NZ developed anti-cancer drug gets trial approval

A promising new anti-cancer drug developed in New Zealand will be tested on local patients after US regulators granted approval for a clinical trial.

The "stealth" anti-cancer drug, part of a new class of hypoxia-activated treatments, was designed by the Auckland Cancer Society Research Centre (ACSRC) and the Maurice Wilkins Centre at Auckland University.

Enrolments for the first patient trial of PR610 will begin in a few weeks at Auckland Hospital, Waikato Hospital and in the United States after the US Food and Drug Administration approved a two-phase clinical trial.

The trial will recruit small groups of eligible patients who will be given different doses of the drug and monitored for side effects, blood levels and anti-tumour activity.

When suitable doses are established, a second phase will trial the drug in lung cancer patients with solid tumours.

The trial will initially focus on patients with non-small cell lung cancer who have become resistant to reversible tyrosine kinase inhibitors such as erlotinib or gefitinib.

There is currently no effective treatment when these patients relapse.

PR610 is an irreversible multi-kinase inhibitor, which means it is less susceptible to some of the resistance mechanisms that limit the use of reversible inhibitors.

The drug specifically targets low-oxygen, or hypoxic, regions in tumours.

The drug's designers, Dr Jeff Smaill and Dr Adam Patterson, say it has shown "striking" anti-cancer activity in lab tests.

"We were particularly impressed when we compared PR610 to existing clinical candidates. Only PR610 was able to shrink the drug-resistant lung cancer models," Dr Patterson said.

While the initial trial will focus on lung cancer, future studies would look at other cancers including gastric, breast and pancreatic cancers - conditions which are currently treated with reversible tyrosine kinase inhibitors.

The Cancer Society's Auckland chief executive John Loof said it was especially pleasing to see clinical trials of new drugs being held in New Zealand.

"Local patients can be some of the first involved in furthering our understanding of how these targeted medicines can make such a difference.

"Cancer Society donors and supporters can feel well satisfied that they have underpinned yet another exciting step forward in cancer medicine."

ACSRC co-director Associate Professor Mark McKeage, who is leading the clinical trial, said the exciting new therapy ushered in a new era of personalised medicine in New Zealand.

"For the first time we will be screening patients for the genetic mutation that causes drug resistance and then enrolling them in a trial of a New Zealand drug designed to target that mutation."

PR610 is licensed to Proacta Incorporated, a San Diego biotechnology company which last year began collaborating with Yakult Honsha Co in Japan to research, develop and commercialise the drug.

It is the second novel hypoxia prodrug to be developed by ACSRC.

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