scholarly journals Reticular Dysgenesis-Associated Adenylate Kinase 2 Deficiency Impairs Purine Metabolism and Ribosomal Biogenesis during Myelopoiesis

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3257-3257
Author(s):  
Wenqing Wang ◽  
Andrew Devilbiss ◽  
Martin Arreola ◽  
Thomas Mathews ◽  
Misty Martin-Sandoval ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Adenylate Kinase ◽  
Purine Metabolism ◽  
Rrna Synthesis ◽  
Synthesis Rate ◽  
Ribosomal Biogenesis ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Maturation Defect ◽  
Metabolomics Analysis

Abstract Reticular Dysgenesis (RD) is a particularly grave form of severe combined immunodeficiency (SCID), characterized by maturation arrest of both myeloid and lymphoid lineages paired with sensorineural hearing loss. RD is caused by biallelic mutations in the mitochondrial enzyme adenylate kinase 2 (AK2). AK2 catalyzes the phosphorylation of adenosine monophosphate (AMP) to adenosine diphosphate (ADP) in the mitochondrial intermembrane space. Using a CRISPR/Cas9 AK2 biallelic knock out model in human hematopoietic stem and progenitor cells (HSPCs), we have shown that AK2 -/- HSPCs mimic the neutrophil maturation defect in RD patients. Mitochondrial respiration is compromised in AK2 -/- HSPCs, which leads to a decreased NAD +/NADH ratio resulting in reductive stress. Metabolomics analysis by LC-MS/MS showed a significant accumulation of AMP, along with increased AMP/ADP and AMP/ATP ratios in AK2 -/- HSPCs, suggesting that purine metabolism is compromised by AK2 deficiency. Purine metabolism defects, such as deficiencies in adenosine deaminase (ADA) and purine nucleotide phosphorylase (PNP), have long been recognized as a cause of SCID. Furthermore, pharmacological interference with purine metabolism is a highly effective antiproliferative strategy in cancer therapy. In this study, we sought to investigate whether impaired purine metabolism contributes to the myelopoietic defect caused by AK2 deficiency. Results We explored how purine metabolism affects myelopoiesis by differentiating HSPCs in media containing no nucleosides (nucleoside-), mixed nucleosides (nucleoside+) or adenosine only (adenosine+). We observed no difference in proliferation or neutrophil maturation between nucleosides- and nucleoside+ media for both control and AK2 -/- HSPCs, suggesting that AK2 -/- HSPCs do not rely on exogenous nucleosides. Interestingly, control HSPCs cultured in adenosine+ media showed severe proliferation and neutrophil maturation defects that mimic AK2 deficiency, suggesting that purine imbalance is detrimental to myelopoiesis. Previous metabolomics analysis showed a significant accumulation of inosine monophosphate (IMP) in AK2 -/- HSPCs. Since IMP can be produced through AMP deamination by AMPD, we asked whether the IMP accumulation in AK2 -/- HSPCs is caused by converting excess AMP to IMP. An LC-MS/MS analysis showed that AMPD inhibitor (AMPDi) treatment significantly lowered IMP levels and increased AMP levels in AK2 -/- HSPCs, indicating that AMP deamination is a major source of IMP accumulation in AK2 -/- HSPCs. Furthermore, AMPDi treatment did not improve, but rather slightly aggravated neutrophil differentiation in AK2 -/- HSPCs, suggesting that the AK2 -/- neutrophil maturation defect is not caused by IMP accumulation. This raises the possibility that AK2 -/- HSPCs employ AMP deamination as a mechanism to curtail the toxicity of excess AMP. Since purine is a building block of RNA, and ribosomal RNA (rRNA) constitutes >85% of cellular RNA content, we asked whether rRNA synthesis is compromised by AK2 deficiency. Pyronin Y staining showed a significant decrease in rRNA content in AK2 -/- HSPCs. Nascent peptide synthesis rate was also decreased in AK2 -/- HSPCs, as quantified by OP-puromycin uptake. These findings are corroborated by RNA-seq analysis of AK2 -/- and control HSPCs, which showed that ribosomal subunits, ribosomal biogenesis and ribonucleoprotein complex assembly are among the top down-regulated pathways. The data suggest that defective purine metabolism in AK2 -/- HSPCs impairs ribosomal biogenesis and protein synthesis. Conclusion Our studies showed that purine imbalance in HSPCs impairs myeloid proliferation and neutrophil maturation. AK2 depletion in HSPCs leads to AMP accumulation and defective ribosomal biogenesis. AK2 -/- HSPCs convert excess AMP to IMP, possibly as a means to mitigate AMP toxicity. However, AMP deamination activities alone are not sufficient to lower AMP levels to those of control HSPCs. We are currently testing whether boosting 5'-nucleotidase activities (cNIA, cN1B and cNII) in AK2 -/- HSPCs can decrease AMP levels and rescue the neutrophil maturation defect. As purine metabolic defects are associated with diverse immune and non-immune abnormalities, further understanding of how purine metabolism governs differentiation of human HSPCs will enable us to develop novel therapeutic strategies for RD and other purine disorders. Disclosures Porteus: CRISPR Therapeutics: Current equity holder in publicly-traded company; Allogene Therapeutics: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Versant Ventures: Consultancy; Ziopharm: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Graphite Bio: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Morrison: Garuda Therapeutics: Other: founder and SAB member ; Kojin Therapeutics: Other: SAB member ; Frequency Therapeutics: Other: SAB member ; Ona Terapeutics: Other: SAB member ; Protein Fluidics: Other: SAB member .

Combinatorial Antigen Targeting Strategy for Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Pinar Ataca Atilla ◽  
Mary K McKenna ◽  
Norihiro Watanabe ◽  
Maksim Mamonkin ◽  
Malcolm K. Brenner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Tumor Control ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Introduction: Efforts to safely and effectively treat acute myeloid leukemia (AML) by targeting a single leukemia associated antigen with chimeric antigen receptor T (CAR T) cells have had limited success. We determined whether combinatorial expression of chimeric antigen receptors directed to two different AML associated antigens would augment tumor eradication and prevent relapse in targets with heterogeneous expression of myeloid antigens. Methods: We generated CD123 and CD33 targeting CARs; each containing a 4-1BBz or CD28z endodomain. We analyzed the anti-tumor activity of T cells expressing each CAR alone or in co-transduction with a CLL-1 CAR with CD28z endodomain and CD8 hinge previously optimized for use in our open CAR-T cell trial for AML (NCT04219163). We analyzed CAR-T cell phenotype, expansion and transduction efficacy by flow cytometry and assessed function by in vitro and in vivo activity against AML cell lines expressing high, intermediate or low levels of the target antigens (Molm 13= CD123 high, CD33 high, CLL-1 intermediate, KG1a= CD123 low, CD33 low, CLL-1 low and HL60= CD123 low, CD33 intermediate, CLL-1 intermediate/high) For in vivo studies we used NOD.SCID IL-2Rg-/-3/GM/SF (NSGS) mice with established leukemia, determining antitumor activity by bioluminescence imaging. Results: We obtained high levels of gene transfer and expression with both single (CD33.4-1BBʓ, CD123.4-1BBʓ, CD33.CD28ʓ, CD123.CD28ʓ, CLL-1 CAR) and double transduction CD33/CD123.4-1BBʓ or CD33/CD123.CD28ʓ) although single-transductants had marginally higher total CAR expression of 70%-80% versus 60-70% after co-transduction. Constructs containing CD28 co-stimulatory domain exhibited rapid expansion with elevated peak levels compared to 41BB co-stim domain irrespective of the CAR specificity. (p<0.001) (Fig 1a). In 72h co-culture assays, we found consistently improved anti-tumor activity by CAR Ts expressing CLL-1 in combination either with CD33 or with CD123 compared to T cells expressing CLL-1 CAR alone. The benefit of dual expression was most evident when the target cell line expressed low levels of one or both target antigens (e.g. KG1a) (Fig 1b) (P<0.001). No antigen escape was detected in residual tumor. Mechanistically, dual expression was associated with higher pCD3ʓ levels compared to single CAR T cells on exposure to any given tumor (Fig 1c). Increased pCD3ʓ levels were in turn associated with augmented CAR-T degranulation (assessed by CD107a expression) in both CD4 and CD8 T cell populations and with increased TNFα and IFNɣ production (p<0.001 Fig 1d). In vivo, combinatorial targeting with CD123/CD33.CD28ʓ and CLL-1 CAR T cells improved tumor control and animal survival in lines (KG1a, MOLM13 and HL60) expressing diverse levels of the target antigens (Fig 2). Conclusion: Combinatorial targeting of T cells with CD33 or CD123.CD28z CARs and CLL-1-CAR improves CAR T cell activation associated with superior recruitment/phosphorylation of CD3ʓ, producing enhanced effector function and tumor control. The events that lead to increased pCD3ʓ after antigen engagement in the dual transduced cells may in part be due to an overall increase in CAR expression but may also reflect superior CAR recruitment after antigen engagement. We are now comparing the formation, structure, and stability of immune synapses in single and dual targeting CARs for AML. Disclosures Brenner: Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Founder; Maker Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Other: Founder; Memmgen: Membership on an entity's Board of Directors or advisory committees; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Atilla:Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: founder; Marker Therapeuticsa: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Other: Founder, Patents & Royalties; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Memgen: Membership on an entity's Board of Directors or advisory committees; KUUR: Membership on an entity's Board of Directors or advisory committees.

Evolving Unmet Need in Patients Refractory to Lenalidomide: Overview of the Clinical Trials in Relapsed/Refractory Multiple Myeloma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Maria-Victoria Mateos ◽  
Rohan Medhekar ◽  
Istvan Majer ◽  
Mehmet Turgut
Keyword(s):  
Multiple Myeloma ◽  
Clinical Trials ◽  
Literature Review ◽  
Board Of Directors ◽  
Unmet Need ◽  
Publicly Traded ◽  
First Line ◽  
Advisory Committees ◽  
Line Of Therapy

Introduction: The majority of newly diagnosed multiple myeloma (NDMM) patients are currently treated with lenalidomide-based regimens as their first line of therapy. This trend is likely to continue in the coming years. Typically, lenalidomide is administered until disease progression and has significantly contributed to better outcomes in these patients. However, most patients relapse, and prognosis worsens with each relapse. The choice of optimal treatment for patients who relapse while receiving lenalidomide as first line of therapy is unclear. Moreau et al (Blood Cancer J. 9, 38 [2019]) concluded that there is limited data on approved combinations for treating these patients and are restricted by the low number of lenalidomide-refractory patients enrolled in the pivotal trials. Results from the ongoing clinical trials of the combination of carfilzomib and anti-CD38 antibodies were not available at the time of the Moreau et al publication. The aim of this targeted literature review was to include this new data and to summarize currently available evidence on progression-free survival (PFS) for the treatment of RRMM patients who progressed on lenalidomide-based regimens. Methods: A targeted literature review was conducted to identify registrational clinical trials in patients with RRMM reporting PFS outcomes. PubMed, congress proceedings, and product labels were searched between Jan 2014 to July 2020. In addition to PFS, demographic, disease characteristics and treatment history were extracted for the trial populations to contextualize potential variations in study outcomes. The regimens studied in these trials were classified as lenalidomide-based, proteasome inhibitor (PI)-based and pomalidomide-based. Number of prior lines of therapy, prior exposure and refractoriness to lenalidomide and bortezomib were reported. Results: Twelve registrational trials were identified based on the search criteria (Table 1). Most pivotal trials assessing lenalidomide-based regimens (POLLUX, ELOQUENT-II, TOURMALINE-MM1) except the ASPIRE trial excluded patients who were refractory to lenalidomide. Trials evaluating PI-based regimens (e.g., CANDOR) or pomalidomide-based regimens (e.g., OPTIMISMM) included these patients, with more recent studies enrolling a larger proportion. Percentage of lenalidomide-exposed (and lenalidomide refractory) ranged from 40% (32%) in CANDOR to 98% (90%) in ELOQUENT III. These studies also enrolled a larger proportion of patients who were bortezomib-exposed, although most of these patients were at first relapse, with the exception of ELOQUENT III and ICARIA where most patients were at third relapse. Among lenalidomide-refractory patients, the median-PFS (mPFS) observed for the pomalidomide-based regimens ranged from 9.5 to 10.1 months and that observed for PI-based regimens ranged from 4.9 to 25.7 months. PFS in the lenalidomide-refractory subgroup was considerably shorter than in the ITT population. The mPFS for patients receiving carfilzomib/daratumumab/dexamethasone (KDd; CANDOR) and isatuximab/carfilzomib/dexamethasone (IsaKd; IKEMA) was not reached at median follow-up of 16.9 and 20.7 months respectively. While the mPFS for (KDd) for lenalidomide-refractory patients in CANDOR trial was not yet reached at median follow up of 16.9 months; the mPFS of 25.7 months for KDd in the MMY-1001 trial appears to be the longest among the assessed regimens. Conclusion: Patients refractory to lenalidomide have shorter PFS and represent a population with high unmet need. This targeted literature review suggests that the PI-based KDd regimen provides longer PFS compared to other lenalidomide-sparing regimens in lenalidomide-refractory populations. Heterogeneity across trial populations may limit the comparability of these treatments. Disclosures Mateos: Regeneron: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Consultancy, Honoraria; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie/Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; PharmaMar-Zeltia: Consultancy; GlaxoSmithKline: Consultancy. Medhekar:Amgen Inc.: Current Employment, Current equity holder in publicly-traded company. Majer:Amgen (Europe) GmbH: Current Employment, Current equity holder in publicly-traded company.

scholarly journals Effect of Moderate and Severe Hemophilia a on Daily Life in Children and Their Caregivers: A CHESS Paediatrics Study Analysis

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 43-45
Author(s):  
Kate Khair ◽  
Francis Nissen ◽  
Mariabeth Silkey ◽  
Tom Burke ◽  
Aijing Shang ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Disease Burden ◽  
Hemophilia A ◽  
Daily Life ◽  
Social Activity ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Lost Work ◽  
Hours Of Work

Introduction: Hemophilia A (HA) is a congenital bleeding disorder, caused by a deficiency in clotting factor VIII (FVIII) and characterized by uncontrolled bleeding and progressive joint damage. This analysis assesses the impact of disease burden on the daily life of children with hemophilia A (CwHA) and their caregivers, addressing a deficit of current research on this topic. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey in a Paediatric Population (CHESS Paediatrics) is a retrospective, burden-of-illness study in children with moderate and severe HA (defined by endogenous FVIII [IU/dL] relative to normal; moderate, 1-5%; severe, <1%) across France, Germany, Italy, Spain and the UK. CwHA were recruited and stratified by both age group (0-5 years:6-11 years:12-17 years=1:1:1) and disease severity (severe:moderate=approximately 2:1, prioritizing children with severe HA [CwSHA]). Data for this analysis were captured from physicians, children, and their caregivers. Physicians completed online case report forms for treated children, and the child and/or their caregivers completed a paper-based questionnaire utilizing 5-point Likert scales. For CwHA aged 0-7, the questionnaire was completed by the caregiver, while for CwHA aged 8-17, children and caregivers completed different sections. Hours of care provided by the caregiver and work lost by the caregiver were reported as median values due to non-normal data distribution. Informed consent was obtained for all participants. Upon review, the study was approved by the University of Chester ethical committee. Results: Data from child/caregiver questionnaires were available for 196 CwHA (moderate, 25.5%; severe, 74.5%); the majority of these children, as expected, were receiving prophylaxis (72.4%), and did not have FVIII inhibitors (89.8%; Table 1). There was a direct impact of disease burden on CwHA, particularly with regard to physical and social activities (Figure 1). Overall, it was agreed or strongly agreed by the child or caregiver that 48.0% and 57.5% of children with moderate HA (CwMHA) and CwSHA respectively, have reduced physical activity due to HA, and 46.0% and 57.5%, respectively, have reduced social activity due to HA. A total of 36.0% and 61.0% of CwMHA and CwSHA, respectively, had adapted their treatment in anticipation of physical or social activity (Table 1). Furthermore, 34.0% of CwMHA and 55.4% of CwSHA were frustrated due to their disease, and many (CwMHA, 36.0%; CwSHA, 50.7%) felt that they had missed opportunities (Figure 1). For 66.0% of CwMHA and 76.0% of CwSHA, it was reported that their daily life was compromised due to their HA. Caregivers provided a median (interquartile range [IQR]) of 19.0 (10.0-59.5) and 12.0 (5.0-20.0) hours a week of care for the hemophilia-related needs of their CwMHA (n=30) or CwSHA (n=105), respectively. Of those who responded, 17.4% (n=4/23) and 25.0% (n=20/80) of caregivers to CwMHA or CwSHA, respectively, stated they have lost work due to their caregiving duty. This was more than twice as common for caregivers in families with multiple CwHA (42.9%, n=9/21 responses) compared with those in families with one CwHA (18.5%, n=15/81 responses). Median (IQR) hours of work per week estimated to be lost were 20.0 (17.0-22.0) for caregivers of CwMHA (n=4) and 12.5 (4.50-20.0) for caregivers of CwSHA (n=20). Conclusions: In conclusion, both children and caregivers make sacrifices in their daily lives due to HA; many CwHA reported reduced physical and social activities, fewer opportunities and feelings of frustration due to their HA. Caregivers reported spending a significant number of hours caring for their child and some reported losing work due to their caring responsibilities. However, some outcomes may be limited by the small number of respondents and narrow response options, particularly those regarding the caregiver burden. Responses on the hours of work lost may be subject to selection bias, as caregivers who have lost work may be more likely to respond to this question. Additionally, as this question is targeted at caregivers in employment, it is unknown if some caregivers have left employment due to their caregiving responsibilities. According to this analysis, children/caregivers are frequently required to adapt the child's treatment before the child engages in activities. Overall, the burden of disease was similar in children with moderate and severe HA. Disclosures Khair: Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Haemnet: Membership on an entity's Board of Directors or advisory committees. Nissen:GSK: Research Funding; Novartis: Research Funding; Actelion: Consultancy; F. Hoffmann-La Roche Ltd: Current Employment. Silkey:Aerotek AG: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Burke:HCD Economics: Current Employment; University of Chester: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Shang:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Aizenas:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara:HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Noone:Research Investigator PROBE: Research Funding; Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees.

scholarly journals To Treat or Not to Treat? Understanding Treatment Patterns in Patients with Lower-Risk Myelofibrosis at the Time of Enrollment in the MOST Study

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 49-51
Author(s):  
Rami S. Komrokji ◽  
Brady L. Stein ◽  
Robyn M. Scherber ◽  
Patricia Kalafut ◽  
Haobo Ren ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Lower Risk ◽  
Research Funding ◽  
Symptom Burden ◽  
Risk Groups ◽  
Treatment Patterns ◽  
Low Risk ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Therapy Initiation

Background: Myelofibrosis (MF) is a chronic Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) characterized by extramedullary hematopoiesis, bone marrow fibrosis, splenomegaly, constitutional symptoms, and diminished quality of life. Treatment decisions may involve a variety of factors including prognosis and symptomatology. Data regarding real-world disease and demographic factors that contribute to therapy initiation and choice in pts with lower risk MF are limited. This analysis of data from the ongoing Myelofibrosis and Essential Thrombocythemia Observational STudy (MOST; NCT02953704) assessed whether these factors differ for lower risk pts who were treated vs untreated at enrollment. Methods: MOST is a longitudinal, noninterventional, prospective, observational study in pts with MF or essential thrombocythemia enrolled at clinical practices within the US. Pts included in the analysis (≥18 y), had low risk MF by the Dynamic International Prognostic Scoring System (DIPSS; Blood. 2010;115:1703), or intermediate-1 (INT-1) risk by age >65 y alone. Pt data were entered into an electronic case report form during usual-care visits over a planned 36-month observation period. Pt-reported symptom burden was assessed using the MPN-Symptom Assessment Form (MPN-SAF); Total Symptom Score (TSS) was calculated (0 [absent] to 100 [worst imaginable]; J Clin Oncol. 2012;30:4098). Data were analyzed with basic descriptive and inferential statistics. Results: Of 233 pts with MF enrolled at 124 sites between 11/29/2016 and 03/29/2019, 205 were included in this analysis; 28 were excluded for being INT-1 risk for reasons other than age. Of the 205 pts, 85 (41.5%) were low- and 120 (58.5%) were INT-1 risk; 56.5% (48/85) and 59.2% (71/120), respectively, were being treated at enrollment. Pt characteristics are listed in Table 1A. Fewer low- vs INT-1 risk pts were JAK2 V617F or MPL positive, and more were CALR positive. The proportion of pts with palpable splenomegaly was similar for treated low- and INT-1 risk pts. In low risk pts, the proportion of pts with palpable splenomegaly was higher in untreated vs treated pts; whereas, in INT-1 risk pts, the opposite was observed (ie, lower proportion in untreated vs treated pts). Blood counts were generally similar across cohorts, except median leukocytes were lower for low risk treated pts and platelet counts were elevated in low- vs INT-1 risk pts. The proportion of pts with comorbidities was similar across cohorts, except for fewer cardiovascular comorbidities in low- vs INT-1 risk pts. Mean TSS was lower in low- vs INT-1 risk pts, but the proportion of pts with TSS ≥20 was greater in treated vs untreated pts in both low- and INT-1 risk groups. Fatigue was the most severe pt-reported symptom in all cohorts. Differences in mean TSS and individual symptom scores between risk groups were not significant (P > 0.05), except itching was worse among INT-1 risk pts (P=0.03). Physician-reported signs and symptoms were generally more frequent for untreated vs treated pts, irrespective of risk (all P > 0.05). Most low risk (69.4%) and INT-1 risk pts (61.2%) who were currently untreated at enrollment had not received any prior MF-directed treatment (Table 1B); the most common prior treatment among currently untreated pts was hydroxyurea (HU) in both risk groups. Of currently treated pts, HU was the most common MF-directed monotherapy at enrollment in low-risk pts, and ruxolitinib was most common in INT-1 risk pts. No low risk pts and few INT-1 risk pts were currently receiving >1 MF-directed therapy at enrollment. Conclusion: These real-world data from pts with MF enrolled in MOST show that a substantial proportion of both low- and INT-1 risk pts who had received treatment before enrollment were not being treated at the time of enrollment. Although watch-and-wait is a therapeutic option, the finding that many of these lower risk pts had in fact received prior therapies suggests an unmet need for effective and tolerable second-line treatment options. Treated pts had greater pt-reported symptom burden vs untreated pts, which suggests that high symptom burden may contribute to the decision for treatment. Prospective studies are needed to evaluate symptom burden change with therapy initiation. In this regard, future analyses of data from MOST are planned to assess the longitudinal evolution of the clinical characteristics, treatment patterns, and management of pts with MF. Disclosures Komrokji: Geron: Honoraria; Agios: Honoraria, Speakers Bureau; AbbVie: Honoraria; Incyte: Honoraria; Novartis: Honoraria; BMS: Honoraria, Speakers Bureau; JAZZ: Honoraria, Speakers Bureau; Acceleron: Honoraria. Stein:Incyte: Research Funding; Kartos: Other: educational content presented; Constellation Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Pharmaessentia: Membership on an entity's Board of Directors or advisory committees. Scherber:Incyte Corporation: Current Employment, Current equity holder in publicly-traded company. Kalafut:Incyte: Current Employment, Current equity holder in publicly-traded company. Ren:Incyte: Current Employment, Current equity holder in publicly-traded company. Verstovsek:Incyte Corporation: Consultancy, Research Funding; Roche: Research Funding; Genentech: Research Funding; Blueprint Medicines Corp: Research Funding; CTI Biopharma Corp: Research Funding; NS Pharma: Research Funding; ItalPharma: Research Funding; Celgene: Consultancy, Research Funding; Gilead: Research Funding; Protagonist Therapeutics: Research Funding; Novartis: Consultancy, Research Funding; Sierra Oncology: Consultancy, Research Funding; PharmaEssentia: Research Funding; AstraZeneca: Research Funding; Promedior: Research Funding.

RNA Polymerase I Inhibition with CX-5461 As a Novel Strategy to Target MYC in Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3010-3010 ◽  
Author(s):  
Hans Lee ◽  
Hua Wang ◽  
Heather Lin ◽  
Veera Baladandayuthapani ◽  
Jin He ◽  
...  
Keyword(s):  
Western Blot ◽  
Board Of Directors ◽  
Cell Lines ◽  
Ribosomal Proteins ◽  
Research Funding ◽  
Myeloma Cell ◽  
Ribosomal Biogenesis ◽  
Advisory Committees ◽  
Pol I

Abstract Background: The role of dysregulation of the proto-oncogene MYC in both early and late myeloma progression events is well established. Among key MYC -downstream targets is upregulation of ribosomal biogenesis, resulting in increased protein translational capacity and biomass accumulation that is characteristic of neoplastic cells. Thus, given the relationship between myeloma pathobiology, MYC dysregulation, and ribosomal biogenesis, we hypothesized that selective targeting of ribosomal RNA (rRNA) transcription with the small molecule RNA polymerase (pol) I inhibitor CX-5461 (Senhwa Biosciences) may represent a novel therapeutic strategy in myeloma. Methods: Studies with CX-5461 were performed in human myeloma cell lines, isogenic p53 wild-type (wt) and knock-out (KO) p53 cells generated using sequence-specific zinc-finger nucleases, drug-resistant cell lines, primary patient samples, and myeloma murine xenograft models using NOD-SCID IL2Rgnull mice. Results: CX-5461 treatment of p53 wt (MM1.S, MOLP-8) and p53 mutant (U266, RPMI-8226) myeloma cell lines demonstrated a time- and dose-dependent decrease in cell proliferation with a median inhibitory concentration (IC50) at nM levels after 72 hours. A corresponding increase in cleaved-PARP, cleaved caspase-9, and cleaved caspase-3 expression was seen on Western blot as well as increased Annexin V staining on flow cytometry analysis, although this was more pronounced in p53 wt versus mutant cell lines. CX-5461 also retained activity in a panel of cell lines resistant to standard myeloma therapeutic agents (bortezomib, carfilzomib, lenalidomide, and doxorubicin) and in primary patient samples, including a heavily pretreated relapsed/refractory patient and a de novo plasma cell leukemia patient with del 17p. In vivo studies using a systemic isogenic MM1.S p53 wt and KO myeloma murine xenograft model demonstrated significant improvement in median overall survival in the CX-5461-treated p53 wt cohort (41 days vs. not reached, P .05), although outcomes were more modest in the p53 KO cohort with only a trend towards improved survival (P.1) in the drug-treated mice. To probe the p53-independent effects of CX-5461, gene expression profiling and gene set enrichment analysis was performed on isogenic MM1.S and MOLP-8 p53 wt and KO myeloma cell lines treated with CX-5461 or vehicle. These results suggested downregulation of MYC downstream targets as one p53-independent effect of RNA pol I inhibition. qPCR and Western blot studies revealed rapid downregulation of MYC at the transcript level within 1-hour of CX-5461 treatment followed by decreases in MYC protein levels. Previous studies have suggested ribosomal biogenesis is tightly controlled by an auto-regulatory feedback mechanism in which ribosomal proteins such as RPL5 and RPL11 can bind to the 3'UTR of MYC mRNA and facilitate its degradation through the RNA-induced silencing complex (RISC). Because RNA pol I inhibition is known to induce a nucleolar stress response and increase the availability of free ribosomal proteins, RISC-mediated degradation of MYC mRNA was explored as one possible mechanism of CX-5461-mediated MYC downregulation. Indeed, treatment with CX-5461 led to increased pull-down of RPL5 when immunoprecipitated with the RISC subunit TAR (HIV-1) RNA Binding Protein 2 (TARBP2) compared to vehicle-treated controls, and RNA immunoprecipitation assays with the catalytic RISC subunit, Argonaute 2 (AGO2), demonstrated enrichment of MYC mRNA with CX-5461 treatment. These results suggest that CX-5461 may induce degradation of MYC through the cooperative binding of ribosomal proteins, RISC subunits, and MYC mRNA. Finally, to evaluate the role of MYC expression and ribosomal biogenesis in relation to CX-5461 sensitivity, MYC was overexpressed in the H1112 myeloma cell line, which at baseline does not harbor a MYC translocation. MYC overexpression in H1112pCDH-myc cells led to increased basal pre-rRNA transcript levels compared to H1112pCDH cells, and furthermore, led to enhanced sensitivity to CX-5461. Conclusion: RNA pol I inhibition by CX-5461 is a promising target in myeloma therapy, with downregulation of MYC representing one mechanism of action. Moreover, increased MYC expression enhances sensitivity to CX-5461, providing rationale for the clinical translation of CX-5461 for the treatment of myeloma and other MYC-driven cancers. Disclosures O'Brien: Senhwa Biosciences, Inc.: Employment. Keats:Translational Genomic Research Institute: Employment. Orlowski:Bristol-Myers Squibb: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Acetylon: Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Forma Therapeutics: Consultancy; Genentech: Consultancy; BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Array BioPharma: Consultancy, Research Funding.

scholarly journals Outcomes with Interferon in Essential Thrombocythemia: A Systematic Review and Meta-Analysis

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3147-3147
Author(s):  
Moazzam Shahzad ◽  
Mamoon Ahmed ◽  
Sakina Abbas ◽  
Muhammad Arslan ◽  
Tooba Kashif ◽  
...  
Keyword(s):  
Systematic Review ◽  
Board Of Directors ◽  
Interferon Alpha ◽  
Essential Thrombocythemia ◽  
Research Funding ◽  
Meta Analysis ◽  
Molecular Response ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Hematological Response

Abstract Introduction Essential thrombocythemia (ET) is a BCR-ABL negative myeloproliferative disorder characterized by high burden of symptoms, thrombocytosis, increased risk of thrombosis and bleeding, and risk of progression to Myelofibrosis. Interferon alpha (IFN-α) is a potent immunomodulation agent proposed to be capable of inducing complete hematological remission in patients with myeloproliferative disorders. Many INF- α have been studied for treatment of patients with ET. We present a systematic review and meta-analysis assessing the efficacy of IFN-α therapy in patients with ET. Methods Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a comprehensive literature search was conducted on PubMed, Cochrane, and Clinical trials.gov using MeSH terms and keywords for " Thrombocythemia, Essential " AND " Interferons " in April 2021. We did not place any time constraints. Our search produced a total of 825 records and duplicates were removed. After screening and removing irrelevant and review articles, we included 21 original articles reporting IFN-α as the only treatment for ET in adult patients. The data were collected for baseline characteristics of the participants and efficacy and safety of the intervention. Quality evaluation was done using the NIH quality assessment tool. The inter-study variance was calculated using the Der Simonian-Laird Estimator. Proportions along with 95% Confidence Interval (CI) were extracted to compute pooled analysis using the 'meta' package by Schwarzer et al. in the R programming language (version 4.16-2). Results A total of 388 patients from 21 articles were evaluated. The median age of participants was 54 (35-62) years and 31% (n=64/205) were males. The type of IFN used were Interferon-alpha in 4 studies, pegylated (PEG)IFN-α-2a in 2 studies, IFN-α-2b in 6 studies, recombinant IFN-α-2C in 3 studies, recombinant IFN-y in 1 study, PEG-IFN-2b in 1 study, recombinant IFN-2b in 2 studies, and PEG-IFN in 1 study. The pooled overall hematological response (OHR) was 86.4% (95% Cl 0.67-0.98, I 2= 65%, p=0.02, n=73) with complete hematological response (CHR) of 70.6% (95% Cl 0.54-0.84, I 2=34%, p=0.21, n=65) and partial hematological response (PHR) of 13% (95% Cl 0.02-0.27, I 2=42%, p=0.16, n=65). The pooled overall molecular response (OMR) was 84% (95% Cl 0.72-0.93, I 2=13%, p=<0.01, n=81) with complete molecular response (CMR) of 64.2% (95% Cl 0.41-0.84, I 2=68%, p=<0.01, n=81) and partial molecular response (PMR) of 35% (95% Cl 0.16-0.56, I 2=33%, p=0.01, n=43). Side effects reported were nausea, allergic reactions, liver dysfunction, dose dependent mild myalgia, fever, malaise, itching, persistent fever, headache, and flu like symptoms. Conclusion Interferon alpha, in different formulations shows consistent and high activity in patients with essential thrombocythemia. It resulted in clinical responses, as well as molecular responses. Side effect profiles were consistent among different reports and were reasonable tolerated. There is a large body of evidence supporting actively and safety of this approach in a diverse ET patient population. Figure 1 Figure 1. Disclosures McGuirk: Gamida Cell: Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Astelllas Pharma: Research Funding; Novartis: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Bellicum Pharmaceuticals: Research Funding; Fresenius Biotech: Research Funding; Novartis: Research Funding; EcoR1 Capital: Consultancy; Pluristem Therapeutics: Research Funding. Yacoub: Dynavex: Current equity holder in publicly-traded company; Cara: Current equity holder in publicly-traded company; Ardelyx: Current equity holder in publicly-traded company; Agios: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ACCELERON PHARMA: Membership on an entity's Board of Directors or advisory committees; CTI Biopharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Speakers Bureau; Hylapharm: Current equity holder in publicly-traded company.

scholarly journals A Phase I Trial of the Antibody-Cytokine Fusion Protein F16IL2 in Combination with Anti-CD33 Immunotherapy for Posttransplant AML Relapse

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2345-2345
Author(s):  
Andrew F. Berdel ◽  
Christoph Rollig ◽  
Martin Wermke ◽  
Linus Angenendt ◽  
Leo Ruhnke ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Nk Cells ◽  
Board Of Directors ◽  
Dose Escalation ◽  
Research Funding ◽  
Human Antibody ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Hematopoietic Stem ◽  
Dose Levels

Abstract Introduction Natural killer (NK) cells are key effectors in cancer immunosurveillance and posttransplant immunity, but shortage of environmental growth factors and deficient recognition of malignant cells may limit their anticancer efficacy. We hypothesized that the antibody-mediated anchoring of interleukin-2 (IL-2) to the leukemia-modified extracellular matrix (ECM) would increase NK cell abundance and activity to potentiate antibody-dependent cellular cytotoxicity (ADCC) against acute myeloid leukemia (AML) blasts. In this novel-novel combination dose-escalation phase 1 trial, we enrolled patients with AML relapse after allogeneic hematopoietic stem cell transplantation (HSCT) to evaluate the safety, pharmacokinetics, pharmacodynamics, and preliminary activity of F16IL2, an antibody-cytokine fusion protein composed of the human antibody fragment scFv(F16) in diabody format and two molecules of human IL-2, in combination with the Fc-optimized, ADCC-mediating anti-CD33 monoclonal antibody BI 836858. F16 specifically targets the A1 domain of the ECM protein tenascin C (TnC), which is spliced into the TnC molecule during active angiogenesis and tissue remodeling while it is virtually absent in normal tissues. Methods F16IL2 (10 - 20 Mio IU IV) was administered on days 1, 8, 15 and 22 of 28-day cycles, followed by administration of BI 836858 (10 - 40 mg IV) two days after each F16IL2 infusion. Dose escalation was performed over 4 dose levels (DL). Cohort 1 (10 Mio IU F16IL2 and 10 mg BI 836858, n = 5), cohort 2 (10 Mio IU F16IL2 and 20 mg BI 836858, n = 3), cohort 3 (20 Mio IU F16IL2 and 20 mg BI 836858, n = 4), cohort 4 (20 Mio IU F16IL2 and 40 mg BI 836858, n = 3). Safety and tolerability, pharmacodynamics and -kinetics, clinical efficacy and immune effector cell dynamics were investigated. This trial was registered at EudraCT as #2015-004763-37. Results Between December 2016 and March 2020, 15 patients with a median age of 50 years (range, 20 - 68) were enrolled and treated across 4 dose levels. Six patients (40%) had received two or more prior HSCT. The most frequent drug-related AEs (F16IL2 or BI 836858 or combination) were pyrexia (n = 13, 87%), chills (n = 12, 80%) and infusion-related reactions (n = 9, 60%), consistent with the expected toxicity profile of cytokine-armed or naked mAbs. These events were generally manageable, transient and of grade ≤ 2. One dose-limiting toxicity occurred at each of DL 3 (pulmonary edema) and 4 (acute GVHD). No patient died within the first 30 days of treatment initiation. Whereas no formal maximum tolerated dose (MTD) was reached, the maximum tested dose of 20 Mio IU F16IL2 and 40 mg BI 836858 was considered the recommended dose (RD). Three objective responses (1 CR, 1 CRi, 1 PR in extramedullary AML) were observed among 7 patients treated at the two higher DL, whereas no responses occurred at the two starting DL. Median OS among all 15 patients was 4.8 months (1.5 - 12.9), with a 6- and 12-month OS of 40% and 27%, respectively. Among those 7 patients whose AML was at least temporarily controlled with study treatment (CR/CRi, PR, SD), 12-month OS was 67% vs. 0% in non-responders. Combination therapy stimulated the expansion and activation of NK cells in bone marrow and peripheral blood. Conclusions To the best of our knowledge, this is the first study demonstrating that the strategy of potentiating ADCC with tumor-targeted immunocytokines is feasible in humans. In the difficult-to-treat situation of posttransplant AML relapse, responses were observed at higher DL, even in patients with extramedullary disease. The antibody-mediated targeted delivery of IL-2 to the ECM combined with anti-CD33 immunotherapy represents an innovative experimental approach associated with acceptable safety and encouraging biologic and clinical activity in posttransplant AML relapse. Disclosures Wermke: Novartis, Roche, Pfizer, BMS: Consultancy, Honoraria, Research Funding. Hemmerle: Philogen S.p.A.: Current Employment. Schäfers: Philogen S.p.A.: Research Funding. Rossig: BMS and Celgene: Honoraria; Pfizer: Honoraria; Novartis: Honoraria; AdBoards by Amgen: Honoraria. Stelljes: Pfizer: Consultancy, Research Funding, Speakers Bureau; Kite/Gilead: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Medac: Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Rueter: Boehringer Ingelheim Pharma GmbH & Co. KG: Current Employment. Neri: Philogen S.p.A.: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Multiple patents on vascular targeting; ETH Zurich: Patents & Royalties: CD117xCD3 TEA. Berdel: Philogen S.p.A.: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees. Schliemann: Roche: Consultancy; Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Astellas: Consultancy; Pfizer: Consultancy; BMS: Consultancy, Other: travel grants; Boehringer-Ingelheim: Research Funding; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding; AstraZeneca: Consultancy; Abbvie: Consultancy, Other: travel grants.

scholarly journals Efficacy and Safety of Voxelotor in Adolescents and Adults with Sickle Cell Disease: HOPE Trial 72-Week Analysis

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 19-19
Author(s):  
Jo Howard ◽  
Kenneth I. Ataga ◽  
R. Clark Brown ◽  
Maureen Achebe ◽  
Videlis Nduba ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Board Of Directors ◽  
Research Funding ◽  
Efficacy And Safety ◽  
Cell Disease ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Time Points ◽  
Indirect Bilirubin ◽  
Safety Signals

Background: Sickle cell disease (SCD) is a lifelong, inherited disorder characterized by mutations in the hemoglobin (Hb) subunit β gene that leads to the production of sickle hemoglobin (HbS). When HbS is deoxygenated, polymerization leads to red blood cell sickling and damage, resulting in hemolysis, chronic anemia, and episodic vaso-occlusive crises (VOCs). Patients with SCD are at an increased risk of developing long-term complications, including stroke, leg ulcers, and other end-organ damage. Lower Hb levels highly correlate with increased morbidity and early mortality in SCD. Voxelotor (Oxbryta®) is an oral, once-daily HbS polymerization inhibitor indicated for the treatment of SCD in adults and adolescent patients ≥12 years of age. The 24-week analysis of the HOPE trial demonstrated that treatment with voxelotor 1500 mg resulted in a significantly greater proportion of patients achieving a >1 g/dL Hb increase compared with placebo (51.1% vs 6.5%, P<0.001), which was associated with concordant improvements in hematological markers of hemolysis (indirect bilirubin and reticulocyte percentage). Here we report the evaluation of efficacy and safety of voxelotor 1500 mg at 72 weeks, the conclusion of the placebo-controlled HOPE trial. Methods: In the randomized, double-blinded, placebo-controlled, phase 3 HOPE trial, adults and adolescents (aged 12-65 years) with SCD were randomized to receive voxelotor (1500 mg or 900 mg) or placebo. Included patients had an Hb level of 5.5 to 10.5 g/dL at enrollment and 1 to 10 vaso-occlusive crises in the 12 months prior to screening. Concurrent hydroxyurea was allowed if the dose had been stable for ≥90 days at enrollment. Changes from baseline in Hb and hemolysis markers (absolute and percentage reticulocyte, indirect bilirubin levels, and lactate dehydrogenase levels) and safety were assessed at week 72. Results: 89% (95% CI, 82.4% to 95.4%) of patients receiving voxelotor 1500 mg achieved a Hb increase of >1 g/dL at 1 or more time points during the 72-week treatment period compared with 25% (95% CI, 16.2% to 33.8%) of those receiving placebo (P<0.001). The mean change in Hb from baseline at week 72 was 1.0 g/dL in patients treated with voxelotor 1500 mg compared with 0.0 g/dL in patients receiving placebo (Figure 1; P<0.001). Mean change from baseline to average Hb throughout the 72-week duration was 1.26 g/dL in patients treated with voxelotor 1500 mg. Consistent with the week 24 analysis, significant improvements in markers of hemolysis (assessed by difference in adjusted mean percent change versus placebo) were seen in indirect bilirubin (-26.6% [95% CI, -40.2% to -12.9%]) and reticulocyte percentage (-18.6% [95% CI, -33.9% to -3.3%]) in the voxelotor 1500 mg group relative to placebo, with favorable trends of reduction in other markers, such as absolute reticulocyte count (-5.8% [95% CI, -23.4% to 11.9%] and lactate dehydrogenase (-4.8% [95% CI, -13.8% to 4.1%]). The overall incidence rate of VOCs was numerically lower in the 1500 mg arm compared with placebo, but was not statistically significant. Rates of non-SCD and SCD-related treatment-emergent adverse events were similar between the treatment groups, with no new safety signals noted through week 72. Conclusions: Voxelotor 1500 mg resulted in durable improvements in Hb levels and markers of hemolysis out to 72 weeks of treatment, with approximately 90% of patients achieving an increase in Hb >1 g/dL at 1 or more time points during the study. Treatment with voxelotor remained well tolerated, with no new safety signals detected with longer-term follow-up. These results support the sustained and chronic use of voxelotor to reduce anemia and hemolysis, thereby potentially mitigating the associated morbidity and mortality of SCD. Disclosures Howard: Imara, Inc., Novartis, Resonance Health: Honoraria; Agios, Forma Therapeutics, Inc., Global Blood Therapeutics, Imara, Inc., Novo Nordisk, Novartis: Membership on an entity's Board of Directors or advisory committees. Ataga:Editas Medicine: Honoraria; Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Shire/Takeda: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; Forma Therapeutics: Consultancy; Modus Therapeutics: Honoraria; Bioverativ: Honoraria, Membership on an entity's Board of Directors or advisory committees. Achebe:Global Blood Therapeutics: Consultancy. Hassab:Global Blood Therapeutics: Research Funding. Agodoa:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Tonda:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Gray:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Lehrer-Graiwer:Global Blood Therapeutics: Other: Former employee and former equity holder. Vichinsky:Pfizer: Research Funding; Agios: Research Funding; Global Blood Therapeutics: Consultancy.

scholarly journals Gabarap Loss Mediates Immune Escape in High Risk Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 891-891
Author(s):  
Annamaria Gulla ◽  
Eugenio Morelli ◽  
Mehmet K. Samur ◽  
Cirino Botta ◽  
Megan Johnstone ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Clinical Outcome ◽  
Board Of Directors ◽  
Research Funding ◽  
Immune Escape ◽  
Publicly Traded ◽  
Advisory Committees

Abstract Immune therapies including CAR T cells and bispecific T cell engagers are demonstrating remarkable efficacy in relapsed refractory myeloma (MM). In this context, we have recently shown that proteasome inhibitor bortezomib (BTZ) results in immunogenic cell death (ICD) and in a viral mimicry state in MM cells, allowing for immune recognition of tumor cells. Induction of a robust anti-MM immune response after BTZ was confirmed both in vitro and in vivo: treatment of 5TGM1 MM cells with BTZ induced tumor regression associated with memory immune response, confirmed by ELISPOT of mouse splenocytes. We have confirmed the obligate role of calreticulin (CALR) exposure in phagocytosis and the ICD process, since BTZ-induced ICD is impaired in CALR KO MM cells both in vitro and in vivo. We further showed that the therapeutic efficacy of BTZ in patients was correlated with ICD induction: BTZ-induced ICD signature was positively correlated with OS (p=0.01) in patients enrolled in the IFM/DFCI 2009 study. Together, these studies indicate that ICD is associated with long-term response after BTZ treatment. In this work, we reasoned that genomic or transcriptomic alterations associated with shorter survival of MM patients after BTZ treatment may impair activation of the ICD pathway. To this aim, we performed a transcriptomic analysis of purified CD138+ cells from 360 newly diagnosed, clinically-annotated MM patients enrolled in the IFM/DFCI 2009 study. By focusing on genes involved in the ICD process, we found that low levels of GABA Type A Receptor-Associated Protein (GABARAP) were associated with inferior clinical outcome (EFS, p=0.0055). GABARAP gene locus is located on chr17p13.1, a region deleted in high risk (HR) MM with unfavorable prognosis. Remarkably, we found that correlation of low GABARAP levels with shorter EFS was significant (p=0.018) even after excluding MM patients with del17p; and GABARAP is therefore an independent predictor of clinical outcome. GABARAP is a regulator of autophagy and vesicular trafficking, and a putative CALR binding partner. Interestingly, among a panel of MM cell lines (n=6), BTZ treatment failed to induce exposure of CALR and MM cell phagocytosis by DCs in KMS11 cells, which carry a monoallelic deletion of GABARAP. This effect was rescued by stable overexpression of GABARAP. Moreover, CRISPR/Cas9-mediated KO of GABARAP in 3 ICD-sensitive cell lines (AMO1, H929, 5TGM1) abrogated CALR exposure and ICD induction by BTZ. GABARAP add-back by stable overexpression in KO clones restored both CALR exposure and induction of ICD, confirming GABARAP on-target activity. Similarly, pre-treatment of GABARAP KO cells with recombinant CALR restored MM phagocytosis, further confirming that GABARAP impairs ICD via inhibition of CALR exposure. Based on these findings, we hypothesized that GABARAP loss may alter the ICD pathway via CALR trapping, resulting in the ICD resistant phenotype observed in GABARAP null and del17p cells. To this end, we explored the impact of GABARAP KO on the CALR protein interactome, in the presence or absence of BTZ. Importantly, GABARAP KO produced a significant increase of CALR binding to stanniocalcin 1 (STC1), a phagocytosis checkpoint that mediates the mitochondrial trapping of CALR, thereby minimizing its exposure upon ICD. Consistently, GABARAP KO also affected CALR interactome in BTZ-treated cells, which was significantly enriched in mitochondrial proteins. Importantly, co-IP experiments confirmed GABARAP interaction with STC1. These data indicate a molecular scenario whereby GABARAP interacts with STC1 to avoid STC1-mediated trapping of CALR, allowing for the induction of ICD after treatment with ICD inducers; on the other hand, this mechanism is compromised in GABARAP null or del17p cells, and the STC1-CALR complex remains trapped in the mitochondria, resulting in ICD resistance. To functionally validate our findings in the context of the immune microenvironment, we performed mass Cytometry after T cell co-culture with DCs primed by both WT and GABARAP KO AMO1 clones. And we confirmed that treatment of GABARAP KO clones with BTZ failed to activate an efficient T cell response. In conclusion, our work identifies a unique mechanism of immune escape which may contribute to the poor clinical outcome observed in del17p HR MM patients. It further suggests that novel therapies to restore GABARAP may allow for the induction of ICD and improved patient outcome in MM. Disclosures Bianchi: Jacob D. Fuchsberg Law Firm: Consultancy; MJH: Honoraria; Karyopharm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Richardson: AstraZeneca: Consultancy; Regeneron: Consultancy; Protocol Intelligence: Consultancy; Secura Bio: Consultancy; GlaxoSmithKline: Consultancy; Sanofi: Consultancy; Janssen: Consultancy; Takeda: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Chauhan: C4 Therapeutics: Current equity holder in publicly-traded company; Stemline Therapeutics, Inc: Consultancy. Munshi: Legend: Consultancy; Karyopharm: Consultancy; Amgen: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Oncopep: Consultancy, Current equity holder in publicly-traded company, Other: scientific founder, Patents & Royalties; Abbvie: Consultancy; Takeda: Consultancy; Adaptive Biotechnology: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy. Anderson: Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Janssen: 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; Millenium-Takeda: 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; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees.

scholarly journals 16p Deletion Involving BCMA Locus Is Frequent and Predominantly Observed with del17p

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1590-1590
Author(s):  
Mehmet K. Samur ◽  
Anil Aktas-Samur ◽  
Romain Lannes ◽  
Jill Corre ◽  
Anjan Thakurta ◽  
...  
Keyword(s):  
Single Cell ◽  
Board Of Directors ◽  
Copy Number ◽  
Copy Number Alterations ◽  
Sequencing Data ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Similar Frequency ◽  
Targeting Therapy ◽  
Almost All

Abstract New generation immunotherapies in Multiple Myeloma (MM) targeting BCMA, have shown remarkable clinical benefits. However relapse still occurs due to tumor intrinsic and extrisic resistance mechanisms including antigen loss related to mutation, deletion and splicing pattern changes. Two recent case reports including ours highlighted biallelic loss of BCMA as a cause for resistance to anti-BCMA targeting therapy. In both studies BCMA locus at 16p was deleted bringing in focus importance of del16p. Here, we have evaluated 2883 MM patients at diagnosis and relapse to understand frequency characteristics of somatic events targeting BCMA. We first evaluated the frequency of deletion involving the BCMA locus (16p13.13) in MM patients from multiple studies using WGS sequencing data as well as using Affymetrix Cytoscan HD and SNP 6.0 arrays. We observed del16p in 8.58 % (7.6% to 14.6% in individual studies) of newly-diagnosed patients (n=2458). Similar frequency was observed in relapsed MM patients not previously exposed to BCMA targeting therapy. Next, we evaluated genome wide copy number alterations (CNAs) in all patients with loss of BCMA locus and observed similar frequency of loss in both hyperdiploid MM (HMM) and non-HMM suggesting its independence from cytogentic subtypes of MM. Overall copy number loss was significantly higher in patients with BCMA loss compared to rest of the MM patients. Patients with loss of BCMA locus have increased mutational load (8202 with 95% HDI 6921 and 9535) compared to those without BCMA locus loss (6975 with 95% HDI 6626 - 7343); probability of difference greater than 0 was 96.8% and difference of the means were 1222 [95% CI -112 - 2589] We next evaluated co-occurrence of BCMA loss with other high risk events and observed del1p and del17p as being significantly associated with loss of BCMA locus [Odds ratio 19.37 (13.13-25.80), FDR = 1.57e-65; and 8.8 (6.39-12.15), FDR = 5.57E-39, respectively)]. Furthermore, we observed that when both BCMA and TP53 loss are present, they have same log ratio (sequencing) or smoothed copy numbers (SNP array). Similarly, we used CDKN2C as a proxy to chromosome 1p loss and observed that when both BCMA and CKDN2C loss are present in the same patient they tend to show similar copy number values. These data suggested a possibility of co-occurrence of these events in the same cell. To further investigate this observation, we used single cell DNA sequencing data from patients with sub clonal and clonal BCMA locus loss. scDNA sequencing showed that almost all cells with BCMA deletion also had TP53 deletion (95%). Interestingly, almost all cells with BCMA loss also had p53 loss, while not all cells with p53 loss had BCMA loss suggesting that the chronology of this copy number alternation may suggest first p53 loss followed by BCMA loss. We further investigated whether a bi-allelic BCMA loss was observed after anti-BCMA targeted CAR-T cell therapy by imputing the copy number alterations using single cell RNA sequencing data. Our data from this case also indicated that BCMA loss tend to co-occur with TP53 deletions (OR=5.67 [95% CI 4.12-7.84], p value < 0.0001). Moreover, TP53 mutations were also more frequent in patients with del16p and del17p, compared to patients who only had del16p or del17p. In summary, our data from large scale copy number profiles at the diagnosis and relapse showed that monoallelic BCMA deletions are frequent events, patients with these events show increased aneuploidy, mostly deletions, potentially making these cells vulnerable for biallelic loss of genes, especially under the pressure of targeted therapy. Our results also highlight that BCMA expressions in bulk sample may not detect the presence or absence of cells with target loss and therefore combining strategies at bulk and single cell level are necessary to understand the disease status. These results suggest the need to study del16p in patients being targeted for BCMA-directed therapy and its association with other risk factors in MM. Disclosures Thakurta: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Anderson: Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: 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; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees. Munshi: Takeda: Consultancy; Adaptive Biotechnology: Consultancy; Amgen: Consultancy; Karyopharm: Consultancy; Celgene: Consultancy; Abbvie: Consultancy; Oncopep: Consultancy, Current equity holder in publicly-traded company, Other: scientific founder, Patents & Royalties; Novartis: Consultancy; Legend: Consultancy; Pfizer: Consultancy; Janssen: Consultancy; Bristol-Myers Squibb: Consultancy.

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