Theravance公司推出新型抗生素

一种新型注射抗生素的体外试验和人体临床试验结果显示：用于治疗革兰氏阳性细菌导致的严重感染，药物抵抗性较小而体外活性极其强大。在2005年4月荷兰哥本哈根举行的欧洲临床微生物学和感染疾病学会年会上报道了这项结果。

一项临床试验设计用于评估这种新型Telavancin抗生素的耐药性发展情况，在金黄色葡萄球菌中的综合研究资料显示，Telavacin对突变耐药菌株有较低活性。这种药物显示出对革兰氏细菌有强大的光谱活性，包括万古霉素中度抗药性金黄色葡萄球菌和万古霉素耐药金黄色葡萄球菌菌株。另外一项试验显示：这种药物在血浆、皮肤大水疱中有着很好的穿透性，能够达到杀灭S aureus包括甲氧苯青霉素耐药菌株的有效浓度。在血透患者中进行的临床试验结果显示：对中度～中度肾功能损害患者建议降低用药剂量。

在一项计划研究对S aureus以及其它革兰氏阳性细菌有效的多价药物研究方案中，Theravance公司发现了这种新型脂甘油肽，Televancin。Televancin具有独特的多功能作用机制，该公司相信能够加速杀灭细菌减少耐药细菌生成的危险。该药正在进行III期临床试验，治疗复杂的皮肤以及皮肤结构的感染、以及医院内获得性肺炎。在临床使用中所能达到的较大浓度，观察到对细菌胞膜功能，例如膜去极化以及通透性，都有直接作用。
 
Injectible Antibiotic Shows Potent Activity
 
The results of in vitro studies and human clinical studies of a new injectable antibiotic showed low potential for drug resistance as well as potent in vitro activity for serious infections caused by Gram-positive bacteria. These results were presented at the annual European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), held in Copenhagen (Denmark) in April 2005.

A study designed to evaluate the potential of the antibiotic for development of resistance to the new drug, called telavancin, among a collection of Staphylocaccus aureus revealed that telavancin has a low potential for resistant mutant selection. The compound exhibited potent in vitro activity across a broad spectrum of Gram-positive organisms, including vancomycin-intermediate S aureus and vancomycin-resistant S aureus strains. Another study showed excellent penetration of the drug in plasma and skin blister fluid, achieving concentrations well above those shown to be bactericidal against S aureus, including methicillin-resistant strains. Still another study of the drug used in hemodialysis subjects concluded that a dosage reduction is recommended for patients with moderate-to-severe renal impairment.

Televancin is a novel lipoglycopeptide discovered by Theravance (So. San Francisco, CA, USA) through the application of multivalent drug design in a program dedicated to finding new antibiotics for serious infections due to S aureus and other Gram-positive pathogens. Televance has a unique multifunctional mechanism of action that the company believes speeds bacterial killing and reduces the risks of inducing resistance. The compound is currently in phase III study for the treatment of complicated skin and skin structure infections and hospital-acquired pneumonia. At higher, clinically achievable concentrations, direct effects on bacterial plasma membrane function, such as membrane potential depolarization and increased permeability, were observed.