pci-32765 and Multiple-Myeloma

Ibrutinib (Imbruvica™) is an irreversible, potent inhibitor of Bruton's tyrosine kinase (BTK). Over the last few years, ibrutinib has developed from a promising drug candidate to being approved by FDA for the treatment of three B cell malignancies, a truly remarkable feat. Few, if any medicines are monospecific and ibrutinib is no exception; already during ibrutinib's initial characterization, it was found that it could bind also to other kinases. In this review, we discuss the implications of such interactions, which go beyond the selective effect on BTK in B cell malignancies. In certain cases, the outcome of ibrutinib treatment likely results from the combined inhibition of BTK and other kinases, causing additive or synergistic, effects. Conversely, there are also examples when the clinical outcome seems unrelated to inhibition of BTK. Thus, more specifically, adverse effects such as enhanced bleeding or arrhythmias could potentially be explained by different interactions. We also predict that during long-term treatment bone homoeostasis might be affected due to the inhibition of osteoclasts. Moreover, the binding of ibrutinib to molecular targets other than BTK or effects on cells other than B cell-derived malignancies could be beneficial and result in new indications for clinical applications.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Atrial Fibrillation; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Mantle-Cell; Lymphoproliferative Disorders; Mice; Multiple Myeloma; Osteoclasts; Phosphorylation; Piperidines; Protein Binding; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Waldenstrom Macroglobulinemia

Ibrutinib (Imbruvica™) is a small molecule, first-in-class, once-daily, orally available, Bruton's tyrosine kinase inhibitor that is under development for the treatment of B cell malignancies, including chronic lymphocytic leukaemia (CLL), mantle cell lymphoma (MCL) and diffuse large B cell lymphoma (DLBCL), as well as multiple myeloma (MM), follicular lymphoma (FL) and Waldenstrom's macroglobulinemia (WM). It has been developed by Pharmacyclics, Inc. and Janssen Biotech, Inc. Ibrutinib acts by blocking B-cell antigen receptor signalling, thereby reducing malignant proliferation of B cells and inducing cell death. Based chiefly on findings from a phase Ib/II study, ibrutinib has been approved in the USA for the treatment of MCL in previously treated patients and is one of the first approvals through the US FDA's Breakthrough Therapy Designation Pathway. An application has been filed in the EU seeking regulatory approval in this indication. In both the USA and EU, further applications have been filed with regulatory bodies seeking approval for the use of ibrutinib in patients with previously treated CLL/small lymphocytic lymphoma (SLL). Phase III trials are underway worldwide to evaluate ibrutinib in the treatment of patients with CLL/SLL, DLBCL and MCL, and the agent is in phase II development for use in WM, FL and MM. This article summarizes the milestones in the development of ibrutinib leading to its first approval in MCL.

Topics: Adenine; Antineoplastic Agents; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Follicular; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Mantle-Cell; Multiple Myeloma; Piperidines; Pyrazoles; Pyrimidines; Waldenstrom Macroglobulinemia

We evaluated ibrutinib, a once-daily inhibitor of Bruton's tyrosine kinase, combined with bortezomib and dexamethasone in patients with relapsed or relapsed/refractory multiple myeloma who had received 1-3 prior therapies.. This was a phase 2, single-arm, open-label, multicentre study (NCT02902965). The primary endpoint was progression-free survival (PFS).. Seventy-six patients were enrolled; 74 received ≥1 dose of study treatment. After median follow-up of 19.6 months, median PFS was 8.5 months (95% CI: 6.2-10.8); median overall survival was not reached. Overall response rate was 57% (95% CI: 45-68), and median duration of response was 9.5 months (95% CI: 6.9-10.6). Grade 3/4 AEs occurred in 73% of patients and fatal AEs occurred in 15% of patients. Incidence of major haemorrhage was 5%; one patient died from cerebral haemorrhage. After an observed increased incidence of serious (42%) and fatal (11%) infections, enrolment was suspended to implement risk-minimisation measures. The safety profile was otherwise consistent with known safety profiles of the individual drugs.. Ibrutinib combined with bortezomib and dexamethasone elicited clinical responses. However, efficacy assessments conducted at potential restart of enrolment indicated that the targeted PFS could not be reached with additional patient enrolment, and the study was terminated.

Topics: Adenine; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Bortezomib; Dexamethasone; Drug Resistance, Neoplasm; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Multiple Myeloma; Neoplasm Staging; Piperidines; Prognosis; Recurrence; Retreatment; Treatment Outcome

Patients with multiple myeloma (MM) inevitably relapse on initial treatment regimens, and novel combination therapies are needed. Ibrutinib is a first-in-class, once-daily inhibitor of Bruton's tyrosine kinase, an enzyme implicated in growth and survival of MM cells. Preclinical data suggest supra-additivity or synergy between ibrutinib and proteasome inhibitors (PIs) against MM. This phase 1/2b study evaluated the efficacy and safety of ibrutinib plus the PI carfilzomib and dexamethasone in patients with relapsed/refractory MM (RRMM). In this final analysis, we report results in patients who received the recommended phase 2 dose (RP2D; ibrutinib 840 mg and carfilzomib 36 mg/m

Topics: Adenine; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone; Drug Resistance, Neoplasm; Female; Follow-Up Studies; Humans; Male; Middle Aged; Multiple Myeloma; Neoplasm Recurrence, Local; Oligopeptides; Piperidines; Prognosis; Pyrazoles; Pyrimidines; Salvage Therapy; Survival Rate

Novel therapies with unique new targets are needed for patients who are relapsed/refractory to current treatments for multiple myeloma. Ibrutinib is a first-in-class, once-daily, oral covalent inhibitor of Bruton tyrosine kinase, which is overexpressed in the myeloma stem cell population. This study examined various doses of ibrutinib ± low-dose dexamethasone in patients who received ≥2 prior lines of therapy, including an immunomodulatory agent. Daily ibrutinib ± weekly dexamethasone 40 mg was assessed in 4 cohorts using a Simon 2-stage design. The primary objective was clinical benefit rate (CBR; ≥minimal response); secondary objectives included safety. Patients (n = 92) received a median of 4 prior regimens. Ibrutinib + dexamethasone produced the highest CBR (28%) in Cohort 4 (840 mg + dexamethasone; n = 43), with median duration of 9·2 months (range, 3·0-14·7). Progression-free survival was 4·6 months (range, 0·4-17·3). Grade 3-4 haematological adverse events included anaemia (16%), thrombocytopenia (11%), and neutropenia (2%); grade 3-4 non-haematological adverse events included pneumonia (7%), syncope (3%) and urinary tract infection (3%). Ibrutinib + dexamethasone produced notable responses in this heavily pre-treated population. The encouraging efficacy, coupled with the favourable safety and tolerability profile of ibrutinib, supports its further evaluation as part of combination treatment.

Topics: Adenine; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone; Disease-Free Survival; Female; Humans; Male; Middle Aged; Multiple Myeloma; Piperidines; Pyrazoles; Pyrimidines; Recurrence; Survival Rate

This phase 1, dose-finding study investigated ibrutinib and carfilzomib ± dexamethasone in patients with relapsed or relapsed/refractory multiple myeloma (≥2 lines of therapy including bortezomib and an immunomodulatory agent). Of 43 patients enrolled, 74% were refractory to bortezomib and 23% had high-risk cytogenetics. No dose-limiting toxicities were observed. The recommended phase 2 dose was ibrutinib 840 mg and carfilzomib 36 mg/m

Topics: Adenine; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone; Diarrhea; Disease-Free Survival; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Fatigue; Female; Humans; Male; Middle Aged; Multiple Myeloma; Neoplasm Recurrence, Local; Oligopeptides; Outcome Assessment, Health Care; Piperidines; Pyrazoles; Pyrimidines

Multiple myeloma (MM) is a haematological B cell malignancy characterised by clonal proliferation of plasma cells and their accumulation in the bone marrow. The aim of the present study is the evaluation of biological effects of Ibrutinib in human MM cell lines alone or in combination with different doses of Bortezomib. In addition, the relationship between the expression of TRPML2 channels and chemosensitivity of different MM cell lines to Ibrutinib administered alone or in combination with Bortezomib has been evaluated. By RT-PCR and Western blot analysis, we found that the Ibrutinib-resistant U266 cells showed lower TRPML2 expression, whereas higher TRPML2 mRNA and protein levels were evidenced in RPMI cells. Moreover, TRPML2 gene silencing in RPMI cells markedly reverted the effects induced by Ibrutinib alone or in combination with Bortezomib suggesting that the sensitivity to Ibrutinib is TRPML2 mediated. In conclusion, this study suggests that the expression of TRPML2 in MM cells increases the sensitivity to Ibrutinib treatment, suggesting for a potential stratification of Ibrutinib sensitivity of MM patients on the basis of the TRPML2 expression. Furthermore, studies in vitro and in vivo should still be necessary to completely address the molecular mechanisms and the potential role of TRPML2 channels in therapy and prognosis of MM patients.

Topics: Adenine; Apoptosis; Bortezomib; Cell Line, Tumor; Cell Proliferation; Humans; Multiple Myeloma; Piperidines

The oncogenic microRNA-21 contributes to the pathogenesis of multiple myeloma. Ibrutinib (also referred to as PCI-32765), an inhibitor of Bruton's tyrosine kinase, while its effects on multiple myeloma have not been well described. Here, we show that microRNA-21 is an oncogenic marker closely linked with progression of multiple myeloma. Moreover, ibrutinib attenuates microRNA-21 expression in multiple myeloma cells by inhibiting nuclear factor-κB and signal transducer and activator of transcription 3 signaling pathways. Taken together, our results suggest that ibrutinib is a promising potential treatment for multiple myeloma. Further investigation of mechanisms of ibrutinib function in multiple myeloma will be necessary to evaluate its use as a novel multiple myeloma treatment.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Aged; Cell Line, Tumor; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; Male; MicroRNAs; Middle Aged; Multiple Myeloma; NF-kappa B; Piperidines; Promoter Regions, Genetic; Protein Binding; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; STAT3 Transcription Factor

Topics: Adenine; Humans; Multiple Myeloma; Oligopeptides; Piperidines; Pyrazoles; Pyrimidines

Topics: ADAMTS13 Protein; Adenine; Antibodies, Monoclonal; Antineoplastic Agents; Central Venous Catheters; fms-Like Tyrosine Kinase 3; Genetic Therapy; Graft vs Host Disease; Hematologic Diseases; Hemophilia B; Humans; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid, Acute; Multiple Myeloma; Mutation; Piperidines; Protein Kinase Inhibitors; Purpura, Thrombotic Thrombocytopenic; Pyrazoles; Pyrimidines; Recombinant Proteins; Societies, Medical; Thrombosis

Multiple Myeloma (MM) is a haematologic malignancy characterized by the accumulation of clonal plasma cells in the bone marrow. Over the last 10-15 y the introduction of the proteasome-inhibitor bortezomib has improved MM prognosis, however relapse due to bortezomib-resistance is inevitable and the disease, at present, remains incurable. To model bortezomib-resistant MM we generated bortezomib-resistant MM cell lines (n = 4 ) and utilised primary malignant plasma cells from patients relapsing after bortezomib treatment (n = 6 ). We identified enhanced Bruton's tyrosine kinase (BTK) activity in bortezomib-resistant MM cells and found that inhibition of BTK, either pharmacologically with ibrutinib (0.5 μM) or via lenti-viral miRNA-targeted BTK interference, re-sensitized previously bortezomib-resistant MM cells to further bortezomib therapy at a physiologically relevant concentration (5 nM). Further analysis of pro-survival signaling revealed a role for the NF-κB p65 subunit in MM bortezomib-resistance, thus a combination of BTK and NF-κB p65 inhibition, either pharmacologically or via further lenti-viral miRNA NF-κB p65 interference, also restored sensitivity to bortezomib, significantly reducing cell viability (37.5 ± 6 .9 %, ANOVA P ≤ 0 .001). Accordingly, we propose the clinical evaluation of a bortezomib/ibrutinib combination therapy, including in patients resistant to single-agent bortezomib.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Bortezomib; Cell Survival; Drug Resistance, Neoplasm; Humans; Immunohistochemistry; MicroRNAs; Multiple Myeloma; Neoplasm Recurrence, Local; Piperidines; Proteasome Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Real-Time Polymerase Chain Reaction; RNA Interference; Signal Transduction; Transcription Factor RelA; Tumor Cells, Cultured

Ibrutinib (Imbruvica), a small-drug inhibitor of Bruton tyrosine kinase (BTK), is currently undergoing clinical testing in patients with multiple myeloma, yet important questions on the role of BTK in myeloma biology and treatment are outstanding. Using flow-sorted side population cells from human myeloma cell lines and multiple myeloma primary samples as surrogate for the elusive multiple myeloma stem cell, we found that elevated expression of BTK in myeloma cells leads to AKT/WNT/β-catenin-dependent upregulation of key stemness genes (OCT4, SOX2, NANOG, and MYC) and enhanced self-renewal. Enforced transgenic expression of BTK in myeloma cells increased features of cancer stemness, including clonogenicity and resistance to widely used myeloma drugs, whereas inducible knockdown of BTK abolished them. Furthermore, overexpression of BTK in myeloma cells promoted tumor growth in laboratory mice and rendered side population-derived tumors that contained high levels of BTK more sensitive to the selective, second-generation BTK inhibitor, CGI1746, than side population-derived tumors that harbored low levels of BTK. Taken together, these findings implicate BTK as a positive regulator of myeloma stemness and provide additional support for the clinical testing of BTK-targeted therapies in patients with myeloma.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Antineoplastic Agents; beta Catenin; Bone Marrow Cells; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Humans; Lentivirus; Mice; Multiple Myeloma; Neoplastic Stem Cells; Piperidines; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Side-Population Cells; Signal Transduction

Proteasome-inhibiting drugs (PI) are gaining importance in hematologic oncology. The proteasome carries three proteolytically active subunits (β1, β2, β5). All established PI (bortezomib and carfilzomib), as well as experimental drugs in the field (dalanzomib, oprozomib, and ixazomib), by design target the rate-limiting β5 subunit. It is unknown whether β2-selective proteasome inhibition can also be exploited toward anticancer treatment. Combining PI with the pan B-cell-directed Bruton tyrosine kinase inhibitor ibrutinib appears a natural option for future improved treatment of multiple myeloma (MM) and B-cell lymphomas. However, bortezomib induces phosphorylation of IκB and activation of NF-κB in MM cells, while ibrutinib inhibits the IκB/NF-κB axis, suggesting antagonistic signaling. A β2-selective proteasome inhibitor may lack such antagonistic signaling effects.. We recently introduced LU-102, the first β2-selective PI available for preclinical testing. We here compare bortezomib with carfilzomib and LU-102 in MM and MCL in vitro with regard to their effects on pIκB/NF-κB signaling and their cytotoxic activity in combination with ibrutinib.. LU-102 reduced phosphorylation of IκB, in contrast to bortezomib and carfilzomib, and was a superior inhibitor of NF-κB activation in MM cells. This translated into highly synergistic cytotoxicity between LU-102 and ibrutinib, which was able to overcome BTZ resistance and CFZ resistance. By contrast, BTZ lacked consistent synergistic cytotoxicity with ibrutinib.. Ibrutinib is highly synergistic with β2-selective proteasome inhibition against MM and MCL in vitro. Novel β2-selective proteasome inhibitors may be exploited to overcome bortezomib/carfilzomib resistance and boost the activity of BTK inhibitors against B-cell-derived malignancies.

Topics: Adenine; Antineoplastic Agents; Boronic Acids; Bortezomib; Cell Line, Tumor; Drug Resistance, Neoplasm; Drug Synergism; Humans; I-kappa B Proteins; Lymphoma, Mantle-Cell; Multiple Myeloma; Oligopeptides; Phosphorylation; Piperidines; Proteasome Inhibitors; Pyrazines; Pyrazoles; Pyrimidines

To investigate the proliferation inhibitory role and mechanism of PI3Kδ inhibitor CAL-101 on multiple myeloma (MM) cells, and to provide new therapeutic options for MM treatment.. MM cell lines U266 and RPMI8226 cells were treated with various concentrations of CAL-101. MTT assay and CalcuSyn software were performed to determine the inhibitory effect of CAL-101 and the synergistic effect with PCI- 32765, SAHA (suberoylanilide hydroxamic acid), BTZ (Bortezomib) on MM cells. The protein expression level of p-AKT, p-ERK, AKT, ERK and PI3Kδ processed by CAL-101 were analyzed by Western blot.. CAL-101 at concentration of 15, 20, 25, 30 and 40 μmol/L could induce significant dose-dependent proliferation inhibition on U266 cells after treatment for 48 hours. The cell proliferation inhibition rates were (33.54 ± 1.23)%, (41.72 ± 1.78)%, (53.67 ± 2.01)%, (68.97 ± 2.11)% and (79.25 ± 1.92)%, respectively. Similar results were found in RPMI8226 cell line. Western blots showed high expression level of p-AKT, p-ERK, AKT, ERK and PI3Kδ in cell lines and MM primary cells. p-AKT and p-ERK protein expression levels were down-regulated significantly by CAL-101 treatment. Synergistic effect has been verified between CAL-101 and PCI-32765, SAHA and Bortezomib in U266 cell line, and PCI-32765, Bortezomib in RPMI8226 cell line with CI values less than 1.. CAL-101 could inhibit proliferation of MM cell lines. High levels of p-AKT, p-ERK, AKT, ERK and PI3Kδ protein expression were observed in both cell lines and primary cells. Down-regulation of p-AKT and p-ERK probably related with the mechanism of CAL-101 in MM cell proliferation inhibition. CAL-101 has significant synergistic effect with PCI-32765, SAHA and BTZ.

Topics: Adenine; Boronic Acids; Bortezomib; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Humans; Multiple Myeloma; Phosphoinositide-3 Kinase Inhibitors; Piperidines; Protein Kinase Inhibitors; Purines; Pyrazines; Pyrazoles; Pyrimidines; Quinazolinones

Ibrutinib (previously known as PCI-32765) has recently shown encouraging clinical activity in chronic lymphocytic leukaemia (CLL) effecting cell death through inhibition of Bruton's tyrosine kinase (BTK). In this study we report for the first time that ibrutinib is cytotoxic to malignant plasma cells from patients with multiple myeloma (MM) and furthermore that treatment with ibrutinib significantly augments the cytotoxic activity of bortezomib and lenalidomide chemotherapies. We describe that the cytotoxicity of ibrutinib in MM is mediated via an inhibitory effect on the nuclear factor-κB (NF-κB) pathway. Specifically, ibrutinib blocks the phosphorylation of serine-536 of the p65 subunit of NF-κB, preventing its nuclear translocation, resulting in down-regulation of anti-apoptotic proteins Bcl-xL, FLIP(L) and survivin and culminating in caspase-mediated apoptosis within the malignant plasma cells. Taken together these data provide a platform for clinical trials of ibrutinib in myeloma and a rationale for its use in combination therapy, particularly with bortezomib.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Amides; Antineoplastic Agents; Boronic Acids; Bortezomib; Caspases; Cell Survival; Humans; I-kappa B Proteins; Lenalidomide; Multiple Myeloma; NF-kappa B; NF-KappaB Inhibitor alpha; Nitriles; Phosphorylation; Piperidines; Protein-Tyrosine Kinases; Pyrazines; Pyrazoles; Pyrimidines; RNA, Messenger; Signal Transduction; Thalidomide; Tumor Cells, Cultured

Bruton tyrosine kinase (Btk) has a well-defined role in B-cell development, whereas its expression in osteoclasts (OCs) further suggests a role in osteoclastogenesis. Here we investigated effects of PCI-32765, an oral and selective Btk inhibitor, on osteoclastogenesis as well as on multiple myeloma (MM) growth within the BM microenvironment. PCI-32765 blocked RANKL/M-CSF-induced phosphorylation of Btk and downstream PLC-γ2 in OCs, resulting in diminished TRAP5b (ED50 = 17 nM) and bone resorption activity. PCI-32765 also inhibited secretion of multiple cytokines and chemokines from OC and BM stromal cell cultures from both normal donors (ED50 = 0.5 nM) and MM patients. It decreased SDF-1-induced migration of MM cells, and down-regulated MIP1-α/CCL3 in MM cells. It also blocked MM cell growth and survival triggered by IL-6 or coculture with BM stromal cells or OCs in vitro. Importantly, PCI-32765 treatment significantly inhibits in vivo MM cell growth (P < .03) and MM cell-induced osteolysis of implanted human bone chips in SCID mice. Moreover, PCI-32765 prevents in vitro colony formation by stem-like cells from MM patients. Together, these results delineate functional sequelae of Btk activation mediating osteolysis and growth of MM cells, supporting evaluation of PCI-32765 as a novel therapeutic in MM.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Bone Marrow; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chemokines; Coculture Techniques; Cytokines; Down-Regulation; Gene Expression; Humans; Immunoblotting; Mice; Mice, SCID; Multiple Myeloma; Osteoclasts; Osteolysis; Piperidines; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Reverse Transcriptase Polymerase Chain Reaction; Stromal Cells; Tumor Microenvironment; Xenograft Model Antitumor Assays

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Bone Marrow; Humans; Multiple Myeloma; Piperidines; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines

Our findings therefore provide a strong rationale for investigating Btk inhibitors in MM and WM to target both tumor cells and their supporting BM microenvironment and thereby both suppress tumor cell growth and abrogate MM-induced bone disease.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Cell Growth Processes; Disease Models, Animal; Humans; Mice; Molecular Targeted Therapy; Multiple Myeloma; Piperidines; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Waldenstrom Macroglobulinemia