MSD has launched a new intravenous antibiotic in the UK capable of treating certain Gram-negative bacterial infections, offering a new weapon in the fight against antimicrobial resistance.

Zerbaxa is a combination product containing ceftolozane, a cephalosporin antibacterial drug that kills bacteria by interfering with the production of certain molecules essential to building their protective cell walls, and tazobactam, which blocks the action of certain enzymes called beta-lactamases, whih enable bacteria to break down beta-lactam antibiotics like ceftolozane, making them resistant to the antibiotic’s action.

The drug is now available in the UK to treat complicated intra-abdominal infections, acute pyelonephritis and complicated urinary tract infections  in hospital settings, offering an alternative to current standard of care with carbapenems, to which there is currently growing antimicrobial resistance.

The move follows European approval back in September, on the back of data showing Zerbaxa to be at least as effective as other antibiotics in curing infections. 

In one trial involving 1,083 patients who mostly had kidney infection or in some cases a complicated urinary-tract infection, the drug successfully treated the infection in about 85% of the cases, compared with 75% of those treated with the antibiotic levofloxacin. In a second study involving 993 patients with complicated intra-abdominal infections, both Zerbaxa and another antibiotic, meropenem, were able to cure around 94% of patients.

Antimicrobial resistance is one of the biggest threats facing public health in the 21st century. The Department of Health has estimated that AMR already costs the European Union at least 1.5 billion Euros per year and claims around 25,000 lives - with estimated 3,000 in the UK. But experts are forecasting that the annual death rate in Europe will rocket to 390,000 by 2050, and from 700,000 to 10 million, globally, highlighting the urgent need for new antibiotics.

MSD picked up the antibiotic through its $9.5-billion purchase of Cubist Pharmaceutical earlier this year.