Local cancer drug approved for first clinical trial in United States and New Zealand

The US Food and Drug Administration (FDA) has granted approval for PR610, an anticancer “stealth” drug invented in New Zealand, to move forward to human clinical trials through its approval of an Investigational New Drug (IND) Application for the drug.

The first clinical trial, a phase I/II study, will be conducted at Auckland City Hospital, Waikato Hospital and sites in the United States.

Patient enrolment is expected to commence in the coming weeks. Initially, the trial will recruit small groups of study-eligible patients to different dose levels of PR610 followed by monitoring of its side-effects, blood levels and anti-tumour activity.

PR610 belongs to an exciting new class of hypoxia-activated pro-drugs for the treatment of cancer, designed by Dr Jeff Smaill and Dr Adam Patterson from the Auckland Cancer Society Research Centre (ACSRC) and Maurice Wilkins Centre for Molecular Biodiscovery.

It is licensed to Proacta Incorporated, a San Diego based biotechnology company that last year engaged in the collaboration for research, development, and commercialisation of PR610 in Japan with Yakult Honsha Co., Ltd. (Tokyo: 2267). Proacta announced today that the IND had been approved, allowing this novel first-in-class treatment to enter human trials.

Initial development of PR610 will focus on patients with non-small cell lung cancer who have become resistant to reversible tyrosine kinase inhibitors such as erlotinib and /or gefitinib. Currently there is no effective treatment when these patients relapse. The phase I part of the phase I/II trial will investigate suitable doses in patients with solid tumours, before moving on to focus on patients with this type of cancer in the phase II part of the trial.

PR610, which specifically targets low-oxygen (hypoxic) regions in tumours, has shown promising activity in the laboratory. “The tumour dose intensity achieved by this hypoxia targeting technology results in striking anti-cancer activity,” says Dr Smaill. “We were particularly impressed when we compared PR610 to existing clinical candidates,” adds Dr Patterson. “Only PR610 was able to shrink the drug-resistant lung cancer models.”

“PR610 will be the second novel hypoxia prodrug from the Auckland Cancer Society Research Centre to be taken to clinical trial by Proacta, and speaks to the continued innovation achieved by our staff in cancer chemotherapy,” says ACSRC Co-Director Distinguished Professor Bill Denny.

“It’s especially pleasing to see clinical trials of new drugs being held in New Zealand,” says John Loof, CEO of the Cancer Society Auckland Division. “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.”

“This exciting new therapy ushers 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,” says ACSRC Co-Director, Associate Professor Mark McKeage, the Clinical Oncologist leading the Auckland City Hospital trial, referring to the phase II part of the phase I/II trial.

“Our scientists are inventing drugs at the forefront of the international fight against cancer,” says Professor Rod Dunbar, Director of the Maurice Wilkins Centre. “The progression of this first-in-class cancer drug to clinical trials is a great credit to New Zealand and offers further hope for our cancer patients.”