Ehrlich II –2nd World Conference on Magic Bullets

Divalproex-Valproate: Is The Discovery, Research & Development With This Molecule And Its' Formulations Complete?
REED RC¹, KASTELEIJN-NOLST TRENITE DGA², O’BRIEN TJ³, VAN RAAY L³, HOGAN RE⁴, MORRIS MJ⁵, DEDEURWAERDERE S⁶, DUTTA S¹, ROSENFELD W⁷ and ABOU-KHALIL B.^8
1Abbott, Global Pharmaceutical R&D, Abbott Park, USA, ²Universita di Roma, Sapienza II, Rome, Italy, ³University of Melbourne, Australia, ⁴Washington University, St Louis, USA, ⁵University of New South Wales, Kensington, Australia, ⁶Australian Nuclear Science & Technology Organisation, ⁷Comprehensive Epilepsy Center, St. Louis, USA, ⁸Vanderbilt University, Nashville, USA
Background: Valproic acid (VPA) syrup entered the USA (1979) for epilepsy. Due to nausea, an enteric-coated, delayed-release (DR) formulation was developed. Extended-release (ER) forms of antiepileptic drugs should increase compliance and tolerability. Recognizing that DR was not sustained-release, divalproex-ER tablet was developed for once-daily (QD) administration.

Methods: Data from >12 published or ongoing studies were analyzed to distinguish kinetics of VPA and DR vs. ER (Abbott).

Results: AAN 2005_M98 937_Ann Pharmacother The absolute bioavailability of ER is 89%; AAPS 2003_M95 414_J Clin Phamacol 2004;44:737 42 & ASCPT 2003_Biopharm Drug Dispos 2004;25:345 52. 8-20% greater doses are needed to achieve equivalent VPA AUC. Food does not interfere with the ER absorption. A meta-review of ER studies shows superior tolerability vs DR. ER functional half-life is >24h in induced, 40h in non-induced patients. ER displays net-zero-order absorption, clearly distinct from other forms. ER is approved for QD use; not DR. A structured simulation shows marked fluctuation in VPA concentrations with QD DR and clinical toxicity & breakthrough seizures reported with pharmacy substitution of DR for ER. In the rat epilepsy model, total peak plasma VPA are not more efficacious vs continuous iv VPA; AUC is the relevant metric, giving impetus for ER use. Minimal variability in lot-to-lot mg potency (+ 2-3%) exists. A prospective, placebo-controlled trial on the pharmacodynamic EEG effect of small VPA changes via constant infusion, with paroxysmal photosensitive response is underway.

Conclusions: 1. Divalproex-ER exhibits unique kinetics.AES 2004_Submitted Ther Drug Monit 2. ER development was complex & time-consuming. 3. Divalproex celebrates 25 years of use in the USA (30+ years use elsewhere in the world), yet clinicians are still learning about the clinical utility of VPA and the ER formulation.

Uncovering Tumor Systems Biology By Biomodulatory Therapy Strategies REICHLE A Department of Hematology and Oncology, University Hospital Regensburg, Germany How can get structured therapies in metastatic cancer a source for detecting tumor-associated systems-biological processes as adjustable sizes available for biomodulatory therapies? A therapy-derived methodological approach to explore tumor-associated systems biology should be explicated and developed by means of analyses of recently published biomodulatory therapy approaches introducing combined immunomodulatory, anti-inflammatory and angiostatic therapy in the treatment for advanced chemorefractory tumors of quite different origin. Biomodulatory therapy approaches in tumors intend to develop systems-terms that provide a basis for broadening therapy-relevant capacities by regulating biological systems processes for tumor control. Combined targeted therapies of tumor-associated wound healing mechanisms, namely inflammation and neoangiogenesis, have shown that ─ using an approach for understanding systems biology as adjustable size ─ we may break through the barrier of complexity of tumor-stroma-interactions in a therapeutically relevant way.	Digoxin plasma concentrations of four different dosing schedules commonly used in clinical settings. reinbach R^1, VILLA L^2, FERNANDEZ P^2, GIRAUDO P^3, VENEGAS R^1. ^1Universidad de Concepción, Facultad de Medicina, Concepción, Chile ^2Universidad de Concepción, Facultad de Farmacia, Concepción, Chile ^3Laboratorio Clínico Diagnomed, Concepción, Chile Background: The different therapeutic schedules used for the prescription of digoxin have little theoretical support and are based mainly on the patients clinical response. The aim of this study was to measure digoxin plasma levels in patients using four different prescription schedules. Methods: A total of 175 patients were included in this study with previous written consent. Inclusion criteria: patients who had been prescribed Digoxin for at least 1 month prior to the study. Four groups of patients were studied. Group I (n=56) digoxin 0.25 mg/day, from monday to friday. Group II (n= 30) digoxin 0.25 mg/day, from monday to saturday. Group III (n= 53) digoxin 0.25 mg/day continuously. Group IV (n= 36) digoxin 0.125 mg/day continuously. Plasma digoxin levels were measured in two consecutive mondays, before taking the daily dose of the drug, serum creatinine and creatinine clearance was calculated. Therapeutic plasma concentration range was set between 0.5 and 2 ng/ml. Digoxin was determined using immune analyses through a fluorimetric enzyme. Results:   Group I Group II Group III Group IV Total Patients 56 30 53 36 Age 65 ± 13 68 ± 11 61 ± 13 67 ± 12 Female % 68 63 57 68 Digoxin 1^st(ng/ml) 1.14 ± 0.77 1.38 ± 0.57 1.62 ± 0.74 1.12 ± 0.40 Digoxin 2^nd (ng/ml) 1.19 ± 0.88 1.42 ± 0.60 1.74 ± 0.76 1.15 ±0.48 Digoxin average (ng/ml) 1.15 ± 0.80 1.40 ± 0.55 1.68 ± 0.70 1.14 ± 0.43 Creatinin Clearance < 50 ml/min 34 33 23 36 93% in group I, 80% in group II, 75% in group III and 94% in group IV had therapeutic digoxin levels. Low creatinine clearance, age over 65 and drug interactions were risk factors associated with supratherapeutic levels, mostly seen in group II and group III with 20% and 24% respectively. Conclusions: 1) Digoxin plasma levels proportionally increase as the weekly dose increases 2) Similar therapeutic plasma levels are observed in group I, II and IV 3) High proportion of supratherapeutic levels are seen when Digoxin is used with Amiodarone and in patients with Creatinine clearence smaller than 50 mL/min.
Pathogenesis And Targeted Treatment Of BCR-ABL Negative Myeloproliferative Neoplasms REITER A III. Medizinische Klinik, Universitätsmedizin Mannheim, Mannheim, Germany The chronic myeloproliferative neoplasms (MPN) are clonal disorders characterized by excess proliferation and normal maturation of cells from one or more myeloid lineages. The most common MPN are chronic myeloid leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). Rare subtypes include chronic eosinophilic leukaemia (CEL), chronic myelomonocytic leukemia (CMML) and systemic mastocytosis (SM). The constitutive activation of the BCR-ABL protein tyrosine kinase as consequence of the reciprocal translocation t(9;22) in CML has become the paradigm for molecular pathogenesis and targeted treatment with tyrosine kinase inhibitors, e.g. imatinib. Meanwhile, it has become evident that acquired constitutive activation of protein tyrosine kinases is also a central feature in the pathogenesis of BCR-ABL negative MPN. The most commonly involved genes are the receptor tyrosine kinases PDGFRA, PDGFRB, FGFR1 or c-KIT and the non-receptor tyrosine kinases JAK2 and ABL. Activation occurs as a consequence of specific point mutations or diverse fusion genes generated by chromosomal translocations, insertions or deletions. Mutant kinases are constitutively active in the absence of the natural ligands resulting in deregulation of hemopoiesis in a manner analogous to BCR-ABL in CML. The most common point mutation is JAK2 V617F which is identified in most patients with PV and about 50% of patients with ET and PMF while a KIT D816V mutation is found in 80-90% of patients with SM. The most common fusion gene is FIP1L1-PDGFRA which is present in a substantial proportion of patients with CEL. Imatinib induces high response rates in patients associated with constitutive activation of PDGFR, PDGFR, ABL, and some KIT mutants. Other inhibitors under development are promising candidates for effective treatment of patients with constitutive activation of JAK2, FGFR1 and imatinib-resistant KIT mutants. The indolent clinical course of distinct subtypes, e.g. PV or ET, and the efficacy and safety of currently used therapies will necessitate that JAK2 inhibitors have a favourable toxicity profile in the short- and long-term. Important questions for future studies remain the unknown molecular pathogenesis of approximately 30% of MPN patients and the potential role of additional genetic events in the pathogenesis of MPN.	Some Aspects On Xenobiotic Metabolism, From Hepatic Function To Prospective Drugs REKKA EA, KOUROUNAKIS PN Department of Pharmaceutical Chemistry, School of Pharmacy, Aristotelian University of Thessaloniki, Thessaloniki, Greece Xenobiotic metabolising enzymes, mainly cytochrome P450, are regulated intrinsically. The influence of amino acid residue 374 on CYP2D6 mediated metabolism of metoprolol will be presented as an example. However, they are also affected by environmental factors like diseases, drugs or diet. Stress influences drug metabolism. The influence of cold hypoxic preservation and normothermic reoxygenation of liver slices on CYP3A oxidation will be given. Stressors (fasting, restraint) lead to increased resistance to xenobiotics. Experimental arthritis reduces P450 activity. Toxic agents also affect drug metabolism. Since high levels of glucocorticoids appear during stress, the effect of corticosterone on drug metabolism is examined. It is concluded that augmented metabolic activity can be stimulated as response to need. Triamcinolone increases drug metabolism of arthritic rats. It also ameliorates the impaired metabolic activity due by toxic agents. P450 inducers, such as PCN and spironolactone restore the reduced enzyme activity caused by toxic compounds and decreases cholesterol in hypercholesterolemic rats. PCN is a CYP inducer free of other activities. The effect of various pregnenolone 16α substituents on drug metabolism is studied. Since the 16α-CN is found to be the most potent, the effect of the position of CN in cyanopregnenolones on drug metabolism is reported. Various drugs interact with P450. The examined interaction of analogues of diphenhydramine and cimetidine on P450 indicates structural features determining this action. The ability of some non steroidal anti-inflammatory drugs to induce P450 and peroxisomal proliferation is examined, in order to investigate their interrelationships. Although oxidations are the most common metabolic reactions, several compounds are reductively biotransformed. Microsomal reduction of metyrapone analogues is examined and applications for safer insecticides are suggested. Food constituents influence drug metabolism. Guaiazulene is found to inhibit several CYPs and to protect from paracetamol hepatotoxicity. Vitamin E increases metabolic processes. Finally, the effect of new antidyslipidemic morpholines acting as squalene synthase inhibitos and novel compounds combining antioxidant and anxiolytic structures on cytochrome P450 will be given.
Receptor Tyrosine Kinases As Therapeutic Targets In Malignant Glioma, Present Status And Application In China REN H^1, JIANG T^2, RAINOV NG^3 ^1Harbin Medical Univ., Harbin, China; ^2Tian Tan Hosp., Beijing, China; ^3Klinikum Augsburg, Augsburg, Germany Background: Receptor tyrosine kinases (RTK) and related cellular signalling pathways are important targets for treatment of malignancies. As novel anti-cancer agents, small molecule RTK inhibitors inhibit the phosphorylation and activity of the protein kinases, leading to blockade of the receptor-mediated signaling pathways in tumour cells. However, thus far, the majority of protein kinase inhibitors lack clinical utility as single agents. The aim of the study is to investigate the cellular and molecular effect of RTK inhibitor imatinib mesylate in malignant glioma cells. In addition, we briefly review application of some of the RTK inhibitors in the same malignancy. Methods: The expression of genes was analyzed by qRT-PCR and western blotting in malignant glioma cells. Proliferation was measured by MTT assays and drug synergy was assessed by Chou-Talalay method; Cell cycle and apoptosis were analyzed by flow cytometry and migration by monolayer migration assays. siRNA was applied to knockdown platelet-derived growth factor receptor-B (PDGFRB) expression in glioma cells. Multi-immunoblot was performed on Imatinib-treated and control cells. Results: Imatinib treatment was lack of growth inhibition activity in glioma cells. The treatment was more effective in inhibiting the phosphorylation of Bcr-Abl in K562 cells than that of PDGFRB in glioma cells. Knockdown of PDGFR-B by siRNA showed similar responses on an Antibody microarray as in the case to imatinib treatment in U87 glioma cells. In addition, imatinib induced specific changes in downstream signalling pathways of the cells. Most prominently, continous activation of extracellular signal-regulated kinases (ERK1/2) signaling and its downstream effectors, e.g. dual phosphatases and immediate early genes (IEG), MKP1 and -3, and ribosomal protein S6 (rpS6) were stably increased or altered by both immunoblot and qRT-PCR analysis. Continous activation of ERK induced by imatinib treatment was related to S-phase re-entry in U87 cells. Conclusions: 1) Imatinib treatment induced a complex and dynamic modulation of downstream signal transduction pathways in glioma cells; 2) Synergistic interaction of Imatinib with chemotherapy agents may be related to cell cycle control mechanisms and could be potentially important in a clinical setting.	Long-Term Sequential Deferiprone-Deferoxamine Versus Deferiprone Alone For Thalassaemia Major Patients: A Randomised Clinical Trial RESTIVO PANTALONE G¹, MAGGIO A^1, VITRANO A^1, CAPRA M^2, CUCCIA L^2, GAGLIARDOTTO F^2, FILOSA A^2 , ROMEO MA^2 , MAGNANO C^2, CARUSO V^2, ARGENTO C^2, GERARDI C^2, CAMPISI S^2, VIOLI P^2, MALIZIA R^2, CIANCIULLI P^2, RIZZO M^2, D’ASCOLA DG^2, QUOTA A^2, PROSSOMARITI L^2, FIDONE C^2, ROCCAMO G^2, LOMBARDO T^2, CIANCIO A^2, MEO A^2, COMMENDATORE F^2, CAROLLO A^2, GIUGNO R^2, GIUFFRIDA G^2, GALATI M^2, RIGANO P^1, PEPE A^2, D'AMICO G^2, MORABITO A^2 and GLUUD C^3 ^1U.O.C.Ematologia II con Talassemia, A.O. “V. Cervello”,Palermo,Italy; ^2Members of the Italian Society for Thalassaemia and Haemoglobinopathy;Italy; ^3 Copenhagen Trial Unit, Centre for Clinical Intervention Research, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark Background: Changes in chelation treatment and transfusion practices have improved the prognosis of thalassaemia major patients dramatically. Controversial results have so far been published and no trial with treatment duration longer than 18 months has been published. Methods: This study is a long-term sequential DFP-DFO treatment versus DFP alone trial. The main aims were: variations on multiple determinations of serum ferritin values, mortality, adverse events, and costs. Multicentre randomised open-label tria. DFP at 75mg/kg, divided into 3 oral daily doses, for 4 days per week and DFO by subcutaneous infusion at 50mg/kg/day for the remaining 3 days per week versus DFP alone at 75mg/kg for 7 days. Five years follow-up. Results: 275 consecutive thalassaemia patients were assessed for eligibility. 62 were excluded because of not meeting inclusion criteria or refusal to participate, leaving 213 patients for randomisation and intention-to-treat analysis. The coefficient of regression treatment–year shows a statistically significant serum ferritin reduction in sequential DFP-DFO patients compared with DFP alone patients (p=0.005). Kaplan-Meier survival curves for the two chelation treatments did not show any statistically significant difference (long-rank test, p=0.3145). Adverse events were comparable across groups. Conclusions: Sequential DFP-DFO treatment compared with DFP alone significantly decreases serum ferritin concentration during treatment for 5 years without significant differences regarding mortality or adverse effects. Authors’ disclosure statement: Trial Registration: Clinical Trials NCT00733811
Neonatal Abstinence Syndrome And Cerebral Infarction Following Maternal Codeine Use During Pregnancy REYNOLDS EW^1, REIL-ROMERO RMS^2, BADA HS^1 ^1University of Kentucky, Lexington KY USA. ^2Louisiana State University, Shreveport LA USA Background: Neonatal withdrawal from maternal drugs is common in many neonatal intensive care unitss. Codeine-containing cough preparations given to pregnant mothers can cause neonatal abstinence syndrome. Many women do not consider prescription cough syrups when asked about drug use. Maternal medication or illicit drug use, including opiates, has been identified as a cause of perinatal arterial stroke. Since codeine is an opiate with pharmacodynamic effects similar to morphine, it is reasonable to investigate if maternal codeine use can have effects on the fetus similar to other opiates, including cerebral infarction. Methods: We present 3 cases of newborn infants with perinatal arterial stroke associated with in utero exposure to codeine. The first infant had infarction of the left middle and anterior cerebral arteries. Her mother received a codeine-containing cough medicine for an URI for 2 weeks prior to delivery. The second infant had infarction of the left occipito-temporal region. The mother had been hospitalized with pneumonia and received a codeine-containing cough medicine also for about 2 weeks prior to delivery. A third case has recently been added. None of the infants had other identifiable causes for cerebral infarction. All presented with seizures and signs of neonatal abstinence. All were eventually discharged to home. Results: Perinatal arterial stroke can be a consequence of many illegal drugs, including opiates. Neonatal abstinence syndrome as a result of maternal codeine use has been documented, even in non-addicted mothers. Opiates have been shown to cause neonatal thrombocytosis, apoptosis in microglia and neurons and vasoconstriction in the placental circulation and middle cerebral arteries. It is reasonable to assume that codeine, may have similar effects on the fetus when administered to the pregnant mother. Conclusion: Physicians should investigate maternal medication use, including codeine-containing cough preparations, when evaluating newborn infants with neonatal abstinence syndrome and/or evidence of cerebral infarction, particularly if the mother does not have a history of illegal drug use. This discussion raises questions about the safety of codeine-containing treatments and other “magic bullets” for pregnant women.	Vindesine And Razoxane, An Effective Drug Combination For Soft Tissue Sarcomas RHOMBERG W^1, EITER H^1, SCHMID F^2, SAELY C^3 ^1Department of Radiation Oncology, Academic Teaching Hospital, Feldkirch; and in behalf of the Austrian Society of Radiation Oncology [OEGRO], ^2Internal Med., General Hospital, Bregenz, ^3Internal Medicine, Gen. Hosp. Feldkirch, Austria Background: Vindesine and Razoxane were shown to enhance the radiation response and to suppress distant metastasis in animal systems. Both drugs affect main steps of the metastatic cascade. During the past 15 years, these drugs were evaluated in translational research studies in a variety of soft tissue sarcomas [STS] with emphasis given to the radiation response and the dynamics of metastasis. Methods: In a phase II study, 23 patients with unresectable (n=7) and oligometastatic STS (n=16) received a basic treatment with razoxane (2x125 mg daily) and vindesine (2 mg iV/ week) supported by radiotherapy and occasionally by surgery. Long-term treatment was intended in patients with metastatic disease. Thirty-six patients with comparable stages and prognostic parameters treated with contemporary chemotherapy served as non-randomised, retrospective controls. In addition, the outcome of a small multicenter study on vascular soft tissue sarcomas is reported. This study was performed by the Austrian Society of Radio-Oncology, using the same treatment regimen and study endpoints. Results: In the first study, the combination of razoxane+vindesine+radiotherapy led to 89% major responses (CR + PR). The median number of new metastases after 6 months was 0 (range, 0-40) and after 9 months likewise 0 (0-70). The corresponding numbers in the control group were 4.5 (range, 0-40) and 9 (0->100) [p<0.001]. The progression-free survival at 6 months was 74% in the study group and 23% in the controls. The median survival from the occurrence of the first metastasis or time of unresectability was 20+ months versus 9 months [p<0.001]. The combined treatment was well tolerated but normal tissue reactions were enhanced. In the OEGRO study, 6 of 8 patients with unresectable measurable angiosarcomas showed a CR. The median survival time from the start of the treatment is 23+ months for 12 patients with macro-scopic and microscopic residual disease. The progression-free survival at 6 months was 75%.