Antitumor activity of ipatasertib combined with chemotherapy: results from a phase Ib study in solid tumors.

BACKGROUND: This phase Ib study evaluated the safety, tolerability, pharmacokinetics, and preliminary efficacy of the oral AKT inhibitor ipatasertib and chemotherapy or hormonal therapy in patients with advanced or metastatic solid tumors to determine combined dose-limiting toxicities (DLTs), maximum tolerated dose, and recommended phase II doses and schedules. PATIENTS AND METHODS: The clinical study comprised four combination treatment arms: arm A (with docetaxel), arm B [with mFOLFOX6 (modified leucovorin, 5-fluorouracil, and oxaliplatin)], arm C (with paclitaxel), and arm D (with enzalutamide). Primary endpoints were safety and tolerability; secondary endpoints were pharmacokinetics, clinical activity per Response Evaluation Criteria in Solid Tumors v1.1, and prostate-specific antigen levels. RESULTS: In total, 122 patients were enrolled. Common adverse events were diarrhea, nausea, vomiting, decreased appetite, and fatigue. The safety profiles of the combination regimens were consistent with those of the background regimens, except for diarrhea, hyperglycemia, and rash, which were previously observed with ipatasertib treatment. The only combination DLT across all treatment arms was one event of grade 3 dehydration (ipatasertib 600 mg and paclitaxel). Recommended phase II doses for ipatasertib were 600 mg (and mFOLFOX6) and 400 mg (and paclitaxel), respectively. The maximum assessed dose of ipatasertib 600 mg combined with docetaxel or enzalutamide was well tolerated. Coadministration with enzalutamide (a cytochrome P450 3A inducer) resulted in approximately 50% lower ipatasertib exposure. CONCLUSIONS: Ipatasertib in combination with chemotherapy or hormonal therapy was well tolerated with a safety profile consistent with that of ATP-competitive AKT inhibitors. CLINICAL TRIAL NUMBER: NCT01362374.

A phase I, open-label dose-escalation study of continuous treatment with BIBF 1120 in combination with paclitaxel and carboplatin as first-line treatment in patients with advanced non-small-cell lung cancer.

BACKGROUND: BIBF 1120 is an oral potent inhibitor of vascular endothelial growth factor receptor, fibroblast growth factor receptor and platelet-derived growth factor receptor, the three key receptor families involved in angiogenesis. This phase I, open-label dose-escalation study investigated BIBF 1120 combined with paclitaxel (Taxol) and carboplatin in first-line patients with advanced (IIIB/IV) non-small-cell lung cancer. PATIENTS AND METHODS: Patients received BIBF 1120 (starting dose 50 mg b.i.d.) on days 2-21 and paclitaxel (200 mg/m2) and carboplatin [area under curve (AUC)=6 mg/ml/min] on day 1 of each 21-day cycle. Primary end points were safety and BIBF 1120 maximum tolerated dose (MTD) in this combination. Pharmacokinetics (PK) profiles were evaluated. RESULTS: Twenty-six patients were treated (BIBF 1120 50-250 mg b.i.d.). BIBF 1120 MTD was 200 mg b.i.d. in combination with paclitaxel and carboplatin. Six dose-limiting toxicity events occurred during treatment cycle 1 (liver enzyme elevations, thrombocytopenia, abdominal pain, and rash). Best responses included 7 confirmed partial responses (26.9%); 10 patients had stable disease. BIBF 1120 200 mg b.i.d. had no clinically relevant influence on the PK of paclitaxel 200 mg/m2 and carboplatin AUC 6 mg/ml/min and vice versa. CONCLUSIONS: BIBF 1120 MTD was 200 mg b.i.d when given with paclitaxel and carboplatin; this combination demonstrated an acceptable safety profile. No relevant changes in PK parameters of the backbone chemotherapeutic agents or BIBF 1120 were observed.

Long-term survival in patients with advanced non-small-cell lung cancer treated with atezolizumab versus docetaxel: Results from the randomised phase III OAK study.

BACKGROUND: Atezolizumab (anti-programmed death-ligand 1 [PD-L1]) received approval from the US Food and Drug Administration and European Medicines Agency for previously treated advanced non-small-cell lung cancer based on OAK-a randomised, phase III trial that showed significantly improved survival with atezolizumab versus docetaxel regardless of PD-L1 expression. With longer follow-up, we summarised the characteristics of long-term survivors (LTSs). METHODS: In OAK (NCT02008227), patients were randomised 1:1 to receive atezolizumab or docetaxel until loss of clinical benefit or disease progression, respectively. Overall survival was evaluated after a 26-month minimum follow-up, including in patient subgroups defined by best overall response (BOR). LTSs were defined as patients who lived ≥24 months since randomisation. Non-LTSs died within 24 months, and patients censored before 24 months were excluded from the analysis. The baseline characteristics, including biomarkers, BOR, subsequent non-protocol therapy (NPT) and safety, are reported. RESULTS: Survival benefit with atezolizumab was observed across all patient subgroups defined by BOR. More atezolizumab-treated patients were LTSs versus those treated with docetaxel (28% versus 18%). Most atezolizumab responders were LTSs (77%) versus only 48% of docetaxel responders. However, 21% of atezolizumab-arm LTSs had progressive disease (PD) as BOR, and more atezolizumab-arm LTSs than non-LTSs continued treatment post-PD. Fifty-two percent of docetaxel-arm LTSs received immunotherapy as subsequent NPT. Despite extended treatment duration in atezolizumab-arm LTSs (median, 18 months), atezolizumab was well tolerated. CONCLUSIONS: After >2 years of follow-up, atezolizumab continued to provide durable survival benefit versus docetaxel, with tolerable safety. Atezolizumab-arm LTSs were enriched for patients with high PD-L1 expression and included PD-L1-negative patients. Long-term survival was not limited to responders.

Clinical trials with human tumor necrosis factor: in vivo and in vitro effects on human mononuclear phagocyte function.

The purpose of this investigation was to understand the biological effects of recombinant human tumor necrosis factor used as therapy for cancer. We studied changes in mononuclear phagocyte function following exposure to this cytokine in vitro or in vivo. Tumor necrosis factor increased phorbol myristate acetate-induced hydrogen peroxide production 8- to 20-fold in peripheral blood monocytes and peritoneal macrophages in vitro in a dose-dependent manner. Similarly, tumor necrosis factor increased phorbol myristate acetate-induced peroxide production 2.3-fold in monocytes isolated from nine patients following an i.v. infusion of this cytokine (40 to 200 micrograms/m2). In addition, tumor necrosis factor induced a 2.3-fold increase in tissue factor-like activity in mononuclear phagocytes in vitro. In vivo, tumor necrosis factor induced a trend toward higher procoagulant activity in monocytes, although this change was not statistically significant. We also noted a trend toward increased activated partial thromboplastin times and the presence of fibrin D-dimer in patients treated with tumor necrosis factor, demonstrating activation of the coagulation and fibrinolytic systems. Thus, in vivo treatment of humans with i.v. recombinant human tumor necrosis factor induced functional changes in mononuclear phagocytes similar to those noted with in vitro treatment.

Human mononuclear phagocyte transglutaminase activity cross-links fibrin.

The physiologic function of the monocyte transglutaminases is not known. In this study, we detected Factor XIII A-subunit antigen and "tissue" transglutaminase antigen in human monocytes by polyacrylamide gel electrophoresis and immunoblotting techniques. Flow cytometric analysis demonstrated that 27% and 49% of the total Factor XIII antigen in monocytes and human peritoneal macrophages, respectively, are expressed on the surface of the cells. Monocytes maintained in culture for 8 days had a 4-fold increase in Factor XIIIa activity and a 3.2-fold increase in the amount of Factor XIII antigen/mg cell protein. However, there was no increase in the "tissue" transglutaminase activity or antigen levels in cultured monocytes. In addition, we identified a Factor XIII deficient individual who does not express Factor XIII activity or antigen in plasma, platelets, monocytes, lymphocytes or erythrocytes. Intact monocytes from normal donors were able to cross-link fibrin formed in the plasma from the Factor XIII deficient individual. This suggests that transglutaminase activity expressed by peripheral blood monocytes may play a physiologic role in cross-linking fibrin during blood clotting or inflammation.

Effect of diethyldithiocarbamate (DDC) on human monocyte function and metabolism.

Recent evidence indicates that phagocytic cells play a major role in tissue inflammation. The release of enzymes, lipid metabolites such as prostaglandins, and reactive oxygen species by these cells appear to mediate the inflammatory process. In this study we have evaluated the effects of diethyldithiocarbamate (DDC) on human monocyte function and metabolism. We demonstrate that DDC impairs that antibody-dependent cytoxicity (ADCC) of monocytes to red cell targets. The concentration of DDC which caused maximal suppression of ADCC also prevented the burst of oxidative metabolism in monocytes stimulated by sensitized red cells targets or phorbol myristate acetate (PMA). DDC also impairs the lipid metabolism of these cells as indicated by a decrement in malonyldialdehyde (MDA) production. These data indicate that DDC impairs the activity of two major biochemical pathways in monocytes which are related to the inflammatory process, i.e., the release of oxygen metabolites and prostaglandins.

Tumor necrosis factor induces tissue factor-like activity in human leukemia cell line U937 and peripheral blood monocytes.

The induction of procoagulant activity (PCA) by human recombinant tumor necrosis factor (rTNF) was studied in human monoblastic leukemia cell line U937 and human peripheral blood monocytes. Using a one-step recalcificating clotting assay, PCA in cell lysates or whole cell preparations was measured by comparison to a rabbit brain thromboplastin standard. There was a dose- and time-dependent increase in PCA when U937 cells were cultured with rTNF. The effect of rTNF was not enhanced by recombinant human interferon-gamma (rIFN gamma). Cycloheximide inhibited the expression of PCA by U937 cells, showing that protein synthesis was necessary to mediate the effects of rTNF. Whole cell preparations demonstrated that greater than 80% of the PCA was expressed on the surface of the cells. The PCA functioned as a tissue factor-like substance, since it required coagulation factor VII and factor X. rTNF also increased PCA in human monocytes in a dose- and time-dependent manner. This effect was abrogated by boiling the rTNF for ten minutes, and was not inhibited by adding polymyxin-B to the cultures, making it unlikely that endotoxin accounted for the observed effects. These results suggest that TNF-induced expression of tissue factor by mononuclear phagocytes may modulate immunologic, inflammatory, and hemostatic processes.

Activation of monocyte and granulocyte antibody-dependent cytotoxicity by phorbol myristate acetate.

We have characterized the effects of phorbol myristate acetate (PMA) on human monocyte and neutrophil oxidative metabolism and antibody-dependent cytotoxicity toward anti-D sensitized human erythrocytes (RBC) and a human lymphoblastoid cell line (CEM). Hexose monophosphate shunt activity was measured by [1-(14)C]glucose oxidation and target lysis by (51)Cr release. PMA produced a dose-dependent stimulation of hexose monophosphate shunt activity. Neutrophils responded with higher hexose monophosphate shunt activity and at a lower PMA concentration than did monocytes. PMA increased monocyte lysis of antibody-sensitized RBC by two-thirds, but did not affect lysis of CEM targets. Neutrophils were unable to lyse either antibody-sensitized or nonsensitized RBC without the addition of PMA. When PMA was added, lysis of both targets increased markedly. Neutrophils without PMA were able to lyse a small number of both antibody-sensitized and nonsensitized CEM targets. PMA also increased neutrophil lysis of these targets. Target lysis by neutrophils from a patient with chronic granulomatous disease, cells unable to produce reactive oxygen species, was not increased by PMA. Chronic granulomatous disease monocytes, however, responded to PMA by more than doubling lysis of antibody-sensitized RBC. Hypoxia inhibited PMA augmentation of antibody-sensitized RBC lysis by neutrophils, but not by monocytes. Generation of reactive oxygen species by the xanthine-xanthine oxidase system inhibited CEM growth, but did not cause lysis, indicating that in some cases oxidative injury may be nonlytic. We suggest that PMA augments neutrophil cytotoxicity to tumor and RBC targets by stimulating reactive oxygen species-mediated lysis, but in monocytes augmentation of lysis is due to activation of a nonoxidative mechanism of lysis.

Identification of normal human peripheral blood monocytes and liver as sites of synthesis of coagulation factor XIII a-chain.

Factor XIII is the fibrin-stabilizing factor that covalently cross-links fibrin monomers to form a highly organized, stable fibrin clot. The plasma form of factor XIII is a heterodimer, a2b2, consisting of two a-chains and two b-chains; the intracellular form, such as in platelets and placenta, is a dimer, a2, consisting of a-chains only. The catalytic function of factor XIII, a transglutaminase, resides in the a-chain. To address questions regarding sites of synthesis of factor XIII a-chain, an EcoRI restriction fragment from the protein-coding region of the factor XIII a-chain cDNA was used as a probe for Northern blot analysis. The cDNA probe showed hybridization with a single approximately 4.0-kilobase (kb) message in poly (A)+ mRNA prepared from normal human peripheral blood monocytes and normal human liver. The results demonstrate conclusively that factor XIII a-chains are actively synthesized in circulating monocytes and in liver. To our knowledge, these data represent the first demonstration of synthesis of any blood coagulation factor in primary uncultured and unstimulated monocytes or macrophage cells.

Oxygen dependence of human alveolar macrophage-mediated antibody-dependent cytotoxicity.

We studied the metabolic characteristics of the human alveolar macrophage-mediated antibody-dependent cytotoxicity (ADCC) reaction, using an anti-D sensitized human erythrocyte target system. Metabolic experiments demonstrated a high resting rate of glucose metabolism in macrophages, but no oxidative metabolic burst was found to accompany the ADCC reaction. These findings were confirmed by oxygen consumption studies, showing a high resting rate of oxygen consumption by macrophages, but no change in the rate of oxygen consumption upon the addition of antibody-sensitized target cells. An anaerobic mechanism for ADCC was anticipated and investigated. Surprisingly, the macrophage-mediated ADCC reaction was found to be highly oxygen dependent. The macrophages of one chronic granulomatous disease patient were also studied and found to have a very low rate of oxidative metabolism in response to phagocytic stimuli. With oxygen present, these macrophages failed to produce significant ADCC, suggesting again that some oxidative mechanism was necessary in the macrophage-mediated ADCC reaction. Various oxygen radical scavengers were also studied. Glutathione inhibited ADCC significantly, and benzoic acid inhibited ADCC only slightly. All other scavengers had no significant inhibitory effect. Then, a known antioxidant and inhibitor of mixed-function oxidases, diethyldithiocarbamate, was found to produce a significant inhibition of the ADCC reaction. We believe this compound may be scavenging or inhibiting the production of some oxygen-dependent species important in the ADCC reaction.

Sphingosine inhibits monocyte tissue factor-initiated coagulation by altering factor VII binding.

Tissue factor is a lipoprotein, expressed on the surface of cells, which binds coagulation Factor VII or VIIa, leading to activation of Factors X and IX with subsequent fibrin generation. Cellular tissue factor activity is important in pathophysiologic processes such as inflammation and disseminated intravascular coagulation. In this study, the long-chain base sphingosine inhibited coagulation initiated by lipopolysaccharide-stimulated intact human monocytes. Sphingosine (5-100 microM) also profoundly inhibited thromboplastin-initiated coagulation (greater than 90% decrease in thromboplastin activity). This inhibition was dose- and time-dependent. Sphingosine inhibited neither the intrinsic pathway of coagulation nor thrombin generation of fibrin. The sphingosine analogues sphingomyelin, ceramide, or N-acetylsphingosine did not affect thromboplastin activity, suggesting that the polar head of sphingosine was necessary for interaction of the molecule with the coagulation system. Investigation of the biochemical mechanism revealed that sphingosine (5-50 microM), but neither sphingomyelin nor ceramide, inhibited specific binding of radiolabeled Factor VII to lipopolysaccharide-stimulated intact monocytes. The results suggest that sphingosine may regulate monocyte tissue factor-initiated coagulation by modulating Factor VII binding to tissue factor. Sphingosine may represent a new class of inhibitors of hemostasis.