Noxopharm (ASX: NOX) has reported interim clinical benefits from an ongoing 24-week trial combining its Veyonda drug with radiotherapy in treating prostate cancer patients.
Previously known as NOX66, Veyonda is an experimental anti-cancer formulation of the drug idronoxil, which was developed to preserve and enhance idronoxil’s anti-cancer activity in the body.
It works by boosting the DNA damaging effects of radiotherapy and cytotoxic chemotherapy, while activating the body’s innate immune system.
In this latest Direct and Abscopal Response to Radiotherapy program (DARRT-1), the stage 1 component comprised evaluating late stage prostate cancer sufferers that were treated with a combination of Veyonda and palliative radiotherapy doses.
As part of the program, Noxopharm is seeking to generate “greater shrinkage” across irradiated and non-irradiated tumours, as well as alleviation of pain and reduction of prostate specific antigen (PSA) levels.
Over the first 12 weeks, 12 patients received three different Veyonda doses – four with 400mg per day, four with 800mg/day, and four with 1,200mg/day.
Additionally, low-dose radiotherapy was applied to a single metastasis.
Interim data revealed all three Veyonda doses were “well-tolerated” with no serious side-effects.
Efficacy was measured at day one and then compared again at week 12, with prostate specific antigen (PSA) levels, pain and aggregate soft tissue lesion seizes all noted.
According to Noxopharm, “encouraging efficacy signals” were identified in the patients on the 800mg and 1,200mg/day doses.
Of those patients, most reported a reduction in pain, and either a decrease in aggregate tumour size or displayed stable disease at 12 weeks.
“We are very encouraged by these results as these men are right at the end of their treatment journey and are receiving radiotherapy principally to alleviate their pain and enhance their remaining quality of life,” Noxopharm chief medical officer Dr Greg van Wyk said.
“That a number of patients derived a meaningful clinical benefit in this trial in terms of pain relief and apparent reduction in tumour loads gives us great hope that we can advance Veyonda to market to help many more men in this way,” Dr van Wyk added.
Stage 2 of DARRT-1
Results are still anticipated for stage 2 of DARRT-1 which involves an expanded study to include an extra 12 patients.
Stage 2 was initiated at the 1,200mg dose, but comprises patients with bone lesions. Because of the difficulty in accurately gauging the size of these lesions, measurements will only be taken on pain and PSA.
The final four patients for this stage of the trial have been screened and are anticipated to be fully enrolled within the next two weeks.
The entire trial is expected to run for 24 weeks in total, with final results anticipated in early May for the stage 1 cohort. Interim results from stage 2 are scheduled for release in July, with the completed trial due to be published in October.
“The 24-week data is going to be even more important because we are seeing PSA levels in some men still falling at the 12-week point,” Noxopharm chief executive officer Dr Graham Kelly noted.
He added the 24-week data will provide a “much clearer picture” of the “full clinical benefit” and the impact treatment will have on survival times.
“But, even before that point, the company believes that this 12-week data justifies its belief that Veyonda is a potentially transformative anti-cancer drug,” Dr Kelly said.