Pre-clinical studies confirm the abscopal effect, and DARRT treatment can control diseases at six months.
FREMONT, CA: A drug development company Noxopharm Limited pre-clinical evidence confirmed the result from a series of experiments in mice to explore the interaction between Veyonda and radiotherapy. It is concluded that Noxopharm’s lead drug candidate Veyonda, has the potential to produce off-target responses known as an abscopal effect.
First, the patient is given Veyonda dose to ensure drug presence in all tumors; after that, a low dosage of radiotherapy is directed to one or two tumors. This treatment has lasting disease control at six months. Under the DARRT trial treatment regimen, an experiment was conducted on mice to investigate the interaction between radiotherapy and Veyonda. It is concluded that a short course of treatment can control many high proportions of diseases.
The DARRT treatment report will outline the impact on PSA response, pain levels, and tumor response. The DARRT treatment regimen entails a 5-day course of radiotherapy with Veyonda administered daily for up to 3 weeks.
Fourteen men with last-stage progressive and metastatic prostate cancer underwent the study. No standard treatment options were left for these patients. Under this treatment, patients were given a dose of Veyonda with low dose radiotherapy. This method of disease control was proved highly durable for 57% of patients remaining progression-free at six months. Bone pain is a significant issue in prostate cancer because cancer generally spreads to the bones. In three months, the pain level was decreased to 30%, and within six months, some of the patients were pain-free.
The Company has developed a bi-flank mouse model with Australian academic collaborators, in which tumors are grown on both sides of a mouse. The radiation was delivered in a separate way to one side only. This model now has confirmed the following findings:
• Veyonda has an anti-cancer effect on both tumors.
• Radiotherapy has an anti-cancer effect on the irradiated tumor only, with no impact on the non-irradiated tumor.
• A combination of Veyonda and radiotherapy delivered a anti-cancer effect on both sides, consistent with an abscopal effect.
The DARRT treatment regimen showed a high rate of disease control at three months, and this treatment effect is durable. Now the next step is to find how just long-lasting this effect may be and to amend the DARRT-1 protocol to obtain longer-term data for this cohort, including overall survival. These data will be reported in 2020.
It is clear from the pre-clinical studies that the combination of Veyonda and radiotherapy kills cancer cells; this effect is contributing to the initial response to treatment. But control of disease in six months without any ongoing treatment proves the effect of Veyonda.
A short, minimally intrusive and well-tolerated treatment regimen that could be repeated if required. The next task is to find any disease progression occurred in the absence of further treatment over six months.
DARRT represents a potential paradigm change in the treatment of prostate cancer. The researchers are planning to expand the development plan of Veyonda by adding new updates in the coming years.