Phase 3 PSMAddition Trial Reports Positive Outcomes for mHSPC

Results from the PSMAddition trial were published in a phase 3 setting and showed several clear numbers worth noting.
The trial compared standard double hormone-based treatment alone (ADT + ARPI) versus the same treatment plus a PSMA-targeted radioligand therapy (Pluvicto), in men with metastatic hormone-sensitive prostate cancer.The biggest headline was a 58% lower risk of PSA progression with the PSMA-targeted treatment added to standard care, with a hazard ratio of 0.42 for time to PSA progression.

The study also reported a 28% lower risk of radiographic progression or death, with a hazard ratio of 0.72 and a 95% confidence interval of 0.58 to 0.90, based on a median follow-up of 23.6 months. At 48 weeks, PSA remained below 0.2 ng/mL in 87% of patients in the treatment arm versus 75% in the control arm. Complete responses were also more common, at 57.1% versus 42.3%.

For overall survival, the data were not yet mature, but the hazard ratio was reported at 0.84 with a 95% confidence interval of 0.63 to 1.13, which means there was only a trend at that time and not a definitive survival conclusion. The trial enrolled 1,144 patients, and the primary endpoint was radiographic progression-free survival. Safety remained broadly consistent with prior experience, with grade 3 or higher adverse events occurring in 50.7% of the treatment group versus 43% in the control group.

So, basically: the treatment delayed PSA rise, improved radiographic control, and produced deeper PSA responses, but survival benefit was not yet proven in the reported analysis.

Source.