A Synthetic Lethal Approach to Eradicate AML Via Synergistic Activation of Pro-Apoptotic p53 By MDM2 and BET Inhibitors

Acute Myeloid Leukemia (AML) is a typically-lethal molecularly heterogeneous disease, with few broad-spectrum therapeutic targets. Unusually compared to many other cancers, over 90% of AML patients retain wild type TP53, encoding pro-apoptotic tumor suppressor p53. However, wild-type p53 functions are frequently suppressed by MDM2, an E3 ubiquitin ligase that targets p53 for proteasomal degradation. MDM2 inhibitors (MDM2i), which activate wild-type p53, show encouraging pre-clinical activity, but limited clinical activity. In an effort to find targets that synergize with p53 activation via MDM2i and minimize toxicity, we performed a cell-based synthetic lethal drug screen and a CRISPR viability screen. These screens identified BRD4 inhibition as a candidate synthetic lethal partner of MDM2i. BRD4 is a member of the Bromodomains and Extraterminal (BET) family of proteins, a transcriptional co-activator and already a candidate AML therapeutic target. Surprisingly, we found inhibition of BRD4 alone induces expression of some of p53 target genes. We unexpectedly reveal that BRD4 binds to p53 target genes and acts as a transcriptional repressor of these genes. Synergistic cell killing by the drug combination (MDM2i + BET inhibitor (BETi)) depends on synergistic activation of p53 target genes, such as PUMA and NOXA, due to simultaneous stabilization of p53 by MDM2i and relief of BRD4-mediated repression by BETi. Our combined therapy of MDM2i and BETi is synergistically lethal to human AML cell lines harboring wild type TP53in vitro, against two mouse models of AML in vivo, and against primary human patient blasts in vitro. Furthermore, we used BET PROTACs to selectively and completely induce degradation of BRD4 in cells. Consistent with results from BETi, BET degraders and MDM2i synergize to suppress cell viability with superior potency. Taken together, our data show BRD4 represses p53-mediated transcription activation and apoptosis in AML. Therefore, co-targeting wild-type TP53 and a transcriptional repressor function of BRD4 represent a novel synthetic lethal vulnerability in AML. Disclosures Latif: AbbVie: Consultancy, Honoraria; Takeda UK: Speakers Bureau; Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Kite: Consultancy, Honoraria, Speakers Bureau; Jazz: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria. Higgins:Roche: Current Employment, Current equity holder in publicly-traded company, Other: Support of parent study and funding of editorial support. Copland:Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Cyclacel Ltd: Research Funding; Roche: Research Funding; Epizyme: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: 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, Speakers Bureau; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; Astellas: Speakers Bureau; Gilead: Speakers Bureau.

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Final Results of Phase 1/1b Study of Tenalisib, Dual PI3K δ/γ Inhibitor in Patients with Relapsed/Refractory T-Cell Lymphoma

Blood ◽

10.1182/blood-2019-123954 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 2831-2831 ◽

Cited By ~ 1

Author(s):

Swaminathan P. Iyer ◽

Brad M. Haverkos ◽

Jasmine Zain ◽

Radhakrishnan Ramchandren ◽

Mary Jo Lechowicz ◽

...

Keyword(s):

T Cell ◽

Adverse Events ◽

Board Of Directors ◽

Dose Escalation ◽

Safety Profile ◽

Research Funding ◽

Cell Lymphoma ◽

Phase 1 ◽

Clinical Activity ◽

Advisory Committees

Introduction: Tenalisib (RP6530) is a novel, highly specific, dual PI3K δ/γ inhibitor with nano-molar inhibitory potency at the enzyme and cellular level. PI3K plays a critical role in T-cell development and activation and several studies have validated the PI3K-AKT pathway as a potential therapeutic target in T cell lymphomas. Preliminary results of the ongoing Phase 1/1b T-cell lymphoma (TCL) study demonstrated an acceptable safety profile with encouraging clinical activity in relapsed/refractory TCL (Oki, ASCO 2018 and Iyer, ASH 2018). We now present the final results of the study (NCT02567656). Methods: This study comprised of four-dose escalation cohorts, followed by two dose expansion cohorts at MTD enrolling 20 patients each in PTCL and CTCL cohorts. Patients had histologically confirmed TCL, ECOG PS ≤2, and had received ≥1 prior therapy. Patients received Tenalisib [200 mg BID-800 mg BID (fasting), 800 mg (fed only)] orally until progression or unacceptable toxicity. The primary objectives were to determine the MTD and pharmacokinetic profile. The secondary objective was to evaluate overall response rate (ORR) and duration of response. Responses were evaluated for PTCL and CTCL based on IWG criteria (Cheson 2007) and mSWAT respectively. Adverse events were graded according to CTCAE v4.03. Results: Fifty-eight patients were enrolled in study, 19 in dose escalation and 39 in dose expansion (28 PTCL and 30 CTCL). Median number of prior therapies was 4 (range, 1-15). Safety assessment of 58 patients receiving at least one dose of Tenalisib demonstrated an acceptable safety profile. Treatment related Grade≥3 AEs were elevated ALT/AST (21%), rash (5%), and hypophosphatemia (3%). These events were reversible and managed by withholding study drug. Additionally, in few patients (N=9), steroids were used to manage elevated ALT/AST. There were six treatment related serious adverse events, none of these led to fatal outcome. At end of the study, four (3 CTCL; 1 PTCL) patients who completed minimum 8 cycles of therapy were rolled over to a compassionate use study (NCT03711604) and were followed up. Efficacy assessments demonstrated an ORR of 46% (3 CR and 13 PR) and clinical benefit rate (CR+PR+SD) of 77%. Subset efficacy analysis showed an ORR in PTCL of 47% (3 CR; 4 PR) and in CTCL of 45% (9 PR). The median time to initial response was 1.8 months and was similar in both sub-types. The overall median DOR was 4.91 months (range 0.9-26.6); in PTCL patients the DOR was 6.53 months, (range: 0.97-21.0) and 3.8 months (range: 1.67-25.67) in CTCL patients. In 3 PTCL patients who achieved CR, the median DOR was 19.5 months (range 7.5-21). Conclusion: Tenalisib demonstrated promising clinical activity and an improved safety profile in patients with relapsed/ refractory TCL. Currently, a phase I/II combination study to further evaluate safety and efficacy with romidepsin is ongoing in this target population. Disclosures Iyer: Arog: Research Funding; Bristol-Myers Squibb: Research Funding; Novartis: Research Funding; Seattle Genetics, Inc.: Research Funding; Genentech/Roche: Research Funding; Incyte: Research Funding. Zain:Spectrum: Consultancy; Seattle Genetics: Consultancy. Korman:Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Glaxo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Immune Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyowa: Research Funding; Leo: Research Funding; Menlo: Research Funding; Merck: Research Funding; Novartis: Consultancy, Honoraria, Speakers Bureau; Pfizer: Research Funding; Principia: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Research Funding; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Rhizen: Research Funding; Sun: Honoraria, Membership on an entity's Board of Directors or advisory committees; Syntimmune: Research Funding; UCB: Research Funding; Valeant: Honoraria, Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Dermira: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Routhu:Rhizen Pharmaceuticals S.A.: Employment. Barde:Rhizen Pharmaceuticals S.A.: Employment. Nair:Rhizen Pharmaceuticals S.A.: Employment. Huen:Galderma Inc: Research Funding; Glaxo Smith Kline Inc: Research Funding; Rhizen Pharmaceuticals: Research Funding; Innate Pharmaceuticals: Research Funding.

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A Phase I Study of Bendamustine Combined with Lenalidomide and Dexamethasone in Patients with Refractory or Relapsed Multiple Myeloma.

Blood ◽

10.1182/blood.v114.22.1856.1856 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1856-1856 ◽

Cited By ~ 1

Author(s):

Suzanne Lentzsch ◽

Amy O’Sullivan ◽

Silvana Lalo ◽

Carrie Kruppa ◽

Diane Gardner ◽

...

Keyword(s):

Multiple Myeloma ◽

Partial Response ◽

Board Of Directors ◽

Dose Level ◽

Research Funding ◽

Advisory Board ◽

Clinical Activity ◽

Advisory Committees ◽

Equity Ownership ◽

Grade 3

Abstract Abstract 1856 Poster Board I-882 Background: Lenalidomide is an analog of thalidomide that has shown significant clinical activity in patients with relapsed or refractory multiple myeloma (MM), both as a single agent and in combination with dexamethasone. Bendamustine is a bifunctional alkylating agent that is approved for the treatment of chronic lymphocytic leukemia and indolent non-Hodgkin's lymphoma that has progressed during or relapsed within 6 months following a rituximab-containing regimen. Bendamustine combined with lenalidomide may be an effective treatment option for MM patients, particularly those with preexisting or bortezomib-induced neuropathy. Our primary objective was to determine the maximum tolerated dose (MTD) and safety profile of bendamustine and lenalidomide when administered with dexamethasone for patients with relapsed or refractory MM. Methods: Patients aged ≥18 years with confirmed, measurable stage 2 or 3 MM that was refractory to or progressed after 1 or more prior therapies, including lenalidomide, received bendamustine by intravenous infusion on days 1 and 2, oral lenalidomide on days 1–21, and oral dexamethasone on days 1, 8, 15, and 22 of each 28-day cycle. Treatment was continued until a plateau of best response, as determined by the IBMTR/ABMTR, was reached. Study drug doses were escalated through 4 levels (Table), with 3–6 patients enrolled at each level depending on the rate of dose-limiting toxicity (DLT). After determining the MTD, up to an additional 12 patients will be enrolled in an MTD expansion arm to better evaluate toxicity and clinical activity. Secondary endpoints included preliminary efficacy, as evidenced by objective response, time to disease progression, and overall survival. Results: To date, 11 patients have been enrolled, with a median age of 63 years (range, 38–75 years). The MTD of bendamustine and lenalidomide has not been identified at this point; currently, patients are enrolling on dose level 3 with 100 mg/m2 bendamustine and 10 mg lenalidomide. Thus far, DLT included 1 grade 4 neutropenia at dose level 2. Nine of 11 patients are currently eligible for response assessment. A partial response was observed in 67% of patients, including 1 very good partial response and 5 partial responses (PR). Two patients experienced stable disease and 1 exhibited progressive disease. Grade 3/4 adverse events included grade 3 neutropenia, thrombocytopenia, anemia, hyperglycemia, and prolonged QTC, and 1 grade 4 neutropenia. Conclusions: Bendamustine, lenalidomide, and dexamethasone form a well-tolerated and highly active regimen even in heavily pretreated MM patients, with a PR rate of 67%. Additional updates on response and MTD will be available at the time of presentation. Disclosures: Lentzsch: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cephalon: Consultancy, Membership on an entity's Board of Directors or advisory committees. Off Label Use: Bendamustine is not FDA approved for the treatment of multiple myeloma in the USA. Burt:Millennium: Honoraria; Celgene: Honoraria. Mapara:Resolvyx: Consultancy, Research Funding; Genzyme: Membership on an entity's Board of Directors or advisory committees; Gentium: Equity Ownership; Celgene: Spouse is consultant , has received research funding, and participates on advisory board; Cephalon: Spouse has received funding for clinical trial and participates on advisory board. Redner:Biogen: Equity Ownership; Wyeth: Equity Ownership; Glaxo-Smith-Kline: Equity Ownership; Pfizer: Equity Ownership; Genzyme: Membership on an entity's Board of Directors or advisory committees. Roodman:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy; Acceleron: Consultancy. Zonder:Amgen: Consultancy; Pfizer: Consultancy; Cephalon: Consultancy; Millennium: Consultancy, Speaking (CME only); no promotional talks.

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Identification of Alpha 1-Acid Glycoprotein (AAG) As a Potential Patient Selection Biomarker for Improved Clinical Activity of the Novel KSP Inhibitor ARRY-520 in Relapsed and Refractory Multiple Myeloma (MM)

Blood ◽

10.1182/blood.v120.21.1868.1868 ◽

2012 ◽

Vol 120 (21) ◽

pp. 1868-1868 ◽

Cited By ~ 4

Author(s):

Brian Tunquist ◽

Karin Brown ◽

Gary Hingorani ◽

Sagar Lonial ◽

Jonathan L. Kaufman ◽

...

Keyword(s):

Multiple Myeloma ◽

Board Of Directors ◽

Research Funding ◽

Response Rate ◽

Phase 1 ◽

Clinical Activity ◽

Advisory Committees ◽

Blood Samples ◽

Refractory Multiple Myeloma

Abstract Abstract 1868 Background ARRY-520 is a kinesin spindle protein (KSP) inhibitor that has demonstrated clinical activity in patients with relapsed and refractory multiple myeloma (MM). Although ARRY-520 is administered IV, it displays variable pharmacokinetics (PK) among patients. The degree of binding of certain drugs to serum proteins can alter their free fraction (fu) and PK, with a possible impact on clinical activity. Alpha 1-acid glycoprotein (AAG) is an acute-phase reactant protein that is often elevated in the blood of patients with cancer, including multiple myeloma. We investigated the significance of the interaction of ARRY-520 with AAG, and other relevant blood proteins, using both in vitro models and clinical data. Methods Compound-protein binding was assessed using several in vitro assays. In addition, the effect of increasing concentrations of AAG on MM cell line viability was measured. Patient data were obtained from 3 clinical studies of ARRY-520: a Phase 1 solid tumor study, a Phase 1/2 AML study, and a Phase 1/2 study in MM. The MM Phase 2 portion consists of 2 separate, 2-stage cohorts. Cohort 1 evaluated ARRY-520 administered as a single agent, and cohort 2 investigated ARRY-520 in combination with low-dose dexamethasone (LoDex). The concentrations of multiple proteins, including AAG, and the degree of ARRY-520 total protein binding, were measured in pre- and post-dose blood samples for patients in the analysis. AAG levels in MM patients were further correlated with time-on-study and clinical response rate. Results ARRY-520 exhibits low micromolar affinity for AAG in in vitro assays, but not for other common serum proteins, such as albumin. To investigate whether AAG binding impacts biological activity, we found that increasing AAG concentrations within a clinically relevant range resulted in increasing IC50 values for ARRY-520 on MM cell line viability. Of other MM agents tested, none exhibited high affinity binding to AAG in vitro, and a range of AAG concentrations did not alter the cellular activity of these compounds. Pre-dose concentrations of AAG were measured using blood samples collected from patients on all 3 ARRY-520 studies (0.4 – 4.1 g/L AAG in solid tumor study; 0.5 – 2.4 g/L in AML study; 0.2 – 2.8 g/L in MM study). Post-dose blood samples from the MM study also indicated that AAG levels do not significantly change with time. The fu of ARRY-520 in blood was meaningfully reduced among patients with the highest AAG concentrations. Furthermore, AAG and fu were correlated with changes in clinical PK: CL and Vd decreased with increasing AAG, trends consistent with a lower fu. Among the MM patients, 72 patients were evaluable for AAG determination (27 from the dose-escalation portion, 27 from Cohort 1, and 18 from Stage 1 of Cohort 2). Across all of these cohorts, the group of patients with AAG above an empirically-determined cutoff of 1.1 g/L showed a decreased median time on study (1.5 months vs 4.7 months) and no clinical responses (0/19 vs 12/53) as compared to patients below this cutoff. For example, as reported separately, ARRY-520 in combination with LoDex showed a promising 22% overall response rate (≥PR) in the 1st-stage of Cohort 2. In this cohort, 6 patients were determined to have AAG concentrations above the empirical cutoff. None of these patients had clinical benefit. Excluding these 6 patients would significantly improve the overall response rate (≥PR) from 22% (4/18) to 33% (4/12). Summary AAG has been proposed as a prognostic marker for MM disease severitya. Our preliminary data suggest that AAG levels can affect the free fraction of ARRY-520 in blood over a clinically relevant range both preclinically and in clinical studies. In retrospective analysis, patients with higher AAG levels show a lower fu and therefore may not achieve sufficient exposure to gain therapeutic benefit from ARRY-520. In preclinical analyses, this effect is specific to ARRY-520, suggesting that AAG levels may be predictive for ARRY-520 activity relative to other MM drugs. We hypothesize that prospective screening for AAG may enable exclusion of patients who may not achieve therapeutic exposure to ARRY-520, increasing the overall activity of ARRY-520 and preventing exposure of non-responders to an ineffective therapeutic dose. Further, experiments are currently underway to investigate the relevance of other acute-phase proteins in blood. Disclosures: Tunquist: Array BioPharma: Employment. Off Label Use: ARRY-520 alone and with dexamethasone for the treatment of relapsed/refractory multiple myeloma. ARRY-520 is not currently approved for any indication. Brown:Array BioPharma: Employment. Hingorani:Array BioPharma: Employment. Lonial:Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: 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; Onyx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kaufman:Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy. Zonder:Celgene: Honoraria, Research Funding; Millenium: Honoraria, Research Funding. Orlowski:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. Shah:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau. Hilder:Array BioPharma: Employment. Ptaszynski:Array BioPharma: Consultancy. Koch:Array BioPharma: Employment. Litwiler:Array BioPharma: Employment. Walker:Array BioPharma: Employment.

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The CSF3R T618I Mutation Found In Chronic Neutrophilic Leukemia Removes An O-Linked Glycosylation Site and Increases Receptor Dimerization

Blood ◽

10.1182/blood.v122.21.270.270 ◽

2013 ◽

Vol 122 (21) ◽

pp. 270-270

Author(s):

Julia E. Maxson ◽

Jason Gotlib ◽

Daniel A. Pollyea ◽

Angela G. Fleischman ◽

Anupriya Agarwal ◽

...

Keyword(s):

Clinical Trials ◽

Board Of Directors ◽

Research Funding ◽

Conflicts Of Interest ◽

Glycosylation Site ◽

Wild Type ◽

Advisory Committees ◽

Advisory Boards ◽

Financial Interest ◽

Truncation Mutant

Abstract Background We have recently identified mutations in Colony Stimulating Factor 3 Receptor (CSF3R, aka GCSFR) in ∼60% of chronic neutrophilic leukemia (CNL) and atypical chronic myeloid leukemia (aCML) patients (Maxson et al, NEJM 2013). These mutations fall into two categories: membrane proximal point mutations (the most common of which is T618I) and truncation mutations. Drug and siRNA screening of primary patient samples revealed that the two classes of CSF3R mutations exhibit differential sensitivity to inhibition of SRC or JAK kinases. CSF3R truncation mutations conferred sensitivity to SRC family kinase inhibition, while CSF3R membrane proximal mutations (T618I) conferred sensitivity to JAK kinase inhibition. A patient with the T618I membrane proximal mutation responded to treatment with the FDA approved JAK inhibitor, ruxolitinib. CSF3R truncation mutations have also been observed in a subset of severe congenital neutropenia patients who are at high risk for development of acute myeloid leukemia. Prior studies in this context have shown that truncation mutations result in loss of endocytic and degradation motifs, leading to increased expression of the receptor. The differences in signaling and drug sensitivity of these mutation classes suggest that membrane proximal mutations may activate CSF3R signaling through a distinct, as-yet unknown mechanism. Furthermore, a subset of CNL patients harbor both membrane proximal and truncation mutations on the same allele, though the consequences of these compound mutations are not yet known. Methods CSF3R expression level and banding pattern were assessed by immunoblot of lysates from 293T17 cells transfected with wild type, membrane proximal mutant, or truncation mutant CSF3R. O-linked glycosylation was removed from the receptor by treatment with O-glycosidase and neuraminidase. Ligand independence of the CSF3R mutants was analyzed in murine interleukin-3 (IL3)-dependent Ba/F3 cells. CSF3R dimerization was assessed by co-transfecting CSF3R-Flag and CSF3R-V5 tagged constructs and then immunoprecipitating CSF3R-Flag and detecting co-immunoprecipitation of the CSF3R-V5 by immunoblot. Transforming potential of the CSF3R compound mutations relative to the corresponding point or truncation mutations was assessed by analyzing IL3-independent growth of Ba/F3 cells or mouse bone marrow colony formation. Results To better understand the functional and biochemical differences between membrane proximal and truncation mutant CSF3R, we examined transformation potential, requirement for ligand, and expression patterns in Ba/F3 and 293T17 cells. We found membrane proximal mutations to exhibit rapid transformation potential and ligand independence, while truncation mutations exhibited delayed transformation and ligand hypersensitivity. Unlike the truncation mutations, which induce dramatic overexpression of CSF3R, the T618I mutation did not result in overexpression of the receptor but instead induced a shifted banding pattern, indicative of altered protein modification. We examined the amino acid sequence surrounding the membrane proximal mutations and found residue T618 to be part of a consensus motif for O-glycosylation, wherein wild type CSF3R is O-glycosylated and the T618I mutation abrogates this O-glycosylation event. Furthermore, the T618I mutation exhibited increased receptor dimerization compared to wild type CSF3R, which likely explains its ligand independence. Finally, we found that CSF3R compound mutations have increased transforming potential in Ba/F3 and murine bone marrow colony assays compared with either class of single mutation, further underscoring the different mechanisms of action of the membrane proximal and truncation mutations. Conclusion CSF3R represents a promising therapeutic target for patients with CNL. We show that T618I, the most common CSF3R mutation in CNL, is part of an O-linked glycosylation site. Mutation of this residue leads to loss of O-linked glycosylation and represents a novel mechanism of homodimeric cytokine receptor activation. CSF3R compound mutations are more rapidly transforming relative to the membrane proximal or truncation mutations alone, warranting their further investigation for patient prognosis and therapy. Disclosures: Off Label Use: Ruxolitinib - a JAK1/2 inhibitor that we propose can be used off-label for disease management of CSF3R-mutant neutrophilic leukemia. Gotlib:Incyte: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Travel Support Other. Fleischman:Incyte: Speakers Bureau. Collins:Genoptix: Membership on an entity’s Board of Directors or advisory committees. Oh:Incyte Corporation: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau. Deininger:Novartis: Advisory Boards, Advisory Boards Other, Consultancy, Research Funding; Ariad Pharmaceuticals: Advisory Boards, Advisory Boards Other, Consultancy; Bristol-Myers Squibb: Advisory Boards Other, Consultancy, Research Funding; Celgene: Research Funding; Gilead Sciences: Research Funding. Druker:Bristol-Myers Squibb: PI or co-investigator on BMS clinical trials. OHSU and Dr. Druker have a financial interest in MolecularMD. OHSU has licensed technology used in some of these clinical trials to MolecularMD. Potential conflicts of interest are managed by OHSU. Other; Novartis: PI or co-investigator on Novartis clinical trials. OHSU and Dr. Druker have a financial interest in MolecularMD. OHSU has licensed technology used in some of these clinical trials to MolecularMD. Potential conflicts of interest are managed by OHSU., PI or co-investigator on Novartis clinical trials. OHSU and Dr. Druker have a financial interest in MolecularMD. OHSU has licensed technology used in some of these clinical trials to MolecularMD. Potential conflicts of interest are managed by OHSU. Other; Incyte: PI or co-investigator on clinical trials., PI or co-investigator on clinical trials. Other. Tyner:Incyte Corporation: Research Funding.

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Phase II Study Of Anti-CD19 Antibody Drug Conjugate (SAR3419) In Combination With Rituximab: Clinical Activity and Safety In Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma (NCT01470456)

Blood ◽

10.1182/blood.v122.21.4395.4395 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4395-4395 ◽

Cited By ~ 8

Author(s):

Bertrand Coiffier ◽

Catherine Thieblemont ◽

Sophie de Guibert ◽

Jehan Dupuis ◽

Vincent Ribrag ◽

...

Keyword(s):

B Cell ◽

Board Of Directors ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Clinical Activity ◽

Advisory Committees ◽

Large B Cell Lymphoma ◽

Duration Of Response ◽

Grade 3

Abstract Background SAR3419 is a humanized anti-CD19 antibody conjugated to maytansin DM4, a potent cytotoxic agent. SAR3419 targets CD19, an antigen expressed in the majority of B cell non-Hodgkin lymphomas (NHL). The recommended dose for single agent SAR3419 was previously determined to be 55 mg/m2 administered IV every week for 4 weeks, then bi-weekly. In phase I, clinical activity was shown mainly in patients with follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). (Trial funded by Sanofi). Methods Patients (pts) with a CD20+ and CD19+ DLBCL relapsing or refractory (R/R) after at least 1 standard treatment including rituximab and not candidate for or who already underwent transplantation, were eligible. Refractory disease was defined as unresponsive to or progressing within 6 months of regimen completion. Fresh (or recent formalin-fixed, paraffin-embedded) biopsy was required before SAR3419 start. Pts received 375 mg/m2 of rituximab (R) IV and 55 mg/m² of SAR3419 on day 1, 8, 15, 22 (35-day cycle 1), followed by bi-weekly R and SAR3419 at the same doses for 2 additional 28-day cycles, provided there was no disease progression or other study discontinuation criteria met. The primary objective was the overall response rate (ORR) following Cheson 2007 criteria, with the first tumor assessment being done 42 days after the last study treatment administration. Secondary objectives were: safety, pharmacokinetics (PK), duration of response (DOR), progression free survival (PFS), overall survival (OS) and correlation of the antitumor and biological activity of the combination with tumor biomarker status. Results Fifty-three pts were enrolled, 52 treated. Median age was 66.5 years (range 38-85), 50% were male; 23%, 33% and 40% of patients had received 1, 2 or ≥3 prior chemo/immunotherapy regimens for DLBCL, respectively. Of the enrolled patients, 3.8% had received no prior regimen for DLBCL and therefore were excluded from primary analysis for efficacy. Seventy-three percent had stage III/IV disease, 59% had elevated lactate dehydrogenase (LDH), and 63% had bulky disease. Sixty percent were refractory to first regimen (primary refractory), 16% were refractory to last regimen and 24% were relapsed pts. The ORR in the per-protocol population (n=45) was 31.1% (80% confidence interval (CI): 22.0% to 41.6%). Among the 14 responders, 5 had progressed at the time of analysis, with duration of response beyond 6 months for 3 of them. The ORR was 58.3% (80% CI: 36.2% to 78.1%) for patients with relapsed DLBCL (n=12), 42.9% (80% CI: 17.0% to 72.1%) for pts refractory to last regimen (n=7) and 15.4% (80% CI: 6.9% to 28.4%) for primary refractory pts (n=26). Overall survival and PFS data are not yet mature. Biomarkers and PK data will be presented at the meeting. The most common (≥10%) all grades non-hematologic treatment-emergent adverse events (TEAEs) were asthenia (25.0%), nausea (21.2%), cough (19.2%), diarrhea (17.3%), weight decrease (17.3%), vomiting (15.4%), dyspnea (15.4%), abdominal pain (13.5%), back pain (13.5%), pyrexia (13.5%) and constipation (11.5%). Related grade 3-4 TEAEs were: 1 syncope, 1 bronchospasm, 2 neutropenia and 1 anemia. No TEAEs led to treatment discontinuation, no grade 3-4 peripheral neuropathy or grade 3-4 ocular events were observed. Two pts experienced grade 2 keratitis, both rapidly recovered with local treatment. Hematological toxicity was moderate, with grade 3-4 neutropenia and thrombocytopenia in 15.7% and 9.8% pts, respectively. No complications related to neutropenia were reported. Grade 3 transaminase increase was observed in 1 patient. Conclusions The combination of SAR3419 plus R showed moderate ORR in R/R DLBCL; however the study population was of poor prognosis (60% refractory to first line therapy). In the relapsed DLBCL patients a higher ORR was observed. SAR3419 plus R presented with a favorable safety profile. Further investigations on biomarker expression are ongoing to identify a sub-group of pts who could have better benefited from this combination. Disclosures: Coiffier: Sanofi: Membership on an entity’s Board of Directors or advisory committees. Off Label Use: Phase II of SAR3419. Ribrag:Johnson & Johnson: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Bayer: Research Funding; Takeda: Membership on an entity’s Board of Directors or advisory committees; Servier: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Cartron:LFB: Honoraria; GSK: Honoraria; Roche: Consultancy, Honoraria, Speakers Bureau. Casasnovas:Roche: Consultancy, Honoraria, Research Funding. Hatteville:Sanofi: Employment. Zilocchi:Sanofi: Employment. Oprea:Sanofi: Employment. Tilly:Amgen: Research Funding; Janssen: Honoraria; Pfizer: Honoraria; Takeda: Membership on an entity’s Board of Directors or advisory committees; Roche: Honoraria; Celgene: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding.

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Indatuximab Ravtansine (BT062) In Combination With Lenalidomide and Low-Dose Dexamethasone In Patients With Relapsed and/Or Refractory Multiple Myeloma: Clinical Activity In Len/Dex-Refractory Patients

Blood ◽

10.1182/blood.v122.21.758.758 ◽

2013 ◽

Vol 122 (21) ◽

pp. 758-758 ◽

Cited By ~ 17

Author(s):

Kevin R. Kelly ◽

Asher Chanan-Khan ◽

George Somlo ◽

Leonard T Heffner ◽

David S Siegel ◽

...

Keyword(s):

Multiple Myeloma ◽

Partial Response ◽

Board Of Directors ◽

Research Funding ◽

Clinical Activity ◽

Antibody Drug Conjugate ◽

Advisory Committees ◽

Safety And Efficacy ◽

Dose Levels ◽

Antibody Drug

Abstract Background BT062 (Biotest AG Dreieich, Germany) is an antibody-drug conjugate, comprising the anti-CD138 chimerized MAb (nBT062) and the maytansinoid DM4 as cytotoxic agent. Once bound to CD138 on a target cell, the conjugate is internalized and releases DM4, leading to target cell death. CD138 (Syndecan-1) is highly overexpressed on various solid tumors and in hematological malignancies, and represents one of the most specific target antigens for identification of multiple myeloma (MM) cells. Data from two studies investigating BT062 as single agent demonstrated an acceptable tolerability profile and evidence of clinical activity in patients with heavily pretreated relapsed and/or refractory MM (1, 2). Preclinical studies showed enhanced anti-MM activity when BT062 was combined with lenalidomide and dexamethasone (Len/Dex). Based on these data, a Phase I/IIa study in MM was initiated to evaluate the safety and efficacy of BT062 in combination with Len/Dex. Objectives To determine the dose-limiting toxicities (DLTs), the maximum tolerated dose (MTD), the recommended phase II dose (RPTD), pharmacokinetics (PK), and anti-MM activity of increasing doses of BT062 (days 1, 8, and 15, every 4 weeks) in combination with Len (25 mg, daily on days 1-21) and low dose Dex (40 mg on days 1, 8, 15, and 22) in patients with relapsed and/or refractory MM. Methods This is a prospective, open label, dose-escalation, multicenter Phase I/IIa study. The Phase I part includes dose escalation, and the Phase IIa the expansion of the MTD or RPTD cohort. Patients aged ≥18 years with relapsed and/or refractory MM who have failed at least one prior therapy were eligible to participate. Prior treatment with Len and/or Dex was allowed. Patients with clinical response (or no evidence of progressive disease) and without unacceptable toxicities were eligible for additional treatment cycles. Patients were enrolled in cohorts of at least 3 at each dose level; DLT in the first cycle triggered cohort expansion. Toxicities were assessed by CTCAE v4 and clinical response was assessed according to International Myeloma Working Group criteria. Results As of July 2013, a total of 15 patients have received BT062 at dose levels of 80 mg/m2 (N=3), 100 mg/m2 (N=6) or 120 mg/m2 (N=6). Two patients at the highest dose level discontinued study due to toxicity (DLT), another patient withdrew consent. The other 12 patients remain on treatment; median duration 144 days (range 8–385). The median number of prior therapies was 4 (range 1–11), 87% of patients had prior Len exposure, and 50% were Len/Dex refractory. The maximum administered dose (MAD) has been reached at 120 mg/m2, with mucosal inflammation (CTC grade 3) as DLT in one, and anemia (CTC grade 3) in a second of the 6 patients treated at this dose level. About 85% of reported Adverse Events (AE) were of CTC grade 1 or 2. The most common reported AEs were fatigue, hypokalemia, and diarrhea. Amongst the 9 patients currently evaluable for efficacy, responses were observed across all dose levels with a overall response rate (ORR) of 78%; including 1 patient with complete response (120 mg/m2), 1 patient with very good partial response (80 mg/m2), and 5 patients with partial response (80 and 100 mg/m2). Two other patients achieved disease stabilization, resulting in a clinical benefit in 100% of the evaluated patients. Interestingly, partial response was observed in 3 patients refractory to prior treatment with Len/Dex. The MTD has been defined as 100 mg/m2 and is currently expanded to further evaluate the safety and efficacy of BT062 at the RPTD. Conclusion Preliminary data from this ongoing study indicate that BT062 is well tolerated in combination with Len/Dex at dose levels that induce responses in patients with relapsed and/or refractory multiple myeloma, including Len/Dex-refractory patients. Updated results on safety and efficacy will be presented. References 1. Jagannath et al, BT062, an Antibody-Drug Conjugate Directed Against CD138, Shows Clinical Activity in Patients with Relapsed or Relapsed/Refractory Multiple Myeloma. Blood. 2011; 118: Abstract 305. 2. Heffner et al, BT062, an Antibody-Drug Conjugate Directed Against CD138, Given Weekly for 3 Weeks in Each 4 Week Cycle: Safety and Further Evidence of Clinical Activity. Blood. 2012; 120: Abstract 4042. Disclosures: Somlo: Celgene: Research Funding, Speakers Bureau; NIH: Research Funding; Millennium: Speakers Bureau. Heffner:Genentech: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Biotest: Honoraria, Research Funding; Onyx: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding. Siegel:Millennium: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Onyx: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Zimmerman:Celgene: Honoraria; Millennium: Honoraria; Onyx: Honoraria. Jagannath:Millennium: Honoraria; Celgene: Honoraria. Munshi:Celgene: Consultancy; Novartis: Consultancy; Millennium: Consultancy. Lonial:Millennium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Onyx: Consultancy. Ruehle:Biotest AG: Employment. Chavan:Biotest Pharmaceuticals: Employment. Patel:Biotest Pharmaceuticals: Employment. Rothenburger:Biotest AG: Employment. Wartenberg-Demand:Biotest AG: Employment. Haeder:Biotest AG: Employment. Anderson:Gilead: Consultancy; Sanofi Aventis: Consultancy; Onyx: Consultancy; Celgene: Consultancy; Acetylon: Equity Ownership; Oncopep: Equity Ownership.

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Response to Treatment Among SF3B1 Mutated Myelodysplastic Syndromes (MDS): A Case-Control Study from the MDS Clinical Research Consortium (MDS CRC)

Blood ◽

10.1182/blood.v126.23.1697.1697 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1697-1697 ◽

Cited By ~ 2

Author(s):

Rami S. Komrokji ◽

Amy E. DeZern ◽

Katrina Zell ◽

Najla H. Al Ali ◽

Eric Padron ◽

...

Keyword(s):

Board Of Directors ◽

Lower Risk ◽

Research Funding ◽

Somatic Mutations ◽

Response To Treatment ◽

Wild Type ◽

Advisory Committees ◽

Baseline Characteristics ◽

Matching Criteria

Abstract Introduction Somatic mutations in SF3B1 ,a gene encoding a core component of RNA splicing machinery, have been identified in patients (pts) with myelodysplastic syndrome (MDS). The SF3B1 mutation (MT) is more commonly detected in pts with ring sideroblasts (RS) morphology and is associated with favorable outcome. The pattern of response among SF3B1 mutated MDS pts to available treatment options, including erythropoiesis stimulating agents (ESA), hypomethylating agents (HMA) and lenalidomide is not known. The distinct underlying disease biology among such pts may alter response to treatment. Methods Pts treated at MDS CRC institutions with MT vs wild-type SF3B1 (WT) controls were matched 1:2. Matching criteria were age at diagnosis, year of diagnosis and International Prognostic Scoring System (IPSS) category at diagnosis. IPSS category was split into two groups (Low or Int-1 vs. Int-2 or High). Matching was performed using the R package by calculating a propensity score, which was then used to determine the two most similar WT SF3B1 patients for each SF3B1-mutated pt, without replacement. Additionally, to be included in the population, pts also had to have been treated with one of the following: ESAs, HMA, or lenalidomide. Response to treatment was evaluated by international Working Group criteria (IWG 2006) and classified as response if hematological improvement or better was achieved (HI+). Survival was calculated from date of treatment until date of death or last known follow-up, unless otherwise noted. Results: We identified 48 Pts with MT and 96 matched controls. Table 1 summarizes baseline characteristics comparing MT vs WT SF3B1 cohorts. SF3B1 MT was detected more often in association with RS, as expected. The majority of pts had lower-risk disease by IPSS and revised IPSS (IPSS-R). Pts with MT had higher platelets than controls. The most common concomitant somatic mutations observed were TET2 (30%), DNMT3A (21%), and ASXL1 (7%). Median follow-up time from diagnosis was 35 months (mo). Median overall survival (OS) from diagnosis was significantly longer for patients with SF3B1 MT (108.5 mo (68.8, NA)) than wild-type controls (28.3 mo (22.3, 36.4); p < 0.001). Patients with an SF3B1 MT had a decreased hazard of death (hazard ratio [HR]: 0.49 (95% confidence limits [95% CL]: 0.29, 0.84); p = 0.009) ESA was the first line therapy for 43 pts (88%) with MT and 55 WT Pts (56%). For ESA treated pts, 14 out 40 MT Pts responded (35%) compared to 9/56 among WT Pts (16%), p 0.032. Among those treated with HMA therapy, 5 out 21 (24%) MT pts responded compared to 11/46 (24%) WT Pts (p 0.99). Finally, for Pts treated with lenalidomide 4/16 (25%) and 4/21 (19%) responded among SF3B1 MT and WT Pts respectively, p 0.7. Conclusions SF3B1 somatic mutation in MDS is commonly associated with RS, lower risk disease, and better OS. Pts with SF3B1 mutation had higher response to ESA compared WT SF3B1. No difference in response to HMA or lenalidomide was observed compared to WT patients. Response rates to lenalidomide and HMA were low in both MT patients and controls. Biologically rational therapies are needed that target this molecular disease subset. Table 1. Baseline characteristics SF3B1 MT (n=48) SF3B1 WT (n=96) P value Age median 65 67 0.6 Gender male 29 (60%) 64(67%) 0.5 Race White 44/45 (98%) 83/90 (92%) 0.34 WHO classification RA RARS RCMD RARS-T Del5 q RAEB-I RAEB-II MDS-U MDS/MPN CMML 3 24 8 4 1 3 3 2 0 0 6 9 17 2 6 10 9 3 11 9 IPSS Low Int-1 Int-2 High 29 (60%) 16 (33%) 3 (6%) 0 21 (22%) 69 (72%) 4 (4%) 2 (2%) < 0.001 IPSS-R Very low Low Intermediate High Very High 15 (31%) 26 (54%) 5 (10%) 2 (4%) 0 11 (11%) 37 (39%) 26 (27%) 18 (19%) 4 (4%) <0.001 Lab values (mean) Hgb Platelets ANC myeloblasts 9.7 274 2.63 1 9.6 108 1.92 2 0.46 <0.001 0.04 0.05 Disclosures Komrokji: Novartis: Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding; Incyte: Consultancy; Pharmacylics: Speakers Bureau. Padron:Novartis: Speakers Bureau; Incyte: Research Funding. List:Celgene Corporation: Honoraria, Research Funding. Steensma:Incyte: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Onconova: Consultancy. Sekeres:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; TetraLogic: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.

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Phase IIa Study of Single-Agent MOR208 in Patients with Relapsed or Refractory B-Cell Non-Hodgkin's Lymphoma

Blood ◽

10.1182/blood.v126.23.1528.1528 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1528-1528 ◽

Cited By ~ 4

Author(s):

Wojciech Jurczak ◽

Pier Luigi Zinzani ◽

Gianluca Gaidano ◽

Andre Goy ◽

Mariano Provencio ◽

...

Keyword(s):

B Cell ◽

Board Of Directors ◽

Research Funding ◽

Cell Lymphoma ◽

Single Agent ◽

Hodgkin's Lymphoma ◽

Clinical Activity ◽

Advisory Committees ◽

Cd20 Antibody ◽

Grade 3

Abstract Introduction: There remains a high unmet medical need for new therapies for patients with relapsed or refractory (R-R) B-cell non-Hodgkin's lymphoma (NHL). CD19 is a B-lymphocyte, lineage-specific surface antigen that is highly expressed by most B-cell NHLs. CD19 expression is maintained on lymphoma cells which have CD20 expression downregulated following treatment with the CD20 antibody, rituximab. Consequently, MOR208 (XmAb5574; MOR00208), an Fc-engineered, humanized, monoclonal antibody that targets CD19, may have clinical utility as a new therapeutic approach to R-R NHL. A phase I study showed MOR208 to be safe and well-tolerated with encouraging single-agent activity in patients with chronic lymphocytic leukemia (CLL); an intravenous dose of 12 mg/kg was recommended for phase II studies. Methods: This is a non-randomized, open-label, multicenter, two-stage, phase IIa study of MOR208 in adult patients with R-R NHL whose disease had progressed after at least one prior therapy containing the CD20 antibody, rituximab. In stage 1, 10 patients were to be enrolled into each of four NHL subtype-specific cohorts: diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), other indolent NHL (iNHL) and mantle cell lymphoma (MCL). Patients were to receive single-agent MOR208, 12 mg/kg intravenously, weekly, for 8 weeks (2 cycles). Those with at least stable disease by the 2007 International Response Criteria could continue MOR208 treatment for an additional 4 weeks (total of 12 weeks of therapy). Patients with a complete or partial response (CR or PR) after 12 weeks could then receive MOR208 as maintenance therapy, every 2 or 4 weeks depending on the investigator's decision, until progression. In stage 2, cohorts with ≥2 responses (CR or PR) were to be expanded by at least 20 additional patients. The primary endpoint was the overall response rate (ORR). Key secondary endpoints included duration of response, safety, immunogenicity of MOR208, pharmacokinetics and pharmacodynamics. Results: The DLBCL and FL cohorts were expanded (to N=35 and N=34 patients, respectively), leading to a total enrollment of 92 patients: 56 (61%) were male; median age was 66.5 (range 35-90) years; 80 (87%) had stage III-IV disease; 41 (45%) had received ≥3 prior lines of therapy and 10 (11%) had received a prior stem-cell transplant. The investigator-assessed ORR across all NHL subtypes was 23% (21/92 patients; 16 not evaluable at cutoff) with clinical activity seen in the DLBCL (26% [9/35]; 2 CR, 7 PR); FL (26% [9/34]; 3 CR, 6 PR) and iNHL (27% [3/11]; 2 CR, 1 PR) cohorts (MCL, 0/12 responses). The iNHL cohort was not expanded as the response pattern in this subgroup was heterogeneous according to lymphoma subtype. The longest durations of response recorded to date are 15.4 months for FL and 14.2 months for DLBCL (both ongoing). Grade ≥3 non-hematologic and hematologic treatment-emergent adverse events (TEAEs) were recorded in 24 (26%) and 14 (15%) of 92 patients, respectively. The most commonly reported grade ≥3 hematologic TEAEs were neutropenia (7 [8%] of 92 patients, anemia (4 [4%]), and thrombocytopenia (4 [4%]); such TEAEs were seen most frequently in the DLBCL cohort (10 [29%] of 35 patients overall; neutropenia, 5 [14%], anemia, 4 [11%], thrombocytopenia, 2 [6%]). Dyspnea was the most commonly reported grade ≥3 non-hematologic TEAE (4 [4%] of 92 patients). Infusion-related reactions were seen in 9 (10%) of 92 patients; all were grade 1-2, except for one case of dyspnea, grade 4. There were no treatment-related deaths. Clinical activity in patients with R-R DLBCL appeared to be dependent on attaining a defined cumulative exposure (AUC0-t) over 8 weeks of around 11,000 day*µg/mL; i.e., at the data cutoff date, all 8 patients with a PR after 2 cycles showed an exposure above this potential threshold level. Conclusions: MOR208 demonstrated encouraging single-agent activity with CRs observed in patients with R-R DLBCL, FL, and iNHL. MOR208 was well tolerated without significant infusional toxicity. These data support further development of MOR208 in combination with other agents (including lenalidomide and bendamustine), and protocols for studies in patients with R-R DLBCL are now being developed. Disclosures Jurczak: CELLTRION, Inc,: Research Funding. Zinzani:Takeda: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; J&J: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Gaidano:Celgene: Research Funding; MorphoSys; Roche; Novartis; GlaxoSmithKline; Amgen; Janssen; Karyopharm: Honoraria, Other: Advisory boards. Goy:Celgene: Consultancy, Research Funding, Speakers Bureau; Allos, Biogen Idec, Celgene, Genentech, and Millennium. Gilead: Speakers Bureau. Robak:Janssen: Consultancy, Research Funding; MorphoSys AG: Consultancy, Honoraria, Research Funding. Maddocks:Novartis: Research Funding; Pharmacyclics: Consultancy, Research Funding; Janssen: Research Funding. Buske:Roche: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Celgene: Honoraria, Other: Travel, Accommodations, Expenses; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Gilead: Consultancy. Korolkiewicz:MorphoSys AG: Employment. Striebel:MorphoSys AG: Employment. Blum:Morphosys: Research Funding; Gilead: Research Funding; Millenium: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Janssen: Research Funding; Novartis: Research Funding; Constellation Pharmaceuticals: Research Funding; Celgene: Research Funding.

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Identification of a Factor X-Interactive Site on the Factor VIII A2 Domain

Blood ◽

10.1182/blood.v128.22.3760.3760 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3760-3760

Author(s):

Masahiro Takeyama ◽

Keiji Nogami ◽

Shoko Furukawa ◽

Midori Shima

Keyword(s):

Board Of Directors ◽

Binding Affinity ◽

Research Funding ◽

Cross Linking ◽

Functional Evaluation ◽

Dependent Manner ◽

Wild Type ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

A2 Domain

Abstract We have experienced a case of acquired hemophilia A with inhibitor recognizing only a factor (F) VIII A2 epitope, and reported the inhibitory mechanism for disappearing FVIII activity (Blood, 124, 4226, 2014). In summary, the patient's inhibitor IgG bound to FVIII A2N (residue 372-562) fragment and inhibited Arg372 cleavage in FVIII by FXa, suggesting that FX(a) bound to FVIII A2 domain. ELISA-based assay showed that FVIII A2 fragment bound to FX (Kd; 338 nM). We hypothesized that FVIII A2 residues 400-429 might be FX binding site according to the 3-D model of FVIII molecule, and prepared synthetic peptides (400-409, 409-419, and 420-429). The 400-409 peptide inhibited the FVIII A2-FX interaction, suggesting that the 400-409 region contributed to FX-interactive site. In this current study, we further performed the localization of a FX-interactive site on the 400-409 region in the A2 domain. A purified FXa generation assay demonstrated the 400-409 peptide decreased the generation of FXa in a dose-dependent manner up to 38% of 100 μM (Ki; 23 ± 9 nM). In comparison, scrambled peptide of 400-409 decreased up to 10% of 100 μM. These data demonstrated that the 400-409 peptide inhibited the generated FXa, suggesting the 400-409 region contributed to regulate the coagulation function. Covalent cross-linking was observed between the biotinylated 400-409 peptide and FX following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) using SDS-PAGE. This cross-linking formation was blocked by the addition of unlabeled 400-409 peptide. N-terminal sequence analysis of the peptide-FX product demonstrated that two sequential residues (Lys408 and Ser409) could not be detected, supporting that two residues participate in cross-link formation. To confirm the significance of these residues in A2 domain for FX-binding, the mutant forms of the A2 domain, converted to alanine, were expressed in BHK system and purified. Compared with wild type FVIII (Kd; 10 ± 3 nM), the binding affinity of Ser409Ala FVIII mutant for FX was no significant difference (Kd; 14 ± 1 nM) on SPR-based assay. Lys408Ala or Lys408Ala/Ser409Ala double FVIII mutant, however, decreased the binding affinity by 3.6~4.3-fold (Kd; 36 ± 7 or 43 ± 2 nM, respectively), suggesting contribution of Lys408Ala to the binding interaction. For the functional evaluation of the association with FVIII mutants to FX, a FXa generation assay was repeated. Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant reacted with varying concentrations of FX decreased by 1.2~1.6-fold (Km; 53 ± 12, 69 ± 15, or 65 ± 15 nM, respectively) compared to wild type FVIII (Km; 43 ± 9 nM), supporting a contribution of these mutants to Km and overall catalytic efficiency. Vmax values were largely unaffected by the mutations with most values within approximately 30% of the wild-type value. On the other hand, Kcat/Km value of Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant were decreased by 0.5~0.7-fold (Kcat/Km; 1.0, 1.3, or 0.9 nM-1min-1, respectively) compared to wild type FVIII (Kcat/Km; 1.8 nM-1min-1), suggesting low catalytic efficacy of Lys408Ala and Ser409Ala. These results indicate that the 400-409 region in the FVIII A2 domain, and in particular Lys408 and Ser409, may contribute to a unique FX-interactive site. Disclosures Nogami: Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding. Shima:Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

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Contempo: Preliminary Results in First-Line Treatment of Follicular Lymphoma with the Oral Dual PI3K-δ,γ Inhibitor, Duvelisib, in Combination with Rituximab or Obinutuzumab

Blood ◽

10.1182/blood.v128.22.2979.2979 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2979-2979 ◽

Cited By ~ 12

Author(s):

Carla Casulo ◽

Juan-Manuel Sancho ◽

Koen Van Eygen ◽

Sven de Vos ◽

Santiago Mercadal ◽

...

Keyword(s):

Bone Marrow ◽

Follicular Lymphoma ◽

Board Of Directors ◽

Median Time ◽

Safety Profile ◽

Research Funding ◽

Bone Marrow Involvement ◽

Clinical Activity ◽

Advisory Committees ◽

Dose Modification

Abstract Background: Duvelisib is an oral, dual inhibitor of PI3K-d,γ, in development for the treatment of hematologic malignancies, including follicular lymphoma (FL). Duvelisib disrupts PI3K-d,γ-mediated signaling within tumor cells and their interactions with the tumor microenvironment, hindering hematologic tumor cell survival. Data from a Phase 1 study of duvelisib indicate the potential for duvelisib to be an effective treatment for FL, with an acceptable safety profile. CONTEMPO (NCT02391545), is designed to evaluate the safety and clinical activity of duvelisib in combination with rituximab (DR) or obinutuzumab (DO) in patients (pts) with previously-untreated CD20+ FL. Methods: In CONTEMPO, duvelisib is administered at 25 mg BID continuously in 28-day treatment cycles, combined either with rituximab (375 mg/m2 for 4 weekly doses, then 1 dose every 2 cycles) or obinutuzumab (1000 mg for 4 weekly doses, then 1 dose every 2 cycles). Pts are assigned 1:1 into the two parallel treatment arms. Key inclusion criteria include: diagnosis of previously-untreated CD20+ FL, Stage II with bulky disease (≥ 7 cm lesion), or Stage III-IV disease, at least 1 measurable disease lesion > 1.5 cm, adequate liver and renal function, and no clinical evidence of transformation to a more aggressive subtype of lymphoma or Grade 3B FL. Prophylaxis for herpes (HSV/VZV) is recommended. For pts with a history of CMV infection requiring treatment, prophylaxis and monitoring of reactivation is recommended. The original protocol mandated PJP prophylaxis when CD4 counts were ≤ 200 cells/mm3, and was subsequently amended to include all pts. Disease response assessments (CT scans and physical exams) occur on Day 1 of Cycle 4 (C4), C8, C12, C16, C20, and C26. Results: As of 19 July 2016 (data cut-off), 28 pts received DR and 27 received DO. For DR pts, the median age was 58 years, most were male (64%), 21% had Gr 1 and 64% Gr 2 disease at baseline, and 54% had bone marrow involvement. Median time from diagnosis was 2.3 months. For DO pts, the median age was 58 years, most were female (59%), 48% had Gr 1 and 30% Gr 2 disease at baseline, and 59% had bone marrow involvement. Median time from diagnosis was 2.6 months. DR pts were on treatment for a median of 3.9 months, DO pts for 4.5 months. The overall response rate (ORR) per IWG criteria for DR was 87% and for DO was 91% (see table) The rate of AEs for DR pts was 93%, with 50% having a ≥ Gr 3 AE. 64% of DR pts had an AE leading to duvelisib dose modification (reduction or hold), while 14% discontinued duvelisib due to an AE. The most common ≥ Gr 3 AEs on DR (> 2 pts) were ALT increased (21%) and rash (14%). The rate of ≥ Gr 3 infections was 11%, including PJP (n=2; no prophylaxis, pre-amendment), followed by lung infection and pneumococcal pneumonia (1 pt, each). One PJP case resolved and the pt continued on study. The second PJP case resolved, however the pt had a subsequent fatal event of acute respiratory distress, the only fatal AE on study. The rate of AEs for DO pts was 89%, with 70% of pts having a ≥ Gr 3 AE. 63% of DO pts had an AE leading to duvelisib dose modification (reduction or hold), while 7% discontinued duvelisib due to an AE. Most common ≥ Gr 3 AEs (> 2pts) on DO were neutropenia (19%), ALT increased (15%), and AST increased (11%). The rate of ≥ Gr 3 infections was 15%, including conjunctivitis, RSV pneumonia, pyelonephritis, and septic shock (1 pt, each). No pts on DO died due to an AE. Conclusions: Preliminary clinical activity with DR (87% ORR, 22% CR) and DO (91% ORR, 18% CR) supports the potential role of duvelisib in combination with an anti-CD20 monoclonal antibody as initial treatment for pts with FL. The safety profile was manageable with appropriate risk mitigation measures, suggesting further investigation of these combinations may be warranted. Disclosures Casulo: Celgene: Research Funding; Infinity: Consultancy, Honoraria. Sancho:Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celltrion, Inc: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Gyan:Amgen: Honoraria; Sanofi: Honoraria; Pierre Fabre: Honoraria; Novartis: Research Funding; Celgene: Research Funding; Fresenius Kabi: Honoraria; Gilead: Consultancy, Speakers Bureau; Mundipharma: Consultancy; Roche: Research Funding. Steelman:Infinity: Employment. Pearlberg:Infinity: Employment. Goy:Genentech: Research Funding; Johnson & Johnson: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Acerta: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Other: Writing support, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding.

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