The first clinical pilot study of roquinimex (Linomide) in cancer patients with special focus on immunological effects

Design, synthesis, in vitro and in silico characterization of new 2-quinolone- L -alaninate-1,2,3-triazoles as novel antimicrobial agents

Due to the ever‐increasing antimicrobial resistance there is an urgent need to continuously design and develop novel antimicrobial agents. Inspired by the broad antibacterial activities of various heterocyclic compounds such as 2‐quinolone derivatives, we designed and synthesized new methyl‐(2‐oxo‐1,2‐dihydroquinolin‐4‐yl)‐L‐alaninate‐1,2,3‐triazole derivatives via 1,3‐dipolar cycloaddition reaction of 1‐propargyl‐2‐quinolone‐L‐alaninate with appropriate azide groups. The synthesized compounds were obtained in good yield ranging from 75 to 80 %. The chemical structures of these novel hybrid molecules were determined by spectroscopic methods and the antimicrobial activity of the compounds was investigated against both bacterial and fungal strains. The tested compounds showed significant antimicrobial activity and weak to moderate antifungal activity. Despite the evident similarity of the quinolone moiety of our compounds with fluoroquinolones, our compounds do not function by inhibiting DNA gyrase. Computational characterization of the compounds shows that they have attractive physicochemical and pharmacokinetic properties and could serve as templates for developing potential antimicrobial agents for clinical use.

Crystal structure and DFT study of benzyl 1-benzyl-2-oxo-1,2-di-hydro-quinoline-4-carboxyl-ate

In the title quinoline derivative, C24H19NO3, the two benzyl rings are inclined to the quinoline ring mean plane by 74.09 (8) and 89.43 (7)°, and to each other by 63.97 (10)°. The carboxyl-ate group is twisted from the quinoline ring mean plane by 32.2 (2)°. There is a short intra-molecular C-H⋯O contact forming an S(6) ring motif. In the crystal, mol-ecules are linked by bifurcated C-H,H⋯O hydrogen bonds, forming layers parallel to the ac plane. The layers are linked by C-H⋯π inter-actions, forming a supra-molecular three-dimensional structure.

2-Oxo-1,2-dihydroquinoline-4-carboxylic acid monohydrate

In the title compound, C10H7NO3·H2O, O—H...O hydrogen bonds involving the carboxyl groups, the keto groups and the lattice water molecules form stepped sheets approximately parallel to {010} which are tied together by pairwise N—H...O interactions. The asymmetric unit contains two independent quinolone derivatives and two water molecules, one of which is disordered over two positions, of equal occupancy.

Diketo acid pharmacophore. 2. Discovery of structurally diverse inhibitors of HIV-1 integrase

Because of its unique role in the viral replication process, HIV-1 integrase (IN) is an important antiretroviral drug target. The beta-diketo acid class of IN inhibitors has played a major role in validating IN as a legitimate target for antiretroviral drug design. S-1360 (1) and L-870,810 (2) are examples of beta-diketo acid related compounds to enter clinical trials. With an aim to discover novel lead compounds with diverse structural scaffolds, we employed common feature pharmacophore models using four known beta-diketo acid analogues including S-1360 (J. Med. Chem. 2005, 1, 111-120). The best-ranked pharmacophore model (Hypo1) contained a hydrophobic (HYA), an H-bond acceptor (HBA), and two H-bond donor (HBD) features. A search of a 3D database containing approximately 150,000 small molecules using Hypo1 found 1700 compounds that satisfied all the features of the pharmacophore query. Of the 1700 compounds, 110 were selected for in vitro screening studies on the basis of their docking scores, predicted binding location inside the active site of IN, and their druglike properties. Forty-eight compounds inhibited IN catalytic activities with an IC50 value less than 100 microM. Twenty-seven structurally diverse inhibitors are reported here. Out of the 27 compounds, 13 compounds inhibited strand transfer activity of IN with an IC50 value less than 30 microM. These compounds are novel, druglike, and readily amenable for synthetic optimization.

Angiogenesis in prostate cancer: its role in disease progression and possible therapeutic approaches

The interaction between cancer cells and their microenvironment is a promising area for the development of novel therapeutic anti-cancer modalities. The formation of new blood vessels, angiogenesis, is an important step in cancer progression. Angiogenesis is a complex multistep process involving close orchestration of endothelial cells, extracellular matrix, and soluble factors. Essentially every step has been found to be regulated by inducers and inhibitors. Prostate cancer has the ability to produce angiogenic factors such as metalloproteinases, vascular endothelial growth factor, fibroblast growth factor 2, transforming growth factor-beta and cyclooxygenase-2. In several studies in prostate cancer an increased microvessel density is associated with poorer prognosis. On the other hand several endogenous inhibitors of angiogenesis have been described in prostate cancer e.g., angiostatin, endostatin, prostate specific antigen (PSA), thrombospondin-1, interleukin 10, interferons and retinoids. The expanding insight in the process of angiogenesis has resulted in a large number of pharmaceutical agents that have been tested in preclinical studies and are currently tested in clinical trials. These agents inhibit endothelial cell proliferation or migration and induce apoptosis. This ultimately will affect the formation of new vessels thereby inducing tumor dormancy. Because antiangiogenic treatment is cytostatic rather than cytotoxic, patients will need long-term therapy to prevent regrowth of the tumor. Prostate cancer is an ideal tumor for antiangiogenic studies because of the availability of a reliable tumor marker, PSA, the indolent clinical course of this cancer and the low rate of proliferation even in metastatic sites. Furthermore, clinical studies showed limited side effects, which is advantageous in this elderly patient group. Whether the ultimate antiangiogenic treatment is effective as a single agent or in combination with radiation therapy, chemotherapy or immunotherapy remains to be determined.

Effect of linomide on gut immune cell distribution and on TNF-alpha in plasma and ascites: an experimental study in the septic rat

A significant reduction of the pan T lymphocytes as well as CD4+ and CD8 subsets of cells in the gut mucosa of the septic rats has previously been demonstrated. In contrast, the populations of major histocompatibility complex (MHC) class II-positive cells and macrophages increased. The aim of this study was to evaluate if the immunomodulator Linomide influenced the immune cell distribution in the small intestinal mucosa in sepsis and, furthermore, if these changes coincide with changes in the concentration of tumor necrosis factor-alpha (TNF-alpha) in plasma or ascites. Polymicrobial sepsis was induced in rats by cecal ligation and puncture (CLP). Three different experimental groups were used: CLP, Linomide p.o. + CLP, and Linomide i.p.+ CLP, with adequate controls. Specimens were taken from the small bowel for immunohistologic staining and grading of mucosal injury. The following monoclonal antibodies were used: W3/25, OX8, R73, OX6, and ED1. All slides were examined by one "blinded" examiner. Mucosal injury was graded from 0 to 5. The immunostained tissues were also analyzed by an automatic color-based image system. All controls had a normal appearance of the mucosa (grade 0-1), whereas the septic animals had a median grade of III (II-IV) mucosal injury. Linomide i.p. + CLP decreased mucosal damage to median I (0-IV, P < 0.05). Linomide had no effects on the immune cell distribution in controls. In CLP rats, a significant reduction in both CD4+ and CD8+ T lymphocytes as well as an increased number of macrophages and MHC class II-positive cells was seen in the villi as compared with sham-operated controls (P < 0.05). Linomide attenuated these changes for CD8+ and T lymphocytes and macrophages. Sepsis caused increased concentrations of TNF-alpha in portal blood and ascites 3 h from CLP induction. This increase was attenuated by Linomide.

Roquinimex (Linomide) vs placebo in AML after autologous bone marrow transplantation

Roquinimex, Linomide, a quinoline derivative with pleiotropic immunomodulatory activity, has previously been shown to enhance natural killer (NK) cell number and activity after ABMT in patients with AML. In this study 278 AML patients in remission were randomized to receive Roquinimex 0.2 mg/kg body weight or placebo twice weekly for 2 years following ABMT. Out of 139 patients in each group, 109 Roquinimex patients and 108 placebo patients were in their first CR. Median age at inclusion was 41 years for Roquinimex patients and 39 years for placebo patients. Twelve patients in each group had their marrow purged prior to reinfusion. Relapse and death were study endpoints. Surviving patients were followed for 2.6 to 6. 9 years. The total number of relapses was 60 in the Roquinimex group and 63 in the placebo group (not significant). Leukemia-free and overall survivals were similar in the two groups. Recovery of platelet counts was significantly delayed in the Roquinimex group as compared to placebo. No other significant differences regarding toxicity parameters were recorded. In conclusion, previous findings on NK cells could not be confirmed and the study showed no benefit for Roquinimex over placebo regarding relapse or survival following ABMT for AML in remission.

Absorption and disposition including enterohepatic circulation of (14C) roquinimex after oral administration to healthy volunteers

The absorption and disposition of roquinimex (Linomide) were studied in four male and two female healthy volunteers. The subjects received a single oral aqueous solution of 14C-labelled roquinimex, about 0.1 mg/kg, after an overnight fast. Blood samples were taken and urine and faeces were collected for 10 days after dosing. The plasma, urine and faeces concentrations of roquinimex and metabolites were determined by high-performance liquid chromatography (HPLC) with radiochemical detection. The metabolites were identified by HPLC-mass spectroscopy (MS). The plasma concentration-time profiles of roquinimex exhibited a rapid absorption followed by a bi-exponential disposition. A secondary peak was observed between 6 and 8 h, indicating enterohepatic circulation (EHC) of roquinimex. The terminal disposition half-life was estimated as 27 h. The primary metabolic pathways of roquinimex were hydroxylation, demethylation and conjugation. The major compound in plasma was roquinimex; metabolites were only occasionally detected. In urine and faeces, roquinimex accounted for 2% of the dose and conjugated and hydroxylated metabolites each accounted for about 30% of the dose. A model was derived for the plasma concentrations of roquinimex and the amount of urinary excreted roquinimex to take into account EHC. This model improved the goodness-of-fit according to common goodness-of-fit criteria. The values of the pharmacokinetic parameters were similar using compartmental and non-compartmental methods, indicating that the contribution of EHC of roquinimex is of minor importance in the evaluation of the pharmacokinetics of roquinimex.

Multiformic modulation of endotoxin effects by linomide

Linomide is a potent immunomodulator that either enhances or suppresses certain immunological processes. Of particular interest is this compound's capacity to inhibit a variety of organ-specific autoimmune diseases. Here, we report on the effects of linomide on several immunological reactions elicited by endotoxin (LPS), both in vivo and in vitro. In rats and mice linomide inhibited the elicitation of endotoxin-induced uveitis (EIU), an acute inflammatory eye disease that develops within 24 h following footpad injection of LPS. Linomide also inhibited the production of TNF-alpha and IL-6 by LPS-stimulated rat and mouse macrophage monolayers. On the other hand, treatment with linomide significantly increased the levels of IL-1beta (mice and less in rats), IL-6 (rats), and TNF-alpha (mice) in serum samples collected 2 h following injection with LPS. The increased production of proinflammatory cytokines in linomide-treated mice was also indicated by the enhanced lethal effect of LPS in these mice. The finding of elevated levels of these cytokines in animals with suppressed EIU is also in line with previous observations of an inverse relationship between EIU severity and levels of TNF-alpha. Data recorded here underscore the unique capacity of linomide to both enhance and suppress the immune system.

[Anti-angiogenesis: a new approach to tumor therapy?]

BACKGROUND

The overall mortality due to metastatic cancer has not or only minimally been reduced in spite of intensive research and many innovations in the field of conventional antineoplastic therapy in the past decade. In the last years it has become a fact that tumor growth is angiogenesis-dependent. Therefore, inhibitors of angiogenesis are a new class of antineoplastic substances with a novel mechanism of action that might be a powerful complement to conventional cytostatic therapy. SUBSTANCES AND CLINICAL TRIALS: Inhibitors of tumor-angiogenesis which have entered clinical trials, with their results published until December 1998 are discussed here. Most results originate from phase-I or phase-II clinical trials. They are discussed and compared in respect to toxicity and response. Also some substances with high therapeutic potential which are still in preclinical testing are discussed.

RESULTS

Many of the investigated angiogenesis inhibitors demonstrated anti-tumor effects in phase-I or phase-II clinical trials. The commonest manifestation was stable disease, followed by partial remissions. In a few cases, complete remissions were observed. The toxicities of these substances differ both in type and degree of side effects.

CONCLUSION

Some antiangiogenic drugs appear to be promising candidates for a clinical use in the therapy of solid tumors. Further conclusions can only be drawn after evaluation of the results of ongoing phase-III clinical trials.

Dissolution rate-limited absorption and complete bioavailability of roquinimex in man

In order to investigate the bioavailability and the rate-limiting step of the absorption of roquinimex, an oral solution and a tablet formulation (Linomide(R)) were given to healthy volunteers. The study was conducted as a randomized three-period crossover study in seven male and seven female healthy volunteers. The subjects received an intravenous infusion, an oral solution and an oral tablet formulation, each of 5 mg (about 0.07 mg kg(-1)), as single doses after an overnight fast on three occasions, with a wash-out period of 3 weeks in between. Venous blood samples were taken over 7 days and the plasma concentrations of roquinimex were determined by high-performance liquid chromatography (HPLC) with ultraviolet (UV)-detection. The pharmacokinetics of roquinimex was characterized by a low plasma clearance, 4.9 mL h(-1) kg(-1) and a small volume of distribution, 0.22 L kg(-1). The oral bioavailability of the drug was complete for both the solution and the tablet formulation. The absorption rate was faster for the solution than for the tablet. The disposition of roquinimex was biphasic, with a terminal disposition half-life of 32 h. Between 4 and 8 hours after dosing, a secondary plasma peak was observed, indicating enterohepatic circulation of the drug. No major sex differences were shown in the pharmacokinetics of roquinimex. In conclusion, dissolution rate-limited absorption of roquinimex was shown, which demonstrates that disintegration and dissolution of the tablet play a major role in the absorption process of roquinimex. Despite the delayed absorption after administration of the tablet, the extent of absorption was complete.

A feasibility study of roquinimex (Linomide) and alpha interferon in patients with advanced malignant melanoma or renal carcinoma

Thirty-one patients with advanced renal carcinoma or malignant melanoma were treated in the first feasibility study of alpha-interferon (Roferon) and the new oral immunomodulating agent, Linomide. Linomide 5 mg or 10 mg p.o. daily was given for 2 weeks; alpha-interferon was then added at 3 MU s.c. three times weekly, escalating in each patient by 3 MU per week, if tolerable, up to 12 MJ. The combination was poorly tolerated with nausea, vomiting, somnolence and myalgia commonly reported. Adverse events accounted for treatment withdrawal in ten patients and contributed to withdrawal in four other patients. Treatment with Linomide alone in the first 2 weeks led to a significant increase in white blood cells, neutrophils and platelets. When alpha-interferon was added, the platelet count decreased significantly over the following 6 weeks. Nineteen patients had white cell phenotype and function measured. After 2 weeks of 5 mg Linomide, a transient but significant decrease in the absolute number of activated T-helper cells (CD4+DR+) was observed. No changes in natural killer (NK) cell number or activity were observed. Twenty-two patients were evaluable for response. One with metastatic renal cell carcinoma had a complete response and six had stable disease. This study does not support the use of the combination because significant toxicity was seen without the anticipated immunological benefits.