A phase 1/2a safety, pharmacokinetics, and efficacy study of the novel nucleoside analog FF-10502-01 for the treatment of advanced solid tumors.

BACKGROUND: The nucleoside FF-10502-01, structurally similar to but with different biologic effects than gemcitabine, shows promising activity both alone and combined with cisplatin in preclinical gemcitabine-resistant tumor models. We conducted an open-label, single-arm, 3 + 3 first-in-human trial to explore the safety, tolerability, and antitumor activity of FF-10502-01 in patients with solid tumors. METHODS: Patients with inoperable metastatic tumors refractory to standard therapies were enrolled. Escalating intravenous FF-10502-01 doses (8-135 mg/m2 ) were administered weekly for 3 weeks in 28-day cycles until progressive disease or unacceptable toxicity was observed. Three expansion cohorts were subsequently evaluated. RESULTS: A phase 2 dose of 90 mg/m2 was determined after evaluating 40 patients. Dose-limiting toxicities included hypotension and nausea. Phase 2a enrolled patients with cholangiocarcinoma (36), gallbladder cancer (10), and pancreatic/other tumors (20). Common adverse events were grade 1-2 rash, pruritus, fever, and fatigue. Grade 3 or 4 hematologic toxicities were observed at low incidences, including thrombocytopenia (5.1%) and neutropenia (2%). Confirmed partial responses (PRs) occurred in five patients with gemcitabine-refractory tumors, including three with cholangiocarcinoma and one each with gallbladder and urothelial cancer. Median progression-free and overall survival rates in patients with cholangiocarcinoma were 24.7 and 39.1 weeks, respectively. Prolonged progression-free survival in patients with cholangiocarcinoma was associated with BAP1 and PBRM1 mutations. CONCLUSION: FF-10502-01 was well tolerated with manageable side effects and limited hematologic toxicity. Durable PRs and disease stabilizations were observed in heavily pretreated biliary tract patients who had received prior gemcitabine. FF-10502-01 is distinct from gemcitabine and may represent an effective therapy.

Numerical investigation of pulsed gas amplifiers operating in hollow-core optical fibers.

Optically pumped molecular gas amplifiers having a gain medium contained in a hollow-core optical fiber are investigated with numerical modeling to understand the primary physical processes that affect amplifier output and efficiency. A comparison of computational results with experimental measurements of incident pump, absorbed pump, and emitted mid-IR from a pulsed, acetylene-filled, hollow-core fiber amplifier [ Opt. Exp.25, 13351 (2017)] is used to explore the effects of various physical processes on pulsed amplifier operation. Single frequency, one-dimensional, time-dependent models are shown to align with experimentally measured lasing thresholds and ratios of absorbed pump to emitted laser energy but significantly over predict the amount of incident pump energy that is absorbed. A two-dimensional, time-dependent model that assumes Gaussian spectral and radial intensity profiles for the pump is developed and shows an improved ability to capture pump absorption. Results indicate that 1D, time-dependent models have utility in guiding experiments but the significant influence of the pump and laser propagation modes and the pump spectral characteristics on efficiency, threshold, and signal output must be explicitly included in high-fidelity high-power modeling.

Theoretical and numerical treatment of modal instability in high-power core and cladding-pumped Raman fiber amplifiers.

Raman fiber lasers have been proposed as potential candidates for scaling beyond the power limitations imposed on near diffraction-limited rare-earth doped fiber lasers. One limitation is the modal instability (MI) and we explore the physics of this phenomenon in Raman fiber amplifiers (RFAs). By utilizing the conservation of number of photons and conservation of energy in the absence of loss, the 3 × 3 governing system of nonlinear equations describing the pump and the signal modal content are decoupled and solved analytically for cladding-pumped RFAs. By comparing the extracted signal at MI threshold for the same step index-fiber, it is found that the MI threshold is independent of the length of the amplifier or whether the amplifier is co-pumped or counter-pumped; dictated by the integrated heat load along the length of fiber. We extend our treatment to gain-tailored RFAs and show that this approach is of limited utility in suppressing MI. Finally, we formulate the physics of MI in core-pumped RFAs where both pump and signal interferences participate in writing the time-dependent index of refraction grating.

Targeting the insulin-like growth factor-1 receptor to overcome bortezomib resistance in preclinical models of multiple myeloma.

Proteasome inhibition with bortezomib is a validated approach to the treatment of multiple myeloma, but drug resistance often emerges and limits its utility in the retreatment setting. To begin to identify some of the mechanisms involved, we developed bortezomib-resistant myeloma cell lines that, unlike previously reported models, showed no ß5 subunit mutations. Instead, up-regulation of the insulin-like growth factor (IGF)-1 axis was identified, with increased autocrine and paracrine secretion of IGF-1, leading to increased activation of the IGF-1 receptor (IGF-1R). Exogenous IGF-1 reduced cellular sensitivity to bortezomib, whereas pharmacologic or small hairpin RNA-mediated IGF-1R suppression enhanced bortezomib sensitivity in cell lines and patient samples. In vitro studies with OSI-906, a clinically relevant dual IGF-1R and insulin receptor inhibitor, showed it acted synergistically with bortezomib, and potently resensitized bortezomib-resistant cell lines and patient samples to bortezomib. Importantly, OSI-906 in combination with bortezomib also overcame bortezomib resistance in an in vivo model of myeloma. Taken together, these data support the hypothesis that signaling through the IGF-1/IGF-1R axis contributes to acquired bortezomib resistance, and provide a rationale for combining bortezomib with IGF-1R inhibitors like OSI-906 to overcome or possibly prevent the emergence of bortezomib-refractory disease in the clinic.

Pilot study to assess toxicity and pharmacokinetics of docetaxel in patients with metastatic breast cancer and impaired liver function secondary to hepatic metastases.

BACKGROUND: Limited clinical data are available regarding the safety of docetaxel in metastatic breast cancer patients with liver dysfunction. METHODS: Eligible patients had breast cancer with impaired liver function secondary to hepatic metastases and were candidates for docetaxel therapy. They were assigned to one of five groups on the basis of total bilirubin, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels. All other causes of liver dysfunction were excluded, and bile duct obstruction was corrected, if possible, prior to study entry. Patients received docetaxel every three weeks. The chemotherapy dose was chosen on the basis of the patient's level of hepatic dysfunction and escalated as tolerated. The primary outcome of this study was safety. The secondary outcomes were pharmacokinetic data and efficacy in terms of time to disease progression. RESULTS: Twenty-three patients were enrolled. No unexpected toxicities occurred. Grade 3/4 fatigue (65%), neutropenia (30%), myalgias (26%), neutropenic fever (26%), vomiting (9%), and rash (9%) were the most common serious adverse events. The median time to progression was three months (range 1-18 months). Pharmacokinetic results indicated that patients with more severe hepatic dysfunction may have been underdosed based on our conservative dosing strategy. CONCLUSIONS: Docetaxel can be administered to patients with metastatic breast cancer and liver dysfunction after dose attenuation. However, because of a narrow therapeutic index in this clinical setting, therapy should be closely monitored with subsequent dose escalation when possible.

Diffuse bone marrow sarcoid-like reaction associated with renal cell carcinoma.

Sarcoid-like reaction has been documented in association with several types of malignancy, including renal cell carcinoma. We report the case of a 41-year-old man with nonmetastatic renal cell carcinoma and concomitant non-caseating granulomas distributed diffusely throughout the bone marrow. The granulomas resolved after nephrectomy. As far as we know, this is the first reported case of a sarcoid-like reaction primarily involving the bone marrow in association with renal cell carcinoma.

A phase 1 study of the irreversible FLT3 inhibitor FF-10101 in relapsed or refractory acute myeloid leukemia.

ABSTRACT: FLT3 tyrosine kinase inhibitors (TKIs) have clinical efficacy for patients with FLT3-mutated AML (acute myeloid leukemia), but their impact is limited by resistance in the setting of monotherapy and by tolerability problems when used in combination therapies. FF-10101 is a novel compound that covalently binds to a cysteine residue near the active site of FLT3, irreversibly inhibiting receptor signaling. It is effective against most FLT3 activating mutations, and, unlike other inhibitors, is minimally vulnerable to resistance induced by FLT3 ligand. We conducted a phase 1 dose escalation study of oral FF-10101 in patients with relapsed and/or refractory AML, the majority of whom harbored FLT3-activating mutations and/or had prior exposure to FLT3 inhibitors. Fifty-four participants enrolled in cohorts receiving doses ranging from 10 to 225 mg per day and 50 to 100 mg twice daily (BID). The dose limiting toxicities were diarrhea and QT prolongation. Among 40 response-evaluable participants, the composite complete response rate was 10%, and the overall response rate (including partial responses) was 12.5%, including patients who had progressed on gilteritinib. Overall, 56% of participants had prior exposure to FLT3 inhibitors. The recommended phase 2 dose was 75 mg BID. FF-10101 potentially represents a next-generation advance in the management of FLT3-mutated AML. This trial was registered at www.ClinicalTrials.gov as #NCT03194685.

Investigations of modal instabilities in fiber amplifiers through detailed numerical simulations.

We present detailed numerical simulations of modal instabilities in high-power Yb-doped fiber amplifiers using a time-dependent temperature solver coupled to the optical fields and population inversion equations. The temperature is computed by solving the heat equation in polar coordinates using a 2D second-order alternating direction implicit method. We show that the higher-order modal content rises dramatically in the vicinity of the threshold and we recover the three power-dependent regions that are characteristic of the transfer of energy. We also investigate the dependence of the threshold on the seed power and the modal content ratio of the seed. The latter has a minimal effect on the threshold while it is shown that for the fiber configuration investigated, the modal instability threshold scales linearly over a wide range with the seed power. In addition, two different gain-tailored core designs are investigated and are shown to have higher thresholds than that of a uniformly doped core. Finally, we show that this full time-dependent model which does not assume a frequency offset between the modes a priori, predicts a reduced threshold when the seed is modulated at the KHz level. This is in agreement with the steady-periodic approach to this phenomenon.

Induction of cell-cycle arrest and apoptosis in glioblastoma stem-like cells by WP1193, a novel small molecule inhibitor of the JAK2/STAT3 pathway.

Glioma stem-like cells (GSCs) may be the initiating cells in glioblastoma (GBM) and contribute to the resistance of these tumors to conventional therapies. Development of novel chemotherapeutic agents and treatment approaches against GBM, especially those specifically targeting GSCs are thus necessary. In the present study, we found that a novel Janus kinase 2/Signal Transducer and Activator of Transcription 3 (JAK2/STAT3) pathway inhibitor (WP1193) significantly decreased the proliferation of established glioma cell lines in vitro and inhibit the growth of glioma in vivo. To test the efficacy of WP1193 against GSCs, we then administrated WP1193 to GSCs isolated and expanded from multiple human GBM tumors. We revealed that WP1193 suppressed phosphorylation of JAK2 and STAT3 with high potency and demonstrated a dose-dependent inhibition of proliferation and neurosphere formation of GSCs. These effects were at least due in part to G1 arrest associated with down-regulation of cyclin D1 and up-regulation of p21( Cip1/Waf-1 ). Furthermore, WP1193 exposure decreased expression of stem cell markers including CD133 and c-myc, and induced cell death in GSCs through apoptosis. Taken together, our data indicate that WP1193 is a potent small molecule inhibitor of the JAK2/STAT3 pathway that shows promise as a therapeutic agent against GBM by targeting GSCs.

Intravenous busulfan plus melphalan is a highly effective, well-tolerated preparative regimen for autologous stem cell transplantation in patients with advanced lymphoid malignancies.

We investigated the administration of intravenous (i.v.) busulfan (Bu) combined with melphalan (Mel) in patients with advanced lymphoid malignancies undergoing autologous stem cell transplantation. Bu 130 mg/m(2) was infused daily for 4 days, either as a fixed dose per body surface area (BSA), or to target an average daily area under the curve of 5000 µmol-min, determined by a test dose of i.v. Bu at 32 mg/m(2) given 48 hours prior to the high-dose regimen, followed by a rest day, followed by 2 daily doses of Mel at 70 mg/m(2). Stem cells were infused the following day. Eighty patients had i.v. Bu delivered per test dose guidance. The median daily systemic Bu exposure was 4867 µmol-min. One hundred two patients (Hodgkin lymphoma n = 49, non-Hodgkin lymphoma n = 12, multiple myeloma = 41) with a median age of 44 years (range: 19-65 years) were treated. The 2-year overall survival and progression-free survival rates were 85% and 57%, respectively, for patients with Hodgkin lymphoma, 67% and 64%, respectively, for patients with non-Hodgkin lymphoma, and 82% and 42%, respectively, for patients with multiple myeloma. The regimen was very well tolerated with treatment-related mortality at 100 days, 1 year, and 2 years of 1%, 3%, and 3%, respectively. Intravenous Bu-Mel was well tolerated. Disease control wa encouraging, and should be explored in larger phase II studies.

Clofarabine ± fludarabine with once daily i.v. busulfan as pretransplant conditioning therapy for advanced myeloid leukemia and MDS.

Although a combination of i.v. busulfan (Bu) and fludarabine (Flu) is a safe, reduced-toxicity conditioning program for acute myelogenous leukemia/myelodysplastic syndromes (AML/MDS), recurrent leukemia posttransplantation remains a problem. To enhance the conditioning regimen's antileukemic effect, we decided to supplant Flu with clofarabine (Clo), and assayed the interactions of these nucleoside analogs alone and in combination with Bu in Bu-resistant human cell lines in vitro. We found pronounced synergy between each nucleoside and the alkylator but even more enhanced cytotoxic synergy when the nucleoside analogs were combined prior to exposing the cells to Bu. We then designed a 4-arm clinical trial in patients with myeloid leukemia undergoing allogeneic stem cell transplantation (allo-SCT). Patients were adaptively randomized as follows: Arm I-Clo:Flu 10:30 mg/m(2), Arm II-20:20 mg/m(2), Arm III-30:10 mg/m(2), and Arm IV-single-agent Clo at 40 mg/m(2). The nucleoside analog(s) were/was infused over 1 hour once daily for 4 days, followed on each day by Bu, infused over 3 hours to a pharmacokinetically targeted daily area under the curve (AUC) of 6000 µMol-min ± 10%. Fifty-one patients have been enrolled with a minimum follow-up exceeding 100 days. There were 32 males and 19 females, with a median age of 45 years (range: 6-59). Nine patients had chronic myeloid leukemia (CML) (BC: 2, second AP: 3, and tyrosine-kinase inhibitor refractory first chronic phase [CP]: 4). Forty-two patients had AML: 14 were induction failures, 8 in first chemotherapy-refractory relapse, 7 in untreated relapse, 3 in second or subsequent relapse, 4 were in second complete remission (CR), and 3 in second CR without platelet recovery (CRp), 2 were in high-risk CR1. Finally, 1 patient was in first CRp. Graft-versus-host disease (GVHD) prophylaxis was tacrolimus and mini-methorexate (MTX), and those who had an unrelated or 1 antigen-mismatched donor received low-dose rabbit-ATG (Thymoglobulin™). All patients engrafted. Forty-one patients had active leukemia at the time of transplant, and 35 achieved CR (85%). Twenty of the 42 AML patients and 5 of 9 CML patients are alive with a projected median overall survival (OS) of 23 months. Marrow and blood (T cell) chimerism studies at day +100 revealed that both in the lower-dose Clo groups (groups 1+2) and the higher-dose Clo groups (groups 3+4), the patients had a median of 100% donor (T cell)-derived DNA. There has been no secondary graft failure. In the first 100 days, 1 patient died of pneumonia, and 1 of liver GVHD. We conclude that (1) Clo ± Flu with i.v. Bu as pretransplant conditioning is safe in high-risk myeloid leukemia patients; (2) clofarabine is sufficiently immunosuppressive to support allo-SCT in myeloid leukemia; and (3) the median OS of 23 months in this high-risk patient population is encouraging. Additional studies to evaluate the antileukemic efficacy of Clo ± Flu with i.v. Bu as pretransplant conditioning therapy are warranted.

A phase I study of vorinostat in combination with idarubicin in relapsed or refractory leukaemia.

Histone deacetylase inhibitors (HDACi) affect chromatin remodelling and modulate the expression of aberrantly silenced genes. HDACi have single-agent clinical activity in haematological malignancies and have synergistic anti-leukaemia activity when combined with anthracyclines in vitro. We conducted a two-arm, parallel Phase I trial to investigate two schedules of escalating doses of vorinostat (Schedule A: thrice daily (TID) for 14 d; B: TID for 3 d) in combination with a fixed dose of idarubicin in patients with refractory leukaemia. Of the 41 patients enrolled, 90% had acute myeloid leukaemia, with a median of 3 prior therapies. Seven responses (17%) were documented (two complete response (5%), one complete response without platelet recovery (2.5%), and four marrow responses). The 3-d schedule of vorinostat was better tolerated than the 14-d schedule. The maximum tolerated dose for vorinostat was defined as 400 mg TID for 3 d. The most common grade 3 and 4 toxicities included mucositis, fatigue and diarrhoea. Correlative studies demonstrated histone acetylation in patients on therapy and modulation of CDKN1A and TOP2A (topoisomerase II) gene expression. Pharmacokinetic analysis confirmed a dose-related elevation in plasma vorinostat concentrations. The combination of vorinostat and idarubicin is generally tolerable and active in patients with advanced leukaemia and should be studied in the front-line setting.

Phase I Study of P-cadherin-targeted Radioimmunotherapy with 90Y-FF-21101 Monoclonal Antibody in Solid Tumors.

PURPOSE: 90Y-FF-21101 is an Yttrium-90-conjugated, chimeric mAb that is highly specific for binding to human placental (P)-cadherin, a cell-to-cell adhesion molecule overexpressed and associated with cancer invasion and metastatic dissemination in many cancer types. We report the clinical activity of 90Y-FF-21101 in a first-in-human phase I study in patients with advanced solid tumors. PATIENTS AND METHODS: The safety and efficacy of 90Y-FF-21101 were evaluated in a phase I 3+3 dose-escalation study in patients with advanced solid tumors (n = 15) over a dose range of 5-25 mCi/m2. Dosimetry using 111In-FF-21101 was performed 1 week prior to assess radiation doses to critical organs. Patients who demonstrated clinical benefit received repeated 90Y-FF-21101 administration every 4 months. RESULTS: 111In-FF-21101 uptake was observed primarily in the spleen, kidneys, testes, lungs, and liver, with tumor uptake observed in the majority of patients. Organ dose estimates for all patients were below applicable limits. P-cadherin expression H-scores ranged from 0 to 242 with 40% of samples exhibiting scores ≥100. FF-21101 protein pharmacokinetics were linear with increasing antibody dose, and the mean half-life was 69.7 (±12.1) hours. Radioactivity clearance paralleled antibody clearance. A complete clinical response was observed in a patient with clear cell ovarian carcinoma, correlating with a high tumor P-cadherin expression. Stable disease was observed in a variety of other tumor types, without dose-limiting toxicity. CONCLUSIONS: The favorable safety profile and initial antitumor activity observed for 90Y-FF-21101 warrant further evaluation of this radioimmunotherapeutic (RIT) approach and provide initial clinical data supporting P-cadherin as a potential target for cancer treatment.

Reduced-toxicity conditioning therapy with allogeneic stem cell transplantation for acute leukemia.

We hypothesized that standardized systemic drug delivery would improve treatment safety and provide better leukemia control. We therefore developed an intravenous busulfan formulation and combined it with fludarabine instead of cyclophosphamide in preparation for allogeneic stem cell transplantation (alloSCT). We used a Bayesian method to compare the outcomes of 67 acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) patients who received intravenous busulfan-cyclophosphamide (BuCy2) with 148 subsequent AML/MDS patients who received busulfan-fludarabine (Bu-Flu). The groups had comparable pretreatment characteristics, except that the Bu-Flu patients were older, more often had unrelated donors and had a shorter follow-up. A greatly improved outcome in the Bu-Flu group is unlikely to be explained by improved supportive care during this time period. Overall, the data support replacing BuCy2 with or without antithymocyte globulin (ATG) with Bu-Flu with or without rabbit-ATG for AML or MDS. We further suggest that the high level of safety and fast recovery from conditioning therapy-related side effects after the Bu-Flu regimen makes it a suitable platform technology for testing additional adjuncts for improved posttransplant immune recovery and long-term disease control in patients who are at high risk of rapidly recurrent disease after alloSCT. The extremely low one-year treatment-related mortality as well as high overall and event-free survival of patients in the Bu-Flu group indicate that it is time to revisit the value of alloSCT compared with conventional maintenance chemotherapy for patients in first complete remission of AML/MDS.

Therapeutic suppression of constitutive and inducible JAK\STAT activation in head and neck squamous cell carcinoma.

The oncogenic role of STAT3 has been elucidated in a number of human malignancies including leukemia, lymphoma, malignant glioma and cancers of the breast, lung, and head and neck (HNSCC). Here we show that WP1066 has profound anti-neoplastic effects in HNSCC, mediated in part by suppression of JAK2-STAT3 signaling. WP1066 inhibited constitutive and inducible STAT3 phosphorylation in both dose- and time-dependant manners. Further, the nuclear translocation of STAT3 was completely inhibited, resulting in decreased DNA binding activity. In vivo testing of WP1066 in a nude mouse orthotopic model of HNSCC demonstrated significant anti-tumor effects, with histological evidence of decreased cellular proliferation and angiogenesis. Collectively, these data suggest that WP1066 suppresses squamous cell carcinoma cell growth, in part through its effects on JAK-STAT pathways, and establishes this small molecule as potentially efficacious agent in the treatment of HNSCC.

Phase II evaluation of intravenous vinorelbine (Navelbine) in recurrent or refractory pediatric malignancies: a Children's Oncology Group study.

BACKGROUND: A Phase II trial was developed to determine the efficacy and toxicity of intravenous vinorelbine, a semi-synthetic vinca alkaloid, in children, adolescent, and young adults with recurrent or refractory solid malignancies. PROCEDURES: Fifty patients were enrolled among three strata: soft tissue sarcomas [rhabdomyosarcoma (RMS), non-rhabdomyosarcoma, primitive neuroepithelial tumor] (20 patients); brain tumors [astrocytoma (4 patients), medulloblastoma (2 patients), other (16 patients)] (22 patients); neuroblastoma (8 patients). Vinorelbine was given weekly for 6 consecutive weeks during an 8-week interval. The response rate and toxicity profile was assessed. RESULTS: Among the first 35 patients treated at 33.75 mg/m(2)/dose, 25 experienced grades 3-4 neutropenia (75%). The dose was decreased to 30 mg/m(2)/dose in the remaining 15 patients. The median age was 10 years (range, 1-25). Four responses (one complete, three partial) occurred within the soft tissue sarcoma strata (all with RMS) and two occurred in the brain tumor group (medulloblastoma and astrocytoma). The most common toxicities were hematological and neurological. CONCLUSION: Vinorelbine at dose of 30 mg/m(2) can be safely administered to children with recurrent or refractory solid malignancies. The study design identified vinorelbine to be active in the sarcoma category, with a response rate of 36% (4/11) among RMS patients.

Exploring home allodynia testing for future clinical and scientific uses.

Allodynia, a painful response to a usually nonpainful stimulus, is common in chronic migraine. The evaluation of allodynia can be important clinically. Dynamic mechanical allodynia (brush) testing has been shown to be both a simple and reliable way to evaluate allodynia. In this study, we show that self-administered brush allodynia testing at home is a feasible means of evaluating and recording allodynia in relationship to chronic migraine.

Phase I/II study of G3139 (Bcl-2 antisense oligonucleotide) in combination with doxorubicin and docetaxel in breast cancer.

PURPOSE: Preclinical data showed enhancement of breast cancer cell death when G3139 was combined with anthracyclines and taxanes. We evaluated the efficacy and safety of a Bcl-2 antisense oligonucleotide, G3139, in combination with doxorubicin (A) and docetaxel (T) in patients with locally advanced breast cancer (LABC). EXPERIMENTAL DESIGN: Following a brief phase I to determine the phase II dose, patients with locally advanced breast cancer received G3139 administered by continuous i.v. infusion for 5 to 7 days with bolus A (50 mg/m2) and T (75 mg/m2) administered on either day 3 or 6 of therapy with G3139. Cycles were repeated every 21 days x 6 in the neoadjuvant setting. Serial plasma samples were obtained for pharmacokinetic analysis. Tissue samples were obtained before and after therapy for pharmacodynamic analysis of Bcl-2 expression. RESULTS: Thirty patients (median age, 49 years; range, 24-71 years) received 160 cycles. During the phase I portion of the trial, the dose of G3139 was escalated from 3 to 7 mg/kg/d (i.v. for 5 days) in combination with AT. During the phase II portion of the trial, several doses and schedules of G3139 were evaluated. There were no pathologic complete responses. Pharmacodynamic studies showed limited Bcl-2 down-regulation in the primary tumors. CONCLUSIONS: G3139 in combination with doxorubicin and docetaxel is well tolerated. No pathologic complete response was seen and pharmacodynamic studies showed very little down-regulation of Bcl-2 in primary tumors, perhaps related to issues with insufficient drug delivery to the intact tumor.

A novel small molecule inhibitor of signal transducers and activators of transcription 3 reverses immune tolerance in malignant glioma patients.

Overcoming the profound immunosuppression in patients with solid cancers has impeded efficacious immunotherapy. Signal transducers and activators of transcription 3 (STAT3) has recently emerged as a potential target for effective immunotherapy, and in this study, we describe a novel small molecule inhibitor of STAT3 that can penetrate the central nervous system (CNS) in mice and in physiologically relevant doses in vitro and reverse tolerance in immune cells isolated from glioblastoma multiforme (GBM) patients. Specifically, it induces the expression of costimulatory molecules on peripheral macrophages and tumor-infiltrating microglia, stimulates the production of the immune-stimulatory cytokines interleukin 2 (IL-2), IL-4, IL-12, and IL-15, and induces proliferation of effector T cells from GBM patients that are refractory to CD3 stimulation. We show that the functional enhancement of immune responses after STAT3 inhibition is accompanied by up-regulation of several key intracellular signaling molecules that critically regulate T-cell and monocyte activation. Specifically, the phosphorylation of Syk (Tyr352) in monocytes and ZAP-70 (Tyr319) in T cells are enhanced by the STAT-3 inhibitor in marked contrast to toll-like receptor and T-cell receptor agonists, respectively. This novel small molecule STAT3 inhibitor has tremendous potential for clinical applications with its penetration into the CNS, easy parental administration, direct tumor cytotoxicity, and potent immune adjuvant responses in immunosuppressed cancer patients.

The novel triterpenoid C-28 methyl ester of 2-cyano-3, 12-dioxoolen-1, 9-dien-28-oic acid inhibits metastatic murine breast tumor growth through inactivation of STAT3 signaling.

We and others have reported that C-28 methyl ester of 2-cyano-3, 12-dioxoolen-1, 9-dien-28-oic acid (CDDO-Me) effectively inhibits the growth of multiple cancer cell types. Our previous studies indicated that prolonged CDDO-Me treatment inactivated extracellular signal-regulated kinase signaling in acute myelogenous leukemia cells. Whether treatment with CDDO-Me has an earlier effect on other proteins that are important for either signal transduction or oncogenesis is unknown. Constitutively activated signal transducer and activator of transcription 3 (STAT3) is frequently found in human breast cancer samples. Constitutively activated STAT3 was shown to up-regulate c-Myc in several types of cancer and has a feedback effect on Src and Akt. To examine the effects of CDDO-Me on STAT3 signaling in breast cancer, we used the murine 4T1 breast tumor model, which is largely resistant to chemotherapy. In vitro, after treatment of 4T1 cells with 500 nmol/L CDDO-Me for 2 h, we found (a) inactivation of STAT3, (b) inactivation of Src and Akt, (c) 4-fold reduction of c-Myc mRNA levels, (d) accumulation of cells in G(2)-M cell cycle phase, (e) abrogation of invasive growth of 4T1 cells, and (f) lack of apoptosis induction. In in vivo studies, CDDO-Me completely eliminated 4T1 breast cancer growth and lung metastases induced by 4T1 cells in mice when treatment started 1 day after tumor implantation and significantly inhibited tumor growth when started after 5 days. In vivo studies also indicated that splenic mature dendritic cells were restored after CDDO-Me treatment. In summary, these data suggest that CDDO-Me may have therapeutic potential in breast cancer therapy, in part, through inactivation of STAT3.