Scrapping the new Therapeutic Products Act will leave thousands of New Zealanders exposed to ongoing harm from dodgy medical devices, warn patient safety advocates and legal experts.

The Act - which was due to come into force in 2026 - would have modernised the regulation of medicines and natural health products, and made medical devices (as well as cell, gene and tissue therapies) subject to a similar regulatory regime as drugs.

The industry has backed the move saying the new law was heavy handed and would stop people getting access to the latest life-saving technological advances.

However, Auckland woman Carmel Berry - who was left in constant knife-like pain from plastic mesh implanted during surgery - says she was "living proof" of the old system's failures.

It took more than 10 years of lobbying by her and the other founders of Mesh Downunder to get authorities to take action - a decade in which hundreds of other people were injured.

Carmel Berry says she is "living proof" of the old system's failures. Photo: Supplied

She is horrified that the TPA - which was only signed into law last July - is on the chopping block.

Beginning work to repeal it was number 47 out of 49 points on the government's to-do list for its first 100 days.

"I'm horrified. After so many years of developing and rewriting the act and getting it through ... shame on them."

The Ministry of Health last year paused the use of surgical mesh to fix incontinence until safeguards are in place, including a register and more training for surgeons.

But Carmel says there was now nothing to stop another tragedy like mesh, which has so far cost ACC more than $32.5m in claims.

"Manufacturers took advantage of gynaecologists, in particular, but also urogynaecologists and urologists and brought their product to market without any human testing, no clinical trials.

"And that just can't happen any more."

Consumer Advocacy Alliance spokeswoman Charlotte Korte, who helped found Mesh Down Under, says faulty pacemakers, metal-on-metal artificial joints, contraceptives and breast implants were among dangerous or deadly medical implants used on New Zealand patients over the years.

"Our regulation is absolutely appalling and our harm reporting is the same.

"So we can't identify harmful products, or processes or devices."

Health law expert Laura Hardcastle, from Bell Gully, says the 1981 Medicines Act was more than 40 years old and predated most medical technology now in use.

"This means medical devices are largely largely unregulated."

They have to be registered with Medsafe via an online database, but there is no pre-market assessment.

Furthermore, there is no formal requirement for "untoward events" involving medical devices to be reported.

Major attempts to fix the Medicines Act dated back to the early 2000s, Laura says.

"There's been a lot of criticism of the Act over the years, it's out-of-date and no longer fit for purpose.

"Moreover, as medical technology advances, those gaps are only going to get worse."

New regulations were needed.

"Whether that's more targeted reform of elements of the Medicines Act as it stands, or a statute focusing on medical devices or something else, the reasons for the reform would still seem to be there.

"So it's just a question of when and what comes next."

The medical devices market - which covers everything from bandages to surgical robots - is worth more than $1.8 billion dollars a year in New Zealand.

Medical Technology Association chief executive Cushla Smyth says the new law would have caused long delays for patients in accessing medical breakthroughs.

"The TPA was regulatory over-reach and would have created unnecessary bureaucracy for no real gain because most of those products have already got approval."

Medical devices should not be subjected to the same kind of clinical trials as medicines, she says.

"You can't have blind randomised controlled trials - it would not be ethical for instance to put a placebo pacemaker in a patient."

In the case of surgical mesh, it was not the product that was faulty but deficiencies in surgical training and technique that were to blame for the harm done, Cushla says.

Under the TPA, suppliers would have had to provide a level of detail and documentation not required by any other regulator in the world, she says.

"We're a small market, it just would not be worth it for some ...

"So what we're asking for is light touch system that recognises those overseas approvals and is harmonised with other trusted regulators around the world, like the US FDA [Food and Drug Administration] and Australia's TGA [Therapeutic Goods Administration]."

Medical Technology Association chief executive Cushla Smyth. Photo: Supplied.

Dr Laura agreed most of New Zealand's medical devices were imported and already been through approval processes, so it was important to consider what to do with that information.

However, the US Food and Drug Administration had been criticised over fast-track approvals that did not require extensive clinical trials.

"There's certainly been a lot of controversy over the US FDA regulatory approaches."

Most devices in the US are licensed on the basis that they are similar to a previous model - under the so-called 510(k) process in the Food, Drug and Cosmetic Act.

This "premarket notification" was a concession to the industry, which argued it would stifle innovation if they had to go through the more intensive (and costly) "premarket approval process" every time they made a slight improvement to a device.

"This, in particular, has been the subject of quite a lot of debate and criticism because it doesn't apply necessarily that same degree of rigour as you might see for products that don't have that same comparison to earlier products.

"They go through something called the premarket approval, which tends to be more rigorous ... although that process has also been subject to criticism."

Critics have pointed out that in practice this has meant some devices have been licensed even though the original model was withdrawn from market because it has been shown to be ineffective or even harmful.

The Ministry of Health says if the TPA was repealed, medicines and medical devices would continue to be regulated under the 1981 Medicines Act.

- Ruth Hill / RNZ