Noxopharm confirms durable anti-cancer effect from lead drug Veyonda

Anti-cancer drug developer Noxopharm (ASX: NOX) has set the stage to present its highly-anticipated clinical data to the Clinical Oncology Society of Australia by publishing interim data from a DARRT-1 clinical study using Veyonda to treating patients with late-stage prostate cancer.

Veyonda has been designed to treat patients with late-stage, progressive and metastatic cancer that have limited survival prospects.

However, given the positive results recorded in the DARRT-1 study, the biotech company said it foresees its approach is potentially applicable to other cancers and is “on track to become an important new drug in the management of cancer more generally,” according to Noxopharm’s executive chairman Dr Graham Kelly.

The news comes ahead of the Noxopharm’s presentation to the Clinical Oncology Society of Australia on 12 November this year, with the company already planning to commence a DARRT-2 study next year.

The objective of the DARRT-1 study is to see whether Veyonda can trigger a general immune response, or in other words, achieve an anti-cancer response in body tumours after delivering radiotherapy to just one or two individual tumours.

The DARRT treatment regimen is an experimental and novel immuno-oncology treatment where the individual effects on the immune system of low-dose radiotherapy and Veyonda are being brought together with the aim of achieving a significantly greater effect with a “whole-of-body anticancer” outcome.

Dulling the effects of prostate cancer

According to Noxopharm, the clinical objectives are not to halt or regress cancer progression but rather to attain greater pain relief, generate a better quality of life and extend survivability in patients where palliative care is the only remaining treatment option.

“We are about three-to-four weeks away from seeing the six-month data for the final 11 patients, but even before that, we are seeing an impressive anti-cancer effect from the DARRT therapy.”

“For men who have run out of treatment options, this is a significant outcome,” said Dr Kelly.

Within the interim data results published today, Noxopharm said that the interim data indicates that the DARRT treatment regimen is “on track” to achieve its base objectives.

The DARRT-1 study showed that cancer progression was blocked in 80% of patients over a six-month period. Moreover, the results indicate that at six months, more than 50% of patients continued to experience a “clinically significant reduction” in their pain levels.

The study used gradually escalating doses of 400, 800 and 1200mg of Veyonda in 14 men in parallel to a 1,200mg dose given to a further 11 men – with all 25 patients considered a single group.

From the overall sample group, 22 had evaluable disease – tumours that could be detected via x-rays – with Noxopharm choosing to publish the interim data review with respects to these 22 cases.

The biotech company said that so far, 11 of these have completed their six-month follow-up with the remaining 11 expected to complete their follow-up in mid-November 2019.

A final statistical study report is anticipated in early 2020 and will contain detailed radiographic assessment of the response of both irradiated and non-irradiated tumours.

“DARRT-1 is our first study in metastatic prostate cancer and the results so far are very encouraging,” said Dr Gisela Mautner, chief medical officer of Noxopharm.

“It is impressive to see that the DARRT-1 treatment regimen was able to stabilise the disease progression in the majority of trial participants,” she added.

Dr Mautner also confirmed that the DARRT-1 treatment regimen was well-tolerated with “only minor and easily manageable side effects”.

“This has spurred us on to get underway with the next stage of trialling as quickly as possible. Our aim is to make the DARRT-2 study a US and European-based study in late-stage prostate cancer, with a view to it being the study that leads to submission for marketing approval,” said Dr Kelly.

Second pipeline drug program

In addition to its primary focus on Veyonda in the treatment of prostate cancer, Noxopharm is also progressing a secondary glutamate-inhibition program to develop a treatment for glioblastoma multiforme (GBM), or in other words, brain cancer.

GBM remains a poorly managed cancer, with surgery, radiotherapy, and the chemotherapy drug temozolomide the current standard of care, offering median survival of only 12-15 months.

However, research conducted just recently and published in Nature magazine has indicated that the brain chemical, glutamate, plays a key role in driving the aggressive nature of GBM growth.

According to the research, glutamate is an important neurotransmitter that triggers the passage of electrical impulses between brain cells, and even more importantly, serves as the brain’s main neurotransmitter that facilitates learning and memory.

As a result of a collaboration with UNSW Sydney in 2016, Noxopharm said it already has drugs in its chemical library that are selective glutamate-inhibitors which it intends to develop and harness to treat GBM.

“If we are successful, then we see this approach as potentially having the same benefit as blocking the way sex hormones drive the growth of breast cancer and prostate cancer,” Dr Kelly explained.

“If anti-hormone therapy can deliver very significant survival benefits with highly aggressive forms of breast cancer and prostate cancer, then we see no reason why blocking glutamate function cannot deliver the same benefit for patients with GBM,” he added.