From Despair to Hope: First Arabic Experience of 177 Lu-PSMA and 161 Tb-PSMA Therapy for Metastatic Castration-Resistant Prostate Cancer.

Simple Summary: The recent approval of [177Lu]Lu-prostate-specific membrane antigen (PSMA) for managing metastatic castration-resistant prostate cancer (mCRPC) has catalyzed the innovation of various PSMA-targeted radiopharmaceuticals. In our retrospective study, we explored both safety and efficacy of two beta-emitting PSMA radioligands, [177Lu]Lu and [161Tb]Tb, for mCRPC therapy. Our study included 53 patients and reinforced prior evidence validating the clinical safety and efficacy of these radioligands. Our research suggested that these treatments are characterized by a favorable safety profile with negligible toxicity. Moreover, [161Tb]Tb-PSMA recipients, though trialed in a smaller patient sample, yielded concordant outcomes on par with those receiving [177Lu]Lu-PSMA, highlighting its promise as an alternative therapy and warrants additional investigation. The objective of this retrospective study is to assess the effectiveness and safety of two beta-emitting prostate-specific membrane antigen (PSMA) radioligands, [177Lu]Lu and [161Tb]Tb, in heavily treated patients with metastatic castration-resistant prostate cancer (mCRPC). A total of 148 cycles of beta-emitting PSMA radioligand therapy were given to 53 patients at a specialized cancer care center in Amman, Jordan. This treatment was offered following the exhaustion of all prior treatment modalities. Approximately half of the cases (n = 26) demonstrated an initial partial response to PSMA radioligand therapy. Moreover, roughly one-fourth of the patients (n = 13) exhibited a sustained satisfactory biochemical response, which qualified them to receive a total of six PSMA radioligand therapy cycles and maintain continued follow-up for additional treatment cycles. This was reflected by an adequate prostate-specific antigen (PSA) decline and a concomitant partial response evident on [68Ga]Ga-PSMA positron emission tomography/computed tomography imaging. A minority of patients (n= 18; 34%) experienced side effects. Generally, these were low-grade and self-limiting toxicities. This study endorses previous research evidence about PSMA radioligand therapy's safety and efficacy. It also provides the first clinical insight from patients of Arab ethnicity. This should facilitate and promote further evidence, both regionally and internationally. [ABSTRACT FROM AUTHOR]