Chief executive Dr Graham Kelly has shared his hope drug developer Noxopharm’s (ASX: NOX) NOX66 therapeutic could be a major advance in the treatment of late-stage cancers that have spread to other parts of the body.
The Australian Securities Exchange-listed company fronted the Trans Tasman Radiation Oncology Group Annual Scientific Meeting in Hobart today to present reports from two compassionate cases where NOX66 was given to patients receiving palliative radiation therapy and chemotherapy.
In the first case delivered by Noxopharm Medical Advisory Board chairman Professor Paul de Souza, a 68-year-old prostate cancer patient with metastatic, castrate-resistant disease was tumour free just two months after receiving NOX66 in combination with a course of radiotherapy delivered to tumours found in his vertebral spine and lymph nodes.
The man now needs no treatment and continues to be in remission, 3.8 years later, with undetectable prostate cancer loads in his blood, after having had what is described as a complete abscopal response.
Dr RH Mole introduced the term abscopal effect back in 1953 and it describes where a localised treatment triggers a response at other sites in a patient’s body.
The second patient, a 70-year-old woman with cancer of the smooth muscle cells, known as leiomyosarcoma, had what is known as a partial abscopal response — experiencing a partial reduction in the size of her secondary tumours after receiving NOX66 with chemotherapy, then with palliative doses of radiotherapy to the primary tumour.
At the one-month mark the 70-year-old’s cough went away, and six months later her primary tumour was stable, without an increase to the shrunk, secondary tumours.
Dr Kelly highlighted both patients had experienced an abscopal response which he noted was a very rare phenomenon.
“Both of the patients presented in the case studies have shown a response to treatment at sites which were not subjected to direct radiation therapy . . . an abscopal response,” he said.
The Noxopharm chief said the company was focusing on confirming the compassionate case outcomes in its clinical trials program.
“With two out of two patients with distinctly difference cancer types responding in this way, we now are focused on continuing with our clinical development program to confirm this outcome in a larger number of patients,” he said.
“If all we are able to do is to provide a partial abscopal response in patients as we have seen in case study 2 (the woman with cancer of the smooth muscle cells), we believe this would be a major advance in the treatment of late-stage metastatic cancer.
“Providing a complete abscopal response as seen in case study 1 (the man with prostate cancer) potentially represents a new frontier in cancer therapy.”
Sydney and Hong Kong-based drug developer Noxopharm is currently completing a Phase 1b study of its dosage-formula of the experimental anti-cancer drug idronoxil in 24 men.
Idronoxil inhibits enzymes in the body that are over-expressed in cancer cells and inhibits an oxidase that maintains the transmembrane electron potential of the plasma membrane of cancer cells. The inhibition can sensitise the cancer cells to the effects of chemo or radiotherapy treatment.
Clinical results from the DARRT-1 study, started last year, are being completed at 11 sites worldwide in Australia, New Zealand and the US state of Georgia, are tipped to be released this July.
The company is also planning a Phase 2 study in 80 patients with a broad spectrum of cancers, including rare cancers.
Noxopharm securities were placed in a trading halt this morning pending the release of another announcement. The company’s securities closed at $1 yesterday.