AstraZeneca’s new antibiotic for multidrug resistant (MDR) infections – Zavicefta – has been approved for marketing in the EU.
The European Medicines Agency (EMA) cleared Zavicefta (ceftazidime and avibactam) for the treatment of serious Gram-negative bacterial infections requiring hospitalization.
The new drug combines an established cephalosporin with a new beta lactamase inhibitor designed to overcome one of the key resistant mechanisms that reduce the effectiveness of the beta lactam class of antibiotics, which in addition to cephalosporins also includes penicillin derivatives, monobactams and carbapenems.
It has also already been approved in the US – where it is sold by Allergan – under the Avycaz trade name.
One of the key roles for the new product is in the treatment of infections with carbapenem-resistant Enterobacteriaceae (CRE), a family that includes pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella and Escherichia coli.
Carbapenems such as meropenem, ertapenem, imipenem and doripenem are normally reserved for serious infections caused by drug-resistant Gram-negative bacteria, but rates of resistance to these drugs are on the rise and pose a serious threat to public health.
Some CRE infections are resistant to all known antibiotics and according to some reports can contribute to the death of up to 50% of patients who become infected.
In the UK, cases of CRE have been encountered in some hospitals in Manchester and London, according to the Department of Health, raising the grim prospect of some patients being untreatable even with what are currently last-line drugs.
In 2014 Professor Sally Davies, the UK Chief Medical Officer, warned that countries are facing an ‘apocalypse’ if measures to curb MDR – such as the development of novel antibacterial drugs – are not accelerated.
AZ and Actavis are also testing avibactam in combination with other beta lactam antibiotics, with phase III trials ongoing looking at the drug alongside aztreonam and ceftaroline.
Meanwhile, Merck & Co is also working on a beta lactamase inhibitor called relebactam, and recently started a phase III programme looking at the drug in combination with imipenem.
The Medicines Company also has a candidate called RPXZ7009 in phase III trials, partnered with meropenem, while Roche/Meiji Seika/Fedora recently started trials of their OP0595/RG6080 compound.