Noxopharm, a clinical-stage Australian oncology drug development company, has announced the details of the radiographic review of its DARRT-1 clinical study and is pleased to report a 27% incidence of abscopal response in soft tissue lesions using a combination of Veyonda^® and low-dose radiotherapy. 

An abscopal response, a highly prized clinical response, involves radiation directed at a single tumor which triggers resulting shrinkage of tumors well outside of the field of radiation. It is assumed to be an immune response in the irradiated tumor triggered by using a low, minimally-ablative dose of radiation. Once acknowledged as a very rare event, the growing use of immuno-oncology drugs in combination with radiotherapy has led to increasing reports of abscopal responses in a range of cancers, including lung, breast, and urogenital cancers and melanoma. No such reports have come from studies in prostate cancer with checkpoint inhibitors either alone or in combination with radiotherapy, leading to this cancer gaining a reputation as a “non-immunological” cancer. 

The DARRT-1 study involved 15 men with mCRPC post-taxane and ADT therapy. They received experimental sphingosine-1-phosphate inhibitor, Veyonda, in combination with a palliative dose of external beam radiotherapy to a single tumor, typically a lymph node cluster. An abscopal response was determined on the basis of scans of other nonirradiated soft tissue lesions. 

Dr. Graham Kelly, Noxopharm CEO, said, “To our knowledge, this is the first time that anyone has been able to obtain a meaningful abscopal response rate in prostate cancer. Prostate cancer has developed a reputation as a cancer with poor immune responsiveness, but this outcome suggests that this isn’t the case when a drug with the appropriate effect on the immune system is used. Today’s result positions Veyonda at the forefront of this emerging area of oncology and suggests that we have an exciting new prospective treatment for end-stage prostate cancer.” 

About NoxopharmNoxopharm is a clinical-stage Australian oncology drug development company with offices in Sydney and New York. The company has a primary focus on the development of Veyonda^® and is the major shareholder in the non-oncology drug development company, Nyrada Inc.