Rhizen Pharmaceuticals Research Articles

RNA Sequencing Reveals Mechanisms Underlying Modulation of Hodgkin Lymphoma Cells and Tumor Microenvironment By the PI3K δ/γ Inhibitor, RP6530

INTRODUCTION: Aberrant activation of the phosphoinositide 3-kinase (PI3K) pathway plays a central role in Hodgkin Lymphoma (HL) pathogenesis. The pleiotropic activities of the δ and γ isoforms of PI3K in regulating the interactions of Hodgkin/Reed-Sternberg (HRS) cells with the tumor microenvironment suggest thatPI3K inhibitors might exert a therapeutic potential in the treatment of HL. The dual PI3K δ/γ inhibitor RP6530 was proven to affect HL tumor cells and to exert immunosuppressive activities. However, a genome-wide search for molecular mediators of RP6530 is largely unexplored in HL. The present study was therefore aimed at evaluating the anti-lymphoma functions and the underlying genes affected by RP6530 in HL cell lines.METHODS: We identified differentially expressed genes (DEGs) in two HL cell lines (L-540 and KM-H2) treated with RP6530 for 6 and 24 h by next generation RNA sequencing (RNA-Seq). The expression level of some of these genes was verified in HL cell lines using real time-PCR. Ingenuity Pathway Analysis (IPA) software was used to assign the DEGs to distinct canonical pathways and to predict the biological functions of the transcriptional changes. Gene silencing experiments were used to investigate and validate potential predictive biomarkers of response to RP6530 treatment. Additionally, serum levels of Thymus- and activation-regulated chemokine (TARC/CCL17) were analyzed by commercially available sandwich enzyme-linked immunosorbent assay (ELISA) in RP6530-treated HL patients enrolled in a phase 1 study.RESULTS: RNA-Seq analysis following treatment of L-540 cells for 6 h caused an upregulation of 1544 and downregulation of 839 genes. After a 24 h treatment period, 625 genes remained upregulated while the number of genes that were downregulated increased to 1362 (FDR ≤ 0.1). In KM-H2 cells, treatment with RP6530 for 6 or 24 h upregulated 137 and 980 genes while downregulating 139 and 833 genes, respectively (FDR ≤ 0.1). We further classified modulated genes according to their canonical pathways using the IPA suite. The most significantly upregulated pathways detected in both L-540 and KM-H2 cell lines included apoptosis, p53, death receptor signaling and G1/S cell cycle checkpoint regulation. In contrast, PI3K/AKT, ERK/MAPK, JAK/Stat, CD40, IL-4, IL-6, IL-10 and iNOS signaling were downregulated. We also identified 118 downregulated genes shared between the two cell lines that were associated with glycolysis, HIF1, chemokine and cytokine signaling. Upon RP6530 incubation, RNA-seq analysis showed a strikingly reduced expression of Pyruvate kinase muscle isozyme M2 (PKM2), which is a limiting glycolytic enzyme that catalyzes the final step in glycolysis. Here we show that lactic acid produced by tumor cells, as a by-product of glycolysis, has a critical function in inducing the M2-like polarization of tumor-associated macrophages (TAMs). Furthermore, we demonstrated that this effect was mediated by PKM2 and was inhibited after RP6530 treatment.We also found that the lactate-induced expression of M2 markers by macrophages, i.e., CCL-17 and CCL-22, were markedly inhibited both by RP6530 [-30% and -50% (mean of HL cells), respectively] and PKM2 silencing [-50% and -30% (mean of HL cells), respectively]. However, RP6530 increased the expression of M1 markers, switching the activation of macrophages from an immunosuppressive M2-like phenotype to an inflammatory M1-like state. PKM2 pathway therefore appears to be a critical determinant of RP6530-mediated inhibition of M2 macrophage polarization. Finally, RP6530 reduced the expression of key inflammation- and immunity-related genes as well as cytokines/chemokines and angiogenic factors (including, TARC/CCL17, CCL22, CCL5, IL-7, IL-13, and VEGF) known to be secreted by HRS cells to promote a pro-tumoral microenvironment. As the chemokine TARC/CCL17 is considered a biomarker of disease activity in HL patients, we observed a severe reduction of serum TARC/CCL17 levels in RP6530-treated HL patients that achieved CR or PR, but not in PD patients. Collectively, these findings suggest that RP6530 affects a mechanism of communication between HL tumor cells and tumor microenvironment.CONCLUSIONS: Results demonstrate that RP6530 can affect both HL tumor cells and HL tumor microenvironment, suggesting that a novel therapeutic opportunity may be achievable for the treatment of HL patients. DisclosuresViswanadha:Incozen Therapeutics: Employment. Vakkalanka:Rhizen Pharmaceuticals S A: Employment, Equity Ownership. Santoro:Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees. Carlo-Stella:Boehringer Ingelheim: Consultancy, Honoraria; Rhizen Pharmaceuticals: Research Funding; ADC Therapeutics: Research Funding.

The Novel Calcium Release-Activated Calcium (CRAC) Channel Inhibitor RP4010 Exerts Potent Antitumor Effects in NOD/SCID/IL2Rg-/- Mice with Diffuse Large B Cell Lymphoma (DLBCL) Cell Line Xenografts

INTRODUCTION: Calcium ions (Ca2+) act as second messengers in cell signaling triggering various cellular processes, including gene transcription, secretion, cell proliferation, migration, and apoptosis. Store-operated Ca2+ entry (SOCE) is activated by Ca2+ release from the endoplasmic reticulum. Two genes are responsible for SOCE activity: Stromal interaction molecule 1 (STIM1), an ER Ca2+ sensor that detects store depletion and Orai1, the pore-forming subunit of Ca2+ release-activated Ca2+ (CRAC) channel. Downregulation of Orai1, and consequently SOCE, protects the cells from diverse apoptosis-inducing pathways. As emerging evidence points to the involvement of aberrant CRAC channel activity in human diseases including Diffuse Large B Cell Lymphoma (DLBCL), we hypothesize that the CRAC channel inhibitorRP4010 might represent a unique therapeutic opportunity for DLBCL patients. RP4010 is a potent inhibitor of CRAC channel activity (IC50=60 nM) with demonstrated efficacy across a range of cancer cell lines in vitro . This study aimed at investigating the activity of RP4010 in preclinical DLBCL models.METHODS: The DLBCL cell lineswith GCB phenotype (SUDHL-4, SUDHL-6, SUDHL-16, and SUDHL-10) and ABC phenotype (SUDHL-8, RCK-8, RIVA, and SUDHL-2) were used to investigate in vitro the effects of RP4010 on cell growth and cell death and gene expression. The antitumor efficacy and of RP4010 was also analyzed in NOD/SCID/IL2Rg-/-mice bearing DLBCL cell line xenografts.RESULTS: Incubating GCB-DLBCL and ABC-DLBCL cell lines for up to 72 hours with increasing doses of RP4010 (1.25 - 10 µM)resulted in a significant dose- and time-dependent decrease in cell proliferation. For all cell lines, the peak of the cytostatic effect was detected upon incubation with 10 µM of RP4010 for 72 hours, when an average 80% decrease in cell proliferation over vehicle-treated controls (P ≤ 0.0001) was detected. RP4010 treatment resulted in a significant time- and dose-dependent increase in cell death, as assessed by AnnexinV/PI staining, in GCB-DLBCL cell lines and in two out of four ABC-DLBCL cell lines (SUDHL-8 and SUDHL-2), whereas modest or no effects were detected in the RCK-8 and RIVA ABC-DLBCL cell lines. Exposure to 5 µM RP4010 for 72 hours significantly increased cell death over vehicle-treated controls in SUDHL-4 (90 ± 4% vs. 11 ± 2%), SUDHL-6 (39 ± 4% vs. 16 ± 3%), SUDHL-16 (70 ± 5% vs. 18 ± 4%), SUDHL-10 (49 ± 5% vs. 15 ± 1%), SUDHL-8 (78 ± 4 vs. 8 ± 1%) and SUDHL-2 (57 ± 5 vs. 26 ± 4%) cell lines (P ≤ 0.0001). Interestingly, RP4010 (1.25 - 10 µM) failed to induce any cytotoxic effects on the in vitro growth of hematopoietic colony-forming cells from healthy volunteers. While no activation of caspase-8, -9, -3, or PARP were observed in ABC-DLBCL cell lines treated with RP4010, a potent caspase cleavage was observed upon RP4010 treatment in GCB-DLBCL cell lines. Pretreating cells with the pan-caspase inhibitor Z-VAD-fmk abrogated apoptosis only in GCB-DLBCL cell lines, but not in the ABC-DLBCL cell lines, supporting that RP4010 induces both caspase-dependent and caspase-independent cell death. Gene expression analysis revealed a strong correlation between Orai1 expression and sensitivity to RP4010-induced cell death. Thus, Orai1 has a pivotal role in the establishment of an apoptosis-resistant phenotype in ABC-DLBCL cells. Finally, in vivo experiments were conducted to investigate the antitumor activity of RP4010. Treatment of NOD/SCID/IL2Rg-/-mice bearing DLBCL tumor nodules with increasing dose of RP4010 (30, 60, 90 mg/Kg body weight, PO, 5 days/3 weeks) resulted in a dose-dependent inhibition of tumor growth (TGI) of SUDHL-8 [TGI = 35%, 74%, and 83% at 30, 60, and 90 mg/kg, respectively], RIVA and SUDHL-6[TGI = 66%, 52% at 90 mg/kg, respectively], compared to vehicle-treated controls. No mice experienced any apparent treatment-related toxicity. Despite the marked antitumor activity observed in DLBCL xenografts, RP4010 treatment did not induce any tumor necrosis in healthy tissues (including lungs, livers, spleens, and kidneys), suggesting that RP4010-induced growth inhibition was tumor restricted.CONCLUSIONS: RP4010 is associated with a potent anti-lymphoma activity, suggesting its therapeutic potential in DLBCL. A Phase 1/1b study in Relapsed/Refractory Non-Hodgkin Lymphoma (NHL) patients is currently ongoing in the US (ClinicalTrials.gov Identifier: NCT03119467). DisclosuresViswanadha:Incozen Therapeutics: Employment. Vakkalanka:Rhizen Pharmaceuticals S A: Employment, Equity Ownership. Santoro:Merck: 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. Carlo-Stella:Boehringer Ingelheim: Consultancy, Honoraria; ADC Therapeutics: Research Funding; Rhizen Pharmaceuticals: Research Funding.

The Minnesota Refined Acute GVHD Score Predicts Response to Initial Therapy, Survival and Non-Relapse Mortality after Haploidentical Transplantation with Post-Transplant Cyclophosphamide

Background: Despite prophylactic treatments with immunosuppressive agents, approximately 50% of transplant recipients develop acute GVHD (aGVHD) with an overall response rate (ORR) to steroid front-line therapy of approximately 64% and a 6-month overall survival (OS) of 66% (Martin PJ, BBMT 2012;18:1150-63). Recently, the University of Minnesota (MN) identified a new clinical refined risk score that was more powerful than the IMBTR score to predict response and survival of patients with aGVHD (MacMillan ML et al, BBMT 2015;21:761-7). In particular, at aGVHD onset patients at standard (SR) and high-risk were characterized by opposite outcomes in terms of ORR (69% vs 43%), non-relapse mortality (NRM; 22% vs 44%) and OS (71% vs 52%). This score was mainly based on patients receiving a transplant either from a matched-related-donor or a matched or mismatched unrelated donor. Because haploidentical transplant (Haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) is becoming a widespread option for patients lacking a HLA identical donor, we set to identify whether the refined MN aGVHD risk score is useful in the setting of Haplo-SCT in order to early identify which patients are at higher risk of death for aGVHD and may benefit from upfront, intensified treatments.Methods: Between 2011 and 2016, 318 patients received a Haplo-SCT with PT-Cy. 87 patients (27%) developed aGVHD of grade 2-4. Median age was 56 year old (20-72), 56 were male and 18 (21%) of them received a transplant from a female donor. Graft source comprised peripheral blood stem cells (PBSC) in 64 (73%) and bone marrow (BM) in 23 (37%), 56% of the patients received a reduced intensity (RIC) and 38% a non-myeloablative (NMA) conditioning, 53% had a HCT-CI>3 and 14% an unfavorable (D/R: Neg/Pos) CMV serostatus. Acute GVHD characteristics were as follows: 61 (70%) had grade 2 and 26 (30%) grade 3-4 according to Glucksberg staging, 25 (29%) had a grade A-B and 62 (71%) a grade C-D according to IMBTR index, 63 (72%) had only skin and 24 (28%) also visceral involvement, 65 (75%) were classified as standard risk (SR) and 22 (28%) as high-risk according to the MN risk score2. Front line therapy consisted of steroid in 59% of the subjects and steroid combined with extracorporeal photochemotherapy in 41%.Results: Day 28 cumulative incidence (CI) of non-responder (NR) was 21% (95% CI: 12-29) and CI of aGVHD relapse within 6 months was 8% (95% CI: 1-14). CI of cGVHD was 16% (95% CI: 9-25). 3y-OS was 55% (95% CI: 43-66) and 1y-NRM 23% (95% CI: 15-32). CI of CMV reactivation after aGVHD onset was 40% (95% CI: 29-50). Patients' outcome according to the main variables is summarized in Table I. Day 28 CI of of NR differed between MN SR and high-risk patients: 15% vs 36%, p=0.09. Glucksberg, IMBTR and visceral/non visceral grading had a similar capacity to identify patients with different chance of response. On multivariate analysis no variable was independently associated with day 28 probability of NR: of note, the MN high-risk group had a hazard ratio (HR) of 1.7 (95% CI: 0,2-12,6). Relative to 1y-NRM and 3y-OS rates, patients with high risk MN score were at higher risk od death: relative to SR, 1y-NRM was 50% vs 14% (p=0.0002) and a 3y-OS was 42% vs 60% (p=0.04). The IMBTR score was not capable to distinguish different groups in terms of NRM and OS, while stage 3-4 aGVHD according to Glucksberg grading was associated with a worse NRM, but not OS. Only the distinction between visceral and no-visceral aGVHD yielded results similar to the MN risk score (Table I). On multivariate analysis no variable was an independent predictor of NRM or OS due to the small patients number. Of note, in terms of NRM, high-risk MN group had a HR of 2.7 (95% CI: 0,2-26,8) and visceral GVHD had a HR of 1.5 (95% CI: 0.2-10.2). Relative to OS, high-risk MN group had a HR of 2.0 (95% CI: 0,3-11,3), while visceral GVHD had a HR of 1.7 (95% CI: 0.3-8.7).Conclusion: The refined MN aGVHD risk score is useful to identify at aGVHD onset patients at higher risk of non-response and mortality also in the contest of Haplo-SCT with PT-Cy. This score appears more powerful than the IBMTR, but similar to Glucksberg grading, to identify patients at higher risk. These preliminary observations need to be validated on a larger number of patients in order to identify whether the MN risk score may be useful to orient treatment decisions for aGVHD occurring after Haplo-SCT with PT-Cy. [Display omitted] DisclosuresCarlo-Stella:Rhizen Pharmaceuticals: Research Funding; Boehringer Ingelheim: Consultancy, Honoraria; ADC Therapeutics: Research Funding. Santoro:Merck: 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.

Safety and Anti-Tumour Activity of RP6530, Dual PI3K δ/γ Inhibitor, in Relapsed/Refractory T-Cell Lymphoma: Updated Results from the Dose Expansion Cohort of an on-Going Phase I/Ib Study

Introduction: RP6530 is a novel, highly specific, dual PI3K δ/γ inhibitor with nano-molar inhibitory potency at the enzyme and cellular level. Preliminary results from the ongoing Phase 1/1b T-cell lymphoma (TCL) study were presented at ASH 2016 (NCT02567656). The updated results from the escalation phase and further data on the expansion cohort treated at the maximum tolerated dose (MTD) is presented.Methods: This multicenter, open-label, Phase 1/1b study consists of dose escalation cohorts followed by two expansion cohorts enrolling 20 pts with peripheral TCL (PTCL) and 20 pts with cutaneous TCL (CTCL). The primary objective of the study is to determine the MTD and dose limiting toxicity (DLT), and to describe the safety and pharmacokinetic profiles. The secondary objectives are assessment of the overall response rate (ORR) and duration of response. Responses were evaluated for PTCL and CTCL based on IWG criteria (Cheson 2014) and the modified Severity Weighted Assessment Tool (mSWAT) respectively.Results: As of June 20, 2017, a total of thirty seven patients (17 PTCL and 20 CTCL) have been enrolled across the dose escalation and expansion cohorts. The results presented are the pooled data across both cohorts. Nineteen pts (9 PTCL, 10 CTCL) were enrolled in dose escalation [(200 mg BID, n=4; 400 mg BID, n=4; 800 mg BID (Fasting), n=5; 800 mg BID (Fed), n=6)] and eighteen patients (8 PTCL and 10 CTCL) in expansion (800 mg BID Fasting) in a 28 day cycle. Patients had a median of 3 (range: 1-7) and 5 (range: 1-15) prior treatment regimens for PTCL & CTCL respectively.Based on DLTs (transaminitis, rash & neutropenia), MTD was determined to be 800 mg BID fasting. A dose-proportional increase in plasma concentrations was observed in the PK. Safety assessment of 37 patients receiving at least one dose of RP6530 demonstrated an acceptable safety profile. Treatment related AE ≥Grade 3 were observed in thirteen (35%) patients which included elevated ALT/AST (n=9, 24%), rash (n=3, 8%), and neutropenia (n=1, 3%). These events were reversible and managed by withholding study drug. Steroid was given in some cases of transaminitis. There were no treatment related serious adverse events (SAE). Two patients discontinued treatment due to safety reasons. Dose reduction was done in seven patients (19%).As defined by the protocol, response assessments of the twenty evaluable patients receiving at least two cycles of RP6530 showed an ORR of 45% (9/20 patients) out of which 2 (10%) were complete responses [CR] and 7 (35%) were partial responses [PR]. Eight patients showed stable disease (40%). Indication specific analysis showed an ORR of 57% (4/7, 2 CR, 2 PR) in PTCL and 38% (5/13, 5 PR) in CTCL. Twelve patients (12/37, 32%) who discontinued treatment due to a rapid progression of disease before the first efficacy assessment were not considered for efficacy analysis.Conclusion: Based on the updated emerging data, RP6530 shows encouraging preliminary clinical activity as a single agent and appears to have an acceptable and manageable safety profile in relapsed/refractory TCL. Recruitment in the expansion cohort is currently on-going to reach a total of 40 patients and results will be further evaluated. DisclosuresRamchandren:Curis: Consultancy; Gilead Sciences: Consultancy; Seattle Genetics: Consultancy; Janssen: Research Funding; Merck: Research Funding; Pharmacyclics: Research Funding. Barde:Rhizen Pharmaceuticals SA: Employment. Nair:Rhizen Pharmaceuticals SA: Employment.

Endothelial dysfunction and its critical role in COVID-19-associated coagulopathy: Defibrotide as an endothelium-protective, targeted therapy.

To the Editor: Recent publications emphasize that patients with COVID-19 commonly present with lethal disseminated intravascular coagulopathy (DIC) characterized by increased levels of D-dimer, fibrinogen, and elevated prothrombin time and activated partial thromboplastin time [1]. These abnormalities are associated with increased rates of thromboembolism and a profound prothrombotic state. However, other authors have found that both severe and mild COVID-19 patients show similar levels of endogenous anticoagulants and similar anti-thrombin, protein C, protein S, α2-antiplasmin and plasminogen activator inhibitor-1 (PAI-1) activities [2], suggesting that we need new diagnostic criteria since the COVID-19 coagulopathy is different to the usual forms of disseminated intravascular coagulopathy [3]. These authors conclude that preventive measures for thromboprophylaxis are key and diverse antithrombotic therapies may be especially helpful in COVID-19 patients. It has been also reported that other markers of endothelial stress, including von Willebrand factor (VWF) and thrombomodulin, may predict mortality in COVID-19 patients, suggesting therapeutic strategies to normalize endothelial cell function and protect vascular integrity are indeed vital [2]. The crucial role of endotheliitis in COVID-19 has been substantiated by pathological findings from autopsies [4]. We wish to also highlight the possible role of heparan sulfate and heparanase in the endothelial dysfunction of COVID-19, via the heparan sulfate-heparanase pathway that triggers increased serum levels of inflammatory cytokines as part of disease pathobiology and additional targeted therapies derived thereon. Specifically, SARS-CoV-2 damage to endothelial cells (EC), and subsequent endotheliitis [4] leads to upregulation of heparanase, an endo-β-glucuronidase that degrades the heparan sulfate scaffold of the glycocalyx and subendothelial basement membrane, increasing endothelial dysfunction and allowing extravasation of activated immune cells into the extravascular compartment [5, 6]. Heparan sulfate is an extracellular matrix sulfated glycosaminoglycan that protects mucosal epithelia and a co-receptor for growth factors, cytokines, selectins, and viruses, including SARS-CoV-2. Additionally, heparanase is upregulated by pro-inflammatory molecules and promotes expression of TNF-α, IL-6, MIP-2, and IL-1 in a pro-inflammatory loop, which contributes further to inflammatory cytokines elevations [5]. Defibrotide is a complex mixture of poly-deoxyribonucleotides extracted from porcine gut mucosa with pleiotropic properties, including anti-thrombotic, pro-fibrinolytic, anti-inflammatory, and protective effects on small vessel endothelia [7]. Defibrotide increases tissue plasminogen activator and thrombomodulin expression, enhancing the activity of plasmin to hydrolyze fibrin clots, decreasing VWF, and PAI-1. Platelet adhesion is inhibited via increased nitric oxide and prostaglandin E2 and I2 release. Conversely, defibrotide decreases inflammatory mediators including IL-6, TNF-α, VEGF, thromboxane A2, leukotriene B4, and reactive oxygen species. Defibrotide downregulates endothelial adhesion molecules such as P-selectin, E-selectin, ICAM-1, VCAM-1, and has been shown to inhibit leukocyte-endothelial interactions [8]. Most importantly, defibrotide potently inhibits heparanase activity and its cell surface expression in variety of settings [7, 9]. Moreover, it blocks the heparanase-heparan sulfate axis, by competing with heparan sulfate, and so may in turn inhibit both heparanase-mediated viral release and spread, as well as heparanase-mediated activation of immune cells and elevated inflammatory cytokines [5]. Defibrotide is approved for the treatment of severe veno-occlusive disease/sinusoidal obstruction syndrome and has efficacy in patients with endothelial dysfunction and multiorgan failure, with activity in clinical studies and animal models of graft-versus-host disease incorporating lung injury [7, 8]. Its multitargeted endothelial-based therapeutic properties make it a potentially ideal candidate to treat vascular complications of COVID-19. Clinical studies are either planned or already underway in various countries, including Spain, Italy, and the United States, with the leading Spanish phase 2 study (ClinicalTrials.gov Identifier: NCT04348383) showing promising early results. This study has been financed in part by the Instituto de Salud Carlos III (ISCIII) project COV20/00399. US National Library of Medicine. ClinicalTrials.govhttps://clinicaltrials.gov/ct2/show/NCT04348383 (2020). All authors have contributed equally to this work. Dr. David Garcia Bernal, Dr. Israel Vlodavsky, and Dr. Massimo Iacobelli have no conflict of interest to declare. Dr. Carmelo Carlo-Stella has received research support from ADC Therapeutics and Rhizen Pharmaceuticals; has served as consultant or advisor for Servier, Novartis, Genenta Science srl, ADC Therapeutics, Roche, Sanofi, Karyopharm and Jazz Pharmaceuticals; and has received honoraria for speaker engagements from Bristol-Myers Squibb, Merck Sharp & Dohme, Janssen Oncology, and Astra-Zeneca. Dr. Ruben Jara declares honorarium from Edwards Lifesciences and Getinge. Dr. Paul Richardson serves on advisory committees for Jazz Pharmaceuticals. Dr. Jose M. Moraleda reports grants from Jazz Pharmaceuticals, during the conduct of the study; consulting honoraria and travel expenses from Gilead, consulting honoraria from Novartis, Sandoz, and Takeda, outside the submitted work.

An Open Label, Phase 2 Study to Assess the Efficacy and Safety of Tenalisib (RP6530), a PI3K δ/γ and SIK3 Inhibitor, in Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia (CLL)

Introduction: Despite high response rates to initial treatment, relapse is common in CLL. Although newer agents are approved for treatment recently, CLL remains an incurable disease. Tenalisib (RP6530) is a highly specific and orally available PI3K δ/γ+SIK3 inhibitor. In in-vitro studies, Tenalisib was highly effective (62nM) in demonstrating a cytotoxic effect in patient derived CLL cells and showed very good synergism in combination with fludarabine and ibrutinib at very low concentrations in patient derived primary CLL cells. Tenalisib has demonstrated good clinical activity in patients with T cell lymphomas. Previously, a pooled safety analysis of 93 patients treated with tenalisib monotherapy demonstrated a differentiated safety profile which is largely devoid of immune mediated toxicities (Iyer, ASH 2018). Methods: This trial is a Phase II, open label, multi-center, Simon's two stage study design to evaluate the efficacy and safety of Tenalisib in patients with CLL who have relapsed or are refractory after at least one prior therapy. In stage 1, 20 patients were to be enrolled and an additional 41 patients to be enrolled in stage 2 based efficacy results of stage 1 (>8 responders needed to proceed to stage 2). Patients with previously treated CLL with adequate bone marrow, liver, and renal function, ECOG ≤2, and measurable disease are eligible. Patients with prior exposure to drug that specifically inhibits PI3K were excluded. The primary objective was to assess the anti-tumor activity. The secondary objectives were to assess safety and tolerability, and progression free survival (PFS). The responses were assessed using iwCLL criteria (Hallek 2018). Results: A total of 21 CLL patients predominantly male (86%) with median age was 66 years (range 44-79) were enrolled between Dec 2019 and March 2020 in Stage 1 of the study. 67% of patients had an ECOG score of 1, and 43% had Rai Stage III/IV disease with 67% having spleno/hepatomegaly. Patients had a median of 2 (range: 1-3) prior treatment regimens and 16 (76%) were refractory to last therapy. High risk patients included 15% del 17p, 10% del 11q, 5% ZAP and 5% TP53 mutations. In all 21 evaluable pts with a median follow-up of 4.9 months, 7 patients showed partial response (33%) while the remaining 14 patients showed stable disease (67%). 19 patients (90%) were still continuing therapy while 2 patients discontinued due to disease progression after showing a stable response. There was a median reduction in nodal disease to the extent of 54% in responding patients. The data readouts at C8D1 for all patients is currently awaited. The most common AEs which were mild-moderate in severity included transaminitis (19%), GGT elevation (5%) and neutropenia (5%). There was a related Grade 3 AE of neutropenia (5%). None of the related AEs led to study discontinuation. There were no events of diarrhoea/colitis or pneumonitis in patients who were on therapy for more than 6 months. Conclusions: Tenalisib showed promising single agent anti-tumor activity in patients with CLL with a favourable safety profile. Further data is awaited to estimate the response rates and the decision to move to Stage 2 of the study. Disclosures Robak: Momenta: Consultancy; BioGene: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Takeda: Consultancy; Pfizer: Research Funding; UCB: Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; UTX-TGR: Research Funding; Acerta: Research Funding; Morphosys: Research Funding; AstraZeneca: Honoraria, Research Funding; Bristol Meyers Squibb: Research Funding; Sandoz: Consultancy, Honoraria; Octapharma: Honoraria; Medical University of Lodz: Current Employment; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; GSK: Research Funding; Roche: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding. Routhu:Rhizen Pharmaceuticals S.A>.: Current Employment. Barde:Rhizen Pharmaceuticals S.A: Current Employment. Nair:Rhizen Pharmaceuticals S.A.: Current Employment.

A Multi-Center, Open Label, Phase I/II Study to Assess the Safety and Efficacy of Tenalisib Given in Combination with Romidepsin in Patients with Relapsed/Refractory T-Cell Lymphoma

A Multi-Center, Open Label, Phase I/II Study to Assess the Safety and Efficacy of Tenalisib Given in Combination with Romidepsin in Patients with Relapsed/Refractory T-Cell Lymphoma

Glofitamab Step-up Dosing Induces High Response Rates in Patients with Hard-to-Treat Refractory or Relapsed Non-Hodgkin Lymphoma

Glofitamab Step-up Dosing Induces High Response Rates in Patients with Hard-to-Treat Refractory or Relapsed Non-Hodgkin Lymphoma

Phase 1b Study of BET Inhibitor PLX2853 in Patients with Relapsed or Refractory Acute Myeloid Leukemia or High Risk Myelodysplastic Syndrome

Phase 1b Study of BET Inhibitor PLX2853 in Patients with Relapsed or Refractory Acute Myeloid Leukemia or High Risk Myelodysplastic Syndrome

Severity of Sars-Cov-2 Infection in Patients with Hematologic Malignancies: A COVID-19 and Cancer Consortium (CCC19) Registry Analysis

Severity of Sars-Cov-2 Infection in Patients with Hematologic Malignancies: A COVID-19 and Cancer Consortium (CCC19) Registry Analysis

Nivolumab Combined with Brentuximab Vedotin for Relapsed/Refractory Mediastinal Gray Zone Lymphoma: Primary Efficacy and Safety Analysis of the Phase 2 CheckMate 436 Study

Nivolumab Combined with Brentuximab Vedotin for Relapsed/Refractory Mediastinal Gray Zone Lymphoma: Primary Efficacy and Safety Analysis of the Phase 2 CheckMate 436 Study

Dose-Dense Brentuximab Vedotin Plus Ifosfamide, Carboplatin, and Etoposide (ICE) Is Highly Active for Second Line Treatment in Relapsed/Refractory Classical Hodgkin Lymphoma: Final Results of a Phase I/II Study

Dose-Dense Brentuximab Vedotin Plus Ifosfamide, Carboplatin, and Etoposide (ICE) Is Highly Active for Second Line Treatment in Relapsed/Refractory Classical Hodgkin Lymphoma: Final Results of a Phase I/II Study

Efficacy and Safety of Loncastuximab Tesirine (ADCT-402) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Efficacy and Safety of Loncastuximab Tesirine (ADCT-402) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Rituximab with Dose-Adjusted EPOCH (R-DA-EPOCH) with or without Autologous Stem Cell Transplantation (ASCT) As First Line Treatment in Patients with Aggressive B-Cell Lymphoma with MYC and BCL-2 and/or BCL-6 Gene Rearrangements or Increase Copy Number

Rituximab with Dose-Adjusted EPOCH (R-DA-EPOCH) with or without Autologous Stem Cell Transplantation (ASCT) As First Line Treatment in Patients with Aggressive B-Cell Lymphoma with MYC and BCL-2 and/or BCL-6 Gene Rearrangements or Increase Copy Number

Predictors of Cytopenia after Treatment with Axicabtagene Ciloleucel in Patients with Large Cell Lymphoma

Predictors of Cytopenia after Treatment with Axicabtagene Ciloleucel in Patients with Large Cell Lymphoma

Circulating Biomarkers of COVID-19-Triggered Endotheliopathy: From Conjecture to Certainty

Background: Clinical and analytical data on patients suffering from coronavirus disease-2019 (COVID-19) indicate that endothelial damage plays a key role in the pathophysiology of the disease and is responsible for the pulmonary complications and the thrombotic microangiopathy affecting multiple organs, which contribute directly to mortality (Ackerman et al. N Engl J Med 2020). Detection of biomarkers of endothelial injury in circulating blood may provide critical diagnostic and prognostic information on the disease course (Goshua et al. Lancet Haematology 2020). Endothelial injury is also a cornerstone of pathobiology in other septic and potentially life-threatening inflammatory syndromes.Objectives: To identify circulating markers of endothelial damage in COVID-19 patients, and compare their levels with those observed in other septic syndromes.Methods: Plasma samples from non-critically ill patients with confirmed COVID-19 pneumonia (positive nasopharyngeal swab and confirmatory radiological chest imaging) requiring admission (n=42) were collected during the first 36h of hospitalization. Endothelial damage was evaluated by measuring in plasma: i) markers of endothelial function and activation (sVCAM-1, VWF, ADAMTS-13 activity, Protein C and α2-antiplasmin as a marker of fibrinolysis); ii) heparan sulfate (HS) levels, as indicators of endothelial glycocalyx degradation and loss of endothelial barrier function; and iii) C5b9 deposits on endothelial cells in culture, and soluble C5b9 (sC5b9) levels, to measure complement activation. Circulating dsDNA was analyzed as an indicator of the presence of neutrophil extracellular traps (NETs). ELISA tests were used for sVCAM-1, Protein C, HS, and sC5b9 levels. ADAMTS-13 activity was evaluated by FRETS. VWF, Protein C, and α2-antiplasmin were measured at the Atellica COAG 360 (Siemens Healthineers). C5b9 deposits were assessed by immunofluorescence and dsDNA levels by Quant-iT PicoGreen assay kit. Results were compared with those obtained in healthy donors (controls, n=45), and patients with non-infectious systemic inflammatory response syndrome (NI-SIRS, n=8) and septic shock (SS, n=8).Results: Levels of sVCAM-1 were significantly higher in COVID-19 patients vs. controls, NI-SIRS and SS (159±12 vs. 79±4, 57±8 and 80±10 ng/mL, respectively, p<0.005) (Mean±SDM). VWF was elevated in COVID-19 patients vs. controls (240±26 vs. 96±5%, p<0.001), with similar values in NI-SIRS (271±40%), and significantly reduced vs. SS (476±43%, p<0.001). HS levels in COVID-19 patients were twice those detected in controls (1669±174 vs. 839±36 ng/mL, p=0.001), but they did not differ from those in NI-SIRS (1372±368 ng/mL), and were significantly lower than in SS (3677±880 ng/mL, p<0.001 vs COVID-19). Regarding complement activation, deposits of C5b9 on endothelial cells were significantly increased vs. controls (2-fold, p<0.01), with no notable differences vs. NI-SIRS (3±1-fold) and significantly lower than in SS (8±2-fold, p<0.001). Remarkably, sC5b9 levels were much more elevated in COVID-19 patients (1064±120 vs. 204±11 ng/mL, p<0.001), and no significant differences were observed vs. NI-SIRS (902±160 ng/mL) or SS (958±180 ng/mL). Also of note, presence of NETs was significantly elevated in the plasma of COVID-19 patients vs. controls (16±1.3 vs. 2±0.3 ng/ml, p<0.001), but similar to NI-SIRS (19±5 ng/mL) and clearly inferior to SS (33±6 ng/mL, p<0.001) (Figure). Importantly and in contrast, ADAMTS-13 activity, Protein C, and α2-antiplasmin values were within the normal range in COVID-19 patients.Conclusions: Our data clearly demonstrate the presence of endothelial stress products in the circulating blood of non-critically ill COVID-19 patients. These biomarkers of endothelial injury are suggestive indicators of different aspects of the disease: specifically, release of acute phase reactants, degradation of the endothelial cell glycocalyx, and activation of the complement system. Furthermore, this profile of biomarkers in COVID-19 appears specific, with a differential behavior in comparison with septic shock, in which endothelial damage is also known to be critical. Additional studies are needed to validate these biomarkers as diagnostic and prognostic tools of the endothelial complications in COVID-19 patients, both in early disease and later, as well as supporting specific forms of therapeutic intervention.FigureDisclosuresCarreras:Jazz Pharmaceuticals: Research Funding, Speakers Bureau; German Jose´ Carreras Leukaemia Foundation: Research Funding. Carlo-Stella:Boehringer Ingelheim and Sanofi: Consultancy; ADC Therapeutics and Rhizen Pharmaceuticals: Research Funding; Bristol-Myers Squibb, Merck Sharp & Dohme, Janssen Oncology, AstraZeneca: Honoraria; Servier, Novartis, Genenta Science srl, ADC Therapeutics, F. Hoffmann-La Roche, Karyopharm, Jazz Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees. Moraleda:Sandoz: Consultancy, Other: Travel Expenses; Novartis: Consultancy, Other: Travel Expenses; Gilead: Consultancy, Other: Travel Expenses; Jazz Pharmaceuticals: Consultancy, Research Funding; Takeda: Consultancy, Other: Travel Expenses. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding. Diaz-Ricart:German Jose Carreras Leukaemia Foundation: Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding.

Preliminary Results of a Phase 2 Study of Camidanlumab Tesirine (Cami), a Novel Pyrrolobenzodiazepine-Based Antibody-Drug Conjugate, in Patients with Relapsed or Refractory Hodgkin Lymphoma

Preliminary Results of a Phase 2 Study of Camidanlumab Tesirine (Cami), a Novel Pyrrolobenzodiazepine-Based Antibody-Drug Conjugate, in Patients with Relapsed or Refractory Hodgkin Lymphoma

Ixazomib-Rituximab in Untreated Indolent B-NHL: An Effective, Very Low Toxicity Regimen

Ixazomib-Rituximab in Untreated Indolent B-NHL: An Effective, Very Low Toxicity Regimen

Pembrolizumab with R-CHOP in Previously Untreated Diffuse Large B-Cell Lymphoma: Long Term Follow up and Analysis of the Mechanism of Pdl-1 Tumor Expression

Pembrolizumab with R-CHOP in Previously Untreated Diffuse Large B-Cell Lymphoma: Long Term Follow up and Analysis of the Mechanism of Pdl-1 Tumor Expression

Phase 1 Study of CD19 Targeted 4-1BBL Costimulatory Agonist to Enhance T Cell (Glofitamab Combination) or NK Cell Effector Function (Obinutuzumab Combination) in Relapsed/Refractory B Cell Lymphoma

Phase 1 Study of CD19 Targeted 4-1BBL Costimulatory Agonist to Enhance T Cell (Glofitamab Combination) or NK Cell Effector Function (Obinutuzumab Combination) in Relapsed/Refractory B Cell Lymphoma