DARRT Program

(Direct and Abscopal Response to RadioTherapy)

Veyonda® combined with radiotherapy


Phase 1 multi-centre study – complete

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

The results of DARRT-1 were:

  • 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, and this effect was found to persist for most of those individuals at 24 weeks. [PSA (prostate specific antigen) is an indicator of disease activity in prostate cancer.]

An abscopal effect was noted in four 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 multi-centre study – closed

The DARRT-2 trial examined the combination of Veyonda with low-dose radiotherapy for the treatment of prostate cancer as the major focus, but also included other solid tumours. In this trial Veyonda was combined with the application of low-dose (up to 25 Gy) external beam radiotherapy in 1-5 fractionated doses to a single tumour in a single treatment cycle. Veyonda was administered daily for up to 14 days in conjunction with the single radiotherapy cycle, and then in repeated monthly cycles without radiotherapy.

The Safety Steering Committee determined a dose of Veyonda up to 1600mg to be safe.

This trial is now closed.


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