16 results on '"S. Leichtl"'
Search Results
2. Studies on Heterocyde-Based Pure Estrogen Antagonists
- Author
-
E. von Angerer, S. Leichtl, and C. Biberger
- Subjects
Transcriptional Activation ,Agonist ,Stereochemistry ,medicine.drug_class ,Drug Resistance ,Antineoplastic Agents ,Breast Neoplasms ,In Vitro Techniques ,General Biochemistry, Genetics and Molecular Biology ,Mice ,Structure-Activity Relationship ,chemistry.chemical_compound ,History and Philosophy of Science ,Endocrine Glands ,Amide ,Tumor Cells, Cultured ,medicine ,Animals ,Humans ,Structure–activity relationship ,Moiety ,Benzofuran ,Indole test ,Chemistry ,Estrogen receptor binding ,General Neuroscience ,Estrogen Antagonists ,Benzothiophene ,Tamoxifen ,Receptors, Estrogen ,Female ,HeLa Cells - Abstract
2-Phenylindoles and isosteric structures such as benzo[b]furans and benzo[b]thiophenes were used as estrogen receptor binding moiety for the syntheses of new nonsteroidal antiestrogens. The antiestrogenic potency was considerably enhanced following the introduction of polar functional groups into the side chain in position 1 (indole) or 3 (benzofuran, benzothiophene). The amino compounds could be characterized as mixed agonist/antagonists. Among the derivatives with an amide group compounds without any agonistic activity both in vitro and in vivo were identified. The amide function can be replaced by alkylthio or alkylsulfonyl groups without changing the endocrine profile very much. In this study, the estrogenic activity was determined in a new transcription assay with luciferase as the reporter. The results obtained in this assay were in very good agreement with those from the conventional mouse uterine weight test. Antitumor activity was determined in hormone-sensitive MCF-7 breast cancer cells. There was no difference in activity between partial and pure estrogen antagonists. However, the derivatives with sulfur containing side chains were much more active than the corresponding heterocycles with amino or carbamoyl functions. They reached IC50-values of about 1 nM. 2-Phenylindoles and 2-phenylbenzothiophenes were rather similar in their potencies whereas the benzofuran derivatives were less active probably due to their lower binding affinities for the ER.
- Published
- 1995
- Full Text
- View/download PDF
3. 1-carbamoylalkyl-2-phenylindoles: Relationship between side chain structure and estrrogen antagonism
- Author
-
S. Leichtl, E. von Angerer, Christian Biberger, R. Koop, and Ernst Holler
- Subjects
Transcriptional Activation ,Indoles ,Polyunsaturated Alkamides ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Estrogen receptor ,Breast Neoplasms ,Biochemistry ,HeLa ,Mice ,Radioligand Assay ,Structure-Activity Relationship ,Endocrinology ,In vivo ,Tumor Cells, Cultured ,medicine ,Animals ,Humans ,Structure–activity relationship ,Luciferase ,Receptor ,Molecular Biology ,Sequence Deletion ,Estradiol ,biology ,Chemistry ,Uterus ,Estrogen Antagonists ,Organ Size ,Cell Biology ,biology.organism_classification ,In vitro ,Tamoxifen ,Receptors, Estrogen ,Estrogen ,Molecular Medicine ,Female ,Cell Division ,hormones, hormone substitutes, and hormone antagonists ,HeLa Cells - Abstract
The 2-phenylindole system has proved to be a versatile structure for the design of potent antiestrogens, especially when functional groups have been introduced into the alkyl side chain in position 1. In analogy to steroidal structures such as ICI 164,384 a number of 2-phenylindoles with carbamoylalkyl and aminoalkyl side chains were synthesized. They bind to the calf uterine estrogen receptor with relative binding affinities between 2.1 and 21 (estradiol = 100). The antiestrogenic effect of these compounds was demonstrated by the inhibition of transcriptional activity which was measured in a new luciferase assay with the EREwtc luc as reporter plasmid. The derivative with a methyl-n-propyldodecanamide side chain (4h) antagonized the effect of estradiol (10(-9) M) completely at concentrations of 10(-7) M and higher. As a sensitive model for quantification of estrogenic and antiestrogenic effects in vitro we used HeLa-cells cotransfected both with the reporter plasmid and estrogen receptor expression vectors HEG0 and HE0. In cells transfected with these vectors transcriptional activity was strongly dependent on side chain structure. With mutated receptors we were able to show that this activity was mainly due to TAF-1 whereas TAF-2 remained silent. When we studied the effect of some of the new compounds in vivo using the mouse uterine weight assay, we observed a correlation between transcriptional activity in transfected HeLa cells and estrogenic effects in mice. Two of the 1-carbamoylalkyl-2-phenylindoles (4f, 4h) proved to be "pure" antiestrogens both in vitro and in vivo. In estrogen-sensitive MCF-7 breast cancer cells, they strongly inhibit cellular growth. Some of the IC50-values were close to 10(-8) M.
- Published
- 1994
- Full Text
- View/download PDF
4. PAA14 PATIENT-PERCEIVED SIDE EFFECTS OF CICLESONIDE AS COMPARED TO FLUTICASONE PROPIONATE IN THE TREATMENT OF MODERATE ASTHMA USING THE INHALED CORTICOSTEROID QUESTIONNAIRE
- Author
-
S. Leichtl, van der Thys Molen, and M. Caeser
- Subjects
medicine.medical_specialty ,medicine.drug_class ,business.industry ,Moderate asthma ,Health Policy ,Public Health, Environmental and Occupational Health ,Ciclesonide ,Fluticasone propionate ,chemistry.chemical_compound ,chemistry ,Internal medicine ,medicine ,Corticosteroid ,business ,medicine.drug - Published
- 2006
- Full Text
- View/download PDF
5. [Comparison of addition of theophylline to inhaled steroid with doubling of the dose of inhaled steroid in asthma]
- Author
-
U. Harnest, R. Sakalauskas, N. Vetter, V. W. Steinijans, H. Steffen, Asaf Keller, S. Leichtl, F. Rathgeb, P. Magyar, and D. Ukena
- Subjects
Male ,Pulmonary and Respiratory Medicine ,Adult ,Adolescent ,medicine.drug_class ,Anti-Inflammatory Agents ,Statistics, Nonparametric ,Drug Administration Schedule ,Double-Blind Method ,Theophylline ,Oral administration ,Bronchodilator ,Forced Expiratory Volume ,Administration, Inhalation ,Medicine ,Humans ,Asthma ,Aged ,Inhalation ,Dose-Response Relationship, Drug ,business.industry ,Beclomethasone ,Beclometasone dipropionate ,Middle Aged ,Prognosis ,medicine.disease ,Bronchodilator Agents ,Respiratory Function Tests ,Europe ,Treatment Outcome ,Anesthesia ,Salbutamol ,Corticosteroid ,Female ,Drug Therapy, Combination ,business ,medicine.drug - Abstract
The anti-asthmatic effects of theophylline may supplement those of inhaled steroids in asthma. The aim of the present trial was to study how the addition of theophylline compares to doubling the dose of inhaled steroid in asthmatics who remain symptomatic on beclomethasone dipropionate (BDP) 400 microg x day(-1). The trial was designed as a randomized, double-blind, parallel-group study in several European countries. Sixty nine patients were treated for 6 weeks with theophylline plus BDP 400 microg x day(-1), compared to 64 patients treated with BDP 800 micro x day(-1). The mean+/-SD serum theophylline concentration was 10.1+/-4.2 mg x L(-1). Lung function measurements were made throughout the study and patients kept daily records of peak expiratory flow (PEF), symptoms and salbutamol usage. Forced expiratory volume in one second and PEF at week 6 were significantly increased by both treatments (p
- Published
- 1998
6. Asthma management: the challenge of equivalence
- Author
-
V W, Steinijans, M, Neuhäuser, T, Hummel, S, Leichtl, F, Rathgeb, and A, Keller
- Subjects
Nebulizers and Vaporizers ,Asthma ,Drug Administration Schedule ,Double-Blind Method ,Theophylline ,Therapeutic Equivalency ,Research Design ,Area Under Curve ,Sample Size ,Administration, Inhalation ,Confidence Intervals ,Humans ,Drug Therapy, Combination ,Steroids ,Anti-Asthmatic Agents ,Chlorofluorocarbons ,Randomized Controlled Trials as Topic - Abstract
Increasing prevalence and severity of asthma worldwide encourage the development of new antiasthmatic drugs, alternative treatment regimens and improved formulations of established drugs. Whereas the efficacy of new chemical entities (NCEs) is usually demonstrated by superiority over placebo or a subtherapeutic dose of the active drug, equivalence concepts have to be used in the following situations: the need to replace chlorofluorocarbon (CFC) propellants for inhalative asthma medications by suitable alternatives, and the need to demonstrate that an alternative treatment regimen is not clinically inferior to an established reference treatment. To cover both situations, the recent ICH guidance on biostatistics clearly distinguishes between two-sided equivalence trials and one-sided non-inferiority trials. In this context, non-inferiority always means "not inferior by a clinically relevant amount". After having confirmed non-inferiority, superiority of the alternative test treatment over the reference treatment can additionally be tested without the need to adjust the significance level. The definition of equivalence acceptance limits becomes crucial, particularly in studies conducted in the flat range of the dose-response curve of inhaled steroids. In order to assess the non-inferiority of steroid sparing add-on treatments we propose a one-sided test based on post-/pre-ratios which have substantially reduced coefficients of variation compared to the post-treatment values themselves. The non-inferiority acceptance limit of 0.90 - as opposed to 0.80 in bioequivalence assessment - reflects clinically irrelevant changes of lung function variables. The proposed methodology is illustrated by 2 examples from randomized, double-blind, parallel-group studies comparing inhaled steroid plus theophylline versus doubling the steroid dose in asthmatics who are symptomatic on low-dose inhaled steroid.
- Published
- 1998
7. 2-Phenylbenzo[B]thiophenes: Mammary tumor inhibiting activity and antiestrogenic potency
- Author
-
S. Leichtl and E. von Angerer
- Subjects
Cancer Research ,medicine.medical_specialty ,Mammary tumor ,Hematology ,Oncology ,business.industry ,Internal medicine ,medicine ,Cancer research ,Potency ,General Medicine ,business - Published
- 1995
- Full Text
- View/download PDF
8. SC8 transcription assays for evaluating estrogenic activity
- Author
-
Christian Biberger, Th. Meyer, S. Leichtl, E. von Angerer, and R. Koop
- Subjects
Chemistry ,Transcription (biology) ,Pharmaceutical Science ,Cell biology - Published
- 1994
- Full Text
- View/download PDF
9. Comparison of the efficacy and safety of ciclesonide 160 microg once daily vs. budesonide 400 microg once daily in children with asthma.
- Author
-
von Berg A, Engelstätter R, Minic P, Sréckovic M, Garcia Garcia ML, Latoś T, Vermeulen JH, Leichtl S, Hellbardt S, and Bethke TD
- Subjects
- Anti-Allergic Agents administration & dosage, Anti-Allergic Agents adverse effects, Anti-Inflammatory Agents administration & dosage, Anti-Inflammatory Agents adverse effects, Asthma physiopathology, Budesonide adverse effects, Child, Double-Blind Method, Female, Humans, Male, Pregnenediones administration & dosage, Pregnenediones adverse effects, Respiratory Function Tests, Treatment Outcome, Anti-Allergic Agents therapeutic use, Anti-Inflammatory Agents therapeutic use, Asthma drug therapy, Budesonide therapeutic use, Pregnenediones therapeutic use
- Abstract
Ciclesonide is an onsite-activated inhaled corticosteroid (ICS) for the treatment of asthma. This study compared the efficacy, safety and effect on quality of life (QOL) of ciclesonide 160 microg (ex-actuator; nominal dose 200 microg) vs. budesonide 400 microg (nominal dose) in children with asthma. Six hundred and twenty-one children (aged 6-11 yr) with asthma were randomized to receive ciclesonide 160 microg (ex-actuator) once daily (via hydrofluoroalkane metered-dose inhaler and AeroChamber Plus spacer) or budesonide 400 microg once daily (via Turbohaler) both given in the evening for 12 wk. The primary efficacy end-point was change in forced expiratory volume in 1 s (FEV1). Additional measurements included change in daily peak expiratory flow (PEF), change in asthma symptom score sum, change in use of rescue medication, paediatric and caregiver asthma QOL questionnaire [PAQLQ(S) and PACQLQ, respectively] scores, change in body height assessed by stadiometry, change in 24-h urinary cortisol adjusted for creatinine and adverse events. Both ciclesonide and budesonide increased FEV1, morning PEF and PAQLQ(S) and PACQLQ scores, and improved asthma symptom score sums and the need for rescue medication after 12 wk vs. baseline. The non-inferiority of ciclesonide vs. budesonide was demonstrated for the change in FEV1 (95% confidence interval: -75, 10 ml, p = 0.0009, one-sided non-inferiority, per-protocol). In addition, ciclesonide and budesonide showed similar efficacy in improving asthma symptoms, morning PEF, use of rescue medication and QOL. Ciclesonide was superior to budesonide with regard to increases in body height (p = 0.003, two-sided). The effect on the hypothalamic-pituitary-adrenal axis was significantly different in favor of ciclesonide treatment (p < 0.001, one-sided). Both ciclesonide and budesonide were well tolerated. Ciclesonide 160 microg once daily and budesonide 400 microg once daily were effective in children with asthma. In addition, in children treated with ciclesonide there was significantly less reduction in body height and suppression of 24-h urinary cortisol excretion compared with children treated with budesonide after 12 wk.
- Published
- 2007
- Full Text
- View/download PDF
10. Roflumilast, a phosphodiesterase 4 inhibitor, reduces airway hyperresponsiveness after allergen challenge.
- Author
-
Louw C, Williams Z, Venter L, Leichtl S, Schmid-Wirlitsch C, Bredenbroker D, and Bardin PG
- Subjects
- Administration, Oral, Adolescent, Adult, Aminopyridines administration & dosage, Benzamides administration & dosage, Bronchial Hyperreactivity chemically induced, Bronchial Hyperreactivity physiopathology, Bronchial Provocation Tests adverse effects, Cross-Over Studies, Cyclopropanes administration & dosage, Cyclopropanes therapeutic use, Dose-Response Relationship, Drug, Double-Blind Method, Follow-Up Studies, Forced Expiratory Volume drug effects, Humans, Male, Middle Aged, Phosphodiesterase Inhibitors administration & dosage, Pilot Projects, Treatment Outcome, Allergens adverse effects, Aminopyridines therapeutic use, Benzamides therapeutic use, Bronchial Hyperreactivity drug therapy, Phosphodiesterase Inhibitors therapeutic use
- Abstract
Background: Roflumilast, an oral, once-daily phosphodiesterase 4 inhibitor, is currently in clinical development for the treatment of asthma., Objectives: This pilot study examined the effect of roflumilast on allergen-induced airway hyperresponsiveness (AHR) to histamine challenge and asthmatic response to allergen challenge., Methods: In a randomized, double-blind, 2-period, crossover trial, 13 patients with mild allergic asthma [mean forced expiratory volume in 1 s (FEV(1)) % predicted = 86%] received a single dose of oral roflumilast 1,000 microg or placebo. Patients were administered roflumilast 60 min before allergen challenge, and asthmatic responses were assessed via change in FEV(1)
- Published
- 2007
- Full Text
- View/download PDF
11. Efficacy and safety of roflumilast in the treatment of asthma.
- Author
-
Bateman ED, Izquierdo JL, Harnest U, Hofbauer P, Magyar P, Schmid-Wirlitsch C, Leichtl S, and Bredenbröker D
- Subjects
- Adolescent, Adult, Aged, Child, Cyclopropanes therapeutic use, Dose-Response Relationship, Drug, Double-Blind Method, Female, Humans, Lung drug effects, Male, Middle Aged, Respiratory Function Tests, Aminopyridines therapeutic use, Anti-Asthmatic Agents therapeutic use, Asthma drug therapy, Benzamides therapeutic use, Phosphodiesterase Inhibitors therapeutic use
- Abstract
Background: The central role of chronic inflammation of the airways in asthma pathogenesis is supported by the efficacy of corticosteroids in controlling clinical symptoms. However, the search continues for potentially safer anti-inflammatory alternatives. Roflumilast is an oral, once-daily phosphodiesterase type 4 inhibitor with anti-inflammatory activity in preclinical models of asthma and chronic obstructive pulmonary disease., Objective: To investigate the dose-ranging efficacy and safety of roflumilast in patients with mild-to-moderate asthma., Methods: Patients (N = 693) were randomized in a double-blind, parallel-group, phase 2/3 study. After a 1- to 3-week placebo run-in period, patients (mean forced expiratory volume in 1 second [FEV1], 73% of predicted) were randomized to receive 100, 250, or 500 microg of roflumilast once daily for 12 weeks. The primary end point was change from baseline in FEV1; secondary end points included change from baseline in morning and evening peak expiratory flow., Results: Roflumilast use significantly increased FEV1 (P < .001 vs baseline). Improvements from baseline in FEV1 at the last visit were 260, 320, and 400 mL for the 100-, 250-, and 500-microg dose groups, respectively. Roflumilast, 500 microg, was superior to roflumilast, 100 microg, by 140 mL in improving FEV1 (P = .002). There were also significant improvements from baseline in morning and evening peak expiratory flow in all the dose groups (P < or = .006). Roflumilast was well tolerated at all doses tested. Most adverse events were mild to moderate in intensity and transient., Conclusion: These results support the emerging role of roflumilast, 500 microg/d, in the treatment of asthma.
- Published
- 2006
- Full Text
- View/download PDF
12. Roflumilast, an oral, once-daily phosphodiesterase 4 inhibitor, attenuates allergen-induced asthmatic reactions.
- Author
-
van Schalkwyk E, Strydom K, Williams Z, Venter L, Leichtl S, Schmid-Wirlitsch C, Bredenbröker D, and Bardin PG
- Subjects
- Administration, Oral, Adult, Aminopyridines adverse effects, Asthma physiopathology, Benzamides adverse effects, Cross-Over Studies, Cyclic Nucleotide Phosphodiesterases, Type 4, Cyclopropanes adverse effects, Cyclopropanes therapeutic use, Double-Blind Method, Female, Forced Expiratory Volume drug effects, Humans, Male, 3',5'-Cyclic-AMP Phosphodiesterases antagonists & inhibitors, Allergens immunology, Aminopyridines therapeutic use, Asthma drug therapy, Benzamides therapeutic use, Phosphodiesterase Inhibitors therapeutic use
- Abstract
Background: Asthma is a chronic inflammatory disease with increasing incidence worldwide. Roflumilast is an oral, once-daily inhibitor of phosphodiesterase type 4 that prevents the breakdown of cyclic adenosine monophosphate levels, leading to inhibition of proinflammatory signaling., Objective: The objective of this study was to investigate the effects of repeated doses of 250 or 500 microg of roflumilast on asthmatic airway responses to allergen., Methods: Twenty-three patients with mild asthma with an FEV1 of 70% of predicted value or greater were enrolled in a randomized, double-blind, placebo-controlled, 3-period crossover study. Patients participated in 3 treatment periods (7-10 days) separated by washout periods (2-5 weeks). Patients received 250 microg of oral roflumilast, 500 microg of roflumilast, or placebo once daily. Allergen challenge was performed at the end of each treatment period, followed by FEV1 measurements over the ensuing 24 hours., Results: Late asthmatic reactions (LARs) were reduced by 27% (P = .0110) and 43% (P = .0009) in patients treated with 250 and 500 microg of roflumilast, respectively, versus placebo. Roflumilast, 250 and 500 microg, also attenuated early asthmatic reactions by 25% (P = .0038) and 28% (P = .0046), although not to the same extent as LAR attenuation. Roflumilast was well tolerated. No serious adverse events or discontinuations caused by adverse events were reported., Conclusion: Once-daily oral roflumilast modestly attenuated early asthmatic reactions and, to a greater extent, LARs to allergen in patients with mild allergic asthma. Pronounced suppression of late responses in an allergen challenge model suggests that roflumilast might have anti-inflammatory activity, which could provide clinical efficacy in chronic inflammatory pulmonary diseases, such as asthma.
- Published
- 2005
- Full Text
- View/download PDF
13. 2-Phenylbenzo[b]thiophene-based antiestrogens with mammary tumor inhibiting activity.
- Author
-
Leichtl S and von Angerer E
- Subjects
- Animals, Antineoplastic Agents, Hormonal pharmacology, Drug Screening Assays, Antitumor, Estrogen Antagonists pharmacology, Humans, Mice, Thiophenes pharmacology, Tumor Cells, Cultured, Antineoplastic Agents, Hormonal chemical synthesis, Breast Neoplasms drug therapy, Estrogen Antagonists chemical synthesis, Thiophenes chemical synthesis
- Abstract
In this study we extended our studies on heterocyclic antiestrogens to 2-phenylbenzo[b]thiophenes which can be considered as isosteric to the 2-phenylindole system. We synthesized a number of 6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophenes with carbamoyl and amino functions in the side chain at carbon-3 and analyzed their biological properties. The binding affinities for the estrogen receptor are mainly influenced by the chain length whereas the hormonal profile depends on the nature of the functional group. From this study 3-[10-(2,2,3,3,4,4,4-heptafluorobutyl-methylcarbamoyl) decyl]-6-hydroxy-2-(4-hydroxyphenyl)benzo-[b]thiophene (6e) emerged as an antiestrogen with all the characteristics of a pure antagonist. It did not stimulate gene expression in HeLa cells cotransfected with the expression vector for the human estrogen receptor HEG0 and the luciferase reporter plasmid EREwtc luc nor did it show any estrogenic activity in the mouse uterus weight test. In the latter assay, it completely abrogated the stimulatory effect of estrone. Due to its antiestrogenic potency it strongly inhibited the growth of estrogen-sensitive human MCF-7 breast cancer cells with an IC50 value of 5 nM. These data suggest that an amide function in combination with the fluorination of the terminal carbon atoms is an appropriate modification to abolish the estrogenic action of the 2-phenylbenzothiophene system.
- Published
- 1998
- Full Text
- View/download PDF
14. [Comparison of addition of theophylline to inhaled steroid with doubling of the dose of inhaled steroid in asthma].
- Author
-
Ukena D, Harnest U, Sakalauskas R, Magyar P, Vetter N, Steffen H, Leichtl S, Rathgeb F, Keller A, and Steinijans VW
- Subjects
- Adolescent, Adult, Aged, Asthma diagnosis, Dose-Response Relationship, Drug, Drug Administration Schedule, Drug Therapy, Combination, Europe, Forced Expiratory Volume drug effects, Humans, Middle Aged, Asthma drug therapy, Beclomethasone administration & dosage, Theophylline administration & dosage
- Abstract
The anti-asthmatic effect of theophylline may supplement those of inhaled steroids in asthma. The aim of the present trial was to study how the addition of theophylline compares to doubling the dose of inhaled steroid in asthmatics who remain symptomatic on beclomethasone dipropionate (BDP) 400 micrograms/day. The trial was designed as a randomized, double-blind, parallel-group study in several European countries. 69 patients were treated for 6 weeks with theophylline plus BDP 400 micrograms/day, compared to 64 patients treated with BDP 800 micrograms/day. The mean +/- SD serum theophylline concentration was 10.1 +/- 4.2 mg/l. Lung function measurements were made throughout the study and patients kept daily records of peak expiratory flow rate (PEF), symptoms and salbutamol usage. Forced expiratory volume in one second and PEF at week 6 were significantly increased by both treatments (p < 0.01). PEF variability was reduced by about 30% in both groups. There were significant improvements in asthma symptoms and rescue medication use (p < 0.001). There were no significant differences between the treatment groups. The study demonstrated clinical equivalence of theophylline plus beclomethasone dipropionate 400 micrograms/day and beclomethasone dipropionate 800 micrograms/day in patients whose asthma is not controlled on beclomethasone dipropionate 400 micrograms/d. The results support the use of theophylline as steroid-sparing agent. The combination of low-dose inhaled steroid plus theophylline is a suitable treatment for moderate asthma.
- Published
- 1998
15. Asthma management: the challenge of equivalence.
- Author
-
Steinijans VW, Neuhäuser M, Hummel T, Leichtl S, Rathgeb F, and Keller A
- Subjects
- Administration, Inhalation, Anti-Asthmatic Agents pharmacokinetics, Area Under Curve, Chlorofluorocarbons, Confidence Intervals, Double-Blind Method, Drug Administration Schedule, Drug Therapy, Combination, Humans, Nebulizers and Vaporizers standards, Research Design, Sample Size, Steroids pharmacokinetics, Theophylline pharmacokinetics, Therapeutic Equivalency, Anti-Asthmatic Agents administration & dosage, Asthma drug therapy, Randomized Controlled Trials as Topic methods, Steroids administration & dosage, Theophylline administration & dosage
- Abstract
Increasing prevalence and severity of asthma worldwide encourage the development of new antiasthmatic drugs, alternative treatment regimens and improved formulations of established drugs. Whereas the efficacy of new chemical entities (NCEs) is usually demonstrated by superiority over placebo or a subtherapeutic dose of the active drug, equivalence concepts have to be used in the following situations: the need to replace chlorofluorocarbon (CFC) propellants for inhalative asthma medications by suitable alternatives, and the need to demonstrate that an alternative treatment regimen is not clinically inferior to an established reference treatment. To cover both situations, the recent ICH guidance on biostatistics clearly distinguishes between two-sided equivalence trials and one-sided non-inferiority trials. In this context, non-inferiority always means "not inferior by a clinically relevant amount". After having confirmed non-inferiority, superiority of the alternative test treatment over the reference treatment can additionally be tested without the need to adjust the significance level. The definition of equivalence acceptance limits becomes crucial, particularly in studies conducted in the flat range of the dose-response curve of inhaled steroids. In order to assess the non-inferiority of steroid sparing add-on treatments we propose a one-sided test based on post-/pre-ratios which have substantially reduced coefficients of variation compared to the post-treatment values themselves. The non-inferiority acceptance limit of 0.90 - as opposed to 0.80 in bioequivalence assessment - reflects clinically irrelevant changes of lung function variables. The proposed methodology is illustrated by 2 examples from randomized, double-blind, parallel-group studies comparing inhaled steroid plus theophylline versus doubling the steroid dose in asthmatics who are symptomatic on low-dose inhaled steroid.
- Published
- 1998
16. Comparison of addition of theophylline to inhaled steroid with doubling of the dose of inhaled steroid in asthma.
- Author
-
Ukena D, Harnest U, Sakalauskas R, Magyar P, Vetter N, Steffen H, Leichtl S, Rathgeb F, Keller A, and Steinijans VW
- Subjects
- Administration, Inhalation, Adolescent, Adult, Aged, Dose-Response Relationship, Drug, Double-Blind Method, Drug Therapy, Combination, Female, Humans, Male, Middle Aged, Prognosis, Respiratory Function Tests, Statistics, Nonparametric, Treatment Outcome, Anti-Inflammatory Agents administration & dosage, Asthma drug therapy, Beclomethasone administration & dosage, Bronchodilator Agents administration & dosage, Theophylline administration & dosage
- Abstract
The anti-asthmatic effects of theophylline may supplement those of inhaled steroids in asthma. The aim of the present trial was to study how the addition of theophylline compares to doubling the dose of inhaled steroid in asthmatics who remain symptomatic on beclomethasone dipropionate (BDP) 400 microg x day(-1). The trial was designed as a randomized, double-blind, parallel-group study in several European countries. Sixty nine patients were treated for 6 weeks with theophylline plus BDP 400 microg x day(-1), compared to 64 patients treated with BDP 800 micro x day(-1). The mean+/-SD serum theophylline concentration was 10.1+/-4.2 mg x L(-1). Lung function measurements were made throughout the study and patients kept daily records of peak expiratory flow (PEF), symptoms and salbutamol usage. Forced expiratory volume in one second and PEF at week 6 were significantly increased by both treatments (p<0.01). PEF variability was reduced by about 30% in both groups. There were significant improvements in asthma symptoms and rescue medication use (p<0.001). There were no significant differences between the treatment groups. The study demonstrated clinical equivalence of theophylline plus beclomethasone dipropionate 400 microg x day(-1) and beclomethasone dipropionate 800 microg x day(-1) in patients whose asthma is not controlled on beclomethasone dipropionate 400 microg x day(-1). The results support the use of theophylline as a steroid-sparing agent. The combination of low-dose inhaled steroid plus theophylline is a suitable treatment for moderate asthma.
- Published
- 1997
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.