scholarly journals Rationale for and Results of a Phase I Study of the TGF-β 1/3 Inhibitor AVID200 in Subjects with Myelofibrosis: MPN-RC 118 Trial

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 6-8
Author(s):  
John Mascarenhas ◽  
Heidi E. Kosiorek ◽  
Lilian Varricchio ◽  
Rupali Bhave ◽  
Andrew T. Kuykendall ◽  
...  

Preclinical Rationale: Myelofibrosis (MF) is a chronic myeloproliferative neoplasm for which there are limited therapies. TGFβ plays a pivotal role in the pathobiology of MF by not only promoting bone marrow fibrosis (BMF) and collagen deposition, but also by enhancing the dormancy of normal but not MF hematopoietic stem cells (HSCs). TGFβ has also previously been reported to inhibit normal megakaryocyte (MK) production (Bruno et al Blood 1998). TGFβ1 promotes the synthesis of collagen by normal human mesenchymal stromal cells (MSCs) and activates the TGFβ receptor I/SMAD pathway as well as non-canonical TGFβ pathways. We generated MKs from MF subject mononuclear cells (MNCs) and showed that they elaborated significantly greater levels of TGFβ1 than TGFβ2/3 TGFβ1 treatment reduced the numbers of hematopoietic colonies generated by normal but not MF MNCs. Treatment of MSCs with AVID200, a potent TGFβ1/3 protein trap, significantly decreased MSC proliferation, phosphorylation of SMAD2, and collagen expression. Robust expression of pSMAD2 was observed in the absence of exogenous TGFβ in normal donor or MF-MKs, Addition of AVID200 to -MKs decreased pSMAD2 without affecting total SMAD2/3, indicating that AVID200 blocks the effects of autocrine TGFβ produced by MKs and led to increased numbers of MKs. Moreover, treatment of primary MF MNCs with AVID200 led to increased numbers of progenitor cells with wild type JAK2 and a reduction of mutated colonies. AVID200 blocked TGFβ1-induced p57Kip2 expression and SMAD2 activation by MF MNCs allowing the normal progenitor cells to preferentially cycle, proliferate, and form hematopoietic colonies. Clinical Trial Design: Based on these findings, a phase 1 trial of AVID200 is ongoing in INT-2/high risk MF subjects resistant or intolerant to ruxolitinib; baseline platelet count of ≥ 25 x 109/L, and grade 2/3 BMF. Subjects received intravenous AVID200 (Lots A and B) in dose cohorts of 180 mg/m2 (A), 550 mg/m2 (A), 180 mg/m2 (B) on Day 1 of a 21 day cycle. Cohorts of 3 subjects with a target toxicity rate of 30% were enrolled to estimate the maximum tolerated dose (MTD). A modified toxicity probability interval design was used. Response was assessed by IWG/ELN criteria after 6 cycles of AVID200. Subjects attaining at least a CI or SD with a decrease in BMF by ≥1 grade, continued AVID200. Clinical Trial Results: 10 subjects were enrolled (1 withdrew before receiving treatment) and 9 were treated with AVID200 and were evaluable for DLT assessment [Table1]. Median time after ruxolitinib discontinuation was 3.5 months (0.5-12.2). No DLTs were observed. Grade 3/4 AEs (regardless of attribution) were observed in 6 (66.7%) subjects. Grade 3/4 non-hematologic AEs observed were epistaxis (1, 11.1%), extraocular muscle paresis (1, 11.1%), fatigue (1, 11.1%) and rash (1, 11.1%). Grade 3/4 hematologic AEs were anemia (3, 33.3%) and thrombocytopenia (2, 22.2%) [Table 2]. The median number of cycles received was 5.7 (range 0 - 12). 5 subjects received 6+ cycles and were evaluable. CI occurred in 2 subjects [anemia, spleen and TSS (n=1); TSS (n=1)] 1 of which is still being treated, 2 subjects had SD, 1 subject with 21% blasts prior to study treatment had progressive MPN-BP. 4 subjects failed to reach response evaluation after 6 cycles, 2 had PD due to increasing splenomegaly, 1 subject received an allogeneic transplant and 1 is still being treated [Cycle 2]. The median platelet count at baseline was 114 (range: 42-290) and 159 after cycle 6 [Figure 1]. Maximum changes in platelets from baseline was +64% [range -73%, 169%] in all subjects. 7 subjects had an increase in platelets from baseline during treatment. 2 subjects normalized their platelet count from thrombocytopenic levels. The effect of AVID200 on BMF is currently being examined. 2 subjects remain on treatment. Conclusions: AVID200 a TGFβ1/3 protein trap is well tolerated in advanced MF subjects. Clinical responses were observed at the 550 mg dose and the expansion efficacy cohorts at doses 2 and 3 are enrolling 12 additional subjects. Furthermore, AVID200 therapy improved thrombocytopenia in MF subjects which may be due to AVID200 inhibiting the effects of TGFβ1 on normal MKpoiesis. Updated subject safety and efficacy data along with correlative data will be presented. Disclosures Mascarenhas: Celgene, Prelude, Galecto, Promedior, Geron, Constellation, and Incyte: Consultancy; Incyte, Kartos, Roche, Promedior, Merck, Merus, Arog, CTI Biopharma, Janssen, and PharmaEssentia: Other: Research funding (institution). Kuykendall:Blueprint Medicines: Research Funding; BMS: Research Funding; Incyte: Research Funding; Novartis: Research Funding. Komrokji:Jazz: Honoraria, Speakers Bureau; Abbvie: Honoraria; Agios: Speakers Bureau; BMS: Honoraria, Speakers Bureau; Geron: Honoraria; Incyte: Honoraria; Acceleron: Honoraria; Novartis: Honoraria. Gerds:Gilead Sciences: Research Funding; Imago Biosciences: Research Funding; Sierra Oncology: Research Funding; Celgene: Consultancy, Research Funding; Roche/Genentech: Research Funding; CTI Biopharma: Consultancy, Research Funding; Apexx Oncology: Consultancy; AstraZeneca/MedImmune: Consultancy; Pfizer: Research Funding; Incyte Corporation: Consultancy, Research Funding. Migliaccio:Novartis: Research Funding. O'Connor-McCourt:Forbius: Current Employment. Tremblay:Forius: Current Employment. Nadler:Forbius: Consultancy; Nadler Pharma Associates: Current Employment; Symphogen: Consultancy; Iksuda Therapeutics: Consultancy; Tessa Therapeutics: Consultancy. Mesa:Celgene: Research Funding; Genetech: Research Funding; Samus: Research Funding; Promedior: Research Funding; CTI: Research Funding; LaJolla Pharma: Consultancy; Incyte: Research Funding; Sierra Onc: Consultancy; Abbvie: Research Funding; Novartis: Consultancy. Hoffman:Forbius: Consultancy; Abbvie: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Dompe: Research Funding; Protagonist: Consultancy.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4917-4917
Author(s):  
Joachim B. Kunz ◽  
Eva Roth ◽  
Adil Mirza ◽  
Johann Greil ◽  
Petra Pavel ◽  
...  

Abstract Background Beti-cel ex vivo gene therapy integrates a modified HBB gene into hematopoietic stem cells of patients with TDT, aiming to enable lifelong, stable production of functional adult hemoglobin (Hb). The efficacy and safety of the treatment have been demonstrated in a total of 63 patients treated across 4 clinical trials (HGB-204,-HGB-205, HGB-207, and HGB-212). Here, we present the first patient who received beti-cel outside of the clinical trial setting, a 14-year-old male with a β 0/β + (IVS-1-6) genotype. Methods Following hematopoietic stem cell collection via granulocyte-colony stimulating factor plus plerixafor mobilization and apheresis, CD34+ cells were transduced with the BB305 lentiviral vector encoding HbA T87Q. The patient received hypertransfusion before mobilization and conditioning, maintaining a pre-transfusion Hb level of >11 g/dL. Six days prior to beti-cel infusion, single-agent busulfan myeloablation was initiated (16 single doses at 0.8 mg/kg body weight; 3.2 mg/kg/24 h) with concomitant clonazepam (see Table for treatment timeline). Ursodeoxycholic acid therapy was continued as hepatic veno-occlusive disease (VOD) prophylaxis through inpatient treatment. Results The patient was diagnosed with TDT at the age of 2 years in his home country and has been treated in Germany since the age of 9. Regular transfusion therapy was initiated soon after diagnosis (Table). Aged 9, the patient was started on desferasirox for iron elimination therapy. His annualized red blood cell (RBC) transfusion volume was 174 ml/kg in 2018 and 185 ml/kg in 2019, maintaining his pre-transfusion Hb at or above 9 g/dl. No HLA-related donor was available for allogeneic transplant. At informed consent, the patient was 13 years old and met the eligibility criteria for beti-cel treatment as outlined in the summary of product characteristics (SmPC). The patient was physically fit, with a 90% Lansky score and regular participation in school sports, but reported physical limitations when running extensively. The patient underwent a thorough assessment before admission (Table), which did not reveal any remarkable abnormalities except TDT-related splenomegaly and signs of slight iron overload (liver iron content, 2.0 mg/g dry weight [normal range, 0.17-1.8]). On 11/Feb/2021, the patient was infused with 5.1 × 10 6 CD34+ cells/kg. The patient received 4 RBC and 8 platelet transfusions following infusion until Day 13 and 27, respectively (Table). Neutrophil and platelet engraftment occurred on day 27 post beti-cel infusion. The patient was discharged from inpatient treatment the same day, in excellent general condition, with 90% Lansky score, Hb of 8.2 g/dl, a reticulocyte count of 9.3%, a total white cell count of 1.55/nl, a neutrophil count of 0.75/nl, and a platelet count of 24/nl. At last follow-up (+100 days), the patient felt well and exhibited normal exercise tolerance. He has received neither red blood cell nor platelet transfusions or chelation therapy since discharge. Total Hb was 11.8 g/dl (Table). Granulocytes and lymphocytes had recovered to normal levels. The patient showed continued, albeit slowly improving, thrombocytopenia (platelet count, 31/nl [29/nl at +60 days]), consistent with previous observations after beti-cel therapy. Myeloablation and beti-cel infusion were tolerated well. Adverse events post infusion were febrile neutropenia, elevated C-reactive protein levels, pruritus, gingivitis, mild mucositis, and vertigo, consistent with the SmPC. At +23 and +26 days, the patient experienced transient subjective hearing loss (quickly resolved). No VOD events occurred. Conclusions This is the first real-world patient with TDT treated with beti-cel therapy. The treatment regimen had a tolerability profile consistent with that of mobilization, apheresis, and busulfan myeloablation, matching clinical trial observations. Following treatment, this 14-year-old patient reached a total Hb of 11.8 g/dL at +100 days without requirement of red cell transfusions and continues to exhibit prolonged but slowly improving and asymptomatic thrombocytopenia. Figure 1 Figure 1. Disclosures Schmitt: TolerogenixX Ltd: Current Employment; Therakos/Mallinckrodt: Research Funding; Hexal: Other: Travel grant; Jazz Pharmaceuticals: Other: Travel grant. Schmitt: Bluebird Bio: Other: Travel grants; Novartis: Other: Travel grants, Research Funding; TolerogenixX: Current holder of individual stocks in a privately-held company; Apogenix: Research Funding; MSD: Membership on an entity's Board of Directors or advisory committees; Hexal: Other: Travel grants, Research Funding; Kite Gilead: Other: Travel grants. Kulozik: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Honoraria; BioMedX: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; bluebird bio, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1274-1274
Author(s):  
Warren Fiskus ◽  
Christopher Peter Mill ◽  
Vrajesh Karkhanis ◽  
Bernardo H Lara ◽  
Prithviraj Bose ◽  
...  

LSD1 (KDM1A) is an FAD-dependent amine-oxidase that demethylates mono and dimethyl histone H3 lysine 4 (H3K4Me1 and H3K4Me2), which regulates active enhancers and transcription in AML stem/progenitor cells (LSCs). LSD1 is part of the repressor complexes involving HDACs, CoREST or GFI1, mediating transcriptional repression and differentiation block in LSCs that persist in the minimal residual disease (MRD) following attainment of clinical complete remission, leading to relapse and poor outcome in AML. In AML LSCs, genetic alterations and epigenetic dysregulation of enhancers affect levels of myeloid transcriptional regulators, including c-Myc, PU.1, GATA 2 and CEBPα, and their target genes, which are involved in differentiation block in LSCs. Our present studies demonstrate that CRISPR/Cas9-mediated knockout of LSD1 in the AML OCI-AML5 cells significantly increased the permissive H3K4Me2/3-marked chromatin, reduced H3K27Ac occupancy at super-enhancers and enhancers (SEs/Es) (by ChIP-Seq), especially of c-Myc and CDK6, as well as repressed CoREST, c-Myc, CDK6, and c-KIT, while inducing p21, CD11b, and CD86 levels (log2 -fold change by RNA-Seq, and protein expression by Western analyses). This led to significant growth inhibition, differentiation and loss of viability of OCI-AML5 and patient-derived AML blasts (p < 0.01). Similar effects were observed following exposure of OCI-AML5 (96 hours) to tet-inducible shRNA to LSD1. Knock-down of GFI1 by shRNA (by 90%) also inhibited growth and induced differentiation, associated with upregulation of PU.1, p21 and CD11b levels. Treatment with irreversible (INCB059872, 0.25 to 1.0 µM) or reversible (SP2577, 1.0 to 2.0 µM) LSD1 inhibitor (LSD1i) inhibited binding of LSD1 to CoREST, and significantly induced growth inhibition, differentiation and loss of viability (over 96 hours) of the OCI-AML5, post-myeloproliferative neoplasm (post-MPN) sAML SET2 and HEL92.1.7 cells, as well as patient-derived AML and post-MPN sAML blasts (p < 0.01). Co-treatment with INCB059872 and ruxolitinib synergistically induced apoptosis of the post-MPN sAML SET2 and HEL92.1.7 cells and patient-derived CD34+ post-MPN sAML blasts (combination indices < 1.0). Notably, pre-treatment with the LSD1i for 48 hours significantly re-sensitized ruxolitinib-persister/resistant SET2 and HEL92.1.7 cells to ruxolitinib (p < 0.001). We previously reported that treatment with the BET inhibitor (BETi) JQ1 or OTX015 represses SE/E-driven AML-relevant oncogenes including MYC, RUNX1, CDK6, PIM1, and Bcl-xL, while inducing p21 and p27 levels in post-MPN sAML blasts (Leukemia 2017;31:678-687). This was associated with inhibition of colony growth and loss of viability of AML and post-MPN sAML blasts (p < 0.01). Here, we determined that INCB059872 treatment induced similar levels of lethality in BETi-sensitive or BETi-persister/resistant AML and post-MPN sAML cells. Since BETi treatment also depleted LSD1 protein levels, co-treatment with the BETi OTX015 and LSD1i INCB059872 or SP2577 induced synergistic lethality in AML and post-MPN sAML blasts (combination indices < 1.0). Co-treatment with INCB059872 (1.5 mg/kg) and OTX015 (50 mg/kg) both orally for 21 days, compared to each agent alone or vehicle control, significantly reduced the sAML burden and improved survival of immune-depleted mice engrafted with HEL92.1.7 or HEL92.1.7/OTX015-resistant-GFP/Luc sAML xenografts (p < 0.01). Collectively, these findings strongly support further in vivo testing and pre-clinical development of LSD1i-based combinations with ruxolitinib against post-MPN sAML and with BETi against AML or post-MPN sAML cells. Disclosures Bose: CTI BioPharma: Research Funding; Astellas: Research Funding; NS Pharma: Research Funding; Promedior: Research Funding; Constellation: Research Funding; Incyte Corporation: Consultancy, Research Funding, Speakers Bureau; Celgene Corporation: Consultancy, Research Funding; Blueprint Medicine Corporation: Consultancy, Research Funding; Kartos: Consultancy, Research Funding; Pfizer: Research Funding. Kadia:Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Research Funding; Bioline RX: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees. Bhalla:Beta Cat Pharmaceuticals: Consultancy. Khoury:Stemline Therapeutics: Research Funding; Angle: Research Funding; Kiromic: Research Funding. Verstovsek:Ital Pharma: Research Funding; Pharma Essentia: Research Funding; Astrazeneca: Research Funding; Incyte: Research Funding; CTI BioPharma Corp: Research Funding; Promedior: Research Funding; Gilead: Research Funding; Celgene: Consultancy, Research Funding; NS Pharma: Research Funding; Protaganist Therapeutics: Research Funding; Constellation: Consultancy; Pragmatist: Consultancy; Sierra Oncology: Research Funding; Genetech: Research Funding; Blueprint Medicines Corp: Research Funding; Novartis: Consultancy, Research Funding; Roche: Research Funding.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3229-3229 ◽  
Author(s):  
Ivana N Micallef ◽  
Eric Jacobsen ◽  
Paul Shaughnessy ◽  
Sachin Marulkar ◽  
Purvi Mody ◽  
...  

Abstract Abstract 3229 Poster Board III-166 Introduction Low platelet count prior to mobilization is a significant predictive factor for mobilization failure in patients with non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD) undergoing autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT; Hosing C, et al, Am J Hematol. 2009). The purpose of this study is to assess the efficacy of HSC mobilization with plerixafor plus G-CSF in patients with concomitant thrombocytopenia undergoing auto-HSCT. Methods Patients who had failed successful HSC collection with any mobilization regimen were remobilized with plerixafor plus G-CSF as part of a compassionate use program (CUP). Mobilization failure was defined as the inability to collect 2 ×106 CD34+ cells/kg or inability to achieve a peripheral blood count of ≥10 CD34+ cells/μl without having undergone apheresis. As part of the CUP, G-CSF (10μg/kg) was administered subcutaneously (SC) every morning for 4 days. Plerixafor (0.24 mg/kg SC) was administered in the evening on Day 4, approximately 11 hours prior to the initiation of apheresis the following day. On Day 5, G-CSF was administered and apheresis was initiated. Plerixafor, G-CSF and apheresis were repeated daily until patients collected the minimum of 2 × 106 CD34+ cells/kg for auto-HSCT. Patients in the CUP with available data on pre-mobilization platelet counts were included in this analysis. While patients with a platelet count <85 × 109/L were excluded from the CUP, some patients received waivers and were included in this analysis. Efficacy of remobilization with plerixafor + G-CSF was evaluated in patients with platelet counts ≤ 100 × 109/L or ≤ 150 × 109/L. Results Of the 833 patients in the plerixafor CUP database, pre-mobilization platelet counts were available for 219 patients (NHL=115, MM=66, HD=20 and other=18.). Of these, 92 patients (NHL=49, MM=25, HD=8 and other=10) had pre-mobilization platelet counts ≤ 150 × 109/L; the median platelet count was 115 × 109/L (range, 50-150). The median age was 60 years (range 20-76) and 60.4% of the patients were male. Fifty-nine patients (64.1%) collected ≥2 × 109 CD34+ cells/kg and 13 patients (14.1%) achieved ≥5 × 106 CD34+ cells/kg. The median CD34+ cell yield was 2.56 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 68.5%. The median time to neutrophil and platelet engraftment was 12 days and 22 days, respectively. Similar results were obtained when efficacy of plerixafor + G-CSF was evaluated in 29 patients with platelet counts ≤ 100 × 109/L (NHL=12, MM=10, HD=3 and other=4). The median platelet count in these patients was 83 × 109/L (range, 50-100). The median age was 59 years (range 23-73) and 60.4% of the patients were male. The minimal and optimal cell dose was achieved in 19(65.5%) and 3(10.3%) patients, respectively. The median CD34+ cell yield was 2.92 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 62.1%. The median time to neutrophil and platelet engraftment was 12 days and 23 days, respectively. Conclusions For patients mobilized with G-CSF alone or chemotherapy ±G-CSF, a low platelet count prior to mobilization is a significant predictor of mobilization failure. These data demonstrate that in patients with thrombocytopenia who have failed prior mobilization attempts, remobilization with plerixafor plus G-CSF allows ∼65% of the patients to collect the minimal cell dose to proceed to transplantation. Thus, in patients predicted or proven to be poor mobilizers, addition of plerixafor may increase stem cell yields. Future studies should investigate the efficacy of plerixafor + G-CSF in front line mobilization in patients with low platelet counts prior to mobilization. Disclosures Micallef: Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Jacobsen:Genzyme Corporation: Research Funding. Shaughnessy:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Mody:Genzyme Corporation: Employment, Equity Ownership. van Rhee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3411-3411
Author(s):  
Maro Ohanian ◽  
Martha L. Arellano ◽  
Moshe Y. Levy ◽  
Kristen O'Dwyer ◽  
Hani Babiker ◽  
...  

Abstract INTRODUCTION: APTO-253 represses expression of the MYC oncogene by targeting a conserved G-quadruplex structure in its promoter, down-regulates MYC mRNA and protein levels and induces apoptosis in AML cell lines and marrow samples from patients with AML, MDS, and MPN in vitro. After injection, a large fraction of APTO-253 binds iron and transforms to the Fe(253) 3 complex which retains full activity. APTO-253 has been granted orphan drug designation for AML by the US FDA and is being studied in a Phase 1a/b clinical trial in patients with relapsed or refractory AML (R/R AML) or high-risk myelodysplasias (high-risk MDS) (NCT02267863). AIMS: Primary objectives are to determine the safety and tolerability of APTO-253, MTD, dose limiting toxicities (DLT), and the RP2D. Key secondary objectives are to assess the pharmacokinetic (PK) profile, pharmacodynamic (PD) activity, and preliminary evidence of antitumor activity. METHODS: Eligible patients have R/R AML or high-risk MDS for which either standard treatment has failed, is no longer effective, or can no longer be administered safely. Treatment- emergent adverse events (TEAEs) and tumor responses are evaluated using International Working Group criteria. APTO-253 is administered by IV infusion once weekly on days 1, 8, 15, and 22 of each 28-day cycle; ascending dose cohorts were enrolled at a starting dose of 20 mg/m 2 with planned escalation to 403 mg/m 2. RESULTS: As of June 7, 2021, a total of 18 patients (median age 64.0 years, 16 AML and 2 high-risk MDS) with a median of 2.5 prior treatments (range of 1 - 9) have been treated with APTO-253 at doses of 20 (n=1), 40 (n=1), 66 (n=4), 100 (n=4) and 150 mg/m 2 (n=8). Most patients were RBC (87.5% of AML and 100% of MDS) and/or platelet (75% of AML and 50% MDS) transfusion-dependent. No DLTs or drug-related serious adverse events have been reported. Only 1 patient had a drug-related TEAE of grade 3 or greater (fatigue, Grade 3, probably related). Preliminary PK analysis (Figure 1) showed that serum levels of APTO-253 were dose proportional. C max and AUC 0-72h for C1D1 dosing were 0.06, 0.02, 0.36 ± 0.37, 0.44 ± 0.41 and 0.72 ± 0.70 µM and 0.11, 0.15, 3.98 ± 1.77, 4.79 ± 0.87 and 2.51 ± 1.73 µM*h for dose levels of 20, 40, 66, 100 and 150 mg/m 2, respectively. Plasma levels for Fe(253) 3 were significantly higher than those for the APTO-253 monomer. For example, C max and AUC 0-72h of Fe(253) 3 for C1D1 dosing of patients in Cohort 150 mg/m 2 were 2- and 20- fold higher than the ATPO-253 monomer at 15.09 ± 0.42 µM and 51.52 ± 28.26 µM*h, respectively. Following dosing at 150 mg/m 2, serum concentrations of Fe(253) 3 were above 0.5 µM for &gt; 48 h, which approaches the therapeutic range based on in vitro studies. CONCLUSIONS: APTO-253 has been well-tolerated at doses of 20, 40, 66, 100 and 150 mg/m 2 over multiple cycles and escalated to 210 mg/m 2 (Cohort 6). PK analysis revealed that APTO-253 is rapidly transformed to and co-exists with the Fe(253) 3 in serum from R/R AML and high-risk MDS patients. Enrollment of patients at the 210 mg/m 2 dose level is ongoing and updated clinical data will be presented at the meeting. Figure 1 Figure 1. Disclosures Arellano: KITE Pharma, Inc: Consultancy; Syndax Pharmaceuticals, Inc: Consultancy. Levy: AstraZeneca: Consultancy, Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Honoraria, Speakers Bureau; GSK: Consultancy, Other: Promotional speaker; Janssen Pharmaceuticals: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Morphosys: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Epizyme: Consultancy, Other: Promotional speaker; Takeda: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Dova: Consultancy, Other: Promotional speaker; Novartis: Consultancy, Other: Promotional speaker; TG Therapeutics: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Gilead Sciences, Inc.: Consultancy, Honoraria, Speakers Bureau; Beigene: Consultancy, Honoraria, Speakers Bureau; Amgen Inc.: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau. Mahadevan: caris: Speakers Bureau; Guardanthealt: Speakers Bureau; PFIZER: Other: Clinical trial Adverse events committee; TG Therapeuticals: Other: Clinical trial Adverse events committee. Zhang: Aptose Biosciences, Inc.: Current Employment. Rastgoo: Aptose Biosciences, Inc.: Current Employment. Jin: Aptose Biosciences, Inc.: Current Employment. Marango: Aptose Biosciences, Inc.: Current Employment, Current equity holder in publicly-traded company. Howell: Aptose Biosciences, Inc.: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Research Funding. Rice: Aptose Biosciences, Inc.: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties; Oncolytics Biotech Inc.: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Bejar: Aptose Biosciences, Inc.: Current Employment, Current equity holder in publicly-traded company; Takeda: Research Funding; BMS: Consultancy, Research Funding; Gilead: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Astex: Consultancy; Silence Therapeutics: Consultancy.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1201-1201
Author(s):  
Charles Herbaux ◽  
Stéphanie Poulain ◽  
Damien Roos-Weil ◽  
Jacques-Olivier Bay ◽  
Yann Guillermin ◽  
...  

Abstract Background: Ruxolitinib (RUX), a JAK1/JAK2 inhibitor, and venetoclax (VEN), a BCL-2 inhibitor are 2 drug candidates recently identified as promising candidate for the treatment of T-Cell prolymphocytic leukemia (T-PLL). We recently reported that JAK/STAT pathway inhibition with RUX enhances BCL-2 dependence, thereby sensitizing T-PLL cells to VEN (Herbaux et al., Blood, 2021). We also showed that JAK/STAT pathway mutational status could impact RUX activity. Here, we report results on the 15 first patients who were treated with RUX and VEN oral combination for T-PLL. All patients were refractory to, or ineligible for alemtuzumab, the principal therapeutic option to date. Methods: In this multicenter retrospective study from the French Innovative Leukemia Organization, 15 patients with T-PLL (according to consensus criteria) were included. All patients were informed about the off-label use of this combination and provided informed consent. Patients received a maximum dose of RUX 15 mg twice daily, and VEN 800 mg daily. VEN was started with daily ramp-up from 20 mg to 800 mg over 6 days, with TLS prophylaxis (rasburicase and IV hydration). Responses were assessed by consensus criteria. Next generation sequencing (NGS) was performed using a custom-designed panel of 33 genes, including among others: ATM, TP53, IL2R, JAK1, JAK3, and STAT5B. CytoScan HD microarray (Affymetrix) were used to study copy number variation and or uniparental disomy. In vivo dynamic BH3 profiling (DBP) was performed on samples obtained from two patients on treatment. Results: All 15 patients were refractory or relapsing after chemotherapy (mostly bendamustine and pentostatin), except one. They were either refractory to (n=10) or ineligible (n=5) for alemtuzumab (ineligibility was decided by the treating physician based on age and comorbidities). The median age was 70 years (48-88). Within a week of starting RUX, a transient increase of the absolute lymphocyte count was observed in 66.6% of the patients. Based on the molecular status of the JAK/STAT pathway, we established 2 groups of patients. One with samples where no mutations were found (WT, n=3), and one with at least one mutation in the JAK/STAT pathway (MUT, n=12). The overall response rate (ORR) was 73.3%, with only partial responses. Five patients nearly fulfilled CR criteria except that they had persistent lymphocytosis (over 4 x 10 9/L), all of them were in the MUT group. ORR was 83.3% in the MUT group, and only one patient of the WT group obtained a PR. With a median follow-up of 73 days (22 to 368), the median progression free survival was significantly shorter in the WT group in comparison to the MUT group (1.8 months versus 5.6 months, p=0.04, Figure). Of note, four patients were treated with VEN monotherapy before the start of the combination with RUX. With that treatment, 3 of these patients achieved stable disease followed by progression within 2 to 3 months, while 1 was primary refractory to VEN monotherapy. The most frequent reported adverse events (AEs) of the RUX plus VEN combination were cytopenias, with 46.6% grade 3 or 4 thrombocytopenia and 40% grade 3 or 4 neutropenia. DBP showed that overall priming and BCL2 dependence increased in vivo (n=2) during the treatment with RUX and VEN. Finally, SNP arrays identified clonal evolution in the 3 patients evaluated sequentially (before treatment versus at progression). In one case, emergence of EZH2 and JAK1 mutation was also observed at progression using NGS. Conclusions: These preliminary results suggest promising activity of RUX plus VEN in T-PLL, and justify the development of a prospective clinical trial of this combination. Our data seem to show that this combination may be especially active for patients with JAK/STAT pathway activating mutations and that disease progression is associated with clonal evolution. Updated results will be presented at the meeting. Figure 1 Figure 1. Disclosures Herbaux: Janssen: Honoraria; Roche: Honoraria; Abbvie: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Lemonnier: Gilead: Other: travel grant; Institut Roche: Research Funding. Laribi: Jansen: Research Funding; AstraZeneca: Other: Personal Fees; Takeda: Other: Personal Fees, Research Funding; Novartis: Other: Personal Fees, Research Funding; Astellas Phama, Inc.: Other: Personal Fees; IQONE: Other: Personal Fees; AbbVie: Other: Personal Fees, Research Funding; Le Mans Hospital: Research Funding; BeiGene: Other: Personal Fees. Moreaux: Diag2Tec: Consultancy. Morschhauser: Janssen: Honoraria; Servier: Consultancy; Incyte: Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Chugai: Honoraria; Genentech, Inc.: Consultancy; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genmab: Membership on an entity's Board of Directors or advisory committees. Davids: Ascentage Pharma: Consultancy, Research Funding; MEI Pharma: Consultancy, Research Funding; Merck: Consultancy; Eli Lilly and Company: Consultancy; Adaptive Biotechnologies: Consultancy; Pharmacyclics: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Research to Practice: Consultancy; BeiGene: Consultancy; Surface Oncology: Research Funding; Verastem: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Takeda: Consultancy; Astra-Zeneca: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Celgene: Consultancy; AbbVie: Consultancy; Genentech: Consultancy, Research Funding; Janssen: Consultancy; MEI Pharma: Consultancy. Ysebaert: Abbvie, AstraZeneca, Janssen, Roche: Other: Advisory Board, Research Funding. OffLabel Disclosure: Ruxolitinib and venetoclax are used offlabel for patients refractory to current therapeutic options, based on preclinical data.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2734-2734
Author(s):  
Jochen Greiner ◽  
Vanessa Schneider ◽  
Hubert Schrezenmeier ◽  
Markus Wiesneth ◽  
Lars Bullinger ◽  
...  

Abstract Clinical and preclinical data suggest that acute myeloid leukemia (AML) with mutated nucleophosmin 1(NPM1mut) may constitute an immunogenic leukemia subtype. NPM1mut AML generally correlates with a better prognosis, however the underlying mechanisms still need to be clarified. Checkpoint inhibition targeting Programmed cell death protein 1 (PD-1)/Programmed cell death 1 ligand 1 (PD-L1) has been proven to be an effective novel immunotherapeutic approach in cancer treatment including the treatment of hematological malignancies. Expression of CD34/CD38/CD274 was evaluated in 20 NPM1mut versus 20 wild-type (NPM1wt) AML patient samples via flow cytometry analyses to assess PD-L1 (CD274) expression in leukemic cells, including leukemic progenitor and stem cells (LSC). We also investigated the influence of the anti-PD-1 antibody Nivolumab® on the antigen-specific immune responses in ELISpot assays. Additionally, we assessed the effect of Nivolumab in colony forming unit (CFU) immunoassays. Many AML cases showed relevant expression of PD-L1. Bulk cells of NPM1mut AML showed a significantly higher PD-L1 expression in comparison to NPM1wtAML patients (median of 1.5%, range 0.0-8.5%, versus 0.3%, range 0.1-1.1%). Importantly, PD-L1 expression was detected at a higher level in leukemic progenitor cells (CD34+CD38-) of NPM1mut than of NPM1wtAML (median of 3.3%, range 0.0-17.2%, versus 0.3%, range 0.0-3.0%). In general, the LSC fraction showed a higher PD-L1 expression than the non-LSC fraction. CFU immunoassays showed a significant inhibition of CFU when adding T cells stimulated against various LAA. In all patient samples, effectors activated against at least one LAA were successful to decrease the colony number significantly. Immune effects increased adding Nivolumab to the CTL for several days before starting CFU immunoassays. In summary, we detected higher PD-L1 expression in NPM1mut patients, especially in the leukemic progenitor compartment. This observation further supports the hypothesis that NPM1-directed immune responses might play an important role in tumor cell rejection, which tumor cells try to escape via expression of PD-L1. Immunogenicity of neoantigens derived from NPM1mut with higher PD-L1 expression constitute promising target structures for individualized immunotherapeutic approaches. Disclosures Schrezenmeier: Alexion Pharmaceuticals, Inc.: Honoraria, Research Funding. Bullinger:Pfizer: Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau; Janssen: Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Sanofi: Research Funding, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer Oncology: Research Funding. Döhner:Novartis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Celator: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Astex Pharmaceuticals: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Pfizer: Research Funding; Seattle Genetics: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Pfizer: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Sunesis: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Research Funding; Bristol Myers Squibb: Research Funding; Astex Pharmaceuticals: Consultancy, Honoraria.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 354-354 ◽  
Author(s):  
Raajit K. Rampal ◽  
Srdan Verstovsek ◽  
Sean M Devlin ◽  
Eytan M. Stein ◽  
Tapan M. Kadia ◽  
...  

Abstract Background: Among the most frequent and challenging hematologic manifestations of myelofibrosis (MF) are anemia and thrombocytopenia, the presence of which portends an adverse outcome. Few effective modalities to address these cytopenias exist, particularly thrombocytopenia. Further, although the FDA-approved JAK1/2 inhibitor Ruxolitinib (RUX) has demonstrated significant clinical efficacy in MF patients, RUX frequently results in anemia and thrombocytopenia. Thrombocytopenia in particular often results in dose attenuation of RUX. Thalidomide (THAL) is a first-in-class immunomodulatory agent. Studies of THAL in MF patients, alone and with prednisone, have demonstrated improvements in anemia and thrombocytopenia. We therefore sought to examine whether combination of RUX and THAL could result in improvement in both disease-related and therapy-related cytopenias, as well as improve overall disease response in patients with MF. Here we report initial analysis of this study (NCT03069326). Methods: We conducted a multicenter two stage phase II trial designed to assess the effect of RUX and THAL combination in subjects with primary, post-polycythemia vera, or post-essential thrombocythemia myelofibrosis. Patients taking RUX at the time of enrollment must have had less than PR per IWG-MRT/ELN 2013 criteria, or be refractory, to RUX single-agent therapy. Patients must have been taking RUX for a minimum of 3 months, and must have been on a stable dose of RUX for a minimum of 4 weeks immediately prior to enrollment. Treatment-naïve patients received single-agent RUX for 3 months (run-in phase) per label, and went on to combination therapy if they achieved less then a PR per IWG-MRT/ELN criteria. Each cycle of therapy was 28 days. Response assessment was evaluated according to the IWG-MRT/ELN 2013 criteria. Platelet response criteria in patients with baseline thrombocytopenia (less than lower limit of normal) included: Major response (≥75% increase in platelet count), Intermediate Response (≥50% increase) and Minor Response (≥25% increase). Adverse events were assessed using the NCI CTCAE v. 4.0. The primary endpoint was the proportion of treated subjects that achieved a response by IWG-MRT criteria and by platelet response criteria. Results: A total of 25 patients are planned to be accrued. At the time of this writing, a total of 18 patients have been accrued. The median age was 70.5 years (47-85). 8 patients had received prior therapies other than RUX, including imetelstat, momelotinib, danazol, pomalidomide, darbepoetin alpha and sotatercept. 7 patients enrolled to the run-in phase. 14 patients received red blood cell transfusions prior to study enrollment. Evaluation of platelet count in patients with baseline thrombocytopenia demonstrated a significant increase in platelet count at cycle 3 of therapy compared to baseline (Figure 1A and B; P<0.05). An increase in Hgb was observed over successive cycles of combination therapy (Figure 1C and D). 5 of 18 accrued patients completed ≥6 cycles of combined therapy at the time of abstract submission and were thus evaluable for response assessment. The overall response rate in these patients was 80% (4/5 patients). Clinical Improvement (Anemia response and Symptom response) occurred in 3 patients (both responses observed in all 3 patients). Major platelet response was observed in 4 of 5 patients with baseline thrombocytopenia. 1 patient met criteria for spleen response (Table 1). Grade 3/4 non-hematologic adverse events regardless of attribution included; limb edema, diverticulitis, hypertension, syncope. 1 patient experienced a thromboembolic event. 1 patient experienced a grade 3 hematologic AE (neutropenia). Conclusions: The combination of THAL and RUX has demonstrated a promising efficacy signal in this initial analysis of an ongoing phase II study, and appears to be well tolerated. Platelet count increases were observed in all patients who entered study with baseline thrombocytopenia, a response which appears to be maintained in the majority of patients observed 6 months after starting combination therapy. As well, anemia responses were observed in 3 of 5 evaluable patients. Collectively, these data indicate a potential role for this regimen in patients with anemia and/or thrombocytopenia, who otherwise have limited treatment options. Updated data on duration of response and overall response of all accrued patients will be presented. Disclosures Rampal: Constellation: Research Funding; Celgene: Honoraria; Incyte: Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Stemline: Research Funding. Verstovsek:Italfarmaco: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Stein:Celgene: Consultancy; Bayer: Consultancy; Agios: Consultancy; Daiichi Sankyo: Consultancy; Novartis: Consultancy; Pfizer: Consultancy. Kadia:Pfizer: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy; Amgen: Consultancy, Research Funding; Takeda: Consultancy; Takeda: Consultancy; Celgene: Research Funding; BMS: Research Funding; Novartis: Consultancy; Abbvie: Consultancy; Amgen: Consultancy, Research Funding; Celgene: Research Funding; BMS: Research Funding; Jazz: Consultancy, Research Funding; Abbvie: Consultancy; Jazz: Consultancy, Research Funding. Mauro:Bristol-Myers Squibb: Consultancy; Novartis: Consultancy, Research Funding; Pfizer: Consultancy; Takeda: Consultancy. Pemmaraju:SagerStrong Foundation: Research Funding; daiichi sankyo: Research Funding; novartis: Research Funding; abbvie: Research Funding; cellectis: Research Funding; samus: Research Funding; Affymetrix: Research Funding; stemline: Consultancy, Honoraria, Research Funding; celgene: Consultancy, Honoraria; plexxikon: Research Funding. Bose:Blueprint Medicines Corporation: Research Funding; Astellas Pharmaceuticals: Research Funding; Incyte Corporation: Honoraria, Research Funding; Constellation Pharmaceuticals: Research Funding; Celgene Corporation: Honoraria, Research Funding; Pfizer, Inc.: Research Funding; CTI BioPharma: Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1791-1791 ◽  
Author(s):  
Lilian Varricchio ◽  
John Mascarenhas ◽  
Anna Rita Migliaccio ◽  
Maureen O'Connor-McCourt ◽  
Gilles Tremblay ◽  
...  

Abstract Myelofibrosis (MF) is caused by driver mutations which upregulate JAK/STAT signaling. The only curative treatment for MF is hematopoietic stem cell transplant. Ruxolitinib alleviates many of the symptoms in MF but does not significantly alter survival. There is, therefore, an urgent need for additional rational therapies for MF. Bone marrow fibrosis and collagen deposition are hallmarks of MF which have been attributed to megakaryocyte (MK) derived TGFβ, which also plays a role in myelo-proliferation. There are three isoforms of TGFβ (TGFβ1, β2, and β3). AVID200, which was constructed by fusing TGFβR ectodomains to IgG Fc regions, is a potent TGFβ trap with pM potency against two of the three TGFβ ligands, TGFβ1 and β3 (IC50 values of ~ 3 pM ). AVID200's IC50 for TGFβ2 is ~4,000-fold higher indicating that it has minimal activity against TGFβ2, which is desirable since TGFβ2 is a positive regulator of hematopoiesis. We explored the therapeutic potential of AVID200 by culturing MF or normal donor (ND) mononuclear cells (MNCs) first in the presence of stem cell factor and thrombopoietin (TPO) and then TPO alone in order to generate MK-enriched populations. Although the percentage of mature MKs from ND and MF MNCs was similar, the absolute number of CD41+/CD42+ MKs generated from MF MNCs was two-fold greater than ND MNCs. To determine the levels of TGFβ secreted by the MKs we screened MF and ND MNC conditioned media (CM). We observed significantly higher levels of TGFβ1 but not TGFβ2 and TGFβ3 in MF MK CM. The effects of AVID200 on MKs were then evaluated by measuring the levels of phosphorylated SMAD2. Treatment with 0.001 - 0.1 nM AVID200 decreased phosphorylation of SMAD2, suggesting that AVID200 blocks autocrine MK TGFβ signaling. The increased levels of TGFβ in MF patients promote the proliferation and deposition of collagen by mesenchymal stem cells (MSCs). Cellular proliferation of MSCs was evaluated following treatment with either recombinant TGFβ1 or ND/MF CM in the presence or absence of AVID200. In the absence of AVID200, both recombinant TGFβ1 and MK-derived CM increased the proliferation of MSCs by 1.4- and 1.6-fold respectively, which returned to basal levels with the addition of increasing concentrations of AVID200. These data indicate that AVID200 directly blocks the effect of TGFβ1 on MSCs. MF stroma is characterized by an increase in Type I collagen. We therefore examined if treatment with AVID200 interferes with the ability of TGFβ1 to induce collagen expression by MSCs. MSCs were cultured in presence of recombinant TGFβ1 alone or in combination with varying concentrations of AVID200 for 72 hours. Recombinant TGFβ1 alone induced an increase in COL1A1 mRNA expression as compared to untreated controls (p<0.01). Addition of AVID200 eliminated the TGFβ-mediated increase in COL1A1 expression in a dose dependent manner. ND and MF MK-derived CM also increased COL1A1 expression by MSCs as compared to un-treated controls (p<0.01) and that effect was eliminated by AVID200 treatment (p<0.01). We next demonstrated that TGFβ1 activated pSMAD2 in MSCs without affecting total SMAD2/3 expression and that SMAD2 phosphorylation was reduced by adding AVID200. Furthermore, AVID200 treatment decreased pSTAT3 which is associated with the ability of TGFβ to induce fibrosis. We next investigated the effect of AVID200 on MF hematopoiesis. Briefly, MNCs (which produce TGFβ) from two JAK2V617F+ MF patients were incubated with or without 50 nM of AVID200 and plated in semi-solid media. Treatment with AVID200 did not affect the overall number of colonies generated, but reduced the numbers of JAKV617F+ colonies while increasing the numbers of WT colonies: for PT1, there were 32% JAKV617F+ CFUs in untreated cultures (11 JAKV617F+/34 total colonies) versus 16% JAKV617F+ CFUs (7 JAKV617F+/42 total CFUs) in AVID200 treated cultures; for PT2 there were 100% JAKV617F+ CFUs in untreated cultures (37 JAKV617F+/37 total CFUs) versus 94% JAKV617F+ CFUs (49 JAK2V617F+/52 total CFUs) in AVID200 treated cultures. The in vivo effects of AVID200 on the development of MF in GATA1 low mice will be presented at the meeting. These data indicate that AVID200 selectively suppresses TGFβ1 signaling associated with the proliferation of MSCs and type I collagen synthesis, and depletes MF MNCs of JAK2V617F+progenitor cells. We conclude that AVID200 is a promising agent for treating MF patients which will be evaluated in a phase 1 clinical trial. Disclosures Mascarenhas: Novartis: Research Funding; CTI Biopharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Roche: Research Funding; Janssen: Research Funding; Promedior: Research Funding; Merck: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding. Iancu-Rubin:Incyte: Research Funding; Merck: Research Funding; Summer Road, LLC: Research Funding; Formation Biologics: Research Funding. Hoffman:Incyte: Research Funding; Summer Road: Research Funding; Merus: Research Funding; Janssen: Research Funding; Formation Biologics: Research Funding.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 24-25 ◽  
Author(s):  
Sham Mailankody ◽  
Jeffrey V. Matous ◽  
Michaela Liedtke ◽  
Surbhi Sidana ◽  
Shahbaz Malik ◽  
...  

Background Allogeneic (off the shelf) chimeric antigen receptor (CAR) T cell therapy addresses the logistical challenges, availability and variable product quality of autologous CAR T therapy. ALLO-715 is a genetically modified anti-BCMA AlloCAR Ttm cell product in which the TCR alpha constant gene is disrupted to reduce the risk of graft-versus-host disease (GvHD) and the CD52 gene is disrupted with Talen® technology to permit the use of ALLO-647, an anti-CD52 mAb, for selective and prolonged host lymphodepletion (LD). Methods This is an open-label, Phase 1 trial (NCT04093596) in adults with R/R multiple myeloma who have received ≥3 prior lines of therapy including a proteasome inhibitor, immunomodulator, and anti-CD38 mAb. Patients (pts) must be refractory to their last treatment line. Patients receive LD followed by ALLO-715 at 1 of 4 dose levels (DL) in a 3+3 dose escalation design: 40, 160, 320, and 480 x 106 CAR+ T cells. Several LD regimens are being evaluated. These include: FCA (fludarabine (F) 90 mg/m2, cyclophosphamide (C) 900 mg/m2, and ALLO-647 (A) 39 mg divided over 3 days), FCA+ (same F and C but ALLO-647 (A+) dose of 90 mg divided over 3 days); as well as CA (same C and A divided over 3 days, but no F given). Results As of 08 July 2020, 19 pts had enrolled and 15 had received ALLO-715 at 3 DLs: 3 pts at DL1 (3 FCA and 0 CA); 7 pts at DL2 (4 FCA and 3 CA); 5 pts at DL3 (3 FCA and 2 CA). As of the data cutoff, no pts had received FCA+ or ALLO-715 DL4. Patients were heavily pre-treated and in advanced stage of disease with a median of 5 (range 3-11) prior lines of therapy and 31.6% ISS Stage III at screening. All but 1 had a prior autologous stem cell transplant. 52.6% (10/19) of patients had high risk cytogenetics, and 26.3% (5/19) had extramedullary disease. The most common Grade ≥3 adverse events were anemia (41.2%), neutropenia (41.2%), lymphopenia (29.4%), and thrombocytopenia (29.4%). Four episodes of Grade ≥3 infections occurred in 4 pts. Three of these were Grade 3 and included parvovirus B19, staphylococcal bacteremia, and pneumonia, which resolved with treatment. The fourth was a Grade 5 episode that occurred on day 8 post-ALLO-715 infusion in a rapidly progressing, refractory myeloma pt who, on day 1, developed a non-neutropenic fever and multifocal pneumonia with negative blood and sputum cultures. The patient progressed to respiratory failure and only comfort care was pursued. This death was considered related to conditioning (CA). No DLTs to ALLO-715 had been reported as of the data cutoff. In addition, no neurotoxicity (ICANS) or GvHD had been reported as of the data cutoff. Cytokine release syndrome was reported in 4 pts (24%). Three episodes were Grade 1 and 1 was Grade 2 (Lee Grading); all resolved without tocilizumab or corticosteroids. Fifteen pts were efficacy evaluable (defined as receiving ALLO-715, and undergoing at least one response assessment or discontinuing prior to the first response assessment), with a median follow-up of 2 months (range 0, 10 months). A higher dose of ALLO-715 (DL3) was associated with greater anti-cancer activity with 3/5 pts responding per IMWG (60%, 95% CI 14.7, 94.7). In pts who received DL3 FCA, 2/3 responded (1 sCR and 1 VGPR, Table 1). All DL3 pts who responded experienced at least a VGPR and achieved MRD negative status by local MRD testing. All responses were initially observed at day 14. Four (80%) out of the 5 responders were still in response at the time of the data cutoff. ALLO-715 cell expansion by qPCR was observed at all dose levels. Conclusions These early data suggest that ALLO-715 and ALLO-647 have a manageable safety profile. ALLO-715 shows evidence of clinical activity in the allogeneic setting in pts with R/R multiple myeloma and suggests that higher cell doses are associated with greater anti-cancer activity. Enrollment is ongoing in cohorts with higher ALLO-715 (480M CAR+ T-cells) and ALLO-647 (90mg). Updated safety, efficacy, PK/PD data will be presented. Clinical trial information: NCT04093596. Disclosures Mailankody: Physician Education Resource: Honoraria; PleXus Communications: Honoraria; Takeda Oncology: Research Funding; Janssen Oncology: Research Funding; Allogene Therapeutics: Research Funding; Juno Therapeutics, a Bristol-Myers Squibb Company: Research Funding. Matous:Bristol-Myers Squibb Company: Consultancy, Honoraria, Speakers Bureau. Liedtke:Janssen: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria. Sidana:Janssen: Consultancy. Nath:Actinium: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria. Oluwole:Bayer: Consultancy; Spectrum Pharmaceuticals: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy. Karski:Crisper Therapeutics: Current equity holder in publicly-traded company; Allogene Therapeutics: Current Employment, Current equity holder in publicly-traded company; Nektar Therapeutics: Current equity holder in publicly-traded company, Ended employment in the past 24 months. Lovelace:Allogene Therapeutics: Current Employment, Current equity holder in publicly-traded company. Zhou:Allogene Therapeutics: Current Employment, Current equity holder in publicly-traded company. Nandakumar:Allogene Therapeutics: Current Employment, Current equity holder in publicly-traded company. Balakumaran:Allogene Therapeutics: Current Employment, Current equity holder in publicly-traded company; Merck: Ended employment in the past 24 months. Hari:BMS: Consultancy; Takeda: Consultancy; Janssen: Consultancy; Amgen: Consultancy; GSK: Consultancy; Incyte Corporation: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1066-1066
Author(s):  
Angela Liu ◽  
Marshall Mazepa ◽  
Elizabeth Davis ◽  
Andrew Johnson ◽  
Ana G Antun ◽  
...  

Background: Immune thrombotic thrombocytopenic purpura (iTTP) is a potentially fatal hematologic disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, and ischemic organ impairment. The incidence of iTTP is higher among African-Americans (AA), however, differences in presentation and outcomes have not been fully investigated. In a multi-center cohort of patients with iTTP from the United States Thrombotic Microangiopathy (USTMA) Consortium, we tested the hypothesis that AA race is an independent predictor of poor outcomes including iTTP related mortality and relapse. Methods: We queried data from the USTMA iTTP registry, which currently includes data from 785 individual patients from 15 institutions across the United States. Data from at least one iTTP episode are available for 734 patients. The cohort is 35.1% (N = 272) White, 58.7% (N = 455) African American, 0.4% (N=3) Asian, 1.8% (N=14) Hispanic, and 4.0 % (N=31) other/unknown race. We restricted our analyses to AA and White participants because of small numbers in the other groups. We compared presenting features and treatments using the chi-squared test and t-test for categorical and continuous variables, respectively. A relapse was defined as a recurrent iTTP episode occurring at least 30 days after last therapeutic plasma exchange. To evaluate relapse-free survival, we included only patients enrolled in the registry at their first TTP episode (144 White and 246 AA) since patients presenting with a relapse as their index episode are already confirmed to have relapsing iTTP. Kaplan Meier analysis was used to compare relapse-free survival in White and AA patients, and a Cox regression model was developed to evaluate the independent effect of race on relapse, adjusting for potential confounders including age, sex, and the use of rituximab. Results: Demographics and presenting features of 390 individuals (144 White and 246 AA) presenting with a first episode of iTTP are shown in Table 1. Presenting symptoms including fever, confusion, seizure, memory deficits, stupor, headache, stroke, chest pain, abdominal pain, fatigue, and dark urine were similar between Whites and AA except for petechiae, which were more frequently documented in Whites (28.8% vs 17.7%, p=0.011). Presenting laboratory studies were also comparable though AA had a higher rate of elevated serum troponin (50.6% vs 32.5%, p=0.003), lower hemoglobin level (8.27 ± 0.13 vs 8.81 ± 0.19, p=0.0176) and platelet count (20.3 ± 1.2 vs 26.2 ± 3.2, p=0.0432). In addition to therapeutic plasma exchange and corticosteroids, rituximab was administered to 23.7% of White patients and 22.7% of AA during their first iTTP episode (P=0.815). Median time to platelet count recovery (days of daily plasma exchange until normal platelet count for two consecutive days) was shorter in AA compared with White patients [5 (IQR 4, 10) vs. 8 (IQR 5, 14), log rank P = 0.004]. AA race remained a significant predictor of the shorter time to platelet count recovery [HR 1.44 (95% CI 1.12, 1.85), P=0.004] after adjusting for rituximab therapy [HR 0.60 (95% CI 0.0.46, 0.80), P<0.001], female sex [HR 0.95 (95% CI 0.73, 1.22), P=0.669], age [HR 0.99 (95% CI 0.99, 1.01), P=0.682], platelet count [HR 1.00 (95% CI 0.99, 1.04), P=0.820] and LDH at presentation [HR 1.00 (95% CI 1.00, 1.00), P=0.525]. Death during the first episode occurred in 8.9% of White patients and 5.5% of AA patients (P=0.206). Relapse-free survival after the first episode of iTTP was lower in AA than White patients (Figure 1). AA race was associated with the reduced relapse free survival [HR 1.79 (95% CI 1.08, 2.98), P=0.024] in a Cox regression model adjusted for age [HR 1.00 (95% CI 0.98, 1.01), P=0.683], sex [HR 0.96 (95% CI 0.60, 1.54), P=0.867], and rituximab therapy [HR 0.93 (95% CI 0.55, 1.59), P=0.806]. Conclusion: African Americans with iTTP have a higher relapse rate and shorter relapse free survival after the first episode of the disease compared with Caucasian patients, which is independent of age, sex and rituximab therapy. Contrary to our hypothesis, acute outcomes of iTTP (time to platelet count recovery and mortality) were not worse in AA patients. The factors contributing to the higher relapse rate in AA with iTTP need to be further investigated. Our findings suggest that AA patients may also benefit from closer follow up. Disclosures Farland: Sanofi: Membership on an entity's Board of Directors or advisory committees. Metjian:Sanofi: Membership on an entity's Board of Directors or advisory committees. Raval:Bayer, Inc: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees. Liles:Shire: Other: PI on clinical trial Sickle cell ; Imara: Other: PI on Clinical trial- Sickle cell ; Novartis: Other: PI on clinical trial Sickle cell . Baumann Kreuziger:CSL Behring: Consultancy; Vaccine Injury Compensation Program: Consultancy. McCrae:Dova Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Pfizer Pharmaceutical: Membership on an entity's Board of Directors or advisory committees; Rigel Pharmaceutical: Membership on an entity's Board of Directors or advisory committees; Sanofi Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Zheng:Alexion: Speakers Bureau; Ablynx/Sanofi: Consultancy, Speakers Bureau; Clotsolution: Other: Co-Founder; Shire/Takeda: Research Funding. Cataland:Alexion: Consultancy, Research Funding; Ablynx/Sanofi: Consultancy, Research Funding. Chaturvedi:Shire/Takeda: Research Funding; Sanofi: Consultancy; Alexion: Consultancy.


Sign in / Sign up

Export Citation Format

Share Document