PharmAust gains ethics approval to restart dog cancer trial

ASX-listed oncology innovator, PharmAust, has received Government ethics approval to recommence a trial treating pet dogs suffering from cancer with its oral drug, Monepantel. PharmAust previously announced the first set of trial results had exceeded expectations by demonstrating that MPL tablets can make certain cancer lesions disappear and the recommencement of the trial is the next step on the pathway to commercialisation for the biotechnology specialist.

Despite demonstrating its clinical objectives, the original trial was terminated early because many of the dogs in the trial developed a loss of appetite.

In May 2020, PharmAust announced it had completed studies testing the effects of Monepantel, or “MPL” tablets on 6 pet owners’ dogs with B cell lymphoma that had not received treatment for the cancer previously. All pet dogs achieved reductions in target cancer lesions following a daily high dose of MPL over 28 days, the company said.

Significantly, researchers also found some pet dogs on the trial achieved cancer reductions despite having relatively low drug blood levels. Researchers have developed a new dosing methodology for the recommenced trial that aims to achieve lower drug blood levels that equate with the highest anti-cancer activity.

The trial is due to recommence early in 2021.

PharmAust Chief Scientific Officer, Dr Richard Mollard said: “PharmAust has been testing two independent hypotheses - that MPL tablets could make cancer disappear and that MPL tablets could stop cancer growing. Previously, PharmAust had demonstrated that MPL liquid stops cancer growing.”

“The first set of trial results using the MPL tablets exceeded expectations with the demonstration that MPL tablets can make certain cancer lesions disappear. This continuation into Phase IIb is designed to understand the dosing regimen that will maximise MPL’s anticancer activity.”

PharmAust is primarily focused on developing cancer therapeutics for humans and canines. It specialises in repurposing existing drugs that have already proven to be safe for other uses, removing a number of the traditional hurdles along the road to market.

MPL is a veterinary drug previously registered for use by a major pharmaceutical company as a wormicide. PharmAust discovered independently that MPL interacts in a previously unrecognised manner with the “mTOR” pathway, an important regulatory pathway in mammalian cells. Consequently, it says the drug has potentially relevant therapeutic value in a wide range of diseases including cancer.

PharmAust said the fact that MPL was already approved for use in animals in a number of major jurisdictions - including the European Union, United Kingdom and Australia - meant the development process was simpler and cheaper than it would otherwise be if MPL were a new active pharmaceutical ingredient.

The company’s wholly-owned subsidiary, Pitney Pharmaceuticals owns a number of granted patents for the use of MPL in cancer therapy and neurodegenerative diseases including Parkinson’s and Alzheimer’s.

The cancer-fighting benefits of MPL were also investigated by the Melbourne-based Olivia Newton-John Cancer Research Institute, or “ONJCRI”. ONJCRI researchers tested how the entire genome of cancer cells responded when treated with MPL, using a screening process known as RNA sequencing.

ONJCRI findings showed that changes in the gene expression in the non-cancer cell genome were relatively modest and changes in the three cancer cell lines of melanoma, lung cancer and ovarian cancer were far more significant.

According to PharmAust, ONJCRI’s work showed cancer cell genes involved in promoting the division and proliferation of cells were suppressed and those involved in the death or self-destruction of cells were induced. The results support previous studies that indicate non-cancer cells are not affected by MPL whilst the drug causes cancer cells to stop dividing and spreading, and to self-destruct, the company said.

It’s an exciting time in global cancer research, with many once life-threatening diseases being treated and cured at an increasing rate. Confidence in PharmAust’s cancer-fighting drugs is growing by the day as their safety profile and efficacy against cancer cells continue to be demonstrated by leading research.

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