Privately-held Company Research Articles

ReVenG: A Phase 2 Study of Venetoclax Plus Obinutuzumab Retreatment in Patients with Relapsed Chronic Lymphocytic Leukemia

ReVenG: A Phase 2 Study of Venetoclax Plus Obinutuzumab Retreatment in Patients with Relapsed Chronic Lymphocytic Leukemia

Usability and Performance Testing of Pointcheck™: A Noninvasive Neutropenia Screening Device for Chemotherapy Outpatients

Usability and Performance Testing of Pointcheck™: A Noninvasive Neutropenia Screening Device for Chemotherapy Outpatients

Diversity of Intratumoral Regulatory T Cells in Non-Hodgkin Lymphoma

Introduction: Regulatory T cells (Tregs), a highly immunosuppressive subset of CD4 + T cells, represent a key challenge in the tumor microenvironment by limiting potent antitumor immune responses. While high densities of tumor-infiltrating Tregs are associated with poor prognosis in patients with various types of solid cancers, their prognostic impact in B-cell non-Hodgkin lymphoma (NHL) remains unclear. Emerging studies suggest substantial heterogeneity in the phenotype and suppressive capacities of Tregs, emphasizing the importance of understanding Treg diversity and the need for additional markers to identify highly suppressive Tregs. Our in-depth characterization of Tregs in NHL tumors could open new paths for rational drug design, facilitating selective therapeutic manipulation of Tregs to reduce immunosuppression and improve anti-tumor immunity.Methods: Single-cell suspensions from NHL patients (diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and healthy donors (tonsils and peripheral blood)) were analyzed by fluorescent flow- and mass cytometry to characterize Tregs, focusing on their expression of co-stimulatory and co-inhibitory checkpoint receptors. The immunosuppressive capacity of Tregs was measured by in vitro co-culture of FACS-sorted subsets of Tregs together with autologous CellTrace Violet-labelled T effector cells as responder cells, using samples from FL and tonsils. Live CD4 + T cells were obtained by FACS sorting from DLBCL (n = 3), FL (n = 3) and healthy donor tonsils (n = 3) and subjected to single-cell RNA sequencing (scRNA-seq), Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) and scTCR-seq by the 10X Genomics platform. The computational framework of CIBERSORTx was used to generate unique signature matrices for the three Treg subsets identified by scRNA-seq, to facilitate validation in separate scRNA-seq cohorts (King, Sci Immunol 2021; Roider, Nat Cell Biol 2020), and to impute frequencies of the Treg subsets in cohorts with bulk RNA-seq data (Chapuy, Nat Med 2018; Schmitz, NEJM 2018; Pastore, Lancet Oncol 2015).Results: Immunophenotyping by mass cytometry revealed a subset of activated Tregs identified by co-expression of TIGIT, CTLA-4, PD-1, ICOS and OX40, and higher expression of FOXP3, CD25 and CD45RO, that was present in DLBCL and tonsils, but lacking in peripheral blood. This was validated by fluorescent flow cytometry, demonstrating significantly higher frequencies of activated Tregs in NHL tumors compared to PBMCs and tonsils from healthy donors. The phenotypic heterogeneity of intratumoral Tregs reflected different suppressive capacities as activated Tregs more potently suppressed the proliferation of autologous effector CD4 + and CD8 + T cells than naïve Tregs. For global transcriptomic profiling of CD4 + T cells from FL, DLBCL and tonsillar samples, we integrating scRNA-seq and CITE-seq data from 17,774 cells, revealing 13 distinct cellular states including three states of Tregs: naïve, activated and non-conventional LAG3 +FOXP3 - Tregs. Activated Tregs had higher expression of checkpoint receptors (TNFRSF4, TNFRSF18, ICOS), phosphatases (DUSP2, DUSP4), NF-κB pathway (NFKBIA, TNFAIP3, NFKBIZ, REL), chemokine receptors (CXCR4) and transcription factors (JUNB, IRF1, STAT3) as compared to naïve Tregs. We next used a computational approach to develop unique signature matrices for each Treg subset. This approach demonstrated strong concordance between CIBERSORTx estimated cell abundances of the three Treg subsets and the ground truth, and was validated in two external scRNA-seq cohorts. The development of unique signature matrices for Treg subsets facilitated imputation of their frequencies in bulk RNA-seq datasets. These analyses revealed that higher frequency of activated Tregs was enriched in the germinal B cell subtype of DLBCL and was associated with adverse outcome in FL.Conclusion: This study demonstrates that Tregs infiltrating NHL tumors are transcriptionally and functionally diverse and include highly immunosuppressive activated Tregs co-expressing several checkpoint receptors, which distinguish them from peripheral blood Tregs. Activated intratumoral Tregs could hamper clinical responses to checkpoint blockade, and identifying and targeting their vulnerabilities has the potential to improve anti-tumor immune responses. DisclosuresHolte: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Alizadeh: Cibermed: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; CAPP Medical: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Forty Seven: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Foresight Diagnostics: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Roche: Consultancy, Honoraria; Janssen Oncology: Honoraria; Celgene: Consultancy, Research Funding; Gilead: Consultancy; Bristol Myers Squibb: Research Funding.

CCS1477, a Novel p300/CBP Bromodomain Inhibitor, Enhances Efficacy of Azacitidine and Venetoclax in Pre-Clinical Models of Acute Myeloid Leukaemia and Lymphoma

E1A binding protein (p300) and CREB binding protein (CBP) are two closely related histone acetyl transferases that co-activate key oncogenes such as MYC and IRF4 which are relevant in a number of haematological malignancies. Here we describe the effects of CCS1477, a new orally available inhibitor of the p300/CBP bromodomains, given alone or in combination with azactidine or venetoclax in pre-clinical models of AML and B-cell lymphoma.As a monotherapy, daily oral dosing with CCS1477 (5, 10 and 20mg/kg) caused a significant dose-dependent reduction in tumour growth in a MOLM-16 xenograft model of AML, with regressions observed at the highest and well tolerated dose of 20mg/kg/qd. The inhibition of tumour growth during drug treatment was accompanied by a significant reduction in tumour expression of MYC by qPCR. In murine retroviral transduction and transplantation models of human AML initiated by either MLL-AF10 or MLL-AF9, daily monotherapy by oral gavage with CCS1477 at 30mg/kg for 42 days, caused a highly significant prolongation of survival. All seven control treated mice died of AML within 160 days whereas only one of seven CCS1477 treated mice had died in each model by 300 days.In the MOLM-16 xenograft model, a sub-maximal dose of CCS1477 (10mg/kg) demonstrated superior tumour growth inhibition by comparison with azacitidine (0.5mg/kg i.p) and with significant combination benefit when these two agents were combined. In this same model venetoclax (50 or 100 mg/kg/qd oral) had no effect on tumour growth, indicating that MOLM-16 tumours are intrinsically resistant. CCS1477 dosed daily at 10mg/kg restored sensitivity to venetoclax as evidenced by significantly greater tumour growth inhibition when compared with CCS1477 given alone. In a venetoclax-sensitive xenograft model of AML (MV-4-11), CCS1477 (10mg/kg) and venetoclax (100mg/kg) resulted in a similar and partial reduction in tumour growth over a 21 day dosing period. When venetoclax and CCS1477 were combined there was a significant combination benefit compared to either drug given alone. The DOHH-2 xenograft model of B-cell lymphoma was also sensitive to venetoclax (50mg/kg) and with a similar impact on tumour growth compared with CCS1477 (10mg/kg). In this model the combination of CCS1477 and venetoclax was more profound and caused complete tumour stasis during the dosing period.These data support the clinical testing of CCS1477 in combination with azacitidine and/or venetoclax in AML and B-cell lymphomas. CCS1477 is currently in Phase I/II clinical trials in AML, Non-Hodgkin lymphoma (including B-cell lymphoma) and multiple myeloma. (NCT04068597). DisclosuresBrooks: CellCentric Ltd: Current Employment, Current holder of individual stocks in a privately-held company. Knurowski: CellCentric Ltd: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Hughes: CellCentric Ltd: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Clegg: CellCentric Ltd: Current Employment, Current holder of individual stocks in a privately-held company. West: CellCentric Ltd: Current Employment, Current holder of individual stocks in a privately-held company. Pegg: CellCentric Ltd: Current Employment, Current holder of individual stocks in a privately-held company. Somervaille: Novartis: Consultancy, Honoraria.

Updated Results from MajesTEC-1: Phase 1/2 Study of Teclistamab, a B-Cell Maturation Antigen x CD3 Bispecific Antibody, in Relapsed/Refractory Multiple Myeloma

Updated Results from MajesTEC-1: Phase 1/2 Study of Teclistamab, a B-Cell Maturation Antigen x CD3 Bispecific Antibody, in Relapsed/Refractory Multiple Myeloma

Cryopreserved CAR-like NK Cells Pre-Complexed with the CD30/CD16A Bispecific Innate Cell Engager (ICE®) AFM13 for the Treatment of CD30 + Malignancies

AFM13 is a bispecific tetravalent innate cell engager (ICE®) with two binding sites for CD16A and CD30 on immune cells and tumor cells, respectively. AFM13 is designed to potently activate anti-tumoral responses of natural killer (NK) cells, through antibody-dependent cellular cytotoxicity (ADCC) and macrophages via antibody-dependent cellular phagocytosis (ADCP) towards CD30 + tumor cells. It is widely known that the number of NK cells and their anti-tumor activity are often compromised in patients with cancer, including CD30 + malignancies such as Hodgkin lymphoma (HL) (Reiners, K.S. et al., Mol Ther 2013;21:895-903). Accumulating evidence suggests that the selective, high affinity binding of ICE® to CD16A enables stable pre-complexing with NK cells to enhance ADCC.Early clinical studies with AFM13 have demonstrated safety and efficacy, both as mono- and combination therapy with an anti-PD-1 checkpoint inhibitor (pembrolizumab) (Bartlett, N.L. et al., Blood 2020;136(21):2401-2409), in patients with relapsed or refractory (R/R) HL or peripheral T cell lymphoma (PTCL). Currently, AFM13 monotherapy is being evaluated in a registration-directed Phase 2 study to treat patients with PTCL (NCT04101331). Additionally, a Phase 1b/2a study in patients with PTCL (NCT03192202) previously demonstrated that NK cell numbers pre- and post-dosing of AFM13 may positively correlate with anti-tumoral response (Sawas, A. et al., Blood 2020;136(1):25-26). Therefore, the safety and efficacy of freshly prepared cord blood-derived allogeneic NK cells pre-complexed with AFM13, followed by three weekly infusions of AFM13 monotherapy, is currently being evaluated in patients with R/R CD30 + lymphomas in a Phase 1 dose escalation study (NCT04074746). The first four enrolled patients, all with HL, have shown a response rate of 100% without any safety concerns (Rezvani, K. et al., presentation AACR 2021).To further develop this CAR-like NK cell immunotherapeutic towards an off-the-shelf product, we evaluated the feasibility of cryopreservation of pre-complexed NK cells and assessed the biological activity of such cryopreserved and pre-complexed NK cells after thawing. In this study, the cell surface retention, suitability for NK cell preloading, and cytotoxic activity of AFM13 and other CD30-specific antibody formats was assessed. Furthermore, the compatibility of these formats with cryopreservation of the resulting CAR-like NK cell product was investigated. Cell surface retention assays on primary NK cells confirm substantially slower dissociation kinetics of the tetravalent bispecific ICE® compared to corresponding IgG1 or Fc-enhanced IgG1, enabling efficient and durable pre-complexing of NK cells with ICE®. Surface plasmon resonance analyses confirm long retention of ICE® independent of the CD16A polymorphism. More importantly, these assays demonstrate that the high ADCC potency and efficacy of NK cells, pre-complexed with CD16A-specific tetravalent ICE®, is maintained after one freeze-thaw cycle.These data suggest that high-affinity pre-complexing of adoptive NK cells with bispecific, CD16A-selective ICE® could be a novel cryopreserved off-the-shelf NK cell product for the effective depletion of tumor cells without the limitations and potential risks associated with the CAR-NK cell technology. DisclosuresReusch: Affimed: Current Employment, Current holder of stock options in a privately-held company. Ellwanger: Affimed: Current Employment, Current holder of stock options in a privately-held company. Fucek: Affimed: Current Employment, Current holder of stock options in a privately-held company. Müller: Affimed GmbH: Current Employment, Current holder of stock options in a privately-held company. Schniegler-Mattox: Affimed: Current Employment, Current holder of stock options in a privately-held company. Pahl: Affimed: Current Employment, Current holder of stock options in a privately-held company. Tesar: Affimed: Current Employment, Current holder of stock options in a privately-held company. Koch: Affimed: Current Employment, Current holder of stock options in a privately-held company.

Long-Term Follow-up and Single-Cell Multiomics Characteristics of Infusion Products in Patients with Chronic Lymphocytic Leukemia Treated with CD19 CAR-T Cells

Long-Term Follow-up and Single-Cell Multiomics Characteristics of Infusion Products in Patients with Chronic Lymphocytic Leukemia Treated with CD19 CAR-T Cells

S1918: A Phase II/III Randomized Study of R-Minichop with or without Oral Azacitidine (CC-486) in Participants Age 75 Years or Older with Newly Diagnosed Diffuse Large B Cell Lymphoma, Grade IIIb Follicular Lymphoma, Transformed Lymphoma, and High-Grade B-Cell Lymphomas with MYC and BCL2 and/or BCL6 Rearrangements

S1918: A Phase II/III Randomized Study of R-Minichop with or without Oral Azacitidine (CC-486) in Participants Age 75 Years or Older with Newly Diagnosed Diffuse Large B Cell Lymphoma, Grade IIIb Follicular Lymphoma, Transformed Lymphoma, and High-Grade B-Cell Lymphomas with MYC and BCL2 and/or BCL6 Rearrangements

Preliminary Safety and Efficacy from a Multicenter, Investigator-Initiated Phase II Study in Untreated TP53 Mutant Mantle Cell Lymphoma with Zanubrutinib, Obinutuzumab, and Venetoclax (BOVen)

Preliminary Safety and Efficacy from a Multicenter, Investigator-Initiated Phase II Study in Untreated TP53 Mutant Mantle Cell Lymphoma with Zanubrutinib, Obinutuzumab, and Venetoclax (BOVen)

Profile of Pain Medication Use in Hemophilia and Hemarthrosis: An Analysis of a Pharmacy Claims Database

Introduction: Chronic joint pain associated with bleeding disorders (particularly Hemophilia A and Hemophilia B) is well characterized. The most common treatments reported by patients with bleeding disorders include acetaminophen, traditional nonsteroidal anti-inflammatory drugs (tNSAIDs; cyclooxygenase 1/2 inhibitors, COX-1/2), COX-2 selective NSAIDs, and opioids (Witkop, et al. Haemophilia . 2017;23:556). Up to 50% of patients have reported opioid use to manage both acute and chronic pain(Witkop, et al. Haemophilia . 2017;23:556). The aim of this study was to compare and analyze different types of prescription pain medications in patients with a diagnosis of hemophilia A, B, and hemarthrosis using a pharmacy claims database. Methods: A cross-sectional analysis was conducted on a retrospective cohort of patients with bleeding disorders receiving pain medications in the Truven Health MarketScan Commercial Claims and Encounters database, for which IRB approval was not required. Index encounters were reported from April 1, 2017 to March 30, 2018, with one year of follow up. Patients were outpatients, inpatients, or both. Patient-level demographics were not collected. Results: Unique patients totaling 876 received 5,702 prescriptions. Patient diagnosis codes included Hemophilia A (D66), Hemophilia B (D67), and hemarthrosis (M362), each of which contributed 79.2%, 11.9%, and 8.8%, respectively, to the total prescriptions. Outpatient prescriptions comprised 81.0% of total prescriptions. Scheduled prescriptions comprised 70.8% of all prescriptions, 81.7% of inpatient prescriptions, and 68.2% of outpatient prescriptions (see Table). Schedule II drugs comprised 82.6% and 77.3% of all scheduled inpatient and outpatient prescriptions, respectively (see Table). Schedule IV prescriptions were the next most common, followed by schedule III. Prescription NSAIDs were more common in the outpatient than in the inpatient setting (see Table). Among NSAIDs, celecoxib comprised approximately half of the outpatient NSAID prescriptions and 15.1% of all outpatient prescriptions. Discussion: Regardless of setting, schedule II drugs are the most common form of pain management prescription in patients with hemophilia or hemarthrosis. Prescriptions for scheduled medications appear similar to what might be inferred in previous studies of patient reported use (Witkop, et al. Haemophilia . 2017;23:556). Consistent with self-reports (Witkop, et al. Haemophilia . 2017;23:556), hydrocodone or oxycodone with acetaminophen were confirmed to be the most frequently prescribed schedule II opioids. tNSAIDs, such as those reported in this analysis share gastrointestinal (GI) bleeding risk which may be heightened in persons with hemophilia compared with those who have no bleeding disorders. Celecoxib represents approximately 50% of outpatient NSAID prescriptions in this analysis despite data showing its clinically significant GI event risk is similar to both ibuprofen and naproxen (Nissen, et al. N Engl J Med. 2016:2519). Over-the counter acetaminophen is commonly used to treat chronic joint pain in hemophilia (Witkop, et al. Haemophilia. 2017;23:556) presumably to avoid GI bleeding, yet is reported to be less efficacious than celecoxib (Rodriguez-Merchan, et al. Blood Rev. 2018: 116). The broad use of opioids with their attendant risk of misuse, addiction, and diversion; as well as tNSAIDs, with their attendant GI risks, underscores the limited pain management options available for persons with hemophilia. This cross-sectional prescription claims data analysis highlights the need to identify and develop alternate forms of chronic pain medications for this population who have unique unmet needs (Humphries, et al. Haemophilia. 2015:41). [Display omitted] DisclosuresHelm: Tremeau Pharmaceuticals Inc.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Buckner: Genetech: Honoraria; Spark: Honoraria; Sanofi: Honoraria; Bayer: Honoraria; Pfizer: Honoraria; Takeda: Honoraria; American Thrombosis: Membership on an entity's Board of Directors or advisory committees; Hemostasis Network: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Honoraria; CSL Behring: Honoraria; Tremeau Pharmaceuticals: Consultancy, Honoraria; uniQure: Consultancy, Honoraria; BioMarin: Consultancy, Honoraria. Macgregor: Tremeau Pharmaceuticals Inc.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Boice: Tremeau Pharmaceuticals Inc.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Cerasoli: RX Medical Dynamics LLC: Consultancy, Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Khan: Rx Medical Dynamics, LLC: Current Employment. Argoff: Tremeau Pharmaceuticals,Inc: Consultancy.

Prevalence of Acute and Chronic Migraine Among Patients with Von Willebrand Disease

Background: The prevalence of migraine in the general population is approximately 18% in females and 6% in males (Lipton, et. al. Headache 2001;41:646). Among migraineurs, 7-8% experience chronic migraines (CM) (Adams AM, et. al. Cephalalgia 2015;35:563). Von Willebrand factor (VWF), secreted from endothelial cells, is reported to be elevated in migraineurs and in particular during the course of migraine, although its role is unclear (Cesar, et. al. Acta Neurol Scand 1995;91:412; Tietjen, et. al. Neurology 2001;57:334; Tietjen, et. al. Cephalalgia 2018;38:511). Patients with Von Willebrand Disease (VWD) have low levels of or a defective form of VWF, which has led some to hypothesize a lower prevalence of migraine in the VWD population. Conversely, a retrospective case control study found that migraine in VWD patients (n=197) was 6 times more prevalent when compared with age- and sex-match healthy controls (n=197) (18% vs. 3%, respectively)(Hassan, et. al. Intl Journal of Hem, Blood Diseases and Disorders 2014;2:23-5). The current investigation was performed to further explore the relationship between migraine and VWD. Methods: A cross-sectional study was conducted in March 2021 using the InCrowd digital survey tool in which patients with self-reported diagnosis of VWD were invited to participate. The study included 75 VWD patients ≥18 years of age. Survey questions detailed VWD sub-type, gender, clinical diagnosis of migraine, medical specialty diagnosing migraine, migraine treatments, and age of diagnosis. The Lipton Identify Chronic Migraine (ID-CM) tool was used within the survey to identify patients who had experienced chronic migraine(Lipton, et al. Cephalalgia. 2016;36:203). Criteria for designation of chronic migraine from the ID-CM was either the combination of Frequency of Migraine and Symptoms or the combination of Use of Medication and Activity Avoidance. Results: The gender distribution of the 75 participants was 83% female and 17% male. The sub-type of VWD diagnosed was: Type 1 (57%), Type 2 (28%), Type 3 (15%). Fifty-seven percent (57%) of all VWD patients reported being diagnosed with migraine. Rates did not vary significantly by VWD sub-type. Diagnosed migraine was only slightly more common in females (60%, n=62) compared with males (46%, n=7). Average age of diagnosis was 22 years with a median of 17 years (n=43). Two clear clusters defined the age of diagnosis with migraine. The first was between ages 10 and 20 (n=24, 56% of total sample reporting age) and the second was approximately age 30 [28-32] (n=8, 19% of total sample reporting age). Migraine diagnosis was established by primary care physicians (44%), neurologists (44%) hematologists (9%), and headache specialists (2%). Only 4% of surveyed patients met the ID-CM criteria for chronic migraine, yet 71% of patients met the criteria for migraine symptoms. Chronic migraine diagnosis using the ID-CM tool requires a combination of headache frequency (at least half of the past 30 or 90 days), multiple migraine symptoms (present >rarely in the past 30 days), medication use for headache as well as interference with activities (≥10 of the past 30 days) and a headache that either interfered with plans or caused worry for making plans (>rarely in the past 30 days). Frequency of migraine was mentioned by 11% of patients and symptoms by 71%, medication use by 31%, activity limitation by 15%, and changing plans by 25%. Conclusions: This survey illustrates that migraine is significantly more common in people with VWD than in the general population, regardless of VWD sub-type. However, the age-associated incidence pattern follows a similar bimodal distribution as observed in the general population(Victor, et al. Cephalalgia. 2010;30:1065). Notably, the prevalence of diagnosed migraine in VWD males approaches the prevalence in VWD females and exceeds that of females in the general population (Lipton RB, et. al. Headache 2001;41:646). These results suggest a distinct etiology of VWD that makes affected patients more susceptible to migraine. Notably, migraine treatment options may be more limited for these patients, given that traditional NSAIDs are commonly used for fast-acting migraine relief, but their antiplatelet effects and potential for gastrointestinal bleeding make them undesirable in VWD. Further investigation of both the etiology and treatment for VWD migraine is warranted. DisclosuresMacgregor: Tremeau Pharmaceuticals Inc.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Helm: Tremeau Pharmaceuticals Inc.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Cerasoli: RX Medical Dynamics LLC: Consultancy, Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Boice: Tremeau Pharmaceuticals Inc.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Sidonio: Novo Nordisk: Consultancy; Bayer: Consultancy; Pfizer: Consultancy; Catalyst: Consultancy; Genentech: Consultancy, Research Funding; Biomarin: Consultancy; Guardian Therapeutics: Consultancy; Octapharma: Consultancy, Research Funding; Takeda: Consultancy, Research Funding.

Potential Disease-Modifying Activity of Navtemadlin (KRT-232), a First-in-Class MDM2 Inhibitor, Correlates with Clinical Benefits in Relapsed/Refractory Myelofibrosis (MF)

Potential Disease-Modifying Activity of Navtemadlin (KRT-232), a First-in-Class MDM2 Inhibitor, Correlates with Clinical Benefits in Relapsed/Refractory Myelofibrosis (MF)

Myeloid-Biased HSC Require Semaphorin4a from the Bone Marrow Niche for Self-Renewal Under Stress and Life-Long Persistence

A subset of hematopoietic stem cells with inherent myeloid and platelet bias (myHSC) is positioned at the top of hematopoietic hierarchy and considered the most primitive. Notably, lower proliferative output of myHSC correlates with a greater capacity for self-renewal indicating that quiescence is essential for their function. Hence, excessive myHSC expansion following inflammatory challenge is likely to put them at a higher risk of proliferation-induced damage. Given that inflammatory stress is unavoidable throughout live, we hypothesized that myHSC may uniquely depend on quiescence-inducing signals for their protection and long-term persistence. However, the nature of these signals remains largely unexplored.We have previously performed proximity-based analysis of the bone marrow niche to identify novel regulators of HSC quiescence (Silberstein et al, Cell Stem Cell 2016). Briefly, we defined the transcriptional profiles of osteolineage cells which were located in closer proximity to a transplanted HSC (proximal cells), and designated secreted factors with higher expression level in proximal cells as putative regulators of HSC quiescence. For the current study, we selected Semaphorin4a (Sema4a) - a known regulator of neural development, angiogenesis and immune response with no previously documented role in hematopoiesis - and examined its impact on myHSC function during inflammatory stress.We found that Sema4a was expressed in the niche cells (endothelium and osteoprogenitors) in mice and humans. Recombinant Sema4a reduced proliferation of mouse and human hematopoietic stem and progenitor cells ex vivo. Baseline analysis of young Sema4aKO mice revealed mild anemia, thrombocytosis, myeloid bias and a slight reduction in the proportion of HSC in the G0 phase suggesting that Sema4a regulates HSC quiescence and differentiation in vivo. Upon Poly(I:C) injection, Sema4aKO myHSC (Lin -Kit +Sca +CD48 -CD34 -CD150 high) displayed markedly increased cycling and upregulation of alpha-interferon and JAK-STAT signaling while “balanced” HSC (Lin -Kit +Sca +CD48 -CD34 -CD150 low) were unaffected. Similar exaggerated proliferative response in Sema4aKO myHSC was observed upon injection with IL-1β.Next, we investigated the long-term impact of inflammation-induced loss of myHSC quiescence. Aged Sema4aKO mice developed anemia, thrombocytosis, neutrophilia. Most significantly, we observed a two-fold expansion of phenotypic myHSC (but not balanced HSC) which displayed proliferative senescence, increased cellular stress and premature differentiation by scRNA-Seq, and a complete loss of reconstitution upon transplantation. In contrast, young Sema4aKO HSC showed a higher level of post-transplant chimerism consistent with their prior “pre-activated” state. Thus, loss of myHSC quiescence leads to increased sensitivity to inflammatory stressors and enhanced myHSC response but eventual collapse of regenerative function.In order to determine if the microenvironment served as a critical source of Sema4a for myHSC, WT myHSC were transplanted into lethally irradiated WT and Sema4aKO hosts. Strikingly, the majority of Sema4aKO recipients died while all WT recipients survived. Intra-vital imaging at 24 hours revealed a greater number of cells and clusters in Sema4aKO recipients suggesting that excessive early myHSC proliferation led to impaired self-renewal and engraftment failure. Finally, we found that Plexin D1 acts as a functional receptor for Sema4a on myHSC, since Plexin D1-deficient myHSC recapitulated the post-transplant phenotype of young Sema4aKO myHSC described above.Taken together, our data demonstrate that under the conditions of increased myeloid demand, protection from proliferative stress is critical for preserving myHSC function, and highlight a critical but previously unrecognized role for Sema4a-PlxnD1 axis in this process. Our study suggests that therapeutic augmentation of myHSC quiescence may alleviate the negative impact in inflammatory signaling, serve to improve marrow function in inflammatory diseases, and prevent development of myeloid malignancy. DisclosuresRadtke: Ensoma Inc.: Consultancy; 47 Inc.: Consultancy. Kiem: Ensoma Inc.: Consultancy, Current holder of individual stocks in a privately-held company; Homology Medicines: Consultancy; VOR Biopharma: Consultancy. Scadden: Fate Therapeutics: Current holder of individual stocks in a privately-held company; Editas Medicines: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Clear Creek Bio: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Dainippon Sumitomo Pharma: Other: sponsored research; FOG Pharma: Consultancy; Agios Pharmaceuticals: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Garuda Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; VCanBio: Consultancy; Inzen Therapeutics: Membership on an entity's Board of Directors or advisory committees; LifeVaultBio: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Magenta Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees.

Updates from Ongoing, First-in-Human Phase 1 Dose Escalation and Expansion Study of TTI-621, a Novel Biologic Targeting CD47, in Patients with Relapsed or Refractory Hematologic Malignancies

Updates from Ongoing, First-in-Human Phase 1 Dose Escalation and Expansion Study of TTI-621, a Novel Biologic Targeting CD47, in Patients with Relapsed or Refractory Hematologic Malignancies

Efficacy and Safety of Ublituximab in Combination with Umbralisib (U2) in Patients with Chronic Lymphocytic Leukemia (CLL) By Treatment Status: A Sub-Analysis of the Phase 3 Unity-CLL Study

Efficacy and Safety of Ublituximab in Combination with Umbralisib (U2) in Patients with Chronic Lymphocytic Leukemia (CLL) By Treatment Status: A Sub-Analysis of the Phase 3 Unity-CLL Study

Concurrent Pembrolizumab with AVD for Untreated Classical Hodgkin Lymphoma

Concurrent Pembrolizumab with AVD for Untreated Classical Hodgkin Lymphoma

Molecular Biomarker Testing and Targeted Therapy Patterns in Patients with Acute Myelogenous Leukemia (AML) in Community Health Systems in the United States: A Real-World Data Analysis

Molecular Biomarker Testing and Targeted Therapy Patterns in Patients with Acute Myelogenous Leukemia (AML) in Community Health Systems in the United States: A Real-World Data Analysis

Emicizumab Outcomes in Hemophilia A Using Real-World Data from the Canadian Hemophilia Bleeding Disorder Registry

Background: The Canadian Hemophilia Bleeding Disorders Registry (CBDR) is a clinical database including data from all Canadian Hemophilia Treatment Centers (HTCs) to assist in the management of hemophilia and other bleeding disorders. The CBDR launched on July 1, 2015 and integrates the data entry platform for patients, myCBDR, allowing direct entry of treatments, bleeding events, and other patient reported outcomes (PRO) data. Health Canada approved emicizumab in August 2018 for the treatment of persons with hemophilia A (PwHA) with factor (F)VIII inhibitors, and for PwHA without FVIII inhibitors in 2019, enabling some patients without FVIII inhibitors to be provided compassionate access beginning November 2019.Our aim for this analysis was to use the CBDR data to describe the demographics of the emicizumab-treated PwHA population and assess its effectiveness, safety, treatment patterns, and the impact on disease burden.Methods: De-identified data were extracted from the CBDR database for all registered PwHA who had received emicizumab at least once up to December 31, 2020. Disease severity is defined by the level of endogenous clotting FVIII activity. Effectiveness outcomes include number of patients (%) with zero treated bleeds, joint bleeds, and spontaneous bleeds; annualized bleeding rates (ABR) for any bleeds and treated bleeds; Hemophilia Joint Health Score (HJHS); Patient Reported Outcomes Burdens and Experiences (PROBE); and EQ-5D-5L index and visual analog scale (VAS). ABRs were calculated as (total number of bleeds/duration of follow-up [days])*365.25. All analyses were performed based on the observed values, without imputation. This study was approved by the research ethics board of McMaster University and other participating centers, and abides by the guiding principles of the Declaration of Helsinki.Results: 73 PwHA who received emicizumab at least once up to December 31, 2020 were identified. Demographic characteristics, severity, inhibitor status, and treatments are described in Table 1. Median (IQR) age for the entire cohort was 19.7 (10.0, 40.6) years with 45.2% ≤18 years. There were 64 PwHA with severe disease, 7 with moderate disease and 2 with mild disease; both cases with mild disease had current FVIII inhibitors. 49 PwHA had current FVIII inhibitors, 12 had a history of FVIII inhibitors, and 12 had no FVIII inhibitors. 5/73 (6.8%) received immune tolerance induction (ITI) treatment while on emicizumab. Two cases of rash (allergic or acute reactions) were reported (2/73, 2.7%) of which one (reported 6 days after administration) was possibly related to emicizumab according to the reporting HTC. No thromboembolisms or thrombotic microangiopathies were observed.Median ABR (IQR) for the entire study population was 0.0 (0, 0) and 59/73 (80.8%) had no recorded bleeds. In the 14/73 (19.2%) with recorded bleeds, median ABR (IQR) was 2 (1, 3); 8 of those 14 had joint bleeds and 7 had spontaneous bleeds. HJHS was recorded for 23, PROBE Score for 9, EQ-5D-5L for 9 and EQ-5D-5L VAS for 4 PwHA (Table 2).Conclusions: The Canadian population treated with emicizumab had severe disease and current or historical FVIII inhibitors. The bleed outcomes are consistent with earlier publications, showing 80.8% had no recorded bleeds. The CBDR will allow for longitudinal follow-up of this patient population. Our results can inform healthcare practitioners and regulatory authorities on the real-world safety and effectiveness outcomes of emicizumab in PwHA with and without FVIII inhibitors. [Display omitted] DisclosuresPoon: Roche: Honoraria; Pfizer: Honoraria; Novo Nordisk: Honoraria; Bioverativ/Sanofi: Honoraria; CSL-Behring: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; University of Calgary: Current Employment; Takeda: Honoraria. Lee: Roche: Honoraria; Pfizer: Honoraria, Speakers Bureau; Novo Nordisk: Honoraria, Speakers Bureau; CSL Behring: Honoraria; Biovertiv/Sanofi: Honoraria, Research Funding; Bayer: Research Funding, Speakers Bureau; Takeda: Honoraria. Keepanasseril: McMaster University: Current Employment; NovoNordisk Canada: Consultancy. Ibrahim: McMaster University: Current Employment. Nissen: F. Hoffmann-La Roche Ltd: Current Employment, Current holder of stock options in a privately-held company; Novartis: Consultancy; Actelion: Consultancy. Sanabria: F. Hoffmann-La Roche Ltd: Current Employment, Current holder of individual stocks in a privately-held company. Santos: F. Hoffmann-La Roche Ltd.: Current Employment; Roche: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Baxter: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Takeda: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Iorio: McMaster University: Current Employment; Bayer (funding to the institution): Research Funding; BioMarin (funding to the institution): Research Funding; NovoNordisk (funding to the institution): Research Funding; Octapharma (funding to the institution): Research Funding; Pfizer (funding to the institution): Research Funding; Roche (funding to the institution): Research Funding; Sanofi (funding to the institution): Research Funding; Sobi (funding to the institution): Research Funding; Takeda (funding to the institution): Research Funding.

Recombinant CD19 Glycomutant Accurately and Reproducibly Detects CD19-Directed CAR-T Cells By Flow Cytometry

BackgroundCD19-directed chimeric antigen receptor (CAR)-modified T cell therapy expansion and persistence in peripheral blood has been shown to correlate with responses against B cell malignances (Hay, Blood, 2018; Ayuk, Blood Adv, 2021). CAR-T cell enumeration is typically achieved through quantitative PCR (qPCR) or flow cytometry (FC). qPCR, however, requires techniques that may not be locally validated and, unlike FC, cannot simultaneously address T cell immunophenotype. Existing FC reagents to detect CD19 CAR-T cells are mostly specific for a given CAR sequence or bind non-specifically to the introduced protein (e.g. Protein A). Utilizing glycosylation data from the structure of CD19(Teplykov, Proteins, 2018), we created a stable, biotinylated CD19 ectodomain glycomutant reagent (gmCD19) that binds to the CD19-directed scFv in CAR constructs and can be detected by FC.MethodsThe gmCD19 ectodomain (amino acids 21-227, N138Q) was expressed in 293 Freestyle™ cells with a C-terminal 6x Histidine-AviTag™ to facilitate expression, purification, FC detection (with fluorophore-bound streptavidin) and enable tetramer formation. We used FC to determine limit of detection (LoD), defined as the percent of detectable CAR-T cells when spiked into peripheral blood mononuclear cells (PBMC) at known concentrations. We used a CD19-directed CAR-T cell that co-expresses truncated EGFR (EGFRt) to benchmark gmCD19 and compare our reagent with commercially available detection reagents. This was quantitated by Pearson correlation coefficient and Bland-Altman measure of bias - defined as the mean of differences between tests on the same sample. We also tested reagent stability by assessing for decrease in mean fluorescence intensity (MFI) and the percent of CAR-T cells detected after multiple freeze-thaw cycles of the gmCD19 reagent. We compared CAR-T cell detection by gmCD19 with qPCR from actual patient samples treated with axicabtagene ciloleucel (axi-cel) and collected into three different anticoagulants.ResultsgmCD19 detected as few as 0.25% CAR-T cells by FC and was highly correlated with EGFRt expression (r=0.9993, p<0.0001). When benchmarking gmCD19 with EGFRt expression and comparing gmCD19 quantitation with other commercially available CD19 scFv detection reagents (Acro and BioSwan), gmCD19 showed the least bias (0.04 vs -1.225 and 61.66, respectively), and was the only method that demonstrated statistically significant agreement with EGFRt. Following each freeze-thaw cycle of gmCD19, there was no statistically significant decrease in percent of CAR-T cells detected with only a slight decrease in MFI (~2% decrease per cycle). Detection of axi-cel from patient samples was highly correlated with CAR copy number determined by qPCR, regardless of the anticoagulant in which the patient sample was collected (r=0.9387, 0.9849 and 0.9373 for sodium heparin, sodium citrate and EDTA, respectively) with equivalent coefficients of variation (11.0% vs 11.4% for gmCD19 and qPCR, respectively).ConclusionThe availability of multiple CD19-directed CAR-T cell products and the importance of monitoring CAR-T cell expansion and persistence in patients undergoing CAR-T cell therapy creates the necessity for an easily applied, stable, and reliable quantitation FC method. We show that our gmCD19 accurately measures CD19-directed CAR-T cells across a variety of CAR-T cell constructs, including commercially available products. DisclosuresSheih: Umoja Biopharma: Current Employment. Fiorenza: Bristol Myers Squibb: Research Funding; Link Immunotherapeutics: Consultancy. Hirayama: Bristol-Myers Squibb: Consultancy, Honoraria; Novartis: Honoraria. Chou: Genentech: Current Employment. Gauthier: Legend Biotech: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Multerra Bio: Consultancy; Larvol: Consultancy; JMP: Consultancy; Eusapharma: Consultancy. Correnti: Link Immunotherapeutics: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Turtle: PACT Pharma: Consultancy; Amgen: Consultancy; Asher Bio: Consultancy; Myeloid Therapeutics: Current holder of stock options in a privately-held company, Other: Scientific Advisory Board; T-CURX: Other: Scientific Advisory Board; Century Therapeutics: Consultancy, Other: Scientific Advisory Board; Arsenal Bio: Current holder of stock options in a privately-held company, Other: Scientific Advisory Board; Eureka Therapeutics: Current holder of stock options in a privately-held company, Other: Scientific Advisory Board; Caribou Biosciences: Consultancy, Current holder of stock options in a privately-held company, Other: Scientific Advisory Board; Precision Biosciences: Current holder of stock options in a privately-held company, Other: Scientific Advisory Board; Nektar Therapeutics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Juno Therapeutics/BMS: Patents & Royalties: Right to receive royalties from Fred Hutch for patents licensed to Juno Therapeutics, Research Funding; TCR2 Therapeutics: Research Funding; Allogene: Consultancy.

A Comparison of Clinical Outcomes from Updated Zuma-5 (Axicabtagene Ciloleucel) and the International Scholar-5 External Control Cohort in Relapsed/Refractory Follicular Lymphoma (R/R FL)

A Comparison of Clinical Outcomes from Updated Zuma-5 (Axicabtagene Ciloleucel) and the International Scholar-5 External Control Cohort in Relapsed/Refractory Follicular Lymphoma (R/R FL)