With respect, I very carefully said that Novartis
will reveal VISION data at ASCO on 7 June.
On 23 March Novartis announced that the VISION trial met both primary endpoints and that trial findings will be presented at an upcoming medical meeting. We can now see that
Phase III study of lutetium-177-PSMA-617 in patients with metastatic castration-resistant prostate cancer (VISION) is the abstract title of a plenary session presentation at ASCO on 7 June, where we can expect to see top line data disclosed.
It is my
opinion that median survival will be about 14 months, based on the following:
- The VISION trial design assumed median survival to be 13.7 months. IIRC, this was based on Lu-PSMA treatment of 50 patients conducted by the Peter MacCallum hospital in Melbourne, which had mOS of 13.3 months.
- Recruitment started in May 2018, with anticipated patients to be 750
- The actual number of patients was 831. I mention this as a fact, not to insinuate that it had anything to do with mOS.
- Patients had to have progressive PSMA-positive mCRPC
I note that patients were allowed to use other treatment such as Zytiga concurrently with Lu-PSMA, which might have the effect of extending survival over Lu-PSMA monotherapy. On the other hand, the FDA only approved Gallium 68 PSMA imaging last December, after trial recruitment had ended, so it would have been difficult to determine the degree to which patients were PSMA-avid.
It is reasonable to expect that Lu-PSMA would have an immediate impact, but that after a few doses the effect would weaken if PSMA was no longer present. This seems to be confirmed by
Analysis of PSMA expression and outcome in patients with advanced Prostate Cancer receiving 177 Lu-PSMA-617 Radioligand Therapy - PubMed (nih.gov), which showed that there was a correlation between the level of PSMA, and overall survival.
A final thought: if the use of NOX66 enabled patients to complete more courses of Lu-PSMA than expected, can we infer that NOX66 increases PSMA expression by cancer cells and that this is the principal cause of increased survival?
