Abstract
1307
Objectives: Investigators have extensively explored the short-term safety and efficacy data on 177Lu-PSMA-617 radioligand therapy (RLT) in mCRPC patients. However, scarce literature is reported on the long-term outcome of these patients. The current goal of this study is focused on the long-term outcome of mCRPC patients treated with 177Lu-PSMA-617 RLT.
Methods: Among 135 patients, 121 mCRPC patients fulfilled the eligibility criteria and were included in the final analysis. Patients received a median of 3 cycles of 177Lu-PSMA-617 RLT at 6 to 12-week intervals. Primary endpoint included overall survival (OS) and secondary endpoints involved progression-free survival (PFS), predictive factors of OS and PFS, PSA response rate, clinical response, and toxicity assessment.
Results: The median administered cumulative activity was 20 GBq (3.7 - 37 GBq). The estimated median PFS and OS were 12 months (mo) (95% CI: 10.3 - 13 mo) and 16 mo (95% CI: 13 - 17 mo), respectively. Any PSA decline and PSA decline >50% was achieved in 73% and 61% of the patients, respectively. Multivariate analyses revealed only failure to achieve >50% PSA decline as a significant factor associate with a poor PFS. Prognostic factors associated with reduced OS included failure to experience >50% PSA decline, heavily pre-treated patient cohort who received >2 lines of prior treatment options. Patients re-treated with additional treatment options after attaining 177Lu-PSMA refractory disease showed a remarkably prolonged OS. A significant clinical benefit was achieved post 177Lu-PSMA-617 RLT. The most common toxicities observed were fatigue (34.7%), followed by nausea (33%), and dry mouth (24.7%).
Conclusions: The current study supports the short-term safety and efficacy results of high response rates, improved quality of life, and low treatment-related toxicities in patients treated with 177Lu-PSMA-617 radioligand therapy.