According to investigators, additional research is necessary to further understand how lutetium impacts overall survival in patients with metastatic prostate cancer.
Data from the phase 3 clinical trial PSMAfore (NCT04689828) show lutetium (Pluvicto; Novartis) met its primary endpoint with a clinically meaningful and statistically significant benefit in radiographic progression-free survival (rPFS) in patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) after treatment with androgen receptor pathway inhibitor (ARPI) therapy. The data were presented at the 2023 European Society for Medical Oncology (ESMO) Congress in Madrid, Spain.
Lutetium is an intravenous radioligand therapy (RLT) that combines a targeting compound with a therapeutic radionuclide. It is administered into the bloodstream where it targets cells—including prostate cancer cells—that express the transmembrane protein, PSMA.
The open-label, multicenter, randomized study compared the efficacy and safety of lutetium to a change in ARPI (abiraterone or enzalutamide) in patients with PSMA-positive mCRPC who have not previously been exposed to a taxane-containing regimen. The 469 enrolled patients who were randomly assigned to the change in the ARPI arm were allowed to receive lutetium upon confirmation of radiographic progression.
The results demonstrated a 59% reduction in the risk of radiographic disease progression in patients who received lutetium compared to those who experienced a change in ARPI. Further, a median follow-up of 8.6 months showed a consistent clinical benefit in patients with lutetium compared to a change in ARPI, which more than doubles the time to radiographic disease progression (12 months vs 5.6 months, respectively).
In addition, patients who received lutetium presented an improved quality of life compared to patients who had a change in ARPI (7.5 months vs 4.3 months, respectively).
The study’s secondary endpoint was overall survival (OS). However, the unadjusted intent-to-treat OS analysis was unclear, as 84% of patients discontinued ARPI because of radiographic progression crossing over to receive lutetium. Further research will continue to evaluate OS.
“These promising results from PSMAfore could change the treatment paradigm for advanced prostate cancer by allowing patients to potentially avoid or delay taxane-based chemotherapy, which carries a heavy burden of [adverse effects (AEs)],” said Jeff Legos, executive vice president, global head of oncology development at Novartis, in the press release. “While data collection for OS continues, the consistency of the benefit observed on other clinically meaningful efficacy endpoints, together with improved quality of life and favorable safety profile, show the potential of [lutetium] for taxane-naïve patients with mCRPC.”
Most AEs for lutetium were mild in severity. The most frequently reported AEs included dry mouth (57.3%), asthenia (31.7%), nausea (31.3%), anemia (24.2%), and fatigue (22.9%).
“The rPFS data are impressive and the treatment effect is comparable with what was observed in the VISION trial,” said PSMAfore co-principal investigator Oliver Sartor, MD, chairman of the trial steering committee and adjunct professor in the department of urology at Tulane University school of medicine, New Orleans, LA, in a press release. “We look forward to a future where [lutetium] may be a viable therapy for patients in need of alternative, earlier options.”
Novartis. Novartis Pluvicto™ shows clinically meaningful and highly statistically significant rPFS benefit in patients with PSMA-positive metastatic castration-resistant prostate cancer in the pre-taxane setting. News release. October 23, 2023. Accessed October 24, 2023. https://www.novartis.com/news/media-releases/novartis-pluvictotm-shows-clinically-meaningful-and-highly-statistically-significant-rpfs-benefit-patients-psma-positive-metastatic-castration-resistant-prostate-cancer-pre-taxane-setting