DARRT Program

(Direct and Abscopal Response to RadioTherapy)

Veyonda® combined with radiotherapy (RT)

Radiation therapy is a highly effective and commonly used tool in cancer treatment and palliative care.

About 60% of cancer patients will have RT at some point in their treatment journey.[i]

Study Objectives

To demonstrate that in metastatic solid tumours Veyonda® plus low-dose radiotherapy (RT) improves therapeutic outcomes versus radiotherapy alone

The Science

Low-dose radiation to a single tumour triggers an immune response (activation of CD4+ and CD8+ T cells) within the irradiated tumour.

Veyonda® amplifies the immune response and spreads it to tumours throughout the body.

Veyonda® has dual activity – (1) a direct oncotoxic effect (kills cancer cells) and (2) through cancer-specific inhibition of S1P, allows conversion of tumours from COLD to HOT, making them more susceptible to the body’s natural immune system.


Phase 1 study complete.

In this study, Veyonda® was combined with radiotherapy (RT) in patients with metastatic castration-resistant prostate cancer that had progressed on all available treatments.

Notably, DARRT-1 patients had such advanced cancer that RT treatment was palliative, that is, it intended to only reduce pain and other symptoms to improve quality of life for a limited period.

The results of DARRT-1 were very encouraging.

  • Disease progression stopped, or the clinical status improved in a majority of patients at 12 week and 24 week follow up
  • A majority of patients achieved a clinically meaningful pain response at 12 weeks and at 24 weeks. Notably some patients were pain-free at 24 weeks.
  • PSA levels dropped by over 50% in a number of patients at 12 weeks this effect was found to persist for most of those individuals at 24 weeks. PSA (prostate specific antigen) in cancer therapy is an indicator of disease activity.

An abscopal effect was noted in 4 patients, indicative of an immuno-oncological effect. In these patients, both the irradiated tumour and tumours outside of the radiation field shrank. 


A Phase 1b/2a Multicenter Study of NOX66 and External Beam Radiotherapy in Patients with Metastatic Castration-Resistant Prostate Cancer and Other Solid Tumors.

DARRT-2 will aim to recruit patients who have progressed on first or later lines of therapy. Veyonda will be delivered with RT to patients with mCRPC and patients with other solid tumours, specifically breast and lung cancer.

This study is being prepared for sites in North America, Europe, and Australia.

The first patient is expected to be enrolled in Q4 2021. The aim is to ensure enrolment is advancing well by the end of Q1 2022.

Learn more in the Veyonda® White Paper.

[1] https://www.cancer.gov/publications/patient-education/radiationttherapy.pdf 

Veyonda® is currently not approved in Australia or any other country