Australian clinical-stage drug development company Noxopharm (ASX:NOX) has announced that the US patent office has allowed claims relating to the use of a combination of its Veyonda and radiotherapy, including external beam radiotherapy (EBRT), with the purpose of generating abscopal responses in patients with metastatic prostate cancer.
The company said these claims are "fundamental" to helping secure the commercial success of its DARRT (Direct and Abscopal Response to Radiotherapy) therapy involving a combination of Veyonda and low-dose EBRT.
DARRT therapy is a form of immuno-oncology treatment. It involves the delivery of a short course of a low dose of radiotherapy to a single tumour in the body of a patient with metastatic disease. The aim is to trigger a local immune response in the irradiated tumour that spills over into an all-of-body immune response resulting in the resolution of all (complete response) or some (partial response) of the other tumours in the body.
Most solid cancers, including the common prostate, breast and colorectal cancers, have proved to be resistant to immuno-oncology (IO) treatments to date.
Noxopharm said its DARRT-1 study has already delivered a 25 per cent partial abscopal response rate in men with late-stage prostate cancer.
"Compared to current IO treatments, the abscopal response is substantially better tolerated, potentially effective across a broader spectrum of cancer types, considerably more affordable, and more accessible. However, the challenge remains developing a method of lifting the abscopal response rate to a level where it will be accepted as a mainstream treatment," it said.
According to Noxopharm CEO and managing director Graham Kelly, “We see the allowance of this patent application as a major win for the Company in our goal of seeing DARRT therapy become a mainstream cancer treatment.
"Treating metastatic cancer through an abscopal response is arguably the best-tolerated and least destructive form of cancer therapy. Its ability to trigger long-term remission of some or all tumours in the body in a well-tolerated, non-toxic and low-demanding way for the patient clearly marks it as a potentially disruptive treatment. The challenge has been in moving the abscopal response rate from its current very low base. We believe we have met that challenge with a remarkable 25% abscopal response rate in our first clinical effort.
"While those responses were partial, our Phase 2 DARRT study is hoping to take these responses to another level by stepping up the intensity of Veyonda treatment. We also are expanding into breast and lung cancer which provides us with the future opportunity to seek expanded patent coverage. On what we have seen to date, we believe that DARRT therapy has the potential to go on to become a disruptive cancer treatment across most forms of cancer, starting with prostate cancer, which is why the patent news announced today is so important.”