RESUMO
Nonsense mutations promote premature translational termination and cause anywhere from 5-70% of the individual cases of most inherited diseases. Studies on nonsense-mediated cystic fibrosis have indicated that boosting specific protein synthesis from <1% to as little as 5% of normal levels may greatly reduce the severity or eliminate the principal manifestations of disease. To address the need for a drug capable of suppressing premature termination, we identified PTC124-a new chemical entity that selectively induces ribosomal readthrough of premature but not normal termination codons. PTC124 activity, optimized using nonsense-containing reporters, promoted dystrophin production in primary muscle cells from humans and mdx mice expressing dystrophin nonsense alleles, and rescued striated muscle function in mdx mice within 2-8 weeks of drug exposure. PTC124 was well tolerated in animals at plasma exposures substantially in excess of those required for nonsense suppression. The selectivity of PTC124 for premature termination codons, its well characterized activity profile, oral bioavailability and pharmacological properties indicate that this drug may have broad clinical potential for the treatment of a large group of genetic disorders with limited or no therapeutic options.
Assuntos
Códon sem Sentido/genética , Doenças Genéticas Inatas/tratamento farmacológico , Doenças Genéticas Inatas/genética , Oxidiazóis/farmacologia , Oxidiazóis/uso terapêutico , Biossíntese de Proteínas/efeitos dos fármacos , Alelos , Animais , Disponibilidade Biológica , Distrofina/biossíntese , Distrofina/genética , Doenças Genéticas Inatas/sangue , Humanos , Camundongos , Camundongos Endogâmicos mdx , Oxidiazóis/administração & dosagem , Oxidiazóis/farmacocinética , Fenótipo , Biossíntese de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Especificidade por SubstratoRESUMO
STUDY DESIGN: Two replicate, 4-week, randomized, double-blind, placebo-controlled, trials of rofecoxib 25 and 50 mg versus placebo for chronic low back pain. OBJECTIVES: To determine the efficacy and safety of two doses of rofecoxib compared to placebo in the treatment of chronic low back pain. SUMMARY OF BACKGROUND DATA: Although nonsteroidal anti-inflammatory drugs are commonly prescribed for chronic low back pain, their efficacy is unproven and toxicity can be serious. These studies evaluated the efficacy and tolerability of rofecoxib, a selective COX-2 inhibitor, in the treatment of chronic low back pain. METHODS: Patients with chronic low back pain were randomized 1:1:1 to rofecoxib 25 mg, 50 mg, or placebo once daily. Primary endpoint: Low Back Pain Intensity. Secondary endpoints: Pain Bothersomeness, Global Assessments of Response to Therapy, Global Assessment of Disease Status, Roland-Morris Disability Questionnaire, SF-12 Health Survey, Use of Rescue Acetaminophen, and Discontinuations Due to Lack of Efficacy. RESULTS: Combining both studies, 690 patients were randomized to placebo (N = 228), rofecoxib 25 mg (N = 233), or rofecoxib 50 mg (N = 229). Mean (+/- SD) age was 53.4 (+/- 12.9) years, pain duration 12.1 (+/- 11.8) years, 62.3% female. Both rofecoxib groups improved significantly. Mean differences from placebo in pain intensity were -13.50 mm, -13.81 mm (25, 50 mg doses) respectively (P < 0.001). Both regimens were superior to placebo in eight of nine secondary endpoints. Fifty mg provided no advantage over 25 mg. Both rofecoxib regimens were well tolerated, although 25 mg had a slightly better safety profile. CONCLUSIONS: Rofecoxib significantly reduced chronic low back pain in adults and was well tolerated.
