Does Declining Mitochondrial NAD+ and Unscheduled Opening of Mitochondrial Transition Pore Promote Mammalian Aging?
Abstract Abstract SCI-3 The processes that lead to the susceptibility of post-mitotic tissues to diseases of aging are poorly understood, but mitochondria are considered a key regulator. SIRT3 is mitochondrial sirtuin, a member a family of NAD+-dependent deacetylases. We have previously shown that increased levels of NAD+ in mitochondria promote cell survival in a SIRT3-dependent manner, but how this protection is mediated is unknown. Here we show that mitochondrial NAD+ levels decline dramatically with age and that SIRT3 is a critical component and regulator of the mitochondrial transition pore (MTP). Mice lacking SIRT3 exhibit hyperacetylation of the MTP with age, and as a result, develop multiple defects in post-mitotic tissues as they age, including mitochondrial defects, susceptibility to cardiac failure, and learning and memory deficits. In a mouse model of Alzheimer's disease (AD), SIRT3 knockout mice show striking phenotypes including small size, kyphosis, and a markedly reduced lifespan. Similar to mice, human brain samples show that acetylation of the MTP increases with age and with AD. These findings indicate that declining NAD levels with age lead to memory deficits and accelerate age-related diseases in post-mitotic tissues due to a decline in SIRT3 activity and unscheduled opening of the MTP. Disclosures: Sinclair: GlaxoSmithKline: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.
Targeting CD38 Suppresses Induction and Function of T Regulatory Cells to Reverse Immunosuppression in Multiple Myeloma
Abstract We here study targeting CD38 to overcome immunosuppression by CD4+CD25highFoxp3+ T regulatory cells (Tregs) in multiple myeloma (MM). CD38 is differentially expressed on T cell subsets with higher levels on Tregs than CD4+CD25- conventional T cells (Tcons) from MM patients vs. normal donors. CD38 levels and the percentages of CD38high Tregs are further increased by low doses of Pomalidomide (Pom) or Lenalidomide (Len), which could confer further sensitivity to CD38 targeting. This result further support combined targeting CD38 with immunomodulatory drugs (IMiDs) to mitigate tumor-related immunosuppression. Importantly, anti-CD38 mAb SAR650984 (SAR) preferentially decreases Treg while increases Tcon frequencies, which is enhanced by Pom/Len. SAR induces apoptosis and inhibits proliferation of Tregs in Fc-independent manner. It further reduces Foxp3 and IL10 in Tregs, blocks migration of Tregs, and restores proliferation and function of Tcons. Importantly, SAR augments MM cell lysis by CD8+ T and natural killer cells, as seen by enhanced cell surface CD107a for degranulation and IFNγ production. Pom/Len further enhances these effector functions induced by SAR. Ex vivo cocultures of MM cells with peripheral blood mononuclear cells (PBMCs) or Tcons significantly induce Tregs (iTregs) which express even higher CD38 than natural occurring Tregs (nTregs) in a time-dependent manner. CD38 is increased at even higher extent on iTregs induced from Tcons than PBMCs when cocultured with MM cells, indicating the conversion of Tcons into iTregs. This is associated with elevated circulating CD38+ Tregs in MM patients vs. normal donors. Besides upregulated CD38, iTregs, when compared with Tcons alone, express higher levels of CD25, Foxp3, CD44, ICOS, and PD1, while low CD127. PDL1 is concurrently increased on MM cell membrane in these cocultures. Since anti-TGFb, -PD1, or -PDL1 mAb, when added alone, partially blocks iTreg induction from Tcon, cell-cell contact via PD1/PDL1 interaction and TGFb are attributed to induction of iTregs. SAR decreases MM cell- and bone marrow stromal cell-induced iTregs and production of inhibitory cytokines TGFb and IL10, further indicating that SAR targets immunosuppressive function in CD38high iTregs. Finally, CD38 levels correlate with differential inhibition by SAR on Tregs from MM vs normal donors. Taken together, these results show that targeting CD38 can preferentially block potent immunosuppressive Tregs while restore effector function to further against MM. Disclosures Anderson: Oncoprep: Equity Ownership; Acetylon: Equity Ownership; C4 Therapeutics: Equity Ownership; Oncoprep: Equity Ownership; Millennuim: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Acetylon: Equity Ownership; Millennuim: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Equity Ownership; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees.
Abstract Thrombin-activatable fibrinolysis inhibitor (TAFI) activation during thrombolysis may limit the effectiveness of tissue plasminogen activator (tPA) treatment. Our data suggest that an antithrombotic human thrombin analog, E-WE thrombin (ProCase), which is a selective protein C activator under development for treating acute thrombotic emergencies, also promotes tPA-induced fibrinolysis. We found that E-WE thrombin is a poor activator of TAFI compared to wild-type (WT) thrombin. In the presence of thrombomodulin (TM), WT thrombin induced TAFI activation within 5 min. In contrast, detectable amounts of activated TAFI were not generated by E-WE thrombin in the presence of TM until 60 min. Further studies using a quantitative TAFI activity assay showed that E-WE thrombin inhibited thrombin/thrombomodulin-mediated TAFI activation in a concentration-dependent manner. The ability of E-WE to enhance tPA induced clot lysis was also evaluated in vitro. When both E-WE thrombin and tPA were incorporated within plasma clots, lysis was accelerated by up to 74% compared with the addition of tPA alone. We then tested the ability of E-WE thrombin to interrupt arterial-type experimental thrombus formation in baboons when combined with a standard interventional dose of tPA (1mg/kg). Thrombosis was initiated in the baboons by interposing 4mm internal diameter collagen coated ePTFE vascular grafts within an arterio/venous shunt. Thrombus formation was monitored by real-time gamma camera imaging of autologous 111In-labelled platelet accumulation in the grafts for a total of 90 min. Fibrin deposition was determined by direct endpoint measurement of incorporated 125I-labelled fibrinogen. Antithrombotic interventions were injected intravenously at 30 min after graft deployment into the shunt. Treatment with tPA (1mg/kg, iv) reduced fibrin deposition by 57%, but did not reduce graft-associated platelet accumulation compared with controls (n=8 and 9, respectively). E-WE thrombin, at doses ranging from 2-10µg/kg (n=8), interrupted thrombus growth within 10 min of treatment, and reduced platelet and fibrin deposition by 53-70% and 45-58% at 90 min, respectively, compared with controls. When E-WE thrombin (2µg/kg) was co-administered with tPA (1mg/kg), a profound 91% reduction in thrombus fibrin content was observed (n=1), with platelet deposition being reduced by 34%. Bleeding time and volume were also assessed during the studies, with E-WE treated animals showing no increased bleeding compared with controls. However, tPA caused ecchymoses that were not observed with E-WE thrombin treatment. The combination therapy showed no overt anti-hemostatic effects beyond tPA administration alone. These data suggest that E-WE thrombin can inhibit TAFI activation, and co-administration of E-WE thrombin with tPA may improve the efficacy of thrombolysis without additional hemostasis impairment. Disclosures Tucker: Aronora, Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Markway:Aronora, Inc: Employment, Equity Ownership. Wallisch:Aronora, Inc: Employment, Equity Ownership. Verbout:Aronora, Inc: Employment, Equity Ownership. Lorentz:Aronora, Inc: Employment, Equity Ownership. Carris:Aronora, Inc: Employment, Equity Ownership. Gruber:Aronora, Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.
Abstract A proliferation inducing ligand (APRIL) is a natural ligand with higher affinity than BAFF for both B cell maturation antigen (BCMA) and transmembrane activator and CAML interactor (TACI), which are overexpressed on multiple myeloma (MM) cells. APRIL, which is abundantly secreted by myeloma-supporting osteoclasts and macrophages, promotes MM cell progression in vivo and further induces regulatory T cells (Treg) via TACI, but not BCMA, to promote an immunosuppressive MM bone marrow (BM) microenvironment (Blood 2017;130:3066). In preclinical studies, an antagonistic APRIL monoclonal antibody (mAb) significantly inhibited human MM cell growth in SCID-hu mice and abrogated APRIL-induced immunosuppression mediated by Tregs. Here we characterized the ability of BION-1301, a neutralizing APRIL mAb, currently under clinical development in MM (NCT03340883) to overcome protection conferred by APRIL against MM cell lysis induced by the anti-BCMA J6M0 mAb (Blood 2017 130:499). Our studies show that APRIL protects against MM cell lysis induced by J6M0 in the presence of FcR-expressing effector cells (PBMC, monocytes or NK), an effect which is blocked by neutralizing anti-APRIL mAb. APRIL also downregulates J6M0-induced cell membrane CD107a expression on NK cells co-cultured with BCMA-expressing MM cells, which is similarly abrogated by anti-APRIL mAb. Importantly, anti-APRIL mAb also significantly decreases protection conferred by osteoclasts against MM cell lysis induced by J6M0. These data indicate that blocking APRIL with anti-APRIL mAb may enhance BCMA mAb targeted (J6M0)-induced MM cell lysis. Next, using anti-human IgG1 to detect J6M0 binding to MM cell surface BCMA, we found that APRIL in a dose-dependent manner directly competes with J6M0 for binding to BCMA, which was confirmed by ELISA. In addition, APRIL effectively inhibits J6M0 binding to BCMA at 4°C, which argues against APRIL-induced BCMA receptor shedding and/or internalization. In contrast, BAFF affects J6M0 binding to BCMA only at higher concentrations (>1 µg/mL), consistent with > 2-log higher affinity of APRIL vs. BAFF for BCMA. We further assessed APRIL, BAFF, BCMA, and TACI levels in the serum of patients with MM at various stages of disease. Specifically, we used ELISA to measure free APRIL and the ELLA automated immunoassay platform to determine the levels of soluble BAFF, soluble BCMA, and soluble TACI in serum samples from patients with MM (n=193) as well as serum samples from healthy volunteers (HV, n=100). Patient samples included monoclonal gammopathy of undetermined significance (MGUS, n=12), smoldering MM (SMM, n=20), newly diagnosed MM (ND, n=39), post induction pre-autologous stem cell transplant (ASCT, n=55), post-ASCT (n=6), and relapsed refractory MM (RR, n=61). We found that free APRIL levels are significantly increased in serum samples from patients with MM at all stages of disease, when change from baseline levels were compared to those from HVs (post-ASCT: p=0.0003; other groups (MGUS, SMM, ND, pre-ASCT, and RR): p<0.0001). In contrast, average soluble BAFF levels gradually increase with progression of disease from 818.47 pg/mL at MGUS to 1685.50 pg/mL at RR MM. Both soluble BCMA and soluble TACI concentrations are highest in serum from a subset of patients with ND (593550 and 5999.63 pg/mL, respectively) and RR (1088897 and 5050.97 pg/mL, respectively) MM. A detailed analysis of clinical characteristics, treatment and response, as well as measurement of additional cytokines and chemokines is ongoing and will be reported when applicable. Our studies therefore indicate that therapies directed at the APRIL/BCMA and APRIL/TACI axes may simultaneously target MM cells and counteract APRIL-induced immunosuppression, and that combination strategies targeting APRIL with BCMA directed therapy may augment anti-MM activity. Moreover, elevated free APRIL serum levels in MGUS and all stages of MM suggest a role for APRIL in mediating immunosuppression during the development and in the pathogenesis of MM. Disclosures Dulos: Aduro Biotech: Employment. Guelen:Aduro Biotech Europe: Employment. van Zandvoort:Aduro Biotech Europe: Employment. van de Wiel:Aduro Biotech Europe: Employment. van de Crommert:Aduro Biotech Europe: Employment. Lejeune:Aduro Biotech Europe: Employment. Namini:Aduro Biotech: Employment. Eenennaam:Aduro Biotech Europe: Employment, Equity Ownership. van Elsas:Aduro Biotech Europe: Employment. Richardson:Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees. Munshi:OncoPep: Other: Board of director. Anderson:Takeda Millennium: Consultancy; C4 Therapeutics: Equity Ownership; Bristol Myers Squibb: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Oncopep: Equity Ownership.
Natural killer (NK) cells mediate anti-lymphoma activity by spontaneous cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC) when triggered by rituximab, an anti-CD20 monoclonal antibody (mAb) used to treat patients with B cell lymphomas. The balance of inhibitory and activating signals determines the magnitude of NK cell's efficacy by spontaneous cytoxicity. Using a killer cell immunoglobulin-like receptor (KIR) transgenic murine model, we show that blockade of the interface of inhibitory KIRs with MHC class I antigens on lymphoma by anti-KIR antibodies prevents a tolerogenic interaction and augments NK cell spontaneous cytotoxicity. In combination with anti-CD20 mAbs, anti-KIR treatment induces enhanced NK cell-mediated, rituximab-dependent cytotoxicity against lymphoma in vitro and in vivo in syngeneic and KIR transgenic murine lymphoma models. Specifically targeting murine NK cells in vitro, anti-Ly49C/I F(ab')2 increased anti-CD20 mAb-mediated NK cell degranulation as measured by CD107a mobilization and interferon-γ release, as well as increased cytotoxicity as assessed by chromium release. In the syngeneic EL4-huCD20 lymphoma model, anti-Ly49C/I F(ab')2 enhanced the anti-lymphoma activity of anti-CD20 mAb in vivo (Fig 1A-1B) and was NK cell-dependent with efficacy abrogated by NK cell depletion with anti-Asialo-GM1. To validate these observations and the potential efficacy of a fully human anti-KIR mAb (IPH2101, lirilumab), we demonstrated, in vitro, dose-dependent KIR2DL3 saturation and tumor lysis following blockade of KIR2DL3/HLA-C with lirilumab. In the transgenic KIR murine model, lirilumab therapy improved survival in an NK cell-dependent manner in both a prophylactic and therapeutic HLA+ (221 HLA-Cw3) lymphoma model. In combination, lirilumab therapy synergistically enhanced rituximab's anti-lymphoma efficacy in vivo in an NK cell-dependent manner (Fig 2A-C). These results support a therapeutic strategy of combination, rituximab and KIR blockade through lirilumab, illustrating the potential efficacy of combining a tumor targeting therapy with an NK cell agonist thus stimulating the post-rituximab anti-lymphoma immune response. Disclosures: Thielens: Innate Pharma: Employment, Equity Ownership. Sola:Innate Pharma: Employment, Equity Ownership. Chanuc:Innate Pharma: Employment, Equity Ownership. Fuseri:Innate Pharma: Employment. Bonnafous:Innate Pharma: Employment, Equity Ownership. Vivier:Innate Pharma: Membership on an entity’s Board of Directors or advisory committees. Romagne:Innate Pharma: Employment, Equity Ownership, Membership on an entity’s Board of Directors or advisory committees. Andre:Innate-Pharma: Employment, Equity Ownership. Blery:Innate Pharma: Employment, Equity Ownership.
Abstract Acute myeloid leukemia (AML) is a devastating disease; however 20%-30% of patients will achieve long term remission. The long-term follow up of AML patients who received bone marrow transplantation (BMT) is well documented. It remains unclear though whether AML long-term survivors who did not undergo BMT (LTSnoBMT) return to normal health. In order to answer this question a large cohort of AML patients and well matched controls are needed. For the present study, the electronic health records (EHR) of 4.2 million individuals covering over 16 years of follow up were studied. Morbidity and mortality of LTSnoBMT were compared to a large number of age-matched controls. We identified 177 LTS who were in remission two years after AML diagnosis of which 61 were LTSnoBMT. The mortality of LTSnoBMT 10 years after diagnosis was 20%-50% higher in comparison to controls in an age dependent manner with higher mortality among the elderly LTS (Figure 1A, B). While several lab results were different between the LTSnoBMT and controls, most strikingly the red cell distribution width (RDW) of the LTSnoBMT was much higher among elderly LTSnoBMT (Figure 1C). High RDW has been previously reported to correlate with mortality. Recent studies found that high RDW predict AML and even greater correlation of high RDW with mortality among individuals carrying age related clonal hematopoiesis (ARCH) mutations was detected. To investigate the genetic profile of LTSnoBMT, a deep-targeted sequencing method (covering 32 recurrently mutated genes in AML) was used. Remission samples (at least 2 years from diagnosis) from 28 LTSnoBMT were analyzed. In most cases mutations which were detected at diagnosis, were not present in the remission samples. ARCH defining events (most of them new) were found in 64% of the LTSnoBMT. To evaluate whether this high prevalence of ARCH related mutations among LTSnoBMT patients is related to chemotherapy exposure, we also studied 30 individuals with lymphoid malignancies who received chemotherapy and were in remission. The prevalence of ARCH related mutations in the controls was significantly lower (37%) than in the LTSnoBMT (Figure 2A) (p=0.035). Higher prevalence of IDH1/2 mutations was found among LTSnoBMT (Figure 2C) (p=0.017). Furthermore, 70% of the mutations detected in the LTSnoBMT were recurrent (i.e. has more than 5 occurrences in COSMIC data base) compared to 31% in the controls (Figure 2B) (p=0.001). Altogether, AML is a complex disease where even after the sustainable eradication of the malignant clone, the hematopoietic system/microenvironment does not normalize. The reported correlation between ARCH and mortality suggests that the high prevalence of ARCH related mutations among LTS might contribute to the high mortality that we observed. Our findings have both biological and clinical implications. Future studies should determine the reasons why AML - LTS have such high prevalence of ARCH with specific mutations and increased mortality. Furthermore, closer clinical follow up including mutation analysis should be considered for these individuals. Disclosures Cilloni: Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Metzeler:Celgene: Consultancy, Research Funding; Novartis: Consultancy. Ofran:Novartis: Other: Served on a Novartis advisory board.
Abstract Aberrant erythroid differentiation can give rise to anemias and leukemias. Regulated transcription elongation at erythroid loci is vital for specific differentiation steps during blood development. Transcriptional intermediary factor 1 gamma (TIF1γ), whose gene is mutated in the blood deficient zebrafish moonshine mutant, recruits positive elongation factors to erythroid genes, thus relieving paused Pol II. To elucidate the TIF1γ-mediated mechanisms in erythroid differentiation, we have performed a chemical suppressor screen in the bloodless moonshine mutant. Progeny of heterozygous moonshine mutants were treated at 50% epiboly with 4,000 individual chemical compounds with mostly known functional targets. A rescue in blood formation was assessed for by in situ hybridization for β-globin e3 expression in primitive erythrocytes at 22 hours post fertilization (hpf). Using this strategy we have identified peroxisome proliferator-activated receptor alpha (PPARα) agonists, most importantly, Clofibrate to rescue βe3 globin expression at 22 hpf in 70 - 90% of moonshine embryos in a dose-dependent manner. To address whether the rescue by Clofibrate is due to its activation of the PPARα receptor, we either knocked down PPARα using morpholinos or treated zebrafish embryos with the PPARα antagonist GW6471. In both cases we observed a significant reduction in Clofibrate-mediated rescue. To identify the PPARα-interacting proteome in an erythroid progenitor context, human K562 erythroleukemia cells expressing doxycyclin-inducible Flag-PPARα were generated. In these cells, PPARα target genes such as ANGPTL4 and PDK4 are activated starting four hours after doxycyclin addition and this activation is significantly reduced in the presence of the PPARα antagonist GW6471. Large-scale Flag-immunoprecipitation followed by mass spectrometric analysis identified the heterodimerization partner of PPARα, RXR, co-activators (NCOA1, NCOA6) and co-repressors (NCOR2), furthermore 24 subunits of the mediator complex, six subunits of the cohesin (loading) complex, seven RNA polymerase (Pol) II subunits as well as the Cyclin T1 subunit of P-TEFb and both subunits (SUPT5H, SUPT4H1) of DSIF, two proteins with a positive role in transcription elongation. In co-immunoprecipitation experiments using K562 cells, doxycyclin-induced PPARα activation leads to an enhanced interaction of Pol II with both, the Cyclin T1 and CDK9 subunits of P-TEFb. Morpholino-mediated knockdown of the mediator complex subunit med1 prevents Clofibrate-mediated rescue of βe3 globin expression in moonshine embryos. Together these data suggest that PPARα functionally interacts with the mediator complex in hematopoietic progenitors, leading to increased recruitment of the transcription elongation factors to lineage-specific genes. Our studies provide a basic understanding of the processes that regulate transcription elongation in the differentiation of hematopoietic cells, and could lead to novel therapeutic strategies for the treatment of blood diseases and leukemia. Disclosures Zon: FATE Therapeutics, Inc.: Consultancy, Equity Ownership, Founder Other, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Scholar Rock: Consultancy, Equity Ownership, Founder, Founder Other, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.
Background Granulocyte colony-stimulating factor (G-CSF) is the standard of care for mobilization of hematopoietic stem cells (HSCs). G-CSF requires 4-7 days of injections and often multiple aphereses to acquire sufficient CD34+ cells for transplant. The number of CD34+ HSCs mobilized can be variable and patients who fail to mobilize enough CD34+ cells are treated with the combination of G-CSF plus plerixafor. G-CSF use is associated with bone pain, nausea, headaches, fatigue, rare episodes of splenic rupture, and is contraindicated for patients with autoimmune and sickle cell disease. MGTA-145 (GroβT) is a CXCR2 agonist. MGTA-145, in combination with plerixafor, a CXCR4 inhibitor, has the potential to rapidly and reliably mobilize robust numbers of HSCs with a single dose and same-day apheresis for transplant that is free from G-CSF. MGTA-145 plus plerixafor work synergistically to rapidly mobilize HSCs in both mice and non-human primates (Hoggatt, Cell 2018; Goncalves, Blood 2018). Based on these data, Magenta initiated a Phase 1 dose-escalating study to evaluate the safety, PK and PD of MGTA-145 as a single agent and in combination with plerixafor. Methods This study consists of four parts. In Part A, healthy volunteers were dosed with MGTA-145 (0.0075 - 0.3 mg/kg) or placebo. In Part B, MGTA-145 dose levels from Part A were selected for use in combination with a clinically approved dose of plerixafor. In Part C, a single dose MGTA-145 plus plerixafor will be administered on day 1 and day 2. In Part D, MGTA-145 plus plerixafor will be administered followed by apheresis. Results MGTA-145 monotherapy was well tolerated in all subjects dosed (Table 1) with no significant adverse events. Some subjects experienced mild (Grade 1) transient lower back pain that dissipated within minutes. In the ongoing study, the combination of MGTA-145 with plerixafor was well tolerated, with some donors experiencing Grade 1 and 2 gastrointestinal adverse events commonly observed with plerixafor alone. Pharmacokinetic (PK) exposure and maximum plasma concentrations increased dose proportionally and were not affected by plerixafor (Fig 1A). Monotherapy of MGTA-145 resulted in an immediate increase in neutrophils (Fig 1B) and release of plasma MMP-9 (Fig 1C). Neutrophil mobilization plateaued within 1-hour post MGTA-145 at doses greater than 0.03 mg/kg. This plateau was followed by a rebound of neutrophil mobilization which correlated with re-expression of CXCR2 and presence of MGTA-145 at pharmacologically active levels. Markers of neutrophil activation were relatively unchanged (<2-fold vs baseline). A rapid and statistically significant increase in CD34+ cells occurred @ 0.03 and 0.075 mg/kg of MGTA-145 (p < 0.01) relative to placebo with peak mobilization (Fig 1D) 30 minutes post MGTA-145 (7-fold above baseline @ 0.03 mg/kg). To date, the combination of MGTA-145 plus plerixafor mobilized >20/µl CD34s in 92% (11/12) subjects compared to 50% (2/4) subjects receiving plerixafor alone. Preliminary data show that there was a significant increase in fold change relative to baseline in CD34+ cells (27x vs 13x) and phenotypic CD34+CD90+CD45RA- HSCs (38x vs 22x) mobilized by MGTA-145 with plerixafor. Mobilized CD34+ cells were detectable at 15 minutes with peak mobilization shifted 2 - 4 hours earlier for the combination vs plerixafor alone (4 - 6h vs 8 - 12h). Detailed results of single dose administration of MGTA-145 and plerixafor given on one day as well as also on two sequential days will be presented along with fully characterized graft analysis post apheresis from subjects given MGTA-145 and plerixafor. Conclusions MGTA-145 is safe and well tolerated, as a monotherapy and in combination with plerixafor and induced rapid and robust mobilization of significant numbers of HSCs with a single dose in all subjects to date. Kinetics of CD34+ cell mobilization for the combination was immediate (4x increase vs no change for plerixafor alone @ 15 min) suggesting the mechanism of action of MGTA-145 plus plerixafor is different from plerixafor alone. Preliminary data demonstrate that MGTA-145 when combined with plerixafor results in a significant increase in CD34+ fold change relative to plerixafor alone. Magenta Therapeutics intends to develop MGTA-145 as a first line mobilization product for blood cancers, autoimmune and genetic diseases and plans a Phase 2 study in multiple myeloma and non-Hodgkin lymphoma in 2020. Disclosures DiPersio: Magenta Therapeutics: Equity Ownership; NeoImmune Tech: Research Funding; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy; Incyte: Consultancy, Research Funding; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Macrogenics: Research Funding, Speakers Bureau; Bioline Rx: Research Funding, Speakers Bureau; Celgene: Consultancy; Amphivena Therapeutics: Consultancy, Research Funding. Hoggatt:Magenta Therapeutics: Consultancy, Equity Ownership, Research Funding. Devine:Kiadis Pharma: Other: Protocol development (via institution); Bristol Myers: Other: Grant for monitoring support & travel support; Magenta Therapeutics: Other: Travel support for advisory board; My employer (National Marrow Donor Program) has equity interest in Magenta. Biernat:Medpace, Inc.: Employment. Howell:Magenta Therapeutics: Employment, Equity Ownership. Schmelmer:Magenta Therapeutics: Employment, Equity Ownership. Neale:Magenta Therapeutics: Employment, Equity Ownership. Boitano:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Cooke:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Goncalves:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Raffel:Magenta Therapeutics: Employment, Equity Ownership. Falahee:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Morrow:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Davis:Magenta Therapeutics: Employment, Equity Ownership.
Background: Multiple myeloma (MM) is common among the elderly, with 35% of patients (pts) diagnosed being aged ≥75 years (y). With increasing overall life expectancy, the incidence and prevalence of newly diagnosed and previously treated MM patients ≥80 y is expected to increase over time. Because elderly pts are often excluded from clinical trials, data focused on their treatment patterns and clinical outcomes are lacking. The Connect® MM Registry (NCT01081028) is a large, US, multicenter, prospective observational cohort study of pts with newly diagnosed MM (NDMM) designed to examine real-world diagnostic patterns, treatment patterns, clinical outcomes, and health-related quality of life patient-reported outcomes. This analysis reviews treatment patterns and outcomes in elderly pts from the Connect MM Registry. Methods: Pts enrolled in the Connect MM registry at 250 community, academic, and government sites were included in this analysis. Eligible pts were adults aged ≥18 y with symptomatic MM diagnosed ≤2 months before enrollment, as defined by International Myeloma Working Group criteria; no exclusion criteria were applied. For this analysis, pts were categorized into 4 age groups: <65, 65 to 74, 75 to 84, and ≥85 y. Pts were followed from time of enrollment to the earliest of disease progression (or death), loss to follow-up, or data cutoff date of February 7, 2019. Descriptive statistics were used for baseline characteristics and treatment regimens. Survival outcomes were analyzed using Cox regression. Time to progression (TTP) analysis excluded causes of death not related to MM. Results: Of 3011 pts enrolled (median age 67 y), 132 (4%) were aged ≥85 y, and 615 (20%) were aged 75-84 y at baseline. More pts aged ≥85 y had poor prognostic factors such as ISS stage III disease and reduced hemoglobin (<10 g/dL or >2 g/dL <LLN) compared with other age groups, although no notable differences between creatinine and calcium levels were observed across age groups (Table). A lower proportion of elderly pts (75-84 and ≥85 y) received triplet regimens as frontline therapy. More elderly pts received a single novel agent, whereas use of 2 novel agents was more common in younger pts (Table). The most common frontline regimens among elderly pts were bortezomib (V) + dexamethasone (D), followed by lenalidomide (R) + D, whereas those among younger pts included RVD, followed by VD and CyBorD (Table). No pt aged ≥85 y, and 4% of pts aged 75-84 y received high-dose chemotherapy and autologous stem cell transplant (vs 61% in the <65 y and 37% in the 65-74 y age group). The most common maintenance therapy was RD in pts ≥85 y (although the use was low) and R alone in other age groups (Table). In the ≥85 y group, 27%, 10%, and 4% of pts entered 2L, 3L, and 4L treatments respectively, vs 43%, 23%, and 13% in the <65 y group. Progression-free survival was significantly shorter in the ≥85 y age group vs the 75-84 y age group (P=0.003), 65-74 y age group (P<0.001), and <65 y age group (P<0.001; Fig.1). TTP was significantly shorter in the ≥85 y group vs the <65 y group (P=0.020); however, TTP was similar among the 65-74 y, 75-84 y, and ≥85 y cohorts (Fig. 2). Overall survival was significantly shorter in the ≥85 y group vs the 75-84 y, 65-74 y, and <65 y groups (all P<0.001; Fig. 3). The mortality rate was lowest (46%) during first-line treatment (1L) in pts aged ≥85 y (mainly attributed to MM progression) and increased in 2L and 3L (47% and 54%, respectively); a similar trend was observed in the younger age groups. The main cause of death was MM progression (29% in the ≥85 y vs 16% in the <65 y group). Other notable causes of death in the ≥85 y group included cardiac failure (5% vs 2% in <65 y group) and pneumonia (5% vs 1% in <65 y group). Conclusions: In this analysis, elderly pts received similar types of frontline and maintenance regimens as younger pts, although proportions varied with decreased use of triplet regimens with age. Considering similarities in TTP across the 65-74 y, 75-84 y, and ≥85 y cohorts, these real-world data support active treatment and aggressive supportive care of elderly symptomatic pts, including with novel agents. Additionally, further clinical studies specific to elderly patients with MM should be explored. Disclosures Lee: Amgen: Consultancy, Research Funding; GlaxoSmithKline plc: Research Funding; Sanofi: Consultancy; Daiichi Sankyo: Research Funding; Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding. Ailawadhi:Janssen: Consultancy, Research Funding; Takeda: Consultancy; Pharmacyclics: Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy; Cellectar: Research Funding. Gasparetto:Celgene: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; Janssen: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; BMS: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed . Jagannath:AbbVie: Consultancy; Merck & Co.: Consultancy; Bristol-Myers Squibb: Consultancy; Karyopharm Therapeutics: Consultancy; Celgene Corporation: Consultancy; Janssen Pharmaceuticals: Consultancy. Rifkin:Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Durie:Amgen, Celgene, Johnson & Johnson, and Takeda: Consultancy. Narang:Celgene: Speakers Bureau. Terebelo:Celgene: Honoraria; Jannsen: Speakers Bureau; Newland Medical Asociates: Employment. Toomey:Celgene: Consultancy. Hardin:Celgene: Membership on an entity's Board of Directors or advisory committees. Wagner:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; American Cancer Society: Other: Section editor, Cancer journal. Omel:Celgene, Takeda, Janssen: Other: Patient Advisory Committees. Srinivasan:Celgene: Employment, Equity Ownership. Liu:TechData: Consultancy. Dhalla:Celgene: Employment. Agarwal:Celgene Corporation: Employment, Equity Ownership. Abonour:BMS: Consultancy; Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding.
Introduction: For patients with newly diagnosed multiple myeloma (NDMM) who are transplant-eligible, bortezomib/thalidomide/dexamethasone (VTd) is a standard of care (SoC) for induction and consolidation therapy. Clinical practice has evolved to use a modified VTd dose (VTd-mod; 100 mg thalidomide daily), which is reflected in recent treatment guidelines. As VTd-mod has become a real-world SoC, a matching-adjusted indirect comparison (MAIC) of the VTd-mod dose from recent clinical trials versus the dose included in the label (VTd-label; ramp up to 200 mg thalidomide daily) was performed to understand the effect on efficacy of modified VTd dosing for patients with NDMM who are transplant-eligible. Methods: For each outcome (overall survival [OS], progression-free survival [PFS], overall response rates [ORR] post-induction and post-transplant, and rate of peripheral neuropathy), a naïve comparison and a MAIC were performed. Data for VTd-label were obtained from the phase 3 PETHEMA/GEM study (Rosiñol L, et al. Blood. 2012;120[8]:1589-1596). Data for VTd-mod were pooled from the phase 3 CASSIOPEIA study (Moreau P, et al. Lancet. 2019;394[10192]:29-38) and the phase 2 NCT00531453 study (Ludwig H, et al. J Clin Oncol. 2013;31[2]:247-255). Patient-level data for PETHEMA/GEM and CASSIOPEIA were used to generate outcomes of interest and were validated against their respective clinical study reports; aggregate data for NCT00531453 were extracted from the primary publication. Matched baseline characteristics were age, sex, ECOG performance status, myeloma type, International Staging System (ISS) stage, baseline creatinine clearance, hemoglobin level, and platelet count. Results: Patients received VTd-mod (n = 591) or VTd-label (n = 130). After matching, baseline characteristics were similar across groups. For OS, the naïve comparison and the MAIC showed that VTd-mod was non-inferior to VTd-label (MAIC HR, 0.640 [95% CI: 0.363-1.129], P = 0.121; Figure 1A). VTd-mod significantly improved PFS versus VTd-label in the naïve comparison and MAIC (MAIC HR, 0.672 [95% CI: 0.467-0.966], P = 0.031; Figure 1B). Post-induction ORR was non-inferior for VTd-mod versus VTd-label (MAIC odds ratio, 1.781 [95% CI: 1.004-3.16], P = 0.065). Post-transplant, VTd-mod demonstrated superior ORR in both the naïve comparison and MAIC (MAIC odds ratio, 2.661 [95% CI: 1.579-4.484], P = 0.001). For rates of grade 3 or 4 peripheral neuropathy, the naïve comparison and MAIC both demonstrated that VTd-mod was non-inferior to VTd-label (MAIC rate difference, 2.4 [⁻1.7-6.49], P = 0.409). Conclusions: As naïve, indirect comparisons are prone to bias due to patient heterogeneity between studies, a MAIC can provide useful insights for clinicians and reimbursement decision-makers regarding the relative efficacy and safety of different treatments. In this MAIC, non-inferiority of VTd-mod versus VTd-label was demonstrated for OS, post-induction ORR, and peripheral neuropathy. This analysis also showed that VTd-mod significantly improved PFS and ORR post-transplant compared with VTd-label for patients with NDMM who are transplant-eligible. A limitation of this analysis is that unreported or unobserved confounding factors could not be adjusted for. Disclosures Sonneveld: Takeda: Honoraria, Research Funding; SkylineDx: Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; BMS: Honoraria; Amgen: Honoraria, Research Funding; Karyopharm: Honoraria, Research Funding. Mateos:Janssen, Celgene, Takeda, Amgen, Adaptive: Honoraria; AbbVie Inc, Amgen Inc, Celgene Corporation, Genentech, GlaxoSmithKline, Janssen Biotech Inc, Mundipharma EDO, PharmaMar, Roche Laboratories Inc, Takeda Oncology: Other: Advisory Committee; Janssen, Celgene, Takeda, Amgen, GSK, Abbvie, EDO, Pharmar: Membership on an entity's Board of Directors or advisory committees; Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Takeda Oncology.: Speakers Bureau; Amgen Inc, Janssen Biotech Inc: Other: Data and Monitoring Committee. Alegre:Celgene, Amgen, Janssen, Takeda: Membership on an entity's Board of Directors or advisory committees. Facon:Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hulin:celgene: Consultancy, Honoraria; Janssen, AbbVie, Celgene, Amgen: Honoraria. Hashim:Ingress-Health: Employment. Vincken:Janssen: Employment, Equity Ownership. Kampfenkel:Janssen: Employment, Equity Ownership. Cote:Janssen: Employment, Equity Ownership. Moreau:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria.
Abstract Background: Corticosteroids are considered standard first-line systemic therapy for patients with aGVHD, but this approach is effective in only approximately half of all cases. For patients who progress or do not respond to corticosteroids, no specific agent has been identified as standard, and regimens are typically selected based on investigator experience and patient co-morbidities. In preclinical models, JAK inhibition has been shown to impair production of cytokines as well as the differentiation and trafficking of T cells implicated in the pathogenesis of aGVHD. Retrospective studies have suggested that JAK1/JAK2 inhibition with ruxolitinib treatment provides clinical benefit in patients with steroid-refractory GVHD (Zeiser et al, Leukemia 2015;29:2062-2068). Herein, we report preliminary safety results from a prospective randomized, parallel-cohort, open-label phase 1 trial evaluating the potent and selective JAK 1 inhibitor INCB039110 in patients with aGVHD. Methods: Male or female patients 18 years or older who underwent their first allo-hematopoietic stem cell transplant (HSCT) from any donor source and developed grades IIB-IVD aGVHD were eligible for the study. Patients were randomized 1:1 to either a 200 or 300 mg oral daily dose of INCB039110 in combination with corticosteroids, and were stratified based on prior treatment status (treatment-naive [TN] versus steroid-refractory [SR]). The primary endpoint of the study was safety and tolerability; secondary endpoints included overall response rate at Days 14, 28, 56, and 100, non-relapse mortality, and pharmacokinetic (PK) evaluations. Patients were assessed through Day 28 for dose-limiting toxicities (DLTs) and response. A Bayesian approach was used for continuous monitoring of DLTs from Days 1-28. Treatment continued until GVHD progression, unacceptable toxicity, or withdrawal from the study. Acute GVHD was graded according to MN-CIBMTR criteria; adverse events (AEs) were graded according to NCICTCAE v 4.03. Results: Between January and June 2016, 31 patients (TN, n=14; SR, n= 17) were randomized. As of July 25, 2016, data were available from 30 patients who received an oral daily dose of 200 mg (n=14) or 300 mg (n=16) INCB039110 in combination with 2 mg/kg methylprednisolone (or equivalent dose of prednisone). The median durations of treatment were 60.8 days and 56.5 days for patients receiving a daily dose of 200 mg and 300 mg INCB039110, respectively. One DLT of Grade 3 thrombocytopenia was reported. The most frequently reported AEs included thrombocytopenia/platelet count decrease (26.7%), diarrhea (23.3%), peripheral edema (20%), fatigue (16.7%), and hyperglycemia (16.7%). Grade 3 or 4 AEs occurred in 77% of patients and with similar frequency across dose groups and included cytomegalovirus infections (n=3), gastrointestinal hemorrhage (n=3), and sepsis (n=3). Five patients had AEs leading to a fatal outcome, including multi-organ failure (n=2), sepsis (n=1), disease progression (n=1), and bibasilar atelectasis, cardiopulmonary arrest, and respiratory distress (n=1); none of the fatal events was attributed to INCB039110. Efficacy and PK evaluations are ongoing and will be updated at the time of presentation. Conclusion: The oral, selective JAK1 inhibitor INCB039110 can be given safely to steroid-naive or steroid-refractory aGVHD patients. The safety profile was generally consistent in both dose groups. Biomarker evaluation, PK, and cellular phenotyping studies are ongoing. The recommended phase 2 dose will be selected and reported based on PK studies and final safety data. Disclosures Schroeder: Incyte Corporation: Honoraria, Research Funding. Khoury:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Jagasia:Incyte Corporation: Research Funding; Therakos: Research Funding; Janssen: Research Funding. Ali:Incyte Corporation: Research Funding. Schiller:Incyte Corporation: Research Funding. Arbushites:Incyte Corporation: Employment, Equity Ownership. Delaite:Incyte Corporation: Employment, Equity Ownership. Yan:Incyte Corporation: Employment, Equity Ownership. Rhein:Incyte Corporation: Employment, Equity Ownership. Perales:Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chen:Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. DiPersio:Incyte Corporation: Research Funding.
