DiPersio, John F.

Abstract Background In the primary analysis of the phase III COMFORT-I study, the JAK1/JAK2 inhibitor ruxolitinib (RUX) significantly improved splenomegaly, myelofibrosis (MF)-related symptoms, and quality of life (QoL) measures in patients (pts) with MF versus placebo (PBO). An additional analysis (median follow-up 51 weeks [wks)]) showed RUX was associated with a survival advantage versus PBO (Verstovsek et al. N Engl J Med2012). Longer term follow-up (median 102 wks) showed durable SV reductions and QoL improvements. At this time point, RUX continued to be associated with a survival advantage, despite all pts originally randomized to PBO having discontinued or crossed over to ruxolitinib shortly after the primary analysis (Verstovsek et al. ASH 2012. abstract 800). We report additional longer-term follow-up of pts from COMFORT-I. Methods In COMFORT-I, 309 pts were randomized (1:1) to RUX or PBO. RUX starting dose depended on baseline platelet count (100–200´109/L: 15 mg BID; >200´109/L: 20 mg BID). Doses could be titrated for lack of efficacy or excess toxicity as specified in the protocol. Pts receiving PBO could crossover to RUX after the primary analysis (ie, when all pts completed 24 wks and half the pts completed 36 wks of therapy) or at any time if they met protocol-specified criteria for worsening splenomegaly. The primary endpoint was the proportion of pts who achieved a ≥35% reduction in spleen volume (SV) at wk 24. Symptoms were assessed up to wk 24 using the modified MF Symptom Assessment Form v2.0. QoL continued to be evaluated beyond wk 24 using the EORTC QoL Questionnaire-Core 30 (QLQ-C30). Survival was estimated by Kaplan-Meier analysis according to original randomized treatment. To better understand the effect of crossover on the PBO arm, statistical modeling of survival was conducted using a generalized Gamma distribution. Results Median follow-up was 149 wks at the time of this updated analysis. Of 155 pts originally randomized to RUX, 77 remain on therapy. Of 154 pts originally randomized to PBO, 111 crossed over to RUX; the median time to crossover was 41.1 wks (range, 5.1–65.4). At wk 24, pts originally randomized to RUX had a mean SV reduction of −31.6%; this was durable for pts who continued on RUX, where the mean SV reduction at wk 144 was −34.1%. Fifty-nine percent (91/155) of pts originally randomized to RUX achieved a ≥35% SV reduction at any time during study; for these pts, the probability of maintaining this response for >132 weeks from the time of their initial response was 0.53. Pts originally randomized to RUX who continued on therapy experienced durable improvements in the Global Health Status/QoL and functional domains of the EORTC QLQ-C30. Overall survival favored RUX (HR=0.69; 95% CI: 0.46, 1.03; P= 0.067; Fig 1), with 42 and 54 deaths among pts originally randomized to RUX and PBO, respectively. Modeling of the hazard function of death over time to explore the effect of crossover to RUX in pts originally randomized to PBO showed a decrease in hazard for these pts, which corresponded to an increased proportion of pts crossing over to RUX. In pts originally randomized to RUX who continued on therapy, there was no substantial change in the rate, distribution, or severity of nonhematologic adverse events (AEs) with longer-term therapy; most nonhematologic AEs were grade 1 or 2. Mean and median hemoglobin and platelet count remained stable with longer-term therapy. Consistent with this, the incidence of new onset grade 3 or 4 anemia and thrombocytopenia observed after the first 6 months of RUX therapy decreased relative to that seen in the first 6 months of therapy (Fig 2). With approximately 1 year of additional follow up, 4 new cases of acute myeloid leukemia were reported: 2 pts originally randomized to PBO (376 and 666 days after crossover to RUX) and 2 pts originally randomized to RUX (848 and 1143 days after starting RUX). Conclusions After a median follow-up of 149 wks, the hazard ratio for overall survival favored pts originally randomized to RUX over those originally randomized to PBO, the majority of whom crossed over to RUX. The hazard of death for pts originally randomized to PBO decreased as pts crossed over to RUX. SV reductions and QoL improvements were sustained with longer-term therapy. The incidence of new onset grade 3 or 4 anemia and thrombocytopenia decreased with longer-term therapy. Collectively, these data reinforce the durable efficacy and longer-term safety of RUX in pts with MF. Disclosures: Verstovsek: Incyte Corporation: Research Funding. Mesa:Genentech: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding; Incyte Corporation: Research Funding; Lilly: Research Funding. Gotlib:Incyte Corporation: Travel support, Travel support Other; Incyte Corporation: Membership on an entity’s Board of Directors or advisory committees; Incyte Corporation: Research Funding. Levy:Incyte Corporation: Equity Ownership; Incyte Corporation: Employment. Gupta:Incyte Corporation: Consultancy; Novartis: Consultancy; Inctye Corporation: Research Funding; Novartis: Research Funding; Novartis: Speakers Bureau. Deininger:BMS, ARIAD, NOVARTIS: Consultancy; BMS, NOVARTIS, CELGENE, GILEAD: Research Funding; ARIAD, NOVARTIS: Advisory Boards, Advisory Boards Other. Miller:Novartis: Consultancy; Incyte Corporation: Consultancy; Novartis: Research Funding; Incyte Corporation: Research Funding; Novartis: Honoraria; Incyte Corporation: Honoraria. Talpaz:Ariad: Consultancy; Novartis: Consultancy; BMS: Consultancy; Pfizer: Consultancy; Ariad: Membership on an entity’s Board of Directors or advisory committees; Novartis: Membership on an entity’s Board of Directors or advisory committees; BMS: Membership on an entity’s Board of Directors or advisory committees; Pfizer: Membership on an entity’s Board of Directors or advisory committees. Winton:Incyte Corporation: Research Funding; Incyte Corporation: Membership on an entity’s Board of Directors or advisory committees. Arcasoy:Incyte Corporation: Research Funding. Lyons:Lilly: Research Funding; Amgen: Research Funding; Celgene: Research Funding; Incyte Corporation: Research Funding; Gilead: Consultancy; Seattle Genetics: Research Funding; Gilead: Research Funding; Ariad: Research Funding; GlaxoSmithKline: Research Funding; Novartis: Research Funding. Paquette:Incyte Corporation: Consultancy. Raza:Novartis: Speakers Bureau; Onconova Inc: Research Funding. Vaddi:Incyte Corporation: Employment; Incyte Corporation: Equity Ownership. Sun:Incyte: Employment; Incyte: Equity Ownership. Peng:Incyte Corporation: Employment; Incyte Corporation: Equity Ownership. Sandor:Incyte: Employment; Incyte: Equity Ownership. Kantarjian:Ariad: Research Funding; Novartis: Research Funding; BMS: Research Funding; Pfizer: Research Funding.

Abstract Background: Multiple myeloma (MM) is a hematologic cancer characterized by a diversity of genetic lesions-translocations, copy number alterations (CNAs), and single nucleotide variants (SNVs). The prognostic value of translocations and of CNAs has been well established. Determining the clinical significance of SNVs, which are recurrently mutated at much lower frequencies, and how this significance is impacted by translocations and CNAs requires additional, large-scale correlative studies. Such studies can be facilitated by cost-effective targeted sequencing approaches. Hence, we designed a single-platform targeted sequencing approach capable of detecting all three variant types. Methods: We designed oligonucleotide probes complementary to the coding regions of 467 genes and to the IgH and MYC loci, allowing a probe to closely match at most 5 regions within the genome. Genes were selected if they were expressed in an independent RNA-seq MM data set and harbored germline SNP-filtered variants that: (1) occurred with frequency >3%, (2) were clustered in hotspots, (3) occurred in recurrently mutated "cancer genes" (as annotated in COSMIC or MutSig), or (4) occurred in genes involved in DNA repair and/or B-cell biology. IgH and MYC tiling was unbiased (with respect to annotated features within the loci) and spanned from 50 kilobasepairs (kbps) upstream of both regions to 50 kbps downstream of IgH and 100 kbps downstream of MYC. Results: We performed targeted sequencing of 96 CD138-enriched samples derived from MM patients, as well as matched peripheral blood leukocyte normal controls. Sequencing depth (mean 107X) was commensurate with that of available exome sequencing data from these samples (mean 71X). Samples harbored a mean of 25 non-silent variants, including those in known MM-associated genes: NRAS (24%), KRAS (22%), FAM46C (17%), TP53 (10%), DIS3 (8%), and BRAF (3%). Variants detected by both platforms showed a strong correlation (r^2 = 0.8). The capture array detected activating, oncogenic variants in NRAS Q61K (n=3 patients) and KRAS G12C/D/R/V (n=5) that were not detected in exome data. Additionally, we found non-silent, capture-specific variants in MTOR (3%) and in two transcription-related genes that have been previously implicated in cancer: ZFHX4 (5%) and CHD3 (5%). To assess the potential role of deep subclonal variants and our ability to detect them, we performed additional sequencing (mean 565X) on six of the tumor/normal pairs. This revealed 14 manually-reviewed, non-silent variants that were not detected by the initial targeted sequencing. These had a mean variant allele frequency of 2.8% and included mutations in DNMT3A and FAM46C. At least one of these 14 variants occurred in five of the six re-sequenced samples. This highlights the importance of this additional depth, which will be used in future studies. Our approach successfully detected CNAs near expected frequencies, including hyperdiploidy (52%), del(13) (43%), and gain of 1q (35%). Similarly, it inferred IgH translocations at expected frequencies: t(4;14) (14%), t(6;14) (3%), t(11;14) (15%), and t(14;20) (1%). As expected, translocations occur predominantly within the IgH constant region, but also frequently 5' (i.e., telomeric) of the IGHM switch region, and occasionally within the V and D regions. We detected MYC -associated translocations, whose frequencies have been the subject of debate, at 10% (n=9 patients), with five involving IgH, three having both partners in or near MYC, and one having both types. Finally, our platform detected novel IgH translocations with partners near DERL3 (n=2), MYCN (n=1), and FLT3 (n=1). Additional evidence suggests that DERL3 and MYCN may be targets of IgH-induced overexpression: of 84 RNA-seq patient samples, six exhibited outlying expression of DERL3, including one sample in which we detected the translocation in corresponding DNA, and one exhibited outlying expression of MYCN. Conclusion: Our MM-specific targeted sequencing strategy is capable of detecting deeply subclonal SNVs, in addition to CNAs and IgH and MYC translocations. Though additional validation is required, particularly with respect to translocation detection, we anticipate that such technology will soon enable clinical testing on a single sequencing platform. Disclosures Vij: Celgene, Onyx, Takeda, Novartis, BMS, Sanofi, Janssen, Merck: Consultancy; Takeda, Onyx: Research Funding.

Abstract Background: Persistence of minimal residual disease (MRD) after induction, consolidation and salvage therapies is an independent poor prognostic marker in AML. The bone marrow (BM) microenvironment is a protective niche that promotes chemotherapy resistance of leukemia cells. This residual subset of chemotherapy-resistant cells present during remission eventually contributes to the leukemia relapse/persistence. Adhesion of AML cells to BM stroma is dependent on the CXCR4 receptor binding to its ligand CXCL12. High levels of CXCR4 expression correlate with poor survival in AML. It is postulated that blocking the CXCL12/CXCR4 axis will dislodge AML cells from the protective microenvironment and, when combined with chemotherapy, may improve the response to therapy. BL-8040 (BKT140) is a short peptide which inhibits the binding of CXCR4 to CXCL12, resulting in mobilization of leukemic blasts from the BM to the peripheral blood (PB). BL-8040 has strong affinity for the CXCR4 receptor with long receptor occupancy and as a single agent induces differentiation and apoptosis of leukemia cells in preclinical models. A clinical trial assessing the safety and efficacy of BL-8040 in combination with cytarabine (Ara-C) for the treatment of relapsed/refractory AML patients was recently completed (NCT01838395). Here we report results from correlative studies done on samples from patients who participated in this trial. Objective: To assess BL-8040 single agent anti leukemia effects in relapsed/refractory AML. Method: Patients received a once daily SC dose of BL-8040 monotherapy on days 1-2 followed by the same dose of BL-8040 plus Ara-C (1.5g/m2 for patients ≥60; 3g/m2 for patients <60) per day on days 3-7. Six dose levels of BL-8040 (0.5 - 2.0 mg/kg) were tested. PD parameters such as mobilization of leukemic blasts and induction of differentiation and apoptosis were assessed after monotherapy with BL-8040 using frequent PB sampling and BM aspirates at baseline and on day 3 prior to Ara-C administration. Results: 45 patients (including 3 receiving compassionate use BL-8040) with a median age of 61 yrs were treated. The majority of patients had poor risk disease with 24% secondary AML and 17% with prior allogeneic stem-cell transplantation. Most patients were heavily pretreated with 19% relapsing after a short first remission (CR1 ≤12 months), 17% had ≥2 relapses and 45% refractory to 1-2 inductions. The CR+CRi rate was 38% in subjects receiving BL-8040 dose ≥1.0 mg/kg (n=39). Ongoing follow-up (FU) of responding patients (expansion phase; N=19) shows median EFS of 9.3 months (range 4.3-12.8 months). At the time of this analysis 10/19 patients are alive with a FU range of 0.96 - 12.8 months. FACS analysis revealed that BL-8040 monotherapy triggered an average 4.3-fold increase of immature AML blasts (CD45+Low/CD34+/CD117+/HLA-DR+) in PB (i.e., mobilization). Response to treatment was associated with more robust mobilization of AML blasts following BL-8040 monotherapy (responders 9.5 vs non-responders 1.7 fold median). Preferential mobilization of AML blasts over normal cells (4.7 fold vs. 1.4 fold, respectively) was confirmed by FISH analysis in a subset of patients with informative cytogenetic abnormalities. Induction of granulocytic differentiation of immature leukemia progenitors (2.5 fold) in the BM following BL-8040 monotherapy was noted. Finally, induction of AML blasts apoptosis (40% increase) by BL-8040 alone was evident by FACS in day 3 (pre-araC) bone marrow biopsies. Conclusions: The data demonstrate that sustained blockade of the CXCR4-CXCL12 axis with BL-8040 is safe and well tolerated and when given in combination with Ara-C improves the response rate achieved historically with Ara-C alone. In addition, treatment with BL-8040 as a single agent rapidly and efficiently induces mobilization, differentiation and cell death of AML blasts. This selective effect on chemotherapy-resistant cells may be translated into reduction of residual disease arguing for incorporation into front-line trials and such studies are ongoing. Disclosures Foran: Millennium Pharmaceuticals, Inc.: Research Funding; medscape: Honoraria; karyopharm: Honoraria; pfizer: Honoraria; novartis: Honoraria; boehringer ingelheim: Research Funding; agios: Research Funding; Cellerant: Research Funding. DiPersio:Incyte Corporation: Research Funding. Peled:Biokine Therapeutics: Employment. Abraham:Biokine Therapeutics Ltd: Employment. Pereg:BioLineRx Ltd: Employment. Vainstein:BioLineRx Ltd.: Employment. Oberkovitz:BioLineRx Ltd.: Employment. Aharon:BioLineRx Ltd.: Employment. Cortes:ARIAD: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding.

Abstract Background: The bone marrow (BM) niche protects acute myeloid leukemia (AML) cells from chemotherapy. BM homing of AML cells is dependent on CXCR4 and its ligand CXCL12; high levels of CXCR4 expression correlate with poor survival in AML. It is postulated that blocking the CXCL12/CXCR4 axis with a potent CXCR4 antagonist will disrupt the interaction of the leukemic blasts with the BM and augment the anti-leukemic effect of chemotherapy. BL-8040 (BKT140) is a short synthetic peptide which inhibits the binding of CXCR4 to CXCL12, resulting in the mobilization of leukemic blasts from the bone marrow to the peripheral blood. BL-8040 also inhibits CXCR4/CXCL12 mediated pro-survival ERK/Akt signaling and alters balance of pro/anti-apoptotic Bcl-2 proteins. BL-8040 has strong affinity for the CXCR4 receptor with long receptor occupancy, and, in contrast to other CXCR4 inhibitors, as a single agent induces apoptosis of leukemia cells ex-vivo in clinical samples. A clinical trial assessing the safety and efficacy of BL-8040 in combination with cytarabine (Ara-C) for the treatment of adult relapsed/refractory AML patients is currently ongoing (NCT01838395). Objective: To assess the safety, efficacy and pharmacodynamics/pharmacokinetic parameters of BL-8040 in combination with Ara-C in first or second relapse and refractory AML patients. Method: The study includes a dose escalation phase (3+3 design) followed by an expansion phase. Each patient receives a once daily SC dose of BL-8040 monotherapy on days 1-2 followed by the same dose of BL-8040 plus Ara-C (1.5 g/m2 for patients ≥60; 3 g/m2 for patients <60) on days 3-7. Five dose levels of BL-8040 (0.5, 0.75, 1, 1.25 and 1.5 mg/kg) have been tested. Extensive pharmacodynamic parameters such as CXCR4 expression on the leukemic cells, receptor occupancy, mobilization of leukemic cells and induction of apoptosis are being assessed after monotherapy with BL-8040 using peripheral blood sampling (PB) and BM aspirates at baseline and on day 3 prior to Ara-C administration. Clinical response to treatment is evaluated by BM biopsy on day 30 (-/+ 2). Results: Twenty two patients (median age, 61 y; range, 43-74 y) with relapsed/refractory AML were treated during the escalation phase. BL-8040 was escalated up to 1.5 mg/kg (recommended phase 2 dose) without reaching the MTD. Combination of BL-8040 with Ara-C was safe and well tolerated at all doses tested. Only one SAE (Sweet Syndrome) was reported as possibly related to study drug. The primary treatment related AEs were transient injection site and systemic reactions. The composite complete remission including complete remission (CR) and complete remission with incomplete blood count recovery (CRi) rate was 38% in subjects receiving BL-8040 doses of 1 mg/kg and higher (n=16). Two days of BL-8040 monotherapy triggered an average 40.2-fold (range 1.0-350.9) mobilization of immature AML progenitors (CD45+Low/CD34+/CD117+/HLA-DR+) from the BM to the PB. Moreover, a significant apoptotic effect on the immature leukemia progenitors in the BM following 2 days of BL-8040 monotherapy was noted. Flow cytometric evidence of apoptosis by BL-8040 was corroborated by an increase in cleaved caspase 3 positive blasts in day 3 bone marrow biopsies. In addition, BL-8040 treatment resulted in a median decrease of 57.7% (range, -10.4% to -96.2%) in the number of BM Leukemia progenitor cells (CD45+Low/CD34+/CD117+/HLA-DR+ out of total CD45+/CD34+ normal/progenitor cells) compared with the baseline biopsy. This decrease was accompanied with a 3.1 fold increase in granulocytes in the day 3 BM biopsy supporting differentiation effect. Finally, long receptor occupancy (up to 24 hours post dosing) was confirmed by FACS analysis measuring surface CXCR4 staining. Pharmacokinetics analysis confirmed dose incremental BL-8040 exposure with a short plasma half-life. Conclusions: The current data demonstrate that sustained blockade of the CXCR4-CXCL12 axis with BL-8040 has potent anti leukemic activity and in combination with Ara-C may improve the response typically achieved in this advanced AML population. Mechanistically, BL-8040 was able to induce apoptosis of leukemic progenitor cells, overcoming the stroma protection, inducing mobilization and differentiation. Disclosures Rowe: BioLineRx Ltd.: Consultancy; Amgen: Consultancy; BioSight Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees. Uy:Novartis: Research Funding. Altman:Seattle Genetics: Consultancy; Novartis: Consultancy; Spectrum: Consultancy; Astellas: Consultancy; Ariad: Consultancy; BMS: Consultancy. Peled:Biokine Ltd.: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; BiolineRX: Consultancy, Research Funding. Pereg:BioLineRx: Employment. Vainstein:BioLineRx: Employment. Aharon:BioLineRx: Employment. Pemmaraju:Stemline: Research Funding; Incyte: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; LFB: Consultancy, Honoraria. Cortes:Teva: Research Funding; Pfizer: Consultancy, Research Funding; BMS: Consultancy, Research Funding; BerGenBio AS: Research Funding; Novartis: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy.

Abstract Abstract 3224 Poster Board III-161 Background While most centers use 2 × 106 CD34+ cells/kg as the minimal cell dose for autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT), infusion of higher CD34+ cell dose is associated with better outcomes in patients with multiple myeloma (MM) or non-Hodgkin's lymphoma (NHL). Recent evidence suggests a correlation between CD34+ cell yield on Day 1 of collection and total CD34+ cell yield as well as post-transplant outcomes. This analysis was designed to: 1) compare Day 1 collection between patients with NHL or MM mobilized with plerixafor plus G-CSF or placebo plus G-CSF; and 2) determine whether Day 1 CD34+ cell yields correlated with the total mobilization yield and number of apheresis days. Methods Data were obtained from two prospective, randomized, double-blind, placebo-controlled, phase 3 clinical trials that compared the safety and efficacy of plerixafor (0.24 mg/kg/day SQ) plus G-CSF (10 μg/kg/day) with placebo plus G-CSF for mobilization of HSC for auto-HSCT in patients with NHL (3101 Study) or MM (3102 Study). Pearson correlation coefficient was used to evaluate the association of day 1 CD34+ cell collection with total CD34+ cell yield and the number of days of apheresis. Results In the NHL trial, 150 patients were mobilized with plerixafor plus G-CSF and 148 patients underwent mobilization with placebo plus G-CSF. More than half the patients (55.3%) in the plerixafor group collected ≥2 × 106 CD34+ cells/kg on Day 1 of apheresis (Figure 1A). In contrast, 19.6% patients in the placebo group collected ≥ 2 × 106 CD34+ cells/kg on Day 1 of apheresis (p< 0.001). In the MM study, 148 patients were mobilized with plerixafor plus G-CSF and 154 patients were mobilized with placebo plus G-CSF. More than half the patients (52.7%) in the plerixafor group collected ≥6 × 106 CD34+ cells/kg on the first day of collection compared to only 16.9% patients in the placebo group (p<0.001; Figure 1B). There was a strong positive correlation between day 1 collection and the total CD34+ cell yield in patients with NHL (r= 0.86, p-value= <0.0001) or MM (r= 0.87, p-value= <0.0001) in both the plerixafor and placebo groups. For NHL patients, the median Day 1 collection was higher in the plerixafor group compared to the placebo group: 2.66 × 106 vs. 0.77 × 106 CD34+ cells/kg (p<0.001) and this translated into higher total CD34+ cell yields in the two groups respectively: 5.69 × 106 vs. 1.98 × 106 CD34+ cells/kg (p<0.001). Similarly, for MM patients, the median CD34+ cells/kg collected on Day 1 was higher in the plerixafor group compared to the placebo group: 7.01 × 106 vs. 2.29 × 106 CD34+ cells/kg (p<0.001) and this translated into better overall collection in the plerixafor vs. placebo groups: 10.96 × 106 vs. 6.18 × 106 CD34+ cells/kg (p<0.001). A negative correlation was observed between CD34+ cells collected on Day 1 and the number of days of apheresis performed in patients with NHL (r= -0.67, p-value=<0.0001) or MM (r= -0.50, p-value= <0.0001) in both the plerixafor and placebo groups. Consequently, better Day 1 collection in plerixafor-treated NHL or MM patients translated into significantly fewer apheresis days to achieve the target collection compared to placebo treated patients. Conclusions These data support previous reports demonstrating a strong correlation between day 1 CD34+ cell collection and total CD34+ cell yield and apheresis days. These data also demonstrate that addition of plerixafor to G-CSF allows significantly more patients to achieve the target cell collection within 1 day of apheresis compared to G-CSF alone. These findings support the observation that mobilization with plerixafor plus G-CSF reduces the number of apheresis days required to achieve the minimal or optimal cell dose to proceed to transplantation. Disclosures Bolwell: Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Nademanee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stadtmauer:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Maziarz:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Gandhi:Genzyme Corporation: Employment, Equity Ownership. DiPersio:Genzyme: Honoraria.

Abstract Abstract 3230 Poster Board III-167 Background Pre-apheresis peripheral blood (PB) CD34+ cells of < 20 cells/μl is a significant risk factor for poor hematopoietic stem cell (HSC) mobilization and collection in patients with multiple myeloma (MM) undergoing autologous HSC transplantation (auto-HSCT). PB CD34+ cells are routinely monitored to optimize the timing and success of HSC collection after mobilization with cytokines ± chemotherapy. This analysis was designed to compare the efficacy of plerixafor + G-CSF to placebo + G-CSF for mobilization in patients with MM who had pre-apheresis PB CD34+ cell counts < 20 cells/μl. We hypothesized that the addition of plerixafor to G-CSF would improve the stem cell yield in these patients with baseline CD34+ cells < 20 cells/μl. Methods Data were obtained from a prospective, randomized, double-blind, placebo-controlled, phase 3 clinical trial that compared the safety and efficacy of plerixafor (0.24 mg/kg/day SC) + G-CSF (10 μg/kg/day) to placebo + G-CSF for mobilization and auto-HSCT in patients with MM. PB CD34+ cell count was measured on Day 4, prior to first plerixafor/placebo dose, and on Day 5, 10-11 hours post study treatment. The proportion of patients achieving the minimal (≥2 × 106 CD34+ cells/kg) or optimal (≥6 × 106 CD34+ cells/kg) cell doses in 2 apheresis days, apheresis yields, and time to engraftment were compared between the plerixafor and placebo groups for PB CD34+ cell count <10 cells/μl (PB<10) and <20 cells/μl (PB<20). Results In the plerixafor group (n=148), 27 (18%) and 56 (38%) patients had Day 4 PB CD34+ cells/μl <10 and <20 which was as expected identical to the 30 (19%) and 60 (39%) patients in the placebo group, respectively (n=154). Patient characteristics were similar in both groups. Plerixafor + G-CSF resulted in a statistically significant increase in the absolute PB CD34+ cells/ml on Day 5 compared to placebo + G-CSF (p<0.001; Table 1). For patients with PB <10, the median fold increase in PB CD34+ cells in the plerixafor (n = 27) vs. placebo (n = 30) groups was 9.6 vs. 2 (p<0.001). Similarly, for patients with PB <20 the median fold increase in PB CD34+ cells in the plerixafor (n = 56) vs. placebo (n = 60) groups was 6.6 vs. 2 (p<0.001).The median CD34+ cell yield after 2 aphereses was significantly higher in the plerixafor vs. placebo group: 5.44 vs.1.68 × 106 cells/kg (p<0.001; PB<10) and 7.06 vs. 3.27 × 106 cells/kg (p<0.001; PB <20). The proportion of patients achieving ≥2 × 106 CD34+ cells/kg in 2 aphereses was significantly higher in the plerixafor group compared to the placebo group: 92.6% vs. 43.3 % in patients with PB<10 (p<0.001), and 94.6% vs. 66.7% in patients with PB<20 (p<0.001). Similarly, the proportion of patients achieving ≥6 × 106 CD34+ cells/kg in 2 apheresis days was significantly higher in the plerixafor vs. placebo group: 40.7% vs. 3.3 % in patients with PB<10 (p<0.001), and 55.4% vs. 15% in patients with PB<20 (p<0.001). The median time to platelet (19-20 days) and neutrophil (11 days) engraftment was similar in both groups. Conclusions These data demonstrate that in patients with MM who are predicted to fail mobilization based on low PB CD34+ cell count, the addition of plerixafor to G-CSF allows for 2-day collection of the minimal and optimal cell dose in a greater proportion of patients compared to G-CSF alone. Thus, addition of plerixafor to G-CSF can decrease the risk of poor mobilization in patients with MM who have PB CD34+ cell counts < 20 or even < 10 cells/μl. Disclosures Nademanee: Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stadtmauer:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Calandra:Genzyme Corporation: Consultancy, Equity Ownership. DiPersio:Genzyme: Honoraria.

Abstract Abstract 33 Background: Circulating levels of peripheral blood (PB) CD34+ cells/μl are a strong predictor of hematopoietic stem cell (HSC) yields in patients with non-Hodgkin's lymphoma (NHL) undergoing autologous HSC transplantation (auto-HSCT), and are routinely monitored to optimize the timing and success of HSC collection after cytokine ± chemotherapy mobilization. The threshold PB CD34+ cell count to initiate apheresis varies from 5-20 cells/μl, depending on the institution. This analysis compared the efficacy of plerixafor + G-CSF to placebo + G-CSF for HSC mobilization in NHL patients with pre-apheresis PB CD34+ cells/μl <10. Methods: Data were obtained from a randomized, double-blind, phase 3 clinical trial comparing the safety and efficacy of plerixafor (0.24 mg/kg/day SC) + G-CSF (10 μg/kg/day) to placebo + G-CSF for mobilization and auto-HSCT in NHL patients. PB CD34+ cell count was measured on Day 4, before the first plerixafor/placebo dose, and on Day 5, 10-11 hours post study drug treatment. The proportion of patients collecting ≥2 × 106 (minimal) or ≥5 × 106 (optimal) CD34+ cells/kg, apheresis yields, and time to engraftment were compared between the plerixafor and placebo groups for patients with PB CD34+ cells/μl <10. Results: 77/150 (51%) patients and 73/148 (49%) patients in the plerixafor and placebo groups, respectively, had PB CD34+ cells/μl <10 on Day 4, prior to the first dose of study drug. Patient characteristics were similar between both groups. As shown in Table 1, addition of plerixafor to G-CSF resulted in a statistically significant increase in the absolute PB CD34+ cells/μl on Day 5 compared to G-CSF alone (p<0.001). The median fold increase in PB CD34+ cells from Day 4 to Day 5 was significantly higher in plerixafor-treated patients vs. placebo-treated patients: 6.0-fold vs. 1.6-fold (p<0.001). In these hard to mobilize patients, the median CD34+ cell yield after 2 days was significantly higher with plerixafor + G-CSF compared to placebo + G-CSF: 2.92 vs.0.94 × 106 cells/kg (p<0.001), respectively. The median CD34+ cell yield after 4 days was also significantly higher in the plerixafor vs. placebo groups: 3.96 vs.1.25 × 106 cells/kg (p<0.001). Plerixafor + G-CSF allowed a significantly greater proportion of patients with PB CD34+ cells/μl <10 to collect the minimal cell dose in 4 apheresis days: 77.9% vs. 34.2 % patients in the plerixafor and placebo group, respectively collected ≥2 × 106 CD34+ cells/kg in 4 days (p<0.001). The success rate of collecting the ≥5 × 106 CD34+ cells/kg in 4 days was 40.3% with plerixafor + G-CSF compared to only 9.6% with placebo + G-CSF (p<0.001). The proportion of patients collecting the optimal or minimal cell dose in 2 days was also significantly higher in the plerixafor vs. placebo group (p<0.001). The median time to platelet (19-21 days) and neutrophil (10-11 days) engraftment was similar in both groups. Similar, statistically significant increases in PB CD34+ cell collections were obtained when the efficacy of plerixafor + G-CSF was compared to placebo + G-CSF, in patients with a Day 4 PB CD34 cells/μl<20 (data not shown). Conclusions: Plerixafor + G-CSF allowed collection of the minimal transplantable cell dose in 78% patients with PB CD34+ cells/μl <10. These data show that adding plerixafor to G-CSF substantially reduces the risk of mobilization failure in patients with NHL predicted to be poor mobilizers based on low PB CD34+ cell counts. Thus, mobilization with plerixafor + G-CSF in patients with PB CD34+ cells/μl <10 increases stem cell collection efficiency allowing patients to pursue auto-HSCT with more optimal cell doses. Disclosures: Maziarz: Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Bolwell:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Calandra:Genzyme Corporation: Consultancy, Equity Ownership. DiPersio:Genzyme Corporation: Honoraria.

Abstract AMD3100, Plerixafor (A)+G-CSF (G) have safely and effectively allowed aHSC mobilization in Phase I and II studies. This Phase III, multicenter, randomized, double-blind, placebo controlled study compared the safety and efficacy of A+G versus Placebo (P)+G to mobilize and transplant patients with NHL. Methods: Adult NHL patients requiring an aHSC transplant, in first or second CR or PR were eligible to participate. Patients received G (10μg/kg/day) subcutaneously (SQ) for 4 days. On the evening of Day 4, patients received either A (240μg/kg SQ) or P. Patients underwent apheresis on Day 5 after an AM dose of G and 10–11 hours after administration of study treatment. Patients continued to receive the evening dose of study treatment, followed by AM dose of G and apheresis for up to a total of 4 aphereses or until ≥5 x 106 CD34+cells/kg were collected. Only study cells were used for transplant. Patients who failed to mobilize ≥2 x 106 CD34+cells/kg could enter into a rescue arm of A+G, without unblinding of randomized treatment. The primary endpoint was the percentage of patients who achieved ≥5 x 106 CD34+cells/kg in 4 or less aphereses days. All patients will be followed for ≥12 months post-transplant. Results: 298 patients were enrolled and randomized. All patients have completed 100 days follow-up and are included in this intent-to-treat analysis. Baseline characteristics were similar between groups. The primary endpoint was met in 89/150 (59%) patients in the A+G group and 29/148 (20%) patients in the P+G group, p<0.0001. 130/150 (87%) patients in the A+G group and 70/148 (47%) patients in the P+G group collected ≥2 x 106 CD34+cells/kg in 4 or less aphereses days, p<0.0001. Kaplan-Meir Estimates of Time to Trget Collection of ≥ × 106 CD34 + cells/kg Kaplan-Meir Estimates of Time to Trget Collection of ≥ × 106 CD34 + cells/kg The figure shows that more patients in the A+G group reached target after 1 day of apheresis than patients in the P+G group after 4 days of apheresis. A+G rescue was successful in 33/52 rescue patients in the P+G group and 4/10 rescue patients in the A+G group. 135 patients (90%) in A+G group and 82 patients (55%) in P+G group underwent transplantation. Median time to engraftment was Day 10 for PMN and Day 20 for platelets in both groups. Through 100 days, grafts were durable in all but 2 A+G (133/135) patients and in all P+G (82) patients. A+G patients experienced a higher incidence of GI effects (mild to moderate) and injection site erythema than P+G patients. There were 2 drug related serious adverse events in the A+G group and 1 in the P+G group. Conclusions: In this study, the addition of AMD3100 to G-CSF is generally safe and well tolerated and is superior to G-CSF alone for aHSC mobilization in NHL patients. A+G patients were statistically significantly more likely to achieve target cell collection quicker and to achieve sufficient cells for successful transplant than P+G patients.

Abstract AMD3100, Plerixafor (A)+G-CSF (G) have effectively allowed aHSC mobilization in Phase I and II studies. This Phase III, multicenter, randomized, double-blind, placebo controlled study compares the safety and efficacy of A+G Vs. placebo (P)+G to mobilize and transplant patients with MM. Methods: Adult MM patients requiring an aHSC transplant, in first or second CR or PR were eligible to participate. Patients were declared for single or tandem transplant with the second transplant occurring within 6 months from the first. Patients received G (10μg/kg/day) subcutaneously (SQ) for 4 days; on the evening of Day 4 they received either A (240μg/kg SQ) or P. Patients underwent apheresis on Day 5 after an AM dose of G and 10–11 hours after administration of study treatment. Patients continued to receive the evening dose of study treatment followed by AM dose of G and apheresis for up to a total of 4 apheresis or until ≥6 x 106 CD34+ cells/kg were collected. Patients who failed to collect ≥2 x 106 CD34+ cells/kg were eligible for rescue therapy with A+G, without unblinding of randomized treatment. Only study cells were used for transplant. The primary endpoint was the percentage of patients who achieved ≥6 x 106 CD34+ cells/kg in 2 or less apheresis days. All patients will be followed for ≥12 months post-transplant. Results: 302 patients were enrolled and randomized into the study. All have completed 100 days follow-up and are included in this intent-to-treat analysis. Baseline characteristics were similar between groups. The primary endpoint was met in 106/128 (72%) patients in the A+G group and 53/154 (34%) patients in the P+G group, p<0.0001. The figure shows that 54% of A+G patients reached target after 1 day of apheresis but 56% P+G patients required up to 4 days of apheresis to reach target. 7 patients in the P+G group required rescue therapy and all collected ≥2 x 106 CD34+ cells/kg after A+G rescue. 142 patients (96%) in A+G group and 136 patients (88%) in the P+G group underwent transplant. Tandem transplants were performed in 32 and 28 patients in A+G and P+G groups, respectively. Median time to engraftment was Day 11 for PMN and Day 18 for platelets in both groups. Grafts were durable in all patients in both group at ≥100 days post-transplant. Patients in the A+G group experienced more GI effects and injection site erythema than patients in the P+G group. These adverse events were generally mild. There were no drug related serious adverse events in either group. Conclusions: In this study, the addition of AMD3100 to G-CSF is generally safe and well tolerated and is superior to G-CSF alone for aHSC mobilization in MM patients. A+G patients were statistically significantly more likely to achieve target earlier than P+G patients and had successful transplant. Figure Figure

Abstract Background: Chronic GVHD contributes to morbidity and mortality after allogeneic transplantation. Several phase 2 and 3 open label studies suggested that ATLG (formerly referred to as ATG-F) reduces cGVHD without impacting relapse or survival. This report describes the first prospective randomized double blind phase 3 trial to assess the effect of ATLG (Neovii) when added to tacrolimus / methotrexate prophylaxis on cGVHD free survival. Patients and Methods: This study was conducted at 27 sites in the United States and Australia. 260 patients were randomized (132 placebo, 128 ATLG). 6 patients who were randomized never received ATLG/placebo (4 placebo and 2 ATLG). Data presented include the 128 placebo and 126 ATLG patients who underwent treatment and transplant. Patients were ages 18-65 years with a diagnosis of acute myeloid (AML, 64%) or lymphoblastic (ALL, 21%) leukemia in first or subsequent complete remission or myelodysplastic syndrome (MDS, 15%) with less than 10% marrow blasts. Median age was 48 years (18-65) with 55% males. All patients received 8/8 HLA (A, B, C, DR) allele matched unrelated products (80% mobilized peripheral blood, 20% bone marrow). Myeloablative conditioning was with cyclophosphamide and total body irradiation (Cy/TBI, 27%), busulfan and cyclophosphamide (Bu/Cy, 33%), or busulfan and fludarabine (Bu/Flu, 40%). All patients received tacrolimus starting on Day -1 and standard mtx on days 1, 3, 6, and 11 for GVHD prophylaxis. Patients received ATLG or placebo on Days -3, -2, -1 at an ATLG dose of 20 mg/kg per day (60 mg/kg total). The primary endpoint of the study was moderate/severe chronic GVHD free survival. cGVHD was scored by the investigator and then confirmed or overturned by an independent adjudication committee. Secondary endpoints included engraftment, acute GVHD , moderate/severe cGVHD, non-relapse mortality, GVHD and relapse free survival (GRFS), progression free (PFS) and overall survival (OS). The impact of ATLG on immune reconstitution was assessed in 91 patients. Results: Treatment arms were balanced with respect to age, diagnosis, remission status, cytogenetics, graft source (PB or BM), CMV serostatus and conditioning regimen. Median follow up of survivors was 745 days (61, 1425). Regarding the primary endpoint, there was no difference in 2 year moderate/severe cGVHD free survival between ATLG and placebo (48 vs 44%, p = 0.57), nor was there a difference in GRFS (Table 1). Neutrophil engraftment at Day 30 was less in the ATLG arm (85% vs 95%, p=0.00001). Grade 2 or higher infusion reactions were higher in the ATLG arm (16% vs 2.3%, p=0.0001). Reactivation of CMV was similar (27% vs 31%, p=0.58). The Day 180 cumulative incidence of grades 2-4 acute GVHD was lower in the ATLG arm (23 vs 40%, p = 0.003) as was the 2-year cumulative incidence of moderate/severe cGVHD (12 vs 33%, p = 0.000006). However, both 2-year OS and PFS were lower in ATLG treated patients (58 v 76% and 47 vs 67%, respectively) due in part to a higher incidence of relapse (32 vs 19%, p=0.068). Multivariable models confirmed that ATLG was associated with inferior OS, HR 1.85 (1.1-2.9, p=.0075) and PFS, HR 1.63 (1.1-2.41, p=0.015). We then conducted an unplanned post-hoc analysis and discovered a striking influence of conditioning regimen on outcomes. There were no differences in OS or PFS between ATLG and placebo arms in patients receiving Bu/Cy or Bu/Flu but a dramatic difference in patients receiving Cy/TBI conditioning (OS, 88% vs 48% p =0.006 and PFS, 75 vs 29%, p=0.007 in placebo and ATLG arms, respectively). 91 patients (44 ATLG, 47 placebo) participated in the immune reconstitution study. ATLG treatment was associated with lower CD3, CD4, and CD8 counts at Days 30, 100, and 360, respectively. In turn lower CD3, CD4, and CD8 counts assessed as time dependent variables were all associated with inferior OS and PFS as well as higher NRM (data not shown). Conclusion: In this first ever prospective, randomized, double blind trial of ATLG added to tacrolimus /methotrexate in recipients of matched unrelated donor grafts after myeloablative conditioning, there was no significant difference in 2 year moderate/severe cGVHD free survival or GRFS. ATLG did significantly reduce grades 2-4 acute and moderate/severe chronic GVHD. However, overall survival was higher in the placebo arm, driven mainly by patients who received Cy/TBI conditioning. Further analyses are needed to understand the proper role for ATLG in HCT. Disclosures Soiffer: Juno: Membership on an entity's Board of Directors or advisory committees; Kiadis: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Porter:Genentech: Employment; Novartis: Patents & Royalties, Research Funding. Jagasia:Therakos: Consultancy. Szer:Alnylam: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ra Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ritz:Kiadis: Membership on an entity's Board of Directors or advisory committees. Glavin:Neovii Biotech: Employment. Chen:Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding.