-related (MRD) or unrelated (MUD) donor or 9/10 mismatched UD. GVH prophylaxis was based on CsA alone or in combination with Methotrexate in case of mismatch. The primary objective of the study was TRM at day 100. All the pts are evaluable Twenty two were male (73%) and the median age was 57 (32–64). Twenty nine pts (97%) had prior auto-sct. Twenty pts were transplanted from a sibling donor, 8 from MUD and 2 pts had a C or DQ mismatch. At time of allo-sct, 18 pts were in CR and 12 pts in PR. Median time between diagnosis and allo-sct and between auto-sct and allo-sct was 36 mo and 18 mo respectively. Four pts died from a-GVH (n=2) at d 40 and 70, multi-organ failure (n=1) at d 117 and disease progression (n=1) at d 114 respectively. The TRM up to day 100 was 7% (n = 2). The median follow-up is 16 mo (9–40). All pts had a rapid and sustained engraftment. Twenty five pts are alive in CR. One pt died in CR (suicide) one year after transplant. The actuarial 3-year event-free and overall survival are 83% (± 6%). Estimated EFS at 2 years for the 3 different subgroups of diagnosis are 100% for FL and MZL, 89% (± 10%) for MCL and 70% (± 14%) for DLBCL. We conclude that Yttrium-90-ibritumomab tiuxetan (Zevalin) in combination with a fludarabine-based regimen is safe with a very low TRM rate. The results we report here are in pts with a very bad prognosis are very encouraging with a very high response rate and survival. Disclosures: Off Label Use: Zevalin not licensed in France in this indication. Zevalin has been kindly provided by BayerHealthcare company for the study.