EU approves Pfizer antibiotic for superbug infections

Pfizer’s Emblaveo has been approved in the EU with a first-in-class indication in multidrug-resistant (MDR) infections.

The drug – a combination of beta-lactam antibiotic aztreonam with beta-lactamase inhibitor avibactam – is the first drug of this type to get a green light from the European Commission to treat serious infections caused by MDR Gram-negative bacteria in adults.

Pfizer said Emblaveo – which is based on two components that are already approved in products used for other infections – can also be used for ‘superbug’ pathogens that produce metallo-beta-lactamases (MBLa), which are responsible for resistance to almost all beta-lactam antibiotics.

MBL-producing Gram-negative bacteria are on the rise globally and are a priority pathogen for the World Health Organization (WHO), which has said they are an emerging threat.

The new drug's label covers complicated intra-abdominal infections (cIAI), hospital-acquired pneumonia (HAP), including ventilator-associated pneumonia (VAP), and complicated urinary tract infections (cUTI), including pyelonephritis.

The EC is the first regulator to approve the combination, for which marketing applications are also being prepared in other countries, including the US and Canada, where AbbVie holds rights. Use of the drug will likely be reserved for patients who have exhausted other treatment options.

“For healthcare teams treating patients with serious Gram-negative bacterial infections, the prospect of running out of effective treatment options is a daunting but very real threat,” according to Yehuda Carmeli of Tel Aviv Medical Centre in Israel, who was an investigator in the REVISIT study conducted in support of Emblaveo’s marketing application.

He said the EC’s decision is “welcome news for the infectious disease community and provides new hope to critically ill patients affected by antimicrobial resistance.”

REVISIT compared Emblaveo to a regimen based on meropenem and found that it was as effective in treating cIAI, HAP, VAP, and cUTI infections without introducing any additional safety concerns. It was supported by data from the ASSEMBLE study, which focused on MBL infections and showed a cure rate of almost 42% versus 0% for best-available therapy.

Emblaveo is the second antibiotic approved for problem pathogens in the EU this year, raising hopes that after years of neglect due to the difficulty of getting a return on R&D investment for drugs often used as last-line therapy, the pipeline of antimicrobials may be starting to flow again.

In March, Allecra Therapeutics got a green light for Exblifep (cefepime/enmetazobactam), another beta-lactam/beta-lactamase inhibitor combination that has also been cleared in the US.

Antimicrobial resistance (AMR) already kills a million and a half people every year worldwide, and that could reach 10 million deaths by 2050 unless there is a concerted effort to research new antibiotics.

The UK has become something of an international focal point in efforts to tackle the threat of AMR, attempting to shift the economic model for antimicrobials in favour of investment in R&D by setting up a subscription-based system in which developers are paid a fixed annual fee even if their medicines are not used.