scholarly journals Interim Results from Fight-203, a Phase 2, Open-Label, Multicenter Study Evaluating the Efficacy and Safety of Pemigatinib (INCB054828) in Patients with Myeloid/Lymphoid Neoplasms with Rearrangement of Fibroblast Growth Factor Receptor 1 (FGFR1)

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 690-690 ◽  
Author(s):  
Srdan Verstovsek ◽  
Alessandro M. Vannucchi ◽  
Alessandro Rambaldi ◽  
Jason R. Gotlib ◽  
Adam J. Mead ◽  
...  

Abstract Introduction: Myeloid/lymphoid neoplasms (MLNs) with rearrangement of FGFR1 on chromosome band 8p11 are rare but aggressive neoplasms characterized by heterogeneous presentation with myeloid and/or lymphoid proliferation, extramedullary involvement, and rapid progression to blast phase (Strati P, et al., Leuk Lymphoma. 2018;59:1672-1676). FGFR1 gets constitutively activated through fusion genes involving various partner genes, most frequently ZMYM2-FGFR1 or BCR-FGFR1 as consequence of a t(8;13)(p11;q12) or a t(8;22)(p11;q11), respectively. Chemotherapy is usually ineffective, effective targeted treatment has not been described, and allogeneic hematopoietic stem cell transplant (alloHSCT) is the only potentially curative option. Pemigatinib, a selective, potent, oral inhibitor of FGFR1, 2, and 3, has shown efficacy in patients with FGF/FGFR-activated tumors, including cholangiocarcinoma and urothelial carcinoma. We report interim results from the ongoing fight-203 study (NCT03011372) of pemigatinib in patients with FGFR1-rearranged MLNs. Methods: Fight-203 is a phase 2, open-label study enrolling patients ≥ 18 years of age with FGFR1-rearranged MLN. Patients enrolled in the study must have progressed on ≥ 1 prior treatment and be ineligible for alloHSCT. Patients receive a daily oral dose of pemigatinib 13.5 mg on a 21-day cycle (2 weeks on, 1 week off) until disease progression or unacceptable toxicity. The primary endpoint is overall clinical benefit rate, which includes complete clinical (CR) or partial clinical response (PR), and either complete or partial cytogenetic response (CCyR, PCyR). Secondary endpoints include duration of response/benefit, progression-free survival, overall survival, and safety/tolerability. Efficacy is assessed by evaluation of bone marrow histomorphology changes, standard cytogenetic and FISH evaluation of the FGFR1 rearrangement, and PET/CT scan. Results: At data cutoff (July 23, 2018), 14 patients were enrolled. Ten patients who had ≥ 1 response assessment were included in the analysis (Table). Patients received an average of 6.9 cycles of pemigatinib (range, 2-12 cycles). Median number of prior lines of therapy was 3 (range, 0-5), including 2 patients who received alloHSCT. Eight patients (80%) had a major CyR, including 6 patients with CCyR and 2 with PCyR. Eight patients (80%) had a CR or PR in bone marrow, peripheral blood, and extramedullary disease. One patient died of progression to myeloid blast crisis, 2 patients were bridged to alloHSCT, and 7 patients are ongoing. The most common treatment-emergent adverse events (AEs) were hyperphosphatemia (n=7 [70%]), diarrhea (n=5 [50%]) and anemia (n=5 [50%]); hyperphosphatemia was managed with diet and phosphate binders. Nine events in 4 patients (40%) were grade 3/4; 2 of these events (diarrhea and leukopenia) in 2 patients were related to pemigatinib. There were no drug-related AEs leading to dose interruption, dose reduction, or discontinuation. Conclusions: Pemigatinib showed promising efficacy, with an 80% major CyR rate accompanied by complete or partial remission, and was generally well tolerated by patients with FGFR1-rearranged MLN. The protocol was amended to allow continuous dosing, and the study is currently enrolling. Disclosures Verstovsek: Celgene: Membership on an entity's Board of Directors or advisory committees; Italfarmaco: 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. Gotlib:Blueprint Medicines: Consultancy, Honoraria, Research Funding; Deciphera: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Research Funding; Promedior: Research Funding; Kartos: Consultancy; Incyte: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Mead:Celgene: Research Funding; Bristol-Myers Squibb: Consultancy; Evotek: Research Funding; ARIAD: Consultancy; Cell Therapeutics: Consultancy; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Elstar: Research Funding. Hochhaus:Bristol-Myers Squibb: Research Funding; Novartis: Research Funding; Incyte: Research Funding; Takeda: Research Funding; Pfizer: Research Funding. Kiladjian:AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: 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. Hernandez Boluda:Incyte: Consultancy; Novartis: Consultancy. Asatiani:Incyte: Employment, Equity Ownership. Lihou:Incyte: Employment, Equity Ownership. Zhen:Incyte: Employment, Equity Ownership. Reiter:Incyte: Consultancy, Honoraria.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2249-2249
Author(s):  
Kevin H. M. Kuo ◽  
D. Mark Layton ◽  
Katrin Uhlig ◽  
Megan Lynch ◽  
Li Liu ◽  
...  

Background: Thalassemia is a group of inherited blood disorders in which genetic mutation(s) in the α- and/or β-globin locus lead to excess precipitation of β- or α-globin, respectively, and compromised red blood cell (RBC) survival. The condition is characterized by ineffective erythropoiesis and peripheral hemolysis, with resultant anemia. Adenosine triphosphate (ATP) supply appears to be insufficient in thalassemic RBCs to maintain RBC membrane fitness and clearance of globin precipitates. Mitapivat (AG-348) is an oral, small-molecule, allosteric activator of the RBC-specific form of pyruvate kinase (PK-R). PK-R is a key enzyme for maintaining energy homeostasis in RBCs, as they rely almost exclusively on the process of glycolysis to generate ATP. In healthy adults, mitapivat activates wild-type PK-R and increases ATP levels in RBCs. In adults with PK deficiency who were not regularly transfused, oral mitapivat was well tolerated and induced rapid, durable hemoglobin (Hb) increases (NCT02476916). In the Hbbth/3+ mouse model of β-thalassemia, mitapivat increased ATP levels; reduced markers of ineffective erythropoiesis; and improved anemia, RBC survival, and indices of iron overload. These data support the hypothesis that increased ATP synthesis mediated via PK-R activation by mitapivat may improve the survival of thalassemic RBCs in the bone marrow and/or peripheral circulation, and thus represents a novel mechanism to treat patients with thalassemia. Here we present the design of a phase 2, open-label study designed to test this hypothesis and assess the proof of concept of mitapivat in patients with thalassemia. Methods: This phase 2, multicenter, open-label study (NCT03692052) is evaluating the efficacy, safety, pharmacokinetics, and pharmacodynamics of mitapivat in adults with non-transfusion-dependent thalassemia (NTDT). Four sites in North America and the United Kingdom are enrolling patients. The study consists of a 24-week core period followed by a 2-year extension period (Figure). Approximately 17 subjects with NTDT, i.e., β-thalassemia with or without α-globin gene mutations, HbE β-thalassemia, or α-thalassemia (HbH disease), will be enrolled. Non-transfusion dependence is defined as ≤5 units of RBCs transfused in the preceding 24 weeks and no transfusions in the 8 weeks prior to the first day of study drug. The hemoglobin inclusion criterion is ≤10.0 g/dL, which was increased from ≤9.0 g/dL in a recent protocol amendment to better reflect the clinical representation in the NTDT patient population. All eligible patients will receive an initial mitapivat dose of 50 mg twice daily (BID). At the week 6 visit the dose may be increased to 100 mg BID, depending on safety and Hb response. The primary endpoint is the proportion of subjects who achieve an Hb response, defined as an increase in Hb of ≥1.0 g/dL from baseline at any time between week 4 and week 12 (inclusive). Key secondary and exploratory endpoints include changes in Hb and markers of hemolysis; hematopoietic activity; iron metabolism and iron overload; and assessments of safety and pharmacokinetics. The study is currently enrolling. Figure Disclosures Kuo: Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy; Celgene: Consultancy; Novartis: Consultancy, Honoraria; Pfizer: Consultancy. Layton:Cerus Corporation: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Uhlig:Agios: Employment, Equity Ownership. Lynch:Agios: Employment, Equity Ownership. Liu:Agios: Employment, Equity Ownership. Vichinsky:GBT: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Agios: Consultancy, Research Funding; bluebird bio: Consultancy, Research Funding; Novartis: Consultancy, Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 715-715 ◽  
Author(s):  
Jeffrey Jones ◽  
Anthony R. Mato ◽  
Steven Coutre ◽  
William Wierda ◽  
Michael Y. Choi ◽  
...  

Abstract Introduction: The overall outcome of patients (pts) with chronic lymphocytic leukemia (CLL) who relapse after or become refractory to treatment with B-cell receptor (BCR) signaling antagonists, including ibrutinib (IBR) or idelalisib (IDE), is recently being appreciated and appears quite poor. To date, no phase 2 studies have reported efficacy in this population. Venetoclax is a selective, potent, orally bioavailable BCL-2 inhibitor with a BCR-independent mechanism of action and substantial activity in pts with heavily pretreated relapsed or refractory CLL. We report preliminary results from an ongoing phase 2, open-label study evaluating venetoclax monotherapy in CLL pts relapsed after or refractory to IBR or IDE (NCT02141282). Methods: Pts with CLL relapsed after or refractory to IBR (Arm A) or IDE (Arm B) receive venetoclax monotherapy starting at 20 mg followed by a 5-step weekly ramp-up to a final daily dose of 400 mg. Pts with Richter's transformation (RT) suspected by screening PET CT or confirmed by lymph node biopsy are ineligible. The primary objectives are to assess the efficacy (investigator assessed overall response rate, ORR) and safety of venetoclax. Disease and response assessment was performed using iwCLL criteria at weeks 8, 24 and every 12 weeks thereafter. Adverse events (AEs) are monitored throughout the study. Results: As of April 30, 2015, 28 pts were enrolled in the study. Three screened pts were ineligible due to RT. Pt demographics are summarized by treatment arm in the table. Twenty-two entered into Arm A after a median duration on IBR of 15.5 months (range: 1-56). Investigator-reported best responses while on IBR prior to starting venetoclax were 14 partial response (PR), 4 stable disease (SD) and 3 progressive disease (PD); best response for 1 pt is unknown. Six entered into Arm B after a median duration on IDE of 9.7 months (range: 1-34). Investigator-reported best responses while on IDE prior to starting venetoclax were 1 complete response (CR), 3 PR and 2 SD. At last follow-up, the median time on venetoclax was 2.4 months (range: 0.1- 7) for Arm A and 1.7 months (range: 1.2-4.5) for Arm B. Venetoclax discontinuation occurred in 4 pts in Arm A (1 each due to respiratory failure, multi-organ failure, PD of RT, death of unknown cause) and in 1 pt in Arm B (PD prior to first assessment). Fifteen pts in Arm A and 3 in Arm B underwent Week 8 response assessment. In Arm A, 8/15 (53%) achieved a PR, 6/15 (40%) had SD, and 1/15 was inevaluable. In Arm B, 2/4 achieved a PR, 1/4 had SD, and 1/4 had PD prior to first assessment. Pts with SD had evidence of ongoing disease reduction, measured by decreasing circulating lymphocytes and lymph nodes. As of the cutoff date, 23 pts remain on venetoclax therapy. Compared to prior venetoclax monotherapy studies, no new safety signals for venetoclax were observed in either treatment arm. Treatment-emergent AEs (all grades) in >25% of the overall population were neutropenia (57%), anemia (35%), diarrhea (32%) and nausea (32%). Treatment-emergent grade 3/4 AEs in >10% of the overall population were neutropenia (43%; 3/12 of the neutropenic pts developed febrile neutropenia), anemia (29%), thrombocytopenia (18%), hypophosphatemia, hypoxia, leukopenia, and pneumonia (each 11%). Serious AEs in ≥2 pts overall were febrile neutropenia, increased blood potassium, multi-organ failure, and pneumonia (each 7%). Prior to study entry, 7/22 (32%) in Arm A received G-CSF support. One pt with high disease burden developed laboratory TLS in week 4, upon escalating to the 200 mg daily venetoclax dose, evident by hyperuricemia and hyperphosphatemia. Electrolytes returned to normal levels after a dose interruption and intervention. No pts experienced clinical TLS; laboratory changes were not clinically significant. Conclusions: In this group of pts with aggressive disease relapsed after or refractory to BCR-targeted agents, venetoclax monotherapy demonstrated early activity at the 8 week assessment, which occurred within 3 weeks of reaching the target 400 mg daily dose. The majority of evaluable pts achieved PR or SD. Venetoclax monotherapy exhibited a tolerable safety profile without events of clinical TLS. This is the first phase 2 study to show activity in a relatively uniform population of pts previously treated with BCR kinase inhibitors; the data suggests that venetoclax is active in these pts. Enrollment in both arms was ongoing as of the data cut. Figure 1. Figure 1. Disclosures Jones: Genentech, Pharmacyclics; institutional research funding from Abbvie, Pharmacyclics, Genentech, and Gilead: Other: Advisory Board. Off Label Use: Venetoclax is an investigational drug that is not yet approved in this indication.. Mato:AbbVie: Consultancy, Research Funding; Genentech: Consultancy; Pharmacyclics: Consultancy, Research Funding; Pronai Pharmaceuticals: Research Funding; Celgene Corporation: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; TG Therapeutics: Research Funding. Coutre:AbbVie: Research Funding. Wierda:Genentech: Consultancy; AbbVie and Genentech: Research Funding. Choi:AbbVie and Gilead: Membership on an entity's Board of Directors or advisory committees; Gilead: Speakers Bureau; AbbVie: Research Funding. Davids:AbbVie and Janssen: Consultancy; Genentech and Infinity Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics, TG Therapeutics, and Infinity: Research Funding. Lamanna:Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding. Barr:Pharmacyclics: Research Funding; AbbVie and Pharmacyclics: Consultancy. Burns:AbbVie: Employment, Equity Ownership. Montalvo:AbbVie: Employment, Equity Ownership. Zhu:AbbVie: Employment, Equity Ownership. Busman:AbbVie: Employment, Equity Ownership. Potluri:AbbVie: Employment, Equity Ownership. Humerickhouse:AbbVie: Employment, Equity Ownership. Byrd:Pharmacyclics: Research Funding; Genenttech, AbbVie, Acerta, Pharmacyclics: Other: Unpaid consultant.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1528-1528
Author(s):  
Sebastian Stasik ◽  
Jan Moritz Middeke ◽  
Michael Kramer ◽  
Christoph Rollig ◽  
Alwin Krämer ◽  
...  

Abstract Purpose: The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase and key epigenetic regulator involved in transcriptional repression and embryonic development. Loss of EZH2 activity by inactivating mutations is associated with poor prognosis in myeloid malignancies such as MDS. More recently, EZH2 inactivation was shown to induce chemoresistance in acute myeloid leukemia (AML) (Göllner et al., 2017). Data on the frequency and prognostic role of EZH2-mutations in AML are rare and mostly confined to smaller cohorts. To investigate the prevalence and prognostic impact of this alteration in more detail, we analyzed a large cohort of AML patients (n = 1604) for EZH2 mutations. Patients and Methods: All patients analyzed had newly diagnosed AML, were registered in clinical protocols of the Study Alliance Leukemia (SAL) (AML96, AML2003 or AML60+, SORAML) and had available material at diagnosis. Screening for EZH2 mutations and associated alterations was done using Next-Generation Sequencing (NGS) (TruSight Myeloid Sequencing Panel, Illumina) on an Illumina MiSeq-system using bone marrow or peripheral blood. Detection was conducted with a defined cut-off of 5% variant allele frequency (VAF). All samples below the predefined threshold were classified as EZH2 wild type (wt). Patient clinical characteristics and co-mutations were analyzed according to the mutational status. Furthermore, multivariate analysis was used to identify the impact of EZH2 mutations on outcome. Results: EZH2-mutations were found in 63 of 1604 (4%) patients, with a median VAF of 44% (range 6-97%; median coverage 3077x). Mutations were detected within several exons (2-6; 8-12; 14-20) with highest frequencies in exons 17 and 18 (29%). The majority of detected mutations (71% missense and 29% nonsense/frameshift) were single nucleotide variants (SNVs) (87%), followed by small indel mutations. Descriptive statistics of clinical parameters and associated co-mutations revealed significant differences between EZH2-mut and -wt patients. At diagnosis, patients with EZH2 mutations were significantly older (median age 59 yrs) than EZH2-wt patients (median 56 yrs; p=0.044). In addition, significantly fewer EZH2-mut patients (71%) were diagnosed with de novo AML compared to EZH2-wt patients (84%; p=0.036). Accordingly, EZH2-mut patients had a higher rate of secondary acute myeloid leukemia (sAML) (21%), evolving from prior MDS or after prior chemotherapy (tAML) (8%; p=0.036). Also, bone marrow (and blood) blast counts differed between the two groups (EZH2-mut patients had significantly lower BM and PB blast counts; p=0.013). In contrast, no differences were observed for WBC counts, karyotype, ECOG performance status and ELN-2017 risk category compared to EZH2-wt patients. Based on cytogenetics according to the 2017 ELN criteria, 35% of EZH2-mut patients were categorized with favorable risk, 28% had intermediate and 37% adverse risk. No association was seen with -7/7q-. In the group of EZH2-mut AML patients, significantly higher rates of co-mutations were detected in RUNX1 (25%), ASXL1 (22%) and NRAS (25%) compared to EZH2-wt patients (with 10%; 8% and 15%, respectively). Vice versa, concomitant mutations in NPM1 were (non-significantly) more common in EZH2-wt patients (33%) vs EZH2-mut patients (21%). For other frequently mutated genes in AML there was no major difference between EZH2-mut and -wt patients, e.g. FLT3ITD (13%), FLT3TKD (10%) and CEBPA (24%), as well as genes encoding epigenetic modifiers, namely, DNMT3A (21%), IDH1/2 (11/14%), and TET2 (21%). The correlation of EZH2 mutational status with clinical outcomes showed no effect of EZH2 mutations on the rate of complete remission (CR), relapse free survival (RFS) and overall survival (OS) (with a median OS of 18.4 and 17.1 months for EZH2-mut and -wt patients, respectively) in the univariate analyses. Likewise, the multivariate analysis with clinical variable such as age, cytogenetics and WBC using Cox proportional hazard regression, revealed that EZH2 mutations were not an independent risk factor for OS or RFS. Conclusion EZH mutations are recurrent alterations in patients with AML. The association with certain clinical factors and typical mutations such as RUNX1 and ASXL1 points to the fact that these mutations are associated with secondary AML. Our data do not indicate that EZH2 mutations represent an independent prognostic factor. Disclosures Middeke: Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Rollig:Bayer: Research Funding; Janssen: Research Funding. Scholl:Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Abbivie: Other: Travel support; Alexion: Other: Travel support; MDS: Other: Travel support; Novartis: Other: Travel support; Deutsche Krebshilfe: Research Funding; Carreras Foundation: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees. Hochhaus:Pfizer: Research Funding; Incyte: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding; Takeda: Research Funding. Brümmendorf:Janssen: Consultancy; Takeda: Consultancy; Novartis: Consultancy, Research Funding; Merck: Consultancy; Pfizer: Consultancy, Research Funding. Burchert:AOP Orphan: Honoraria, Research Funding; Bayer: Research Funding; Pfizer: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Novartis: Research Funding. Krause:Novartis: Research Funding. Hänel:Amgen: Honoraria; Roche: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Platzbecker:Celgene: Research Funding. Mayer:Eisai: Research Funding; Novartis: Research Funding; Roche: Research Funding; Johnson & Johnson: Research Funding; Affimed: Research Funding. Serve:Bayer: Research Funding. Ehninger:Cellex Gesellschaft fuer Zellgewinnung mbH: Employment, Equity Ownership; Bayer: Research Funding; GEMoaB Monoclonals GmbH: Employment, Equity Ownership. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3279-3279 ◽  
Author(s):  
Ann Janssens ◽  
Michael D. Tarantino ◽  
Robert Bird ◽  
Maria Gabriella Mazzucconi ◽  
Ralph Vincent V. Boccia ◽  
...  

Abstract Abstract 3279 Background: ITP is an autoimmune disorder characterized by increased platelet destruction and suboptimal platelet production. Romiplostim stimulates platelet production via the TPO-receptor, and is recommended for second- and third-line treatment of chronic ITP in adults. We report final data from a large prospective study of romiplostim in adults with ITP of varying duration and severity. Methods: Eligibility criteria were broad: patients ≥18 years of age, who had received prior ITP therapies (final protocol amendment: ≥1, previous amendments: ≥3), with low platelet counts (final amendment: ≤ 30 × 109/L, previous amendments: ≤ 10, ≤ 20 × 109/L) or experiencing uncontrolled bleeding. The only excluded comorbidities were: hematological malignancy, myeloproliferative neoplasms, MDS and bone marrow stem cell disorder. Romiplostim was initiated at 1 (final amendment) or 3 (previous amendments) μg/kg/week, with dose adjustments allowed to maintain platelet counts ≥50 × 109/L. Patients could continue on study until they had access to commercially available romiplostim. Rescue medications were allowed at any time; concurrent ITP therapies could be reduced when platelet counts were > 50 × 109/L. Primary endpoint was incidence of adverse events (AEs) and antibody formation. Secondary endpoint was platelet response, defined as either (1) doubling of baseline count and ≥ 50 × 109/L or (2) ≥20 × 109/L increase from baseline. Results: A total of 407 patients received romiplostim, 60% of whom were female. Median (Q1, Q3) time since ITP diagnosis was 4.25 (1.20, 11.40) years (maximum 57.1 years), with 51% of patients splenectomised and 39% receiving baseline concurrent ITP therapies. Seventy-one percent of patients completed the study, with requirement for alternative therapy and withdrawn consent the most common reasons for discontinuation (5% each). Median (Q1, Q3) on-study treatment duration was 44.29 (20.43, 65.86) weeks (maximum 201 weeks), with a total of 20,201 subject-weeks on study. Incidence and type of AEs were consistent with previous studies. The most common serious treatment-related AEs were cerebrovascular accident, headache, bone marrow reticulin fibrosis (with no evidence of positive trichrome staining for collagen and no evidence suggesting primary idiopathic myelofibrosis), nausea, deep vein thrombosis, hemorrhage and pulmonary embolism, with each reported in 2 of 407 (0.5%) patients. All other serious treatment-related AEs were each reported in one patient. Eighteen patients died; 3 deaths (hemolysis, intestinal ischaema, aplastic anemia) were considered treatment-related. No neutralizing antibodies to romiplostim or TPO were reported. Approximately 90% of patients achieved each of the platelet response definitions, regardless of splenectomy status. Overall, median (Q1, Q3) time to response was 2 (1, 4) weeks for response definition 1, and 1 (1, 3) week for response definition 2. Median (Q1, Q3) baseline platelet count was 14 (8, 21) × 109/L. After 1 week of treatment median (Q1, Q3) platelet count had increased to 42 (18, 101) × 109/L. From week 8 onwards, and excluding counts within 8 weeks of rescue medication use, median platelet counts were consistently above 100 × 109/L (range 101.0–269.5 × 109/L). Median (Q1, Q3) average weekly romiplostim dose was 3.62 (1.99, 6.08) μg/kg. Summary/conclusions: This is the largest prospective study in adult ITP reported to date. The data reported here are similar to those reported for previous romiplostim studies, with romiplostim able to safely induce a rapid platelet response in adult ITP patients with low platelet counts or bleeding symptoms. Romiplostim is an important, well-tolerated, treatment option for adult ITP patients, which significantly increases and maintains platelet counts. Adverse Event Subject Incidence Platelet Response Disclosures: Janssens: Amgen: Consultancy; Roche: Speakers Bureau; GSK: Membership on an entity's Board of Directors or advisory committees. Tarantino:Cangene corporation: Research Funding; Baxter: Research Funding; Talecris: Honoraria, Speakers Bureau; Up-to-date: Patents & Royalties; The Bleeding and Clotting Disorders Institute: Board Member. Bird:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GSK: Membership on an entity's Board of Directors or advisory committees. Boccia:Amgen: Equity Ownership, Honoraria, Speakers Bureau. Lopez-Fernandez:Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kozak:Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Steurer:Amgen: Honoraria. Dillingham:Amgen Limited: Employment, Equity Ownership. Lizambri:Amgen: Employment, Equity Ownership.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2810-2810
Author(s):  
Srdan Verstovsek ◽  
Michael R. Savona ◽  
Ruben A. Mesa ◽  
Stephen Oh ◽  
Hua Dong ◽  
...  

Abstract Background: Simtuzumab (SIM) is a humanized monoclonal antibody that inhibits lysyl oxidase-like molecule 2 (LOXL2), an extracellular matrix enzyme that catalyzes the covalent cross-linking of collagen and is widely expressed across many fibrotic diseases. In pre-clinical models, inhibition of LOXL2 blocks fibroblast activation, which plays an important role in the development of organ fibrosis. In Phase 1 studies, SIM was well-tolerated in patients (pts) with advanced solid tumors, liver fibrosis, and idiopathic pulmonary fibrosis (IPF). A Phase 2, open-label study to determine the efficacy of SIM alone (Stage 1) and combined with ruxolitinib (rux) (Stage 2) in pts with primary myelofibrosis (PMF) and post-ET/PV MF was initiated. Methods: Eligible pts had intermediate-1, intermediate-2, or high risk disease and Eastern Cooperative Oncology Group performance status of <2. The primary endpoint was rate of clinical response as defined by a reduction in bone marrow fibrosis score following 24 weeks of treatment with SIM. Patients were randomized in a 1:1 ratio to receive 200 mg or 700 mg SIM by intravenous infusion every 2 weeks as monotherapy (Stage 1, n=24) or combined with rux (Stage 2, n=30). Patients received SIM for up to 24 weeks. Bone marrow biopsies and aspirates were performed approximately every 3 months. Bone marrow fibrosis scoring was performed and quantified at local investigator sites using the European Consensus on Grading Bone Marrow Fibrosis. Myelofibrosis symptoms were evaluated using the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and changes in hematologic parameters and splenomegaly were assessed. Results: Between 7/14/11 and 9/22/14, 54 pts were randomized and treated (200 mg SIM [n=12], 700 mg SIM [n=12], 200 mg SIM/rux [n=15], and 700 mg SIM/rux [n=15]). In Stage 1, 0 subjects (0%) in the SIM 200 mg group and 2 subjects (16.7%; 90% CI 3.0%, 43.8%) in the SIM 700 mg group showed a reduction in bone marrow fibrosis score from Baseline to Week 24. In Stage 2, 1 subject (6.7%; 90% CI 0.3%, 27.9%) in the SIM 200 mg/rux group and 2 subjects (13.3%, 90% CI 2.4%, 36.3%) in the SIM 700 mg/rux group showed a reduction in bone marrow fibrosis score from Baseline to Week 24. In an exploratory analysis, similar numbers of subjects showed increases in bone marrow fibrosis scores. SIM treatment was not associated with meaningful improvements in hematologic parameters or reductions in MPN-SAF score or spleen size. The most frequent adverse events were those commonly associated with MF, including constitutional symptoms and reductions in hematological parameters. Conclusions: SIM treatment alone or in combination with rux is safe but does not reliably reduce bone marrow fibrosis in pts with MF. The reason for reduction of marrow fibrosis in some patients and increase in others is unclear and may be sampling variability. Clinical studies of SIM in IPF and liver fibrosis are ongoing. Disclosures Savona: Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Research Funding; Astex Pharmaceuticals, Inc: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Mesa:Incyte Corporation: Research Funding; CTI Biopharma: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Pfizer: Research Funding; Promedior: Research Funding; Genentech: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding. Oh:CTI Biopharma: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees. Dong:Gilead Sciences: Consultancy, Equity Ownership. Thai:Gilead Sciences: Employment, Equity Ownership. Gotlib:Allakos, Inc.: Consultancy.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1882-1882 ◽  
Author(s):  
Samuel A Danziger ◽  
Mark McConnell ◽  
Jake Gockley ◽  
Mary Young ◽  
Adam Rosenthal ◽  
...  

Abstract Introduction The multiple myeloma (MM) tumor microenvironment (TME) strongly influences patient outcomes as evidenced by the success of immunomodulatory therapies. To develop precision immunotherapeutic approaches, it is essential to identify and enumerate TME cell types and understand their dynamics. Methods We estimated the population of immune and other non-tumor cell types during the course of MM treatment at a single institution using gene expression of paired CD138-selected bone marrow aspirates and whole bone marrow (WBM) core biopsies from 867 samples of 436 newly diagnosed MM patients collected at 5 time points: pre-treatment (N=354), post-induction (N=245), post-transplant (N=83), post-consolidation (N=51), and post-maintenance (N=134). Expression profiles from the aspirates were used to infer the transcriptome contribution of immune and stromal cells in the WBM array data. Unsupervised clustering of these non-tumor gene expression profiles across all time points was performed using the R package ConsensusClusterPlus with Bayesian Information Criterion (BIC) to select the number of clusters. Individual cell types in these TMEs were estimated using the DCQ algorithm and a gene expression signature matrix based on the published LM22 leukocyte matrix (Newman et al., 2015) augmented with 5 bone marrow- and myeloma-specific cell types. Results Our deconvolution approach accurately estimated percent tumor cells in the paired samples compared to estimates from microscopy and flow cytometry (PCC = 0.63, RMSE = 9.99%). TME clusters built on gene expression data from all 867 samples resulted in 5 unsupervised clusters covering 91% of samples. While the fraction of patients in each cluster changed during treatment, no new TME clusters emerged as treatment progressed. These clusters were associated with progression free survival (PFS) (p-Val = 0.020) and overall survival (OS) (p-Val = 0.067) when measured in pre-transplant samples. The most striking outcomes were represented by Cluster 5 (N = 106) characterized by a low innate to adaptive cell ratio and shortened patient survival (Figure 1, 2). This cluster had worse outcomes than others (estimated mean PFS = 58 months compared to 71+ months for other clusters, p-Val = 0.002; estimate mean OS = 105 months compared with 113+ months for other clusters, p-Val = 0.040). Compared to other immune clusters, the adaptive-skewed TME of Cluster 5 is characterized by low granulocyte populations and high antigen-presenting, CD8 T, and B cell populations. As might be expected, this cluster was also significantly enriched for ISS3 and GEP70 high risk patients, as well as Del1p, Del1q, t12;14, and t14:16. Importantly, this TME persisted even when the induction therapy significantly reduced the tumor load (Table 1). At post-induction, outcomes for the 69 / 245 patients in Cluster 5 remain significantly worse (estimate mean PFS = 56 months compared to 71+ months for other clusters, p-Val = 0.004; estimate mean OS = 100 months compared to 121+ months for other clusters, p-Val = 0.002). The analysis of on-treatment samples showed that the number of patients in Cluster 5 decreases from 30% before treatment to 12% after transplant, and of the 63 patients for whom we have both pre-treatment and post-transplant samples, 18/20 of the Cluster 5 patients moved into other immune clusters; 13 into Cluster 4. The non-5 clusters (with better PFS and OS overall) had higher amounts of granulocytes and lower amounts of CD8 T cells. Some clusters (1 and 4) had increased natural killer (NK) cells and decreased dendritic cells, while other clusters (2 and 3) had increased adipocytes and increases in M2 macrophages (Cluster 2) or NK cells (Cluster 3). Taken together, the gain of granulocytes and adipocytes was associated with improved outcome, while increases in the adaptive immune compartment was associated with poorer outcome. Conclusions We identified distinct clusters of patient TMEs from bulk transcriptome profiles by computationally estimating the CD138- fraction of TMEs. Our findings identified differential immune and stromal compositions in patient clusters with opposing clinical outcomes and tracked membership in those clusters during treatment. Adding this layer of TME to the analysis of myeloma patient baseline and on-treatment samples enables us to formulate biological hypotheses and may eventually guide therapeutic interventions to improve outcomes for patients. Disclosures Danziger: Celgene Corporation: Employment, Equity Ownership. McConnell:Celgene Corporation: Employment. Gockley:Celgene Corporation: Employment. Young:Celgene Corporation: Employment, Equity Ownership. Schmitz:Celgene Corporation: Employment, Equity Ownership. Reiss:Celgene Corporation: Employment, Equity Ownership. Davies:MMRF: Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; TRM Oncology: Honoraria; Abbvie: Consultancy; ASH: Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria. Copeland:Celgene Corporation: Employment, Equity Ownership. Fox:Celgene Corporation: Employment, Equity Ownership. Fitch:Celgene Corporation: Employment, Equity Ownership. Newhall:Celgene Corporation: Employment, Equity Ownership. Barlogie:Celgene: Consultancy, Research Funding; Dana Farber Cancer Institute: Other: travel stipend; Multiple Myeloma Research Foundation: Other: travel stipend; International Workshop on Waldenström's Macroglobulinemia: Other: travel stipend; Millenium: Consultancy, Research Funding; European School of Haematology- International Conference on Multiple Myeloma: Other: travel stipend; ComtecMed- World Congress on Controversies in Hematology: Other: travel stipend; Myeloma Health, LLC: Patents & Royalties: : Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC. Trotter:Celgene Research SL (Spain), part of Celgene Corporation: Employment, Equity Ownership. Hershberg:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Dervan:Celgene Corporation: Employment, Equity Ownership. Ratushny:Celgene Corporation: Employment, Equity Ownership. Morgan:Takeda: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1266-1266 ◽  
Author(s):  
Tomasz Knurowski ◽  
Karen Clegg ◽  
Nigel Brooks ◽  
Fay Ashby ◽  
Neil A Pegg ◽  
...  

Background CCS1477 is a first in class potent, selective and orally bioavailable inhibitor of the bromodomains of p300 and CBP, two closely related histone acetyl transferases with oncogenic roles in haematological malignancies. In pre-clinical studies, CCS1477 was found to be a potent inhibitor of cell proliferation in acute myeloid leukaemia (AML) multiple myeloma (MM) and non-Hodgkin lymphoma (NHL) cell lines. In primary patient AML blast cells CCS1477 inhibited proliferation through a combination of cell cycle arrest at the G1/S transition and an induction of differentiation (up-regulation of CD11b and CD86). CCS1477 has significant anti-tumour activity, inducing tumour regressions in xenograft models of AML and MM. These effects were accompanied by significant reductions in tumour MYC and IRF4 expression. Additionally, there are molecular features of certain haematological malignancies that are likely to increase the sensitivity to p300/CBP inhibition with CCS1477. For example, in B-cell lymphomas there are frequent loss of function mutations in CBP that are associated with heightened sensitivity to pre-clinical inhibition of corresponding non-mutated p300. CCS1477 represents a novel and differentiated approach to inhibiting cell proliferation and survival and offers a potential new therapeutic option for patients who have relapsed or are refractory to current standard of care therapies in AML, MM or NHL. Study Design and Methods This study is the first time that CCS1477 is being dosed in patients with haematological malignancies. The Phase I/IIa study aims to determine the maximum tolerated dose (MTD) and/or recommended Phase II dose (RP2D) and schedule(s) of CCS1477 and investigate clinical activity of CCS1477 monotherapy in patients with haematological malignancies. This study will also characterise the pharmacokinetics (PK) of CCS1477 and explore potential biological activity by assessing pharmacodynamic and exploratory biomarkers. The trial aims to enrol approximately 90 patients and is currently recruiting in the UK with plans to open additional sites in the USA. Key inclusion criteria include patients with confirmed (per standard disease specific diagnostic criteria), relapsed or refractory haematological malignancies (AML, MM and NHL). Patients must have received standard therapy which for the majority of therapeutic indications is at least 2 prior lines of therapy. Single dose and steady state pharmacokinetics will be determined in all patients. AML response will be measured in bone marrow samples. Myeloma response will be evaluated according to the 'International Myeloma Working Group Response Criteria' based on changes in M protein in blood and/or urine, changes in serum free light chains if measurable, and changes on imaging and/or bone marrow if applicable and according to the guidelines. In NHL patients, tumour assessments will be done for measurable disease, non-measurable disease, and new lesions on CT (or magnetic resonance imaging [MRI]) and/or combined with visual assessment of [18F]2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) for response assessment per recent International Working Group consensus criteria (RECIL 2017), until progression The study will begin with two parallel monotherapy dose-escalation arms; Arm 1: Relapsed or refractory NHL and MM; Arm2: Relapsed or refractory AML/high-risk MDS. Once a recommended phase 2 dose/schedule is reached, three monotherapy expansion arms will be opened in AML/high-risk MDS (15 patients), MM (15 patients) and NHL (30 patients). Blood samples along with bone marrow biopsies and aspirates will be collected for exploratory biomarker analysis to understand mechanisms of response to treatment or disease progression. This will include the analysis of tumour-specific and circulating biomarkers, such as tumour DNA, mRNA, proteins or metabolites. In NHL patients, analysis of CBP (and p300) mutations will be undertaken to allow retrospective correlation with tumour response and to determine if loss of function mutations in the genes for either proteins can be utilised as response predictive biomarkers in future studies. Disclosures Clegg: CellCentric Ltd: Employment, Equity Ownership. Brooks:CellCentric Ltd: Employment, Equity Ownership. Ashby:CellCentric Ltd: Employment, Equity Ownership. Pegg:CellCentric Ltd: Employment, Equity Ownership. West:CellCentric Ltd: Employment, Equity Ownership. Somervaille:Novartis: Consultancy. Knapper:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi Sankyo: Honoraria; Jazz: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Tolero: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Davies:ADCT Therapeutics: Honoraria, Research Funding; MorphoSys AG: Honoraria, Membership on an entity's Board of Directors or advisory committees; BioInvent: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Research Funding; Karyopharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma: Honoraria, Research Funding; GSK: Research Funding; Pfizer: Honoraria, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4248-4248 ◽  
Author(s):  
Uwe Platzbecker ◽  
David P. Steensma ◽  
Koen Van Eygen ◽  
Azra Raza ◽  
Valeria Santini ◽  
...  

Background: Current treatment options for red blood cell (RBC) transfusion-dependent (TD) patients with lower risk (LR) myelodysplastic syndromes (MDS) relapsed after or refractory to erythropoiesis-stimulating agents (ESAs) have limited efficacy and durability; new approaches are needed. Imetelstat is a 13-mer lipid-conjugated oligonucleotide that targets the RNA template of human telomerase and is a competitive inhibitor of telomerase enzymatic activity (Asai et al, Cancer Res 2003; Herbert et al, Oncogene 2005). Preclinical, in vivo xenograft models (Dikmen et al, Cancer Res 2005; Hochreiter et al, Clin Cancer Res 2006) and preliminary clinical data from a pilot study conducted at Mayo Clinic (Tefferi et al, Blood Cancer Journal 2016) supported initiation of a study in TD LR MDS patients. A Phase 2 study of imetelstat, IMerge, demonstrated an 8-week RBC transfusion independence (RBC-TI) rate of 42%, 24-week RBC-TI rate of 29%, and 68% erythroid hematologic improvement (HI-E) rate in 38 heavily TD patients (median prior RBC transfusion burden 8 units / 8 weeks over the 16 weeks pre-study period) with LR MDS. Responses were durable with median duration of 8-week RBC-TI of 85.9 weeks by Kaplan Meier estimates (range 8.0-140.9) (Steensma ASH 2018, Fenaux EHA 2019). These Phase 2 results provided further evidence of potential clinical benefit of imetelstat treatment in TD LR MDS, and supported initiation of a Phase 3 trial. Methods: IMerge is two-part, Phase 2/3 study (ClinicalTrials.gov: NCT02598661). The Phase 2 portion of the study described above is closed for enrollment. The Phase 3 portion of the study is open for enrollment of adult patients with International Prognostic Scoring System (IPSS) low or intermediate-1 risk, non-del(5q) MDS, who are TD, are relapsed after or refractory to ESAs, and have not received treatment with lenalidomide or hypomethylating agents. The study is a randomized (2:1) double-blind, placebo-controlled trial to compare efficacy of imetelstat vs. placebo that will enroll approximately 170 patients and will be conducted at approximately 90 centers in North America, Europe, Asia and Middle East. Imetelstat will be administered as 2-hour IV infusion every 4 weeks at 7.5 mg/kg. The primary endpoint of the study is to assess the rate of RBC-TI lasting ≥8 weeks. Secondary endpoints include safety, rate of RBC-TI ≥24 weeks, time to RBC-TI start, RBC-TI duration, rate of HI-E, the amount and relative change in RBC transfusions, rate of CR or PR, overall survival, progression of MDS, pharmacokinetics and effect of treatment on quality of life. Biomarkers relevant to the mechanism of action of imetelstat will be assessed to demonstrate target inhibition and their association with clinical responses. Cytogenetics and mutation analyses will be performed to evaluate the impact of imetelstat on reduction/depletion of malignant clones leading to disease modification. Disclosures Platzbecker: Novartis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria. Steensma:Astex: Consultancy; Arrowhead: Equity Ownership; Summer Road: Consultancy; Onconova: Consultancy; Aprea: Research Funding; Pfizer: Consultancy; Stemline: Consultancy; H3 Biosciences: Other: Research funding to institution, not investigator.. Santini:Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Honoraria; Acceleron: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Menarini: Membership on an entity's Board of Directors or advisory committees. Germing:Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria; Amgen: Honoraria. Font:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees. Díez-Campelo:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Patnaik:Stem Line Pharmaceuticals.: Membership on an entity's Board of Directors or advisory committees. Sherman:Geron Corporation: Employment, Equity Ownership. Dougherty:Geron Corporation: Employment, Equity Ownership. Feller:Geron Corporation: Employment. Sun:Geron Corporation: Employment, Equity Ownership. Wan:Geron Corporation: Employment, Equity Ownership. Huang:Geron Corporation: Employment, Equity Ownership. Rizo:Geron Corporation: Employment, Equity Ownership. Fenaux:Celgene Corporation: Honoraria, Research Funding; Aprea: Research Funding; Astex: Honoraria, Research Funding; Jazz: Honoraria, Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2509-2509
Author(s):  
Gretchen Johnston ◽  
Haley E. Ramsey ◽  
Kristy Stengel ◽  
Shilpa Sampathi ◽  
Pankaj Acharya ◽  
...  

Drugs targeting chromatin-modifying enzymes have entered clinical trials for myeloid malignancies, including INCB059872, a selective irreversible inhibitor of Lysine-Specific Demethylase 1 (LSD1). LSD1 is a component of the CoREST complex, in which it associates with histone deacetylases 1 and 2, the transcriptional co-repressor, mSin3A or mSin3B, and the REST corepressor (RCOR1), so a role in gene expression was expected. While initial studies of LSD1 inhibitors have suggested these compounds may be used to induce differentiation of acute myeloid leukemia, the mechanisms underlying this effect and dose-limiting toxicities are not well understood. Here, we have used precision nuclear run-on sequencing (PROseq) and single-cell RNA-sequencing (scRNAseq) to show that INCB059872 de-represses GFI1/GFI1B-regulated genes to promote a myeloid differentiation gene signature in AML cells while stalling maturation of megakaryocyte progenitor cells. Within 3 days of treatment with INCB059872, the majority of THP-1, which contain an the MLL-translocation, undergo myeloid differentiation. RNAseq analysis indicated that 24h drug treatment upregulated genes involved in hematopoietic cell lineage, which is consistent with the differentiation. In addition, PROseq was used to measure the effects of INCB059872 on nascent transcription at genes and enhancers, as this is one of the best methods to define enhancer activity. In THP-1 cells after 24h treatment, there were 203 genes with at least a 1.5-fold increase in transcription, while there are nearly 1300 enhancers meeting this threshold. Upregulated genes include those associated with myeloid cell differentiation, such as CSF1R and CD86. Given that LSD1 catalyzes the removal of mono- and di-methyl marks from histone H3, we expected that INCB059872 would cause a buildup of histone methylation. Surprisingly, ChIPseq for H3K4me2 and H3K4me1 showed only subtle changes in these marks after 48h drug treatment in THP-1. Only a handful of LSD1i-induced enhancers overlapped with detectable changes in H3K4 methylation. However, our PROseq data is consistent with the increases in H3K27 acetylation seen with OG86 (a compound that disrupts the LSD1:GFI1 interaction) at GFI1 binding sites (PMID: 29590629). Indeed, motif analysis of INCB059872-upregulated enhancers identified the GFI1 recognition sequence as the most highly enriched. Moreover, siRNA inhibition of key components of LSD1-containing chromatin remodeling complexes pinpointed the CoREST complex as mediating the THP-1 myeloid differentiation effects of INCB059872. To investigate on-target thrombocytopenia seen with LSD1 inhibitors in preclinical studies, we analyzed the bone marrow of wild-type mice treated daily with INCB059872 for 0, 4, or 6 days before harvesting and sorting lin-bone marrow cells for scRNA-seq. Notably, one of the most highly upregulated genes in treated cells was Gfi1b. Unsupervised clustering identified 22 clusters, corresponding to unique subpopulations (Fig. 1A). While the distribution of cells into different progenitor populations was mostly unaffected by drug treatment, these data revealed a striking increase in the proportion of cells from treated mice assigned to a megakaryocyte stem/progenitor cluster. Cells within this expanded cluster expressed stem cell markers such as MYCN and PBX1, but also expressed VWF (Fig. 1B). Thus, LSD1 inhibition caused accumulation of megakaryopoiesis-biased stem cells that failed to mature into efficient platelet producers. Finally, we used scRNAseq to analyze bone marrow from an AML patient who responded to treatment with INCB059872 plus azacytidine (AZA). A pre-treatment bone marrow sample was divided into separate cultures to study the effects of INCB059872, AZA, or the combination. Remarkably, unsupervised clustering of patient cells assigned the majority of INCB059872 and combination-treated cells to clusters that were not found in control- or AZA-treated samples. Cells exposed to INCB059872 had upregulated GFI1 and GFI1B, as well as differentiation-related genes that were also observed in AML cell lines. Overall, these data indicate that INCB059872 affects gene expression with kinetics consistent with a loss of CoREST activity to stimulate differentiation of AML blasts, but the inactivation of GFI1/GFI1B impairs megakaryocyte maturation likely explaining thrombocytopenia seen in preclinical models. Disclosures Stubbs: Incyte Corporation: Employment, Equity Ownership. Burn:Incyte: Employment, Equity Ownership. Hiebert:Incyte Corporation: Research Funding. Savona:Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Selvita: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sunesis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer Ingelheim: Patents & Royalties; AbbVie: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3184-3184 ◽  
Author(s):  
Caitlin L. Costello ◽  
Tara K. Gregory ◽  
Syed Abbas Ali ◽  
Jesus G. Berdeja ◽  
Krina K. Patel ◽  
...  

P-BCMA-101 is a novel chimeric antigen receptor (CAR)-T cell product targeting B Cell Maturation Antigen (BCMA). P-BCMA-101 is produced using the piggyBac® (PB) DNA Modification System instead of the viral vector that is used with most CAR-T cells, requiring only plasmid DNA and mRNA. This makes it less costly and produces cells with a high percentage of the favorable T stem cell memory phenotype (TSCM). The higher cargo capacity of PB permits the incorporation of multiple genes in addition to CAR(s), including a safety switch allowing for rapid CAR-T cell elimination with a small molecule drug infusion in patients if desired, and a selection gene allowing for enrichment of CAR+ cells. Rather than using a traditional antibody-based binder, P-BCMA-101 has a Centyrin™ fused to a CD3ζ/4-1BB signaling domain. Centyrins are fully human proteins with high specificity and a large range of binding affinities, but are smaller, more stable and potentially less immunogenic than traditional scFv. Cumulatively, these features are predicted to result in a greater therapeutic index. A Phase 1, 3+3 dose escalation from 0.75 to 15 x 106 P-BCMA-101 CAR-T cells/kg (RP2D 6-15 x 106 cells/kg) was conducted in patients with r/r MM (Blood 2018 132:1012) demonstrating excellent efficacy and safety of P-BCMA-101, including notably low rates and grades of CRS and neurotoxicity (maximum Grade 2 without necessitating ICU admission, safety switch activation or other aggressive measures). These results supported FDA RMAT designation and initiation of a pivotal Phase 2 study. A Phase 2 pivotal portion of this study has recently been designed and initiated (PRIME; NCT03288493) in r/r MM patients who have received at least 3 prior lines of therapy. Their therapy must have contained a proteasome inhibitor, an IMiD, and CD38 targeted therapy with at least 2 of the prior lines in the form of triplet combinations. They must also have undergone ≥2 cycles of each line unless PD was the best response, refractory to the most recent line of therapy, and undergone autologous stem cell transplant or not be a candidate. Patients are required to be >=18 years old, have measurable disease by International Myeloma Working Group criteria (IMWG; Kumar 2016), adequate vital organ function and lack significant autoimmune, CNS and infectious diseases. No pre-specified level of BCMA expression is required, as this has not been demonstrated to correlate with clinical outcomes for P-BCMA-101 and other BCMA-targeted CAR-T products. Interestingly, unlike most CAR-T products patients may receive P-BCMA-101 after prior CAR-T cells or BCMA targeted agents, and may be multiply infused with P-BCMA-101. Patients are apheresed to harvest T cells, P-BCMA-101 is then manufactured and administered to patients as a single intravenous (IV) dose (6-15 x 106 P-BCMA-101 CAR-T cells/kg) after a standard 3-day cyclophosphamide (300 mg/m2/day) / fludarabine (30 mg/m2/day) conditioning regimen. One hundred patients are planned to be treated with P-BCMA-101. Uniquely, given the safety profile demonstrated during Phase 1, no hospital admission is required and patients may be administered P-BCMA-101 in an outpatient setting. The primary endpoints are safety and response rate by IMWG criteria. With a 100-subject sample, the Phase 2 part of the trial will have 90% power to detect a 15-percentage point improvement over a 30% response rate (based on that of the recently approved anti-CD38 antibody daratumumab), using an exact test for a binomial proportion with a 1-sided 0.05 significance level. Multiple biomarkers are being assessed including BCMA and cytokine levels, CAR-T cell kinetics, immunogenicity, T cell receptor diversity, CAR-T cell and patient gene expression (e.g. Nanostring) and others. Overall, the PRIME study is the first pivotal study of the unique P-BCMA-101 CAR-T product, and utilizes a number of novel design features. Studies are being initiated in combination with approved therapeutics and earlier lines of therapy with the intent of conducting Phase 3 trials. Funding by Poseida Therapeutics and the California Institute for Regenerative Medicine (CIRM). Disclosures Costello: Takeda: Honoraria, Research Funding; Janssen: Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Gregory:Poseida: Research Funding; Celgene: Speakers Bureau; Takeda: Speakers Bureau; Amgen: Speakers Bureau. Ali:Celgene: Research Funding; Poseida: Research Funding. Berdeja:Amgen Inc, BioClinica, Celgene Corporation, CRISPR Therapeutics, Bristol-Myers Squibb Company, Janssen Biotech Inc, Karyopharm Therapeutics, Kite Pharma Inc, Prothena, Servier, Takeda Oncology: Consultancy; AbbVie Inc, Amgen Inc, Acetylon Pharmaceuticals Inc, Bluebird Bio, Bristol-Myers Squibb Company, Celgene Corporation, Constellation Pharma, Curis Inc, Genentech, Glenmark Pharmaceuticals, Janssen Biotech Inc, Kesios Therapeutics, Lilly, Novartis, Poseida: Research Funding; Poseida: Research Funding. Patel:Oncopeptides, Nektar, Precision Biosciences, BMS: Consultancy; Takeda, Celgene, Janssen: Consultancy, Research Funding; Poseida Therapeutics, Cellectis, Abbvie: Research Funding. Shah:University of California, San Francisco: Employment; Genentech, Seattle Genetics, Oncopeptides, Karoypharm, Surface Oncology, Precision biosciences GSK, Nektar, Amgen, Indapta Therapeutics, Sanofi: Membership on an entity's Board of Directors or advisory committees; Indapta Therapeutics: Equity Ownership; Celgene, Janssen, Bluebird Bio, Sutro Biopharma: Research Funding; Poseida: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Nkarta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees; Teneobio: Consultancy, Membership on an entity's Board of Directors or advisory committees. Ostertag:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Martin:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Ghoddusi:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Shedlock:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Spear:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Orlowski:Poseida Therapeutics, Inc.: Research Funding. Cohen:Poseida Therapeutics, Inc.: Research Funding.


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