Proposal to fund medicines for people with high blood pressure and bacterial infections

What would the effect be?

From 1 November 2026, ceftolozane with tazobactam (brand name Zerbaxa) would be funded for use in Health New Zealand hospitals to treat people with significant multi-drug resistant bacterial infections.

We estimate that around 20-33 people per year over the next 5 years would receive ceftolozane with tazobactam for the treatment of multi-drug resistant infections.

About multi-drug resistant infections and ceftolozane with tazobactam (Zerbaxa)

Antimicrobial resistance is when microorganisms (such as bacteria, viruses, fungi or parasites) develop resistance to the medicines designed to treat them. Antimicrobial-resistant infections are a growing global health concern because they can be difficult to treat and resistant infections may spread within communities.

When microorganisms become resistant to multiple antimicrobial medicines, they are often referred to as multi-drug resistant organisms (MDRO’s), sometimes known as ‘superbugs.’

New Zealand’s rates of antimicrobial resistance remain relatively low compared with many other countries. However, resistance is increasing in some infections, and antimicrobial use remains high. Continued efforts are needed to help preserve the effectiveness of existing treatments.

Ceftolozane with tazobactam is expected to be used primarily for the treatment of serious infections caused by multidrug-resistant Pseudomonas aeruginosa and Enterobacterales bacteria.

Ceftolozane with tazobactam is a combination medicine of two agents. Ceftolozane, a cephalosporin class antibiotic and tazobactam a beta-lactamase inhibitor.

Ceftolozane belongs to the wider group of antibiotics called beta-lactams. It works by interfering with the building blocks bacteria need to build their cell walls. This causes the bacteria to die as they are unable to maintain the integrity of their cell wall.

Tazobactam is a beta-lactam inhibitor which inactivates the beta-lactamase enzymes bacteria use to protect themselves from antibiotics. This means that when it is combined with antibiotics such as ceftolozane the antibiotic is able to work normally and kill the bacteria.

Ceftolozane with tazobactam would only be administered in hospital and is usually administered in short courses of 5-14 days.

Why we’re proposing this

We first received an application to fund ceftolozane with tazobactam in 2015 for the empiric treatment of complicated intra-abdominal and urinary tract infections. Empiric treatment refers to treatment started before the specific cause of an infection is confirmed.

The application was considered by Pharmac’s Anti-infective Subcommittee in February 2016 and the Pharmacology and Therapeutics Advisory Committee (PTAC) in October 2016. Both committees recommended declining the application, as they considered ceftolozane with tazobactam offered limited additional benefit over existing funded treatments in this setting and was substantially more expensive.

In 2018, Pharmac received a second application seeking funding for use as salvage therapy in people with resistant infections. The Anti-infective Subcommittee reviewed this application in May 2019 and recommended it be declined, noting that the evidence supporting its use against key resistant bacteria was less compelling than for other treatments, such as ceftazidime with avibactam. Pharmac consulted on a proposal to decline the application in December 2023. However, following feedback from infectious diseases specialists and members of the Anti-infective Advisory Committee, a decision to decline was not progressed.

The Anti-infective Advisory Committee reconsidered the application in June 2024 and concluded that both the evidence base and the antimicrobial resistance landscape had changed since its earlier reviews. The Committee considered that declining funding for ceftolozane with tazobactam was no longer appropriate and that the medicine could address an unmet need not met by other funded antibiotics for the treatment of multidrug-resistant organisms (MDROs).

We are now proposing to fund ceftolozane with tazobactam as we have reached a provisional agreement with Merck Sharp & Dohme (New Zealand) Limited, the supplier of Zerbaxa. The medicine has previously been funded and used in some Health New Zealand hospitals through Pharmac's Named Patient Pharmaceutical Assessment (NPPA) process.

Funding through the Pharmaceutical Schedule would mean, for some people, clinicians would no longer need to submit NPPA applications for this medicine, reducing the administrative burden and allowing them to focus more on patient care.

The relevant advisory committee records are:

• Anti-infective Subcommittee February 2016 meeting record [PDF]
• Pharmacology and Therapeutics Advisory Committee (PTAC) October 2016 meeting record [PDF]
• Anti-infective Subcommittee May 2019 meeting record [PDF]
• December 2023 proposal to decline inactive funding applications [PDF]
• Anti-infective Advisory Committee June 2024 meeting record [PDF]

Details about our proposal

From 1 November 2026 ceftolozane with tazobactam would be funded in Health New Zealand hospitals.

Ceftolozane with tazobactam would be listed from 1November 2026 on the hospital medicines list subject to the following hospital medicine restriction:

Restricted

Clinical microbiologist or infectious disease specialist or on the recommendation of a clinical microbiologist or infectious disease specialist

Either:

1. For the treatment of infection with a microorganism proven to be resistant to other funded antibiotics, based on microbiology reporting; or
2. For the treatment of infection with an organism reasonably expected to be resistant to other funded antibiotics but susceptible to ceftolozane with tazobactam

These criteria are based on the recommendation of Pharmac’s clinical advisors on the Anti-infective Advisory Committee.

Anti-infective Advisory Committee meeting of June 2024 – Item 10