SPLASH
In SPLASH, a second PSMA radioligand improved progression-free survival but not, so far, survival.
412 men; rPFS 9.5 vs 6.0 months (HR 0.71); interim OS HR 1.11 (46% of events, 84% crossover). Lantheus deprioritised a US filing pending OS.
Setting
PSMA-positive mCRPC after one ARPI, taxane-naive: 177Lu-PNT2002 vs ARPI switch
Phase
Phase 3
Sponsor
Lantheus (POINT Biopharma)
Registry
Headline result
rPFS HR 0.71; interim OS HR 1.11.
Reported
2024
Enrolled
412
Replication
Smaller effect than PSMAfore (rPFS HR 0.41) with a different ligand and dosing; ECLIPSE (177Lu-PSMA-I&T) met rPFS.
In plain words
What these results mean for people, not percentages
Radiographic progression-free survivalprimarysurrogate endpoint
- Median 9.5 vs 6 months with 177Lu-PNT2002 (PSMA-I&T) compared with ARPI switch; about 3.5 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 29 percent lower chance of the event at any given time (hazard ratio 0.71, likely range 0.55 to 0.92).
- This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
Overall survival (interim)survival endpoint
- The treated group had about 11 percent higher chance of the event at any given time (hazard ratio 1.11).
- The absolute difference, how many more people out of 100 were helped, is not reported here.
- Numerically unfavourable at interim with crossover
- Overall survival counts deaths from any cause, so it is the most direct measure of whether a treatment helps people live longer.
- Numerically unfavourable at interim with crossover.
Be careful
- These results apply to the people the trial enrolled: PSMA-positive mCRPC after one ARPI, taxane-naive: 177Lu-PNT2002 vs ARPI switch. People in a different situation may not see the same effect.
- The trial selected people by a biomarker (PSMA); the result should not be assumed for people whose cancer does not have it.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
412 participants enrolled.
Radiographic progression-free survivalprimary
HR 0.71 (0.55–0.92) · p = 0.0088
177Lu-PNT2002 (PSMA-I&T)
9.5 mo
ARPI switch
6 mo
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Radiographic progression-free survivalprimary | 177Lu-PNT2002 (PSMA-I&T) | 276 | 9.5 months | 0.71 (0.55–0.92) | 0.0088 | link |
| ARPI switch | 136 | 6 months | ||||
| Overall survival (interim) | 177Lu-PNT2002 | — | Numerically unfavourable at interim with crossover | 1.11 | — | link |
| ARPI switch | — | — |
Replication
Smaller effect than PSMAfore (rPFS HR 0.41) with a different ligand and dosing; ECLIPSE (177Lu-PSMA-I&T) met rPFS.