The main premise of this study was to investigate how this new PET imaging agent called fluciclovine, which is an amino acid based imaging agent, could be useful in informing the management of patients with biochemical recurrence of prostate cancer. When we set about designing the study just under five years ago there was no real standardised approach in terms of imaging in this patient category. What we tried to do was in as minimally intrusive way as possible introduce this imaging test into a standard clinical care pathway in a group of patients across the six centres to see how we could change management.
How did you do this?
Quite simply, in order to investigate the impact, the clinical impact, of using this scan in the management of recurrent prostate cancer we set a straightforward primary endpoint actually which was a revision in management plan. So what we did was recorded the intended management plan of patients before they had a scan, we did the scan and then with the clinical scan report to hand the clinicians would then advise on a revised management plan. Where there was a change in that management plan that would count towards the primary endpoint. When we set out this prospective study we did include in the protocol a pre-planned interim analysis which would apply to the first 85 available subjects and we stated there that if the number of patients who had a change in management exceeded 45 then we would stop the study for overwhelming effectiveness. We performed that interim analysis last year and we found that management was changed in 52 out of the 85 subjects, allowing us to close the study early for overwhelming effectiveness.
Can you give us some more information on the outcomes that you found?
Out of the 85 patients we found that 52 out of the 85 had a change in management. We classed the management changes into either major or other. Major management changes were where there was a change in treatment modality such as being changed from salvage therapy to systemic therapy where the scan upstaged patients. Within the other treatment plan change category as well it was where there was change within a treatment modality. As it turned out, all of these patients within this category had a change to planned radiotherapy fields.
What could be the implications?
The implications are very exciting really. Speaking specifically from the UK point of view we've shown that in this study we had a median PSA level of 0.63 when we started out on the study. We didn't really have an imaging test with the potential to be rolled out throughout the UK, to be used uniformly at such low PSA levels. We've shown that almost two out of three patients who come in through the door for a scan leave with a potential change in their treatment. Moving forward we've now got an opportunity, firstly in the clinical realm, to be able to plan patients' treatment more accurately, potentially offer more targeted therapy, things that we couldn't otherwise have with advanced imaging technology. But in research as well there's so much potential we've got, particularly with targeted radiotherapy salvage surgery that is now afforded by such imaging. Having this imaging can allow us to do that.
In terms of next steps for this study in particular, it is absolutely important now, now that we've said almost two out of three patients have had a management change, we need to figure out how that influences patient outcome because that's what matters at the end of the day and that's what we'll be working towards.