Aims: The DARRT-1 Study (NOX66-002A; NCT03307629) is a first-in-human study combining the investigational product NOX66 (idronoxil formulated in a proprietary lipophilic base, for rectal administration). It is hypothesised that NOX66 may enhance the effect of palliative radiotherapy (RT) to provide greater therapeutic benefits at the site(s) of irradiation, whilst boosting an abscopal response within lesions that are not irradiated. The objective of the DARRT-1 study is to evaluate the safety profile of NOX66 and investigate efficacy signals, to establish the dose of administration for further studies.
Methods: A total of twenty-four patients with late stage metastatic castrate-resistant prostate cancer, requiring palliative radiotherapy for symptomatic treatment, will be enrolled into the study. Patients and receive RT (20Gy, 5 fractions) in combination with daily dosing of NOX66 (commencing one day prior to RT, continuing for 7 days post RT). Recruitment planned for four cohorts – Cohorts 1-3 (4 patients each) will receive escalating doses of NOX66 (400mg, 800mg, 1200mg respectively) subject to safety review following treatment with the previous cohort. The dose for Cohort 4 will be determined from analysis of efficacy and safety data following 6 weeks’ treatment of cohorts 1-3. All patients will be followed up for 24 weeks, with measures of efficacy (CT/MRI scan, PSA levels and pain assessment) at 6, 12 and 24 weeks.
Results: First patient commenced treatment on 29th March 2018. At the time of abstract submission (9th August) cohort 1 (patients 1-4), cohort 2 (patients 5-8) and cohort 3 (patient 9) have commenced treatment. Results pertaining to the 6-week and 12-week follow up of cohorts 1-3, and determination of dose for further investigation, will be presented at COSA 2018.