Clock ticking as Argenica nears phase II stroke trial readout

• Argenica’s phase II trial results of lead drug ARG-007 in acute ischaemic stroke patients forecast for early September
• Trial completed in April with safety main endpoint and earlier studies showing promise in protecting brain cells
• Argenica’s ARG-007 would be the first neuroprotective drug on the global market if approved

The countdown is on for investors in Perth-based Argenica Therapeutics (ASX:AGN) with results forecast for September of a phase II trial of its lead product, a neuroprotective treatment known as ARG-007 in acute ischaemic stroke patients.

Argenica’s ARG-007 is a synthetic peptide designed to protect brain cells from dying in the critical minutes and hours after acute neurological events such as stroke, traumatic brain injury (TBI), and hypoxic brain damage.

When it comes to acute neurological events, ‘time is brain’ — with around 1.9 million brain cells dying every minute that blood flow is halted.

But ARG-007 is showing promising signs of preventing such catastrophic damage by protecting brain tissue during and after these critical neurological events.

Initial target most common form of stroke

CEO and managing director Dr Liz Dallimore, who has previously worked as a research scientist in neuroscience, has headed Argenica since its ASX-listing in 2021.

Dallimore said acute ischaemic stroke was the most common type of stroke, caused by a blockage in a blood vessel in the brain.

“Acute ischaemic strokes make up around 85% of strokes with the other type haemorrhagic, which is a bleed on the brain,” she explained.

“They present the same with the only way to differentiate by medical imaging.

“A major reason we’re targeting acute ischaemic stroke is many of these patients have a thrombectomy, where a radiologist inserts a catheter through the wrist or groin and guides it up into the brain to physically remove the clot.”

However, a thrombectomy has risk of reperfusion injury, which occurs when blood flow rapidly returns to previously oxygen-deprived brain tissue after a clot is removed and potentially causes additional damage.

“ARG-007 has a second chance to work by protecting the brain against this secondary injury which can occur through the procedure,” Dallimore said.

Phase II in acute ischaemic stroke complete

Argenica completed dosing of patients in a double-blinded, randomised, placebo controlled phase II trial of ARG-007 in acute ischaemic stroke patients in April.

Involving 92 patients presenting to eight emergency departments around Australia, data-read out from the trial is due in September with safety the main endpoint, determining if the drug asset can advance further in clinical development.

“Safety in a neurology trial is really important because you have to show your drug does no harm,” Dallimore said.

“It’s quite different to an oncology drug where you can have some toxicity because you’re trying to kill a cancer.

“In this case we must ensure we’re doing no harm to the brain or patient and safety is the main aspect big pharma and regulators will look at for ARG-007.

Throughout the trial Argenica has had a data safety monitoring board reviewing all the data and making sure there’s nothing unusual in terms of a safety profile.

The secondary endpoint for the trial will examine efficacy, with a brain scan taken 48-hours post administration of either the placebo or ARG-007.

“We are comparing the placebo group to treatment group to see whether our drug has reduced that brain injury,” Dallimore said.

“By administering our drug prior to the thrombectomy, we believe it has the potential to limit the progression of brain injury following thrombectomy, whereas in the placebo group, that damage may continue to expand.”

Promising preclinical results drive Argenica’s push into human trials

A spinout from the University of Western Australia and Perth-based Perron Institute for Neurological and Translational Science, ARG-007 has shown early success, including in preclinical studies and a phase I trial.

Dallimore said what provided researchers confidence to progress into clinical trials was a non-human primate study that closely reflected how acute ischaemic stroke was treated in hospitals.

“The drug was administered ahead of a standard thrombectomy procedure, simulating the real-world treatment pathway,” she said.

“That study was done out of Canada and showed a 70% reduction in brain injury.”

Dallimore said the study convinced researchers to take the drug forward into clinic trials and list Argenica on the ASX.

First-of-kind ‘holy grail’ therapy targeting high need

ARG-007 would be the first neuroprotective drug on the global market if approved, tapping into a large addressable global market for stroke and potentially other indications.

The global stroke management market was valued at $36.1 billion in 2022, and is projected to reach $74 bn by 2032, driven by several factors including a growing ageing population.

There are more than 45,000 strokes annually in Australia and 795,000 in the US – the world’s largest healthcare markets.

The estimated cost of stroke to the healthcare system in the US is forecast to reach ~US$184.13 bn by 2030.

“There are no neuroprotective drugs on the market and neuroprotection really is the holy grail just because you get almost two million brain cells dying every minute,” Dallimore said.

“Ultimately, we want this drug to be in every ambulance so as soon as a paramedic arrives and suspects a stroke they administer our drug.”

She said a lysis drug, also known as a thrombolytic, is often given to dissolve blood clots in ischaemic stroke.

However, a lysis drug must not be given to patients with haemorrhagic stroke as it can significantly worsen bleeding in the brain.

“ARG-007 will not exacerbate bleeding, and we haven’t really looked at whether its efficacious in haemorrhagic stroke but suspect it probably will be but the main aspect for paramedics is doing no harm to the patient,” she said.

She said success in acute ischaemic stroke opens the doors for use of ARG-007 in other indications.

“Ultimately, it could be given to anyone suspected of having some sort of brain injury whether from stroke, cardiac arrest with blood flow restriction to the brain or an accident,” she said.

“Essentially, what it does is hibernates those brain cells and stops them dying – buying that patient time to get to the hospital and treatment.”

Lining up against few competitors

Dallimore said its closest competitors were in phase II trials with one Spanish company targeting inflammation, which has done a deal with big pharma Merck KGaA who will run its later stage trials.

“The mechanism is very different to ARG-007 with our drug working in the acute phase trying to block the calcium flowing into the brain cells causing the injury,” she said.

“So, their drug is working to treat the inflammation which can also exacerbate brain injury.”

Dallimore said another global company was also in a phase II trial and while its approach was mechanically like ARG-007 extensive comparative work had demonstrated more promising efficacy for Argenica’s treatment.

“If we can hit that primary endpoint in the trial it should be a big value inflection and icing on the cake would be to show efficacy as well,” she said.

Looking to partner for future trials

Argenica is planning its later stage clinical program for ARG-007 working with the US Food and Drug Administration (FDA) to get approval for future studies in the US, along with regulators in Europe and China, where stroke is now the leading cause of death.

“Ideally, we could do some type of deal with a bigger pharma company with an interest in stroke or neurology when we get the Phase II results,” Dallimore said.

“Typically, that might look like they would give us an upfront payment to help fund the trial and then milestone payments along the way.”

At Stockhead, we tell it like it is. While Argenica Therapeutics is a Stockhead client, the company did not sponsor this article.