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•JNJ-75276617 shows preclinical activity in KMT2A- or NPM1-altered leukemia, synergizing with gilteritinib, venetoclax, and azacitidine.•Antiproliferative activity in cells harboring meninmutations M327I and T349M is due to a unique binding mode.

There is a need for novel therapies for relapsed or refractory multiple myeloma, and B-cell maturation antigen (BCMA) is a validated target. Teclistamab is a bispecific antibody that binds BCMA and CD3 to redirect T cells to multiple myeloma cells. The aim of the MajesTEC-1 study was to evaluate the safety, tolerability, and preliminary efficacy of teclistamab in patients with relapsed or refractory multiple myeloma.

B-cell maturation antigen (BCMA), a member of the tumor necrosis factor family of receptors, is predominantly expressed on the surface of terminally differentiated B cells. BCMA is highly expressed on plasmablasts and plasma cells from multiple myeloma (MM) patient samples. We developed a BCMAxCD3 bispecific antibody (teclistamab [JNJ-64007957]) to recruit and activate T cells to kill BCMA-expressing MM cells. Teclistamab induced cytotoxicity of BCMA+ MM cell lines in vitro (H929 cells, 50% effective concentration [EC50] = 0.15 nM; MM.1R cells, EC50 = 0.06 nM; RPMI 8226 cells, EC50 = 0.45 nM) with concomitant T-cell activation (H929 cells, EC50 = 0.21 nM; MM.1R cells, EC50 = 0.1 nM; RPMI 8226 cells, EC50 = 0.28 nM) and cytokine release. This activity was further increased in the presence of a γ-secretase inhibitor (LY-411575). Teclistamab also depleted BCMA+ cells in bone marrow samples from MM patients in an ex vivo assay with an average EC50 value of 1.7 nM. Under more physiological conditions using healthy human whole blood, teclistamab mediated dose-dependent lysis of H929 cells and activation of T cells. Antitumor activity of teclistamab was also observed in 2 BCMA+ MM murine xenograft models inoculated with human T cells (tumor inhibition with H929 model and tumor regression with the RPMI 8226 model) compared with vehicle and antibody controls. The specific and potent activity of teclistamab against BCMA-expressing cells from MM cell lines, patient samples, and MM xenograft models warrant further evaluation of this bispecific antibody for the treatment of MM. Phase 1 clinical trials (monotherapy, #NCT03145181; combination therapy, #NCT04108195) are ongoing for patients with relapsed/refractory MM.

B-cell maturation antigen (BCMA), a member of the tumor necrosis factor family of receptors, is predominantly expressed on the surface of terminally differentiated B cells. BCMA is highly expressed on plasmablasts and plasma cells from multiple myeloma (MM) patient samples. We developed a BCMAxCD3 bispecific antibody (teclistamab [JNJ-64007957]) to recruit and activate T cells to kill BCMA-expressing MM cells. Teclistamab induced cytotoxicity of BCMA+MM cell lines in vitro (H929 cells, 50% effective concentration [EC50] = 0.15 nM; MM.1R cells, EC50= 0.06 nM; RPMI 8226 cells, EC50= 0.45 nM) with concomitant T-cell activation (H929 cells, EC50= 0.21 nM; MM.1R cells, EC50= 0.1 nM; RPMI 8226 cells, EC50= 0.28 nM) and cytokine release. This activity was further increased in the presence of a γ-secretase inhibitor (LY-411575). Teclistamab also depleted BCMA+cells in bone marrow samples from MM patients in an ex vivo assay with an average EC50value of 1.7 nM. Under more physiological conditions using healthy human whole blood, teclistamab mediated dose-dependent lysis of H929 cells and activation of T cells. Antitumor activity of teclistamab was also observed in 2 BCMA+MM murine xenograft models inoculated with human T cells (tumor inhibition with H929 model and tumor regression with the RPMI 8226 model) compared with vehicle and antibody controls. The specific and potent activity of teclistamab against BCMA-expressing cells from MM cell lines, patient samples, and MM xenograft models warrant further evaluation of this bispecific antibody for the treatment of MM. Phase 1 clinical trials (monotherapy, #NCT03145181; combination therapy, #NCT04108195) are ongoing for patients with relapsed/refractory MM.

T-cell–mediated approaches have shown promise in myeloma treatment. However, there are currently a limited number of specific myeloma antigens that can be targeted, and multiple myeloma (MM) remains an incurable disease. G-protein–coupled receptor class 5 member D (GPRC5D) is expressed in MM and smoldering MM patient plasma cells. Here, we demonstrate that GPRC5D protein is present on the surface of MM cells and describe JNJ-64407564, a GPRC5DxCD3 bispecific antibody that recruits CD3+ T cells to GPRC5D+ MM cells and induces killing of GPRC5D+ cells. In vitro, JNJ-64407564 induced specific cytotoxicity of GPRC5D+ cells with concomitant T-cell activation and also killed plasma cells in MM patient samples ex vivo. JNJ-64407564 can recruit T cells and induce tumor regression in GPRC5D+ MM murine models, which coincide with T-cell infiltration at the tumor site. This antibody is also able to induce cytotoxicity of patient primary MM cells from bone marrow, which is the natural site of this disease. GPRC5D is a promising surface antigen for MM immunotherapy, and JNJ-64407564 is currently being evaluated in a phase 1 clinical trial in patients with relapsed or refractory MM (NCT03399799).

T-cell–mediated approaches have shown promise in myeloma treatment. However, there are currently a limited number of specific myeloma antigens that can be targeted, and multiple myeloma (MM) remains an incurable disease. G-protein–coupled receptor class 5 member D (GPRC5D) is expressed in MM and smoldering MM patient plasma cells. Here, we demonstrate that GPRC5D protein is present on the surface of MM cells and describe JNJ-64407564, a GPRC5DxCD3 bispecific antibody that recruits CD3+T cells to GPRC5D+MM cells and induces killing of GPRC5D+cells. In vitro, JNJ-64407564 induced specific cytotoxicity of GPRC5D+cells with concomitant T-cell activation and also killed plasma cells in MM patient samples ex vivo. JNJ-64407564 can recruit T cells and induce tumor regression in GPRC5D+MM murine models, which coincide with T-cell infiltration at the tumor site. This antibody is also able to induce cytotoxicity of patient primary MM cells from bone marrow, which is the natural site of this disease. GPRC5D is a promising surface antigen for MM immunotherapy, and JNJ-64407564 is currently being evaluated in a phase 1 clinical trial in patients with relapsed or refractory MM (NCT03399799).

CD33 is expressed in 90% of patients with acute myeloid leukemia (AML), and its extracellular portion consists of a V domain and a C2 domain. A recent study showed that a single nucleotide polymorphism (SNP), rs12459419 (C > T), results in the reduced expression of V domain–containing CD33 and limited efficacy of V domain–binding anti-CD33 antibodies. We developed JNJ-67571244, a novel human bispecific antibody capable of binding to the C2 domain of CD33 and to CD3, to induce T-cell recruitment and CD33+ tumor cell cytotoxicity independently of their SNP genotype status. JNJ-67571244 specifically binds to CD33-expressing target cells and induces cytotoxicity of CD33+ AML cell lines in vitro along with T-cell activation and cytokine release. JNJ-67571244 also exhibited statistically significant antitumor activity in vivo in established disseminated and subcutaneous mouse models of human AML. Furthermore, this antibody depletes CD33+ blasts in AML patient blood samples with concurrent T-cell activation. JNJ-67571244 also cross-reacts with cynomolgus monkey CD33 and CD3, and dosing of JNJ-67571244 in cynomolgus monkeys resulted in T-cell activation, transient cytokine release, and sustained reduction in CD33+ leukocyte populations. JNJ-67571244 was well tolerated in cynomolgus monkeys up to 30 mg/kg. Lastly, JNJ-67571244 mediated efficient cytotoxicity of cell lines and primary samples regardless of their SNP genotype status, suggesting a potential therapeutic benefit over other V-binding antibodies. JNJ-67571244 is currently in phase 1 clinical trials in patients with relapsed/refractory AML and high-risk myelodysplastic syndrome.

CD33 is expressed in 90% of patients with acute myeloid leukemia (AML), and its extracellular portion consists of a V domain and a C2 domain. A recent study showed that a single nucleotide polymorphism (SNP), rs12459419 (C > T), results in the reduced expression of V domain–containing CD33 and limited efficacy of V domain–binding anti-CD33 antibodies. We developed JNJ-67571244, a novel human bispecific antibody capable of binding to the C2 domain of CD33 and to CD3, to induce T-cell recruitment and CD33+tumor cell cytotoxicity independently of their SNP genotype status. JNJ-67571244 specifically binds to CD33-expressing target cells and induces cytotoxicity of CD33+AML cell lines in vitro along with T-cell activation and cytokine release. JNJ-67571244 also exhibited statistically significant antitumor activity in vivo in established disseminated and subcutaneous mouse models of human AML. Furthermore, this antibody depletes CD33+blasts in AML patient blood samples with concurrent T-cell activation. JNJ-67571244 also cross-reacts with cynomolgus monkey CD33 and CD3, and dosing of JNJ-67571244 in cynomolgus monkeys resulted in T-cell activation, transient cytokine release, and sustained reduction in CD33+leukocyte populations. JNJ-67571244 was well tolerated in cynomolgus monkeys up to 30 mg/kg. Lastly, JNJ-67571244 mediated efficient cytotoxicity of cell lines and primary samples regardless of their SNP genotype status, suggesting a potential therapeutic benefit over other V-binding antibodies. JNJ-67571244 is currently in phase 1 clinical trials in patients with relapsed/refractory AML and high-risk myelodysplastic syndrome.

Background: Intrinsic apoptosis is regulated by the B Cell lymphoma 2 (BCL-2) protein family. Anti-apoptotic family members, such as BCL-2, MCL-1 and BFL-1, sequester their pro-apoptotic counterparts through a highly conserved BH3 binding groove. Disruption of this balance leads to mitochondrial pore formation and subsequent cell death. To evade apoptosis, tumors often upregulate the expression of one or more anti-apoptotic family members and as such they have become attractive targets for anti-cancer drug development. BFL-1 (‘Bcl-2 related gene expressed in fetal liver’, gene name BCL2A1) is a lesser-known anti-apoptotic family member, physiologically mainly expressed in the hematopoietic system.

Myeloproliferative neoplasms (MPNs) are clonal malignant disorders of hematopoiesis arising in the hematopoietic stem cell (HSC) compartment that are characterized by excessive production of mature blood cells of the myeloid lineage. Transformation to secondary acute myeloid leukemia (sAML) represents a significant cause of death among MPN patients and this transformation occurs mainly from the clone carrying the disease phenotype driver mutation. Current treatment options for MPN patients are not curative and are limited to symptomatic treatment. Therefore, identification of novel therapeutic approaches with a clear disease-modifying effect for the treatment of MPNs and intercepting their progression to sAML is an unmet medical need. Mutations in JAK2, thrombopoietin receptor (MPL), and calreticulin (CALR) are phenotypic drivers in the pathogenesis of MPN. CALR mutations (CALRmut) are the second most frequent in MPN. CALRmut are insertions or deletions resulting in a frameshift in the last exon of the gene, causing a loss of the KDEL ER-retention motif and generation of a 36 amino acid positively charged C-terminal neoantigen. Due to loss of the KDEL motif, CALRmut are not confined to the ER and through interaction with MPL are trafficked to the cell surface where they induce persistent MPL activation and oncogenicity. Immunotherapies engaging T cells, such as bispecific cluster of differentiation 3 (CD3) redirection antibodies, show promising response rates in the clinic.

Background:JNJ-75276617 is a highly selective and orally bioavailable small molecule targeting the menin- histone-lysine N-methyltransferase 2A (KMT2A) protein-protein interaction. Pharmacologic disruption of this interaction was previously shown to induce differentiation and block progression of KMT2A-r or NPM1cacute myeloid leukemia (AML) and B-cell acute lymphoblastic leukemia (ALL) in preclinical models (Kwon, ASH 2022). Small-molecule inhibitors including JNJ-75276617 are being explored clinically as a treatment for KMT2A- and NPM1-altered leukemias, which represent an area of high unmet medical need. Hypomethylating agents (e.g. azacitidine, decitabine) in combination with venetoclax have significantly improved clinical outcomes for AML patients and have become a preferred frontline treatment for AML patients ≥75 years of age, or who have comorbidities that preclude use of intensive induction chemotherapy. Although promising responses are seen in the frontline setting, unfortunately many patients relapse highlighting the need for better therapies and more effective combinations. JNJ-75276617 was previously shown to inhibit HOX/Meis1 stemness genes and induce differentiation genes in KMT2A- or NPM1-altered leukemic cells. Here, we evaluated whether JNJ-75276617, which induces differentiation followed by cell death, could enhance the mechanisms of action triggered by venetoclax plus azacitidine, which primarily drives apoptosis by displacing anti-apoptotic proteins.

Background:Multiple myeloma (MM) is a genetically complex and heterogenous malignancy with a poor survival rate and accounts for approximately 10% to 15% of all hematologic cancers. Despite advances in myeloma therapy, MM remains incurable. Deep and durable clinical responses have been observed when targeting the tumor associated antigens BCMA and GPRC5D with immunotherapies. Additionally, data presented at ASCO this year demonstrated a further improvement in ORR when BCMA and GPRC5D bispecifics were given in combination to relapsed or refractory MM patients. These data suggest that broader antigen coverage by redirecting T cells to two tumor surface antigens is an effective means to harness the immune system to deplete cancer cells. Targeting two tumor antigens may also reduce the likelihood of antigen escape as a primary reason for relapse. Here, we describe JNJ-79635322, a trispecific antibody targeting B-cell maturation antigen (BCMA) and G-Protein-coupled receptor class 5 member D (GPRC5D), which are both highly expressed on plasmablasts and plasma cells in myeloma patient samples. Dual antigen recognition on plasma cells with a trispecific T-cell engaging antibody engineered with a CD3 arm has the potential to enhance tumor binding through avidity that could result in efficient depletion of malignant clonal populations and prevent tumor antigen loss mediated resistance.

New treatment options are required for primary systemic AL amyloidosis (AL). This phase 1 dose-escalation component of a phase 1/2 study in relapsed AL aimed to determine the maximum tolerated dose (MTD) of bortezomib once weekly (0.7-1.6 mg/m2; days 1, 8, 15, and 22; 35-day cycles) and twice weekly (0.7-1.3 mg/m2; days 1, 4, 8, and 11; 21-day cycles) and assess preliminary hematologic responses. Thirty-one patients with relapsed AL were enrolled across 7 cohorts. Dose-limiting toxicity included grade 3 congestive heart failure in 2 patients (1 at once weekly, 1.6 mg/m2, and 1 at twice weekly, 1.0 mg/m2). MTD was not defined for either schedule; the maximum doses of 1.6 mg/m2(once weekly) and 1.3 mg/m2(twice weekly) are being used in phase 2 evaluation. Most commonly reported toxicities on both schedules included gastrointestinal events, fatigue, and nervous system disorders. Discontinuations and dose reductions for toxicity were reported in 12 and 4 patients, respectively. No treatment-related deaths occurred. Hematologic responses occurred in 15 (50%) of 30 evaluable patients, including 6 (20%) complete responses. Median time to first response was 1.2 months. Once-weekly and twice-weekly bortezomib appear generally well tolerated in relapsed AL, with promising hematologic responses. This study is registered with http://ClinicalTrials.govunder identifier NCT00298766.

New treatment options are required for primary systemic AL amyloidosis (AL). This phase 1 dose-escalation component of a phase 1/2 study in relapsed AL aimed to determine the maximum tolerated dose (MTD) of bortezomib once weekly (0.7-1.6 mg/m2; days 1, 8, 15, and 22; 35-day cycles) and twice weekly (0.7-1.3 mg/m2; days 1, 4, 8, and 11; 21-day cycles) and assess preliminary hematologic responses. Thirty-one patients with relapsed AL were enrolled across 7 cohorts. Dose-limiting toxicity included grade 3 congestive heart failure in 2 patients (1 at once weekly, 1.6 mg/m2, and 1 at twice weekly, 1.0 mg/m2). MTD was not defined for either schedule; the maximum doses of 1.6 mg/m2 (once weekly) and 1.3 mg/m2 (twice weekly) are being used in phase 2 evaluation. Most commonly reported toxicities on both schedules included gastrointestinal events, fatigue, and nervous system disorders. Discontinuations and dose reductions for toxicity were reported in 12 and 4 patients, respectively. No treatment-related deaths occurred. Hematologic responses occurred in 15 (50%) of 30 evaluable patients, including 6 (20%) complete responses. Median time to first response was 1.2 months. Once-weekly and twice-weekly bortezomib appear generally well tolerated in relapsed AL, with promising hematologic responses. This study is registered with http://ClinicalTrials.gov under identifier NCT00298766.

Empirical approaches to discovery of anticancer drugs and cancer treatment have made limited progress in the cure of cancer in the last several decades. Recent advances in technology and expanded knowledge of the molecular basis of tumorigenesis and metastasis have provided unique opportunities to design novel compounds that rationally target the abnormal molecular and biochemical signals leading to cancer. Several such novel agents have completed advanced stages in clinical development. The excellent clinical results achieved by some of these compounds are creating new paradigms in management of patients with neoplastic diseases. Clinical development of these agents also raises challenges to the traditional methods of drug evaluation and measurement of efficacy.

B cell maturation antigen (BCMA; CD269; TNFRSF17) is a surface receptor, expressed on benign and malignant plasma cells. The restricted expression of BCMA on B-cell lineage makes it an ideal target for multiple myeloma (MM) immunotherapy. BCMAxCD3 bispecific antibody (Teclistamab; JNJ-64007957) has been developed to recruit CD3+T-cells to BCMA+MM cells. Teclistamab demonstrated potent cytotoxicity in a murine xenograft model and against ex vivo primary MM cells.

Pillarisetti: Janssen: Employment. Baldwin:Janssen: Employment. Babich:Janssen: Employment. Majewski:Janssen: Employment. Barone:Janssen: Employment. Li:Janssen: Employment. Zhang:Janssen: Employment. Chin:Janssen: Employment. Luistro:Janssen: Employment. Mendonça:Janssen: Employment. Nanjunda:Janssen: Employment. Rudnick:Janssen Pharmaceuticals R&D: Employment. Bellew:Janssen: Employment. Elsayed:Janssen: Employment, Other: stock options. Attar:Janssen: Employment. Gaudet:Janssen Pharmaceuticals R&D: Employment, Other: Stock options, Patents & Royalties: pending, not yet issued.

Nair-Gupta: Janssen: Employment. Rudnick:Janssen Pharmaceuticals R&D: Employment. Luistro:Janssen: Employment. Chin:Janssen: Employment. Smith:Janssen Research & Development, LLC: Employment, Equity Ownership. McDaid:Janssen Pharmaceuticals Research and Development: Employment. Li:Janssen: Employment. Pillarisetti:Janssen Research and Development, LLC: Employment. Baldwin:Janssen: Employment. Packman:Janssen: Employment. Elsayed:Janssen: Employment. Attar:Janssen: Employment. Gaudet:Janssen Pharmaceuticals R&D: Employment, Other: Stock options, Patents & Royalties: pending, not yet issued.

Gaudet: Janssen Pharmaceuticals R&D: Employment, Other: Stock options, Patents & Royalties: pending, not yet issued. Nemeth:Janssen Pharmaceuticals R&D: Employment, Other: stock, Patents & Royalties: patent pending. McDaid:Janssen Pharmaceuticals Research and Development: Employment. Li:Janssen: Employment. Harman:Janssen Pharmaceuticals R&D: Employment. Millar:Janssen Pharmaceuticals R&D: Employment, Other: stock options. Teplyakov:Janssen Pharmaceuticals R&D: Employment. Wheeler:Janssen Pharmaceuticals R&D: Employment. Luo:Janssen Pharmaceuticals R&D: Employment. Tam:Janssen Pharmaceuticals R&D: Employment, Other: stocks, Research Funding. Wu:Janssen Pharmaceuticals R&D: Employment. Chen:Janssen Pharmaceuticals R&D: Employment. Rudnick:Janssen Pharmaceuticals R&D: Employment. Chu:Janssen Pharmaceuticals R&D: Employment. Hughes:Janssen Pharmaceuticals R&D: Employment. Luistro:Janssen: Employment. Chin:Janssen: Employment. Babich:Janssen: Employment. Kalota:Janssen Pharmaceuticals R&D: Employment, Other: stock. Singh:Janssen Pharmaceuticals R&D: Employment, Other: stock options. Salvati:Janssen Pharmaceuticals R&D: Employment, Other: stock options, Patents & Royalties: patent. Elsayed:Janssen: Employment, Other: stock options. Attar:Janssen: Employment.

B-cell maturation antigen (BCMA) is a tumor necrosis factor (TNF) family surface protein predominantly expressed on terminally differentiated B-cells. BCMA signals through P38/NF-κB pathway upon binding to its ligands; a proliferation inducing ligand (APRIL) and B-cell activator of the TNF family (BAFF) and promote anti-apoptotic gene expression. BCMA expression is elevated in plasma blasts, plasma cells from spleen and bone marrow and correlates with disease progression in multiple myeloma (MM). BCMA expression in premalignant MM settings such as monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) also gives an opportunity for early cancer interception. To target cancer cells expressing BCMA, we developed a BCMAxCD3 bispecific antibody using the Genmab DuoBody® technology (Ab-957) to recruit T cells to BCMA-expressing MM cells so that T cells could be activated and induced to kill BCMA+cancer cells. This antibody can induce cytotoxicity of BCMA+MM cell lines in vitro(H929 cells: EC50=0.15nM, MM1.R cells: EC50=0.06nM, RPMI8226 cells: EC50=0.45nM) with a concomitant T cell activation (H929 cells: EC50=0.21nM, MM1.R cells: EC50=0.1nM, RPMI8226 cells: EC50=0.28nM). In contrast, this antibody was unable to kill BCMA-cancer cell line (MV4-11), demonstrating the specificity of the cytotoxicity. Ab-957 also inhibited tumor development or growth in two BCMA+MM murine xenograft models inoculated with human T cells. Furthermore, this antibody could deplete BCMA+cells in bone marrow samples from MM patient’s in an ex-vivo assaywith an average EC50value of 2.5 nM. Lastly, Ab-957 is well-tolerated in cynomolgus monkey and is being developed for Phase I clinical trial in patients with multiple myeloma.

AML is a cancer of the myeloid lineage that is characterized by the accumulation of abnormal white blood cells in the bone marrow and blood. Existing therapies do not lead to cures, partially due to their inability to eliminate residual leukemic stem cells (LSCs) in the bone marrow. T-cell redirection has been shown to be an effective method of treatment for hematologic malignancies (eg, blinatumomab) and represents an attractive approach to treat AML. CD123 (α-chain of the interleukin-3 receptor) has been shown to be expressed on the surface of AML blasts and LSCs. To eradicate CD123+cells, we developed a bispecific antibody (JNJ-63709178) using the Genmab DuoBody® technology that can bind both CD123 on tumor cells and CD3 on T cells. JNJ-63709178 is a humanized IgG4 bispecific antibody with silenced Fc function. This antibody is able to recruit T cells to CD123-expressing tumor cells and induce the killing of these tumor cells in vitro (MOLM-13, OCI-AML5 and KG-1; EC50= 0.51-0.91 nM). In contrast, this antibody does not kill CD123-cell lines, demonstrating the specificity of cytotoxicity. Consistently, the degree of cell killing correlated with the level of T-cell activation (CD69 and CD25) and cytokine release (TGF-β and TNF-α). Control bispecific antibodies containing a null arm (viral epitope) paired with a CD123 arm (CD123xnull) or a CD3 arm (nullxCD3) did not induce cytotoxicity or T-cell activation in the assays tested. JNJ-63709178 had no effect on T-cell activation when incubated with T cells alone. In AML murine xenograft models, JNJ-63709178 was able to suppress tumor growth and induce tumor regression (MOLM-13 and KG-1, respectively) in the presence of human peripheral blood mononuclear cells (PBMCs) or T cells. Tumor regression correlated with the infiltration of T cells in the tumor and the expression of T-cell activation markers such as CD25, PD1 and TIM3. Furthermore, this antibody was able to induce the killing of primary CD123+cancer cells from the blood of patients with AML without the need to supplement with fresh T cells (EC50= 0.83 nM). These results indicate that JNJ-63709178 can potently and specifically kill CD123+cancer cells in vitro, in vivo and ex vivo. Pharmacokinetic studies in cynomolgus monkeys support twice weekly dosing for human studies. JNJ-63709178 is currently being investigated in a Phase 1 clinical trial in relapsed and refractory AML (ClinicalTrials.gov ID: NCT02715011).

Redirecting T cells to specifically target and kill malignant cells has been validated as an effective anti-cancer strategy in the clinic with the approval of CD19xCD3 BiTE (Blincyto) for acute lymphoblastic leukemia. However, the immunosuppressive nature of the tumor microenvironment potentially poses a significant hurdle to T cell therapies. For instance, the bone marrow (BM) niche is appreciated to be a site of immune privilege at steady state to allow for normal hematopoiesis and immune cell generation. Additionally, in hematological malignancies, the BM niche is protective to leukemic stem cells, a phenomenon that has minimized the efficacy of several anti-cancer drugs including chemotherapy, targeted small molecule inhibitors and antibody based therapies.

Mycosis fungoides (MF) and Sézary syndrome (SS) represent two major instances of cutaneous T-cell lymphoma (CTCL), which are incurable and have shown response to treatment with histone deacetylase (HDAC) inhibitors. Quisinostat is a potent and orally active HDAC inhibitor that has been found to be active in preclinical models and phase 1 trials. The purpose of this phase 2 trial (NCT01486277) is to evaluate the efficacy and safety of quisinostat in patients with previously treated advanced stage IB-IVA MF or SS.Patients with relapsed or refractory, measurable, histopathologically confirmed CTCL, stages IB to IVA MF/SS, were treated with 8mg or 12 mg of oral quisinostat on days 1, 3 and 5 of each week in a 21-day treatment cycle. Patients who were initially randomized to the 8 mg dose cohort and did not have evidence of disease progression were allowed to have their dose increased to 12 mg. The primary efficacy endpoint was the overall cutaneous response rate (RR) measured by the modified Severity Weighted Assessment Tool (mSWAT). Key secondary endpoints included overall global RR, progression-free survival (PFS), 1-year overall survival (OS) rate, duration of response (DOR), and patient-reported outcome (PRO) which included the European Organization for Research and Treatment of Cancer Core (EORTC) questionnaire QLQ-C30 and the Pruritus Intensity Assessment questionnaire. Other secondary endpoints were pharmacodynamic markers, biomarkers predictive of response, and population pharmacokinetics (PK). Safety and tolerability have also been evaluated.Twenty-six patients were enrolled, including 6 patients in the 8 mg dose group and 20 patients in the 12 mg dose group. One patient in the 12 mg dose group discontinued prematurely from the study due to investigator's decision, and was therefore excluded from the response evaluable analysis set. Overall, enrolled patients included 81% male; median age = 61 years (range 32–80 years); 96% white; MF/SS stage: IB/IIA = 35% (n=9) and IIB/III/IVA = 65% (n=17); CTCL type: MF = 96% (n=25), and SS = 4% (n=1); mean Pruritus Intensity Score = 5.1.The preliminary results of this ongoing trial have shown that 6 out of 19 patients (31.6%) in the 12 mg dose group achieved ≥ 50% reduction in mSWAT score at least once, with confirmed response in the skin in 4 patients (1 complete response (CR) and 3 partial response (PR); overall RR = 21.1% with 95% CI: 6.1% to 45.6%). For the other 2 patients, the confirmation of response is pending in 1 patient and the other patient stopped the treatment due to non-drug related adverse event (AE). Nine patients are still on the treatment with the 12 mg dose, and 11 patients have discontinued the drug (6 due to progressive disease (PD), 2 due to investigator's decision, 2 due to AE, and 1 due to death). In the 8 mg dose group, no CR or PR in the skin has been observed, and 4 out of 6 patients have discontinued due to PD. The secondary endpoint results of overall global RR, PFS, 1-year OS rate, DOR, and PROs, as well as biomarker results for AcH3, ac-Tubulin, Cleaved Caspase 3, HR23B and pStat3, will be presented when further analysis results are available.To date, the most common (≥ 5% of patients) drug-related AEs have been nausea (23%), diarrhea (19%), asthenia (12%), thrombocytopenia (12%), hypertension (8%), lethargy (8%), palpitations (8%), pruritus (8%) and vomiting (8%); most of them were grade 2 or lower in severity. Grade 3 or higher AEs included hypertension (4%), lethargy (4%), pyrexia (4%), and hyperkalaemia (4%). One patient in the 8 mg dose group has required dose reduction due to hypertension.The efficacy and safety results from the final analysis will be presented.Preliminary results indicate that oral quisinostat at 12 mg dose on a 3 times weekly schedule is active in the treatment of patients with relapsed or refractory MF/SS not previously treated with an HDAC inhibitor, and has an acceptable safety profile.Child: Cephalon UK : Honoraria; Janssen R&D: Research Funding. Ortiz Romero:Ferrer Farma SA: Honoraria; Eisai: Honoraria. Weichenthal:Merck Inc.: Consultancy, Honoraria. Bernengo:Janssen R&D: Research Funding; NOVARTIS: Research Funding. Pérez Ferriols:Pfizer: Consultancy, Honoraria, Research Funding. Hellemans:Janssen R&D: Employment, Equity Ownership. Elsayed:Janssen R&D: Employment, Equity Ownership. Phelps:Janssen R&D: Employment, Equity Ownership. Forslund:Janssen R&D: Employment. Kamida:Janssen R&D: Employment. Zinzani:Millennium Takeda: Consultancy; Celgene: Consultancy.

Abstract 3676

Treatment goals in patients with relapsed FL are to prolong PFS and improve overall survival (OS). To optimize treatment for individual patients, identification of subgroups most likely to benefit from a specific therapy is important. The international, randomized, phase 3 LYM3001 study in patients with relapsed or refractory FL demonstrated improved PFS with bortezomib-rituximab vs rituximab alone (median 12.8 vs 11.0 months, HR 0.822, p=0.039), plus increased overall response rate (ORR; 63% vs 49%, p=0.0004), complete response rate (CR/CRu; 25% vs 18%, p=0.035), and durable (≥6 months) response rate (50% vs 38%, p=0.002) in an unselected patient population. Here we present exploratory biomarker analyses aimed at identifying patient subgroups deriving a longer PFS benefit with bortezomib-rituximab and showing a trend for better OS.Patients received five 5-week cycles of bortezomib-rituximab (N=336) or rituximab (N=340). Response was assessed using modified International Working Group response criteria. Archived tumor tissue was collected at baseline from 502 (74%) patients; whole blood samples for germ-line DNA were collected on day 1 of cycle 1 from 619 (92%) patients. Protocol-specified candidate biomarkers were based on associations with bortezomib (NF-κB p65, PSMA5, p27, PSMB1/5/8/9) or rituximab (CD68, FCGR2A/3A) activity. Immunohistochemistry assays were used for protein analysis. Taqman SNP assays and PCR/LDR were used for genotyping. Statistical analyses included single-marker analyses, pair-wise combination analyses (n=1140 comparisons), and multiple comparison analyses of all evaluable patients in LYM3001. Clinical covariates included in the analysis were baseline FLIPI score, prior rituximab, time since last anti-lymphoma therapy, region, age, gender, race, Ann Arbor stage, high tumor burden, and number of prior lines of therapy.Single markers and biomarker pairs (n=102) highlighted patient subsets that had significantly improved outcomes with bortezomib-rituximab vs rituximab. For 14 of the pairs, the PFS benefit was ≥6 months. Using false discovery rate (FDR) to control for multiple comparison corrections, one biomarker pair was significant. This pair (presence of the PSMB1 P11A C/G heterozygote, and low CD68 expression [0–50 CD68-positive macrophages in the follicular space]) was associated with significantly improved PFS in patients receiving bortezomib-rituximab vs rituximab (median 16.6 vs 9.1 months, HR 0.407, p<0.0001, FDR=0.051) and had a population frequency of 33% (n=118) in biomarker-evaluable patients (N=356). Patients with high-risk features were represented in the biomarker-selected population (54% high tumor burden, 41% high FLIPI, 30% >2 prior lines of therapy). There was also a trend towards an OS benefit (medians not reached, HR 0.426, p=0.0550), as well as a significantly higher ORR (73.7% vs 47.5%, p=0.0077), a higher CR rate (33.3% vs 23%, p=0.3044), and a significantly longer time to next therapy (median 33.1 vs 14.8 months, p=0.0013). In patients lacking this biomarker pair (N=238) no significant efficacy differences were seen. No other similar studies were available to confirm the reproducibility of these analyses. Therefore, we split the LYM3001 dataset into discovery and confirmation cohorts (7:3 ratio of biomarker-evaluable patients) to enable evaluation and confirmation in independent cohorts of patients The significant biomarker pair of PSMB1 P11A C/G heterozygote and low CD68 was identified in the discovery cohort (N=198) with a PFS advantage with bortezomib-rituximab vs rituximab of 5.7 months (median 14.2 vs 8.4 months, p=0.0003) and an indication of longer OS (HR 0.47, p=0.1291). This biomarker pair also showed a clear PFS advantage in the confirmation cohort (N=108, 8.7-month PFS benefit; median 18.2 vs 9.5 months, HR 0.44, p=0.0817). Other significant biomarker combinations, including combinations of molecular and clinical variables (e.g. high tumor burden) were identified and will be presented.Analyses of the phase 3 LYM3001 trial identified biomarker combinations present in a third of patients offering a significant PFS benefit with bortezomib-rituximab vs rituximab. Use of such biomarker assays in patients with relapsed or refractory FL may aid identification of subgroups deriving maximal benefit from the addition of bortezomib to rituximab therapy.Coiffier: Janssen-Cilag: Consultancy; Roche: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Pfizer: Consultancy; Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Pharmacyclics: Consultancy; MedImmune: Consultancy; CTI: Consultancy. Off Label Use: Bortezomib used in combination with rituximab in patients with relapsed/refractory follicular lymphoma. Li:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Henitz:Janssen Research & Development: Employment. Karkera:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Favis:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Gaffney:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Shapiro:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Theocharous:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Elsayed:Janssen Research & Development: Employment; Johson & Johnson: Equity Ownership. de Velde:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Rule:Johnson & Johnson: Advisory Board, Institutional grant, meeting attendance expenses, Honoraria. Walewski:Janssen-Cilag: Institutional/personal grants, advisory board; Hoffman La Roche: Honoraria, Institutional/personal grants, travel/accommodation expenses; Mundipharma: Honoraria; Celgene: Honoraria. de Vos:Millennium Pharmaceuticals, Inc: Consultancy. Crump:Janssen/Ortho-Biotech: Consultancy. Shpilberg:Janssen-Cilag: Consultancy, Honoraria. Cakana:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Esseltine:Millennium Pharmaceuticals, Inc: Employment; Johnson & Johnson: Equity Ownership. Mulligan:Millennium Pharmaceuticals, Inc.: Employment. Ricci:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership.

Abstract 265

Follicular lymphoma (FL) is an incurable B-cell non-Hodgkin's lymphoma (NHL) representing ∼20% of all NHL. Rituximab (R) is approved for the treatment of CD20+ relapsed/refractory FL, and single-agent bortezomib (Vc; VELCADE®) has shown activity in heavily pretreated patients. Vc and R show additive activity in preclinical models, and the combination was active and well tolerated in a phase 2 study. This randomized, open-label, multi-center, international, phase 3 clinical trial (LYM3001) compared the efficacy and safety of Vc plus R (Vc-R) vs R alone in patients with relapsed or refractory, R-naive or R-sensitive FL.Patients with grade 1/2 measurable FL who had relapsed/progressed following prior therapy (time to progression [TTP] ≥6 months if prior R-containing therapy), ECOG performance status ≤2, and no peripheral neuropathy grade ≥2 were randomized (1:1) to receive 5-week cycles of Vc-R (Vc 1.6 mg/m2, d 1, 8, 15, 22, cycles 1–5, plus R 375 mg/m2, d 1, 8, 15, 22 in cycle 1 and d 1 only in cycles 2–5) or R alone (administered according to the same schedule as for the Vc-R arm). In both groups, treatment was administered for five cycles or until progression or unacceptable treatment-related toxicity. Randomization was stratified by FLIPI score (0–1 vs 2 vs ≥3), prior R therapy (yes vs no), time since last dose of anti-FL therapy (≤1 vs >1 year), and region (US vs EU vs rest of world). Primary endpoint was progression-free survival (PFS); secondary endpoints included overall response rate (ORR), complete response (CR) rate, TTP, and safety/tolerability. Response and progression were assessed by independent radiology committee (IRC) using the modified International Workshop Response Criteria. Planned sample size was 670 patients to provide 90% power (α=0.05, 2-sided) to detect a 33% improvement in median PFS with Vc-R vs R (i.e. 13.3 vs 10 months).Between April 2006 and August 2008, 676 patients (intent-to-treat [ITT] population) were enrolled from 164 centers in 29 countries across Europe, the Americas, and Asia. Baseline characteristics were well balanced between the two arms; median age was 57 years (range 21–84), 54% were female, 75% were Caucasian and 21% were Asian. The majority of patients (93%) had an ECOG performance status of 0 or 1, 51% and 48% had grade 1 and 2 FL, respectively, and 41%, 35%, and 23% had high, intermediate, and low FLIPI score, respectively; 83% had Ann Arbor Stage III or IV, and 38% had bone marrow involvement at baseline. 33% of patients had received 3 or more prior lines of therapy (range 1–6+); 44% had received prior R therapy. The most common prior regimens were CHOP (38%), CVP (25%), single-agent R (17%), R-CHOP (12%), and R-CVP (11%). At a median follow-up of 33.9 months, a total of 440 PFS events were observed by IRC in the ITT population, 212 in the Vc-R arm and 228 events in the R arm. Median PFS improved from 334 days (95% CI: 278, 365) with R alone to 389 days (95% CI: 351, 456) with Vc-R; the hazard ratio was 0.822 (95% CI: 0.681, 0.991). This improvement is statistically significant with a 2-sided P-value of 0.039. The ORR was 63% with Vc-R vs 49% with R (P<0.001), including 25% and 18% verified CR rates, respectively (P=0.035). The durable response rate (>6 months) was 50% with Vc-R vs 38% with R (P=0.002). The median time to subsequent antilymphoma treatment was significantly improved in the Vc-R vs R arm (700 vs 537 days, P=0.027). Median OS was not reached in either group. Patients received a median 25 weeks treatment in both the Vc-R and R groups (range 5–40 and 5–35 in the Vc-R and R groups, respectively). Adverse events (AEs) were reported for 95% of Vc-R and 78% of R patients. The most common AEs were diarrhea (52% Vc-R, 8% R), nausea (29% Vc-R, 7% R), and pyrexia (25% Vc-R, 10% R). Most AEs were grade 1 or 2. Grade ≥3 AEs were reported in 46% of Vc-R and 21% of R patients; the most common grade ≥3 AEs were neutropenia (11% vs 4%) and diarrhea (7% vs 0%). Peripheral sensory neuropathy was reported in 17% of patients in the Vc-R arm vs 1% in the R arm; 3% vs 0% grade ≥3. 18% and 11% of Vc-R and R patients, respectively, had serious AEs, only 4% and 1% of patients discontinued due to drug-related AEs, and there were 9 and 4 on-treatment deaths, respectively.The addition of weekly Vc to R therapy in patients with relapsed FL was associated with statistically significant improvements in PFS, response rate, and time to next antilymphoma treatment, with acceptable additional toxicity.Coiffier: Johnson & Johnson: Honoraria. Off Label Use: Discussion of Velcade in NHL subtypes other than mantle cell lymphoma is included. Mayer:Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Rule:Johnson & Johnson: Consultancy, Speakers Bureau; Roche: Consultancy. Walewski:Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Investigators fee. Crump:Millennium Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy. Shpilberg:Johnson & Johnson: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Hermann:Millennium Pharmaceuticals: Research Funding. Parasuraman:Millennium Pharmaceuticals: Employment, Equity Ownership. Zhu:Johnson & Johnson: Employment. Enny:Johnson & Johnson: Employment, Equity Ownership. Theocharous:Johnson & Johnson: Employment. van de Velde:Johnson & Johson: Employment, Equity Ownership. Elsayed:Johnson & Johnson: Employment, Equity Ownership.

Abstract 857