Despite a positive trial endpoint and FDA approval, a GU medical oncologist is not adopting Lutetium-PSMA in the hormone-sensitive prostate cancer setting. He argues the existing therapy is already highly effective, and new treatments must offer a 'revolutionary,' not just an 'evolutionary,' benefit to justify the added toxicity and cost without a clear overall survival advantage.
Standard clinical trial grading systems for adverse events can be misleading. A side effect like dry mouth (xerostomia) from radioligand therapy may only ever be graded as 1 or 2, making the therapy's safety profile appear benign. However, the long-term, chronic impact of such 'low-grade' toxicities on a patient's quality of life can be profound.
Even for established uses of Lutetium, leading cancer institutions have no standardized protocol for assessing treatment response. Practices vary widely, from PSMA PET scans after every cycle to only scanning when clinical and biochemical markers are discordant. This fundamental uncertainty in monitoring complicates clinical decision-making and interpreting a drug's activity.
The PSMAaddition trial's inclusion criterion of just one PSMA-avid lesion is criticized as biologically arbitrary. A patient could qualify for systemic therapy while having 90% of their tumor volume not expressing the target. This highlights a critical need for more sophisticated biomarkers to truly identify patients who will benefit from targeted radioligand therapy.
The current standard of care for hormone-sensitive prostate cancer is so effective—with half of patients alive at 8 years in some trials—that new additions must clear an exceptionally high bar. Unlike in refractory settings, an incremental improvement in radiographic progression-free survival may not be enough to warrant adoption without a transformative overall survival benefit.
As cancer therapies extend patient lifespans, clinicians are increasingly concerned about long-term morbidities like cardiovascular and thromboembolic events. These late effects are poorly captured by traditional trial endpoints and grading scales, meaning the true 'price' of therapeutic progress is not fully understood, especially in older patient populations.