Overall survival with [177Lu]Lu-PSMA-617 versus cabazitaxel in metastatic castration-resistant prostate cancer (TheraP): secondary outcomes of a randomised, open-label, phase 2 trial

Preparation and evaluation of a novel albumin-binding heterodimer therapeutic radiopharmaceutical with remarkable tumor accumulation and retention

The intricate heterogeneity exhibited across diverse tumor types and the inconsistent expression levels of a specific receptor within tumors make it difficult for single-targeting radiotracers to meet clinical needs. The combination of "dual-targeting" and "albumin-binding" strategies can overcome it and effectively improve tumor uptake and retention of radiopharmaceuticals, thereby enhancing the effect of tumor theranostics. In this study, an albumin binder-conjugated heterodimeric precursor L21 targeting integrin αvβ3 and CD13 was successfully developed and labeled with 68Ga and 177Lu to evaluate therapeutic potential in BxPC-3 xenograft mice. In vitro, [68Ga]Ga-L21 and [177Lu]Lu-L21 exhibited excellent radiochemical stability in phosphate buffered saline (PBS) or fetal bovine serum (FBS) at 37 °C for 5 h. Compared to [68Ga]Ga-L00 without albumin binder, the introduction of albumin binder did not substantially alter the water solubility of [68Ga]Ga-L21, but substantially increased its affinity for serum albumin in FBS. In vivo, [68Ga]Ga-L21 showed significantly higher tumor uptake and longer tumor retention time than [68Ga]Ga-L00 (0.70 ± 0.06 standardized uptake value [SUV] vs. 0.33 ± 0.02 SUV at 3 h, P = 0.0004). [177Lu]Lu-L21 exhibited excellent tumor uptake, tumor-to-nontumor ratios and tumor retention, with tumor uptake keeping 2.79 ± 0.30 percentage of injected radioactive dose per gram of tissue (%ID/g) even at 96 h post-injection. Biodistribution results of [177Lu]Lu-L21 were consistent with SPECT imaging, demonstrating that [177Lu]Lu-L21 is a promising radiopharmaceutical for tumor radionuclide therapy.

The role of PSMA-based radioligand therapy in hormone-sensitive prostate cancer

PURPOSE

Conventional systemic therapies are valuable options in prostate cancer (PCa); however, such treatments can determine adverse events and toxicity. The observed improvement in overall survival, coupled with PSA reduction and a favorable safety profile in the post-taxane castration-resistant PCa (CRPC) setting has prompted the consideration of PSMA-based radioligand therapy (RLT) earlier in the treatment sequence. In this review, we will describe the literature and ongoing clinical trials regarding the use of PSMA-based RLT in hormone-sensitive PCa (HSPC) including the neoadjuvant, de-novo/synchronous metastatic, adjuvant, and early BCR settings.

METHODS

We performed a systematic literature search on the PubMed/MEDLINE/EMBASE and clinicaltrials.gov databases for studies and protocols assessing the role of PSMA-based RLT in HSPC.

RESULTS

The literature search yielded 140 results. After screening titles and abstracts and applying inclusion and exclusion criteria, we selected 25 papers showing the potentialities of earlier RLT in HSPC, with several ongoing trials.

CONCLUSION

Early use of PSMA-based RLT holds significant potential in HSPC patients from the neoadjuvant to the BCR setting. In these stages, the lower tumor burden, more frequent exclusive nodal involvement, and higher organ reserve may improve treatment efficacy and allow for treatment combinations while maintaining a less toxic profile.

State of the Art: Personalizing Treatment for Patients With Metastatic Castration-Resistant Prostate Cancer

Until recently, the treatment of metastatic castration-resistant prostate cancer (mCRPC) relied exclusively on hormonal therapies and taxane chemotherapy. The advent of modern molecular profiling methods applied in the clinic, namely, next-generation sequencing and advanced positron emission tomography (PET) imaging, has allowed for the development of biomarker-driven therapeutics including anti-PD-L1 therapy for microsatellite instability-high or tumor mutation burden-high disease, poly(ADP-ribose) polymerase (PARP) inhibitors for patients with DNA damage repair mutations, and lutetium 177 vipivotide tetraxetan (177Lu-PSMA-617) for patients with prostate-specific membrane antigen (PSMA) PET-avid disease. While these targeted therapies have improved outcomes, there is an opportunity to refine biomarkers to optimize patient selection, understand resistance, and develop novel combination strategies. In addition, studies in the laboratory and in patient-derived samples have shown that a subset of mCRPC tumors lose expression of common prostate cancer markers such as prostate-specific antigen and PSMA because of lineage plasticity and the development of non-androgen receptor (AR)-driven disease. Non-AR-driven prostate cancer has been associated with aggressive behavior and poor prognosis, including in some cases histologic transformation to a poorly differentiated neuroendocrine prostate cancer (NEPC). The clinical management of NEPC typically follows the treatment paradigm for small cell lung cancer and increasingly relies on genomic and phenotypic characterization of disease, including loss of tumor suppressors and expression of cell surface markers such as DLL3. Therefore, both genomic subtyping and phenotypic subtyping are important to consider and can guide the clinical management of patients with advanced prostate cancer.

Expert Opinion on Current Treatment Alternatives for Patients With Prostate Cancer Progressing From the Metastatic Hormone-Sensitive Stage to the Castration-Resistant Stage After Receiving Early Treatment Intensification

For patients with castration-sensitive prostate cancer (mCSPC), treatment intensification with androgen deprivation therapy (ADT) plus new androgen receptor pathway inhibitors (ARPIs) has opened a scenario where no guidance exists to indicate the best treatment after progression to metastatic castration-resistant prostate cancer (mCRPC). Clinical decision-making has become even more complex, with the proven benefit for selected patients of triplet therapy with abiraterone or darolutamide added to the double combination therapy of ADT plus docetaxel. The profile of patients for whom triple therapy would be more beneficial is being defined beyond metastatic disease presentation and volume (eg, poor prognosis features). In October 2023 and October 2024, a panel of eight Spanish medical oncologists with expertise in the management of prostate cancer met to discuss the challenges in treating mCRPC. The scientific evidence was reviewed during this meeting, knowledge and experience were shared, and controversies were discussed until a consensus was reached. This information was collected and turned into a manuscript aimed at helping clinicians determine the optimal treatment sequence after disease progression based on scientific evidence and experts' opinions and consensus. To this end, the profile of mCSPC patients who may have received double or triplet therapy is analyzed, current treatment options are reviewed, and treatment algorithms are proposed. New and expected advancements in this field are also presented.

One-day dual-tracer examination in neuroendocrine neoplasms: a real advantage of low activity LAFOV PET imaging

PURPOSE

Somatostatin receptor (SSTR)-PET is crucial for effective treatment stratification of neuroendocrine neoplasms (NENs). In highly proliferating or poorly differentiated NENs, dual-tracer approaches using additional [18F]FDG PET can effectively identify SSTR-negative disease, usually requiring separate imaging sessions. We evaluated the feasibility of a one-day dual-tracer imaging protocol with a low activity [18F]FDG PET followed by an SSTR-PET using the recently introduced [18F]SiFAlin-TATE tracer in a long axial field-of-view (LAFOV) PET/CT scanner and its implications in patient management.

METHODS

Twenty NEN patients were included in this study. Initially, a low activity [18F]FDG PET was performed (0.5 ± 0.01 MBq/kg; PET scan 60 min p.i.). After 4.2 ± 0.09 h after completion of the [18F]FDG PET, a standard activity of [18F]SiFAlin-TATE was administered (3.0 MBq/kg; PET scan 90 min p.i.). To ensure the quantification accuracy of the second scan, we evaluated the potential impact of residual [18F]FDG activity by segmenting organs with minimal physiological SSTR-tracer uptake, such as the brain and myocardium, and assessing the activity concentrations (ACTs) of tumor lesions. Residual tumor lesion ACTs of [18F]FDG were calculated by factoring fluorine-18 decay, identifying a maximum residual ACT of 15% (R15%). To account for increased [18F]FDG trapping over time, higher residual ACTs of 20% (R20%) were considered. These simulated [18F]FDG ACTs were compared with those measured in the second PET scan with [18F]SiFAlin-TATE. The influence of the dual-tracer PET/CT results on therapeutic strategies was evaluated.

RESULTS

[18F]FDG cerebral uptake significantly decreased in the subsequent SSTR-PET (mean uptake [18F]FDG: SUVmean 6.0 ± 0.4; mean uptake in [18F]SiFAlin-TATE PET: SUVmean 0.2 ± 0.01; p < 0.0001); with similar results recorded for the myocardium. Simulated residual [18F]FDG ACTs represented only a minimal percentage of ACTs measured in the tumor lesions from the second PET scan (R15%: mean 5.2 ± 0.9% and R20%: mean 6.8 ± 1.2%), indicating only minimal residual activity of [18F]FDG that might interfere with the second PET scan using [18F]SiFAlin-TATE and preserved semi-quantification of the latter. Dual-tracer PET/CT findings directly influenced changes in therapy plans in eleven (55%) of the examined patients.

CONCLUSION

LAFOV PET scanners enable a one-day dual-tracer protocol, providing diagnostic image quality while preserving the semi-quantification of two 18F-labeled radiotracers, potentially simplifying the assessment of tumor biology and improving the clinical patient management while reducing logistical challenges. Additionally, low-activity PET imaging facilitates one-day dual-tracer PET examinations.

Outcome of Subsequent Therapies After 177Lu-Vipivotide Tetraxetan for Metastatic Castrate-Resistant Prostate Cancer: A Tertiary Cancer Center Experience

BACKGROUND

177Lu-vipivotide tetraxetan (177Lu-PSMA-617, LuPSMA) improves overall survival in patients with metastatic castration-resistant prostate cancer (mCRPC) after at least one taxane chemotherapy and androgen receptor pathway inhibitor. There are limited data on the clinical course and outcomes of patients with mCRPC after receipt of LuPSMA.

METHODS

We queried an IRB-approved prospectively maintained registry of all patients with mCRPC who received standard-of-care LuPSMA at our institution between June 2022 and January 2024. Clinical data about LuPSMA and subsequent therapies were extracted from the electronic medical record, including the type and number of subsequent systemic therapies, reason for treatment cessation, hematologic toxicity and supportive treatment, and PSA50 response to subsequent therapy (defined as a ≥ 50% decrease in PSA).

RESULTS

A total of 146 patients were evaluated; mean age 72 (range 52-87), observed median follow-up 5.9 months (range 0.51-18.7). Forty-four received systemic treatment after LuPSMA. The most common subsequent treatment after LuPSMA was chemotherapy (n = 27), primarily cabazitaxel ± carboplatin/cisplatin (n = 23), and the median number of cycles received was 4 (range 1-7). In 35/44 men with available hematologic toxicity data, 13 developed grade ≥ 3 anemia, 7 had ≥ grade 3 thrombocytopenia, and 16 received hematologic support. PSA50 to post-LuPSMA treatment occurred in 10/36 (28%) evaluable patients. Median overall survival from subsequent systemic therapy was 7.6 months (95% CI 5.81-NR).

CONCLUSIONS

30% of patients receiving standard-of-care LuPSMA received subsequent therapy, mostly cabazitaxel-containing regimens. Post-LuPSMA treatment appeared tolerable and was associated with a PSA50 response rate of 28%. These outcomes may be biased by limited standard-of-care life-prolonging treatment options at the time of LuPSMA FDA approval, but it also highlights the continued need to develop novel therapeutic strategies for mCRPC post-LuPSMA.

The role of radium-223 in the evolving treatment landscape of metastatic castration-resistant prostate cancer: A narrative review

The treatment of metastatic castration-resistant prostate cancer (mCRPC) has been rapidly evolving over the last two decades. The advent of new androgen receptor pathway inhibitors (ARPIs) such as abiraterone acetate or enzalutamide marks a great advance for treating mCRPC patientd in the pre- and post-docetaxel settings. The subsequent approval of ARPIs in early stages-i.e., metastatic hormone-sensitive (mHSPC) or nonmetastatic CRPC-led to a realignment of subsequent treatment choices upon progression to mCRPC, given the possibility of cross-resistance between ARPIs. Therapies with mechanisms of action different from those of ARPIs are now the focus of new treatment developments. Also, this anomalous situation brings the focus back to well-known treatments currently used later in the treatment sequence. This is the case of radium-223 which, when administered with enzalutamide, has recently been shown to prolong radiographic progression-free survival vs. enzalutamide alone in the first line in asymptomatic or mildly symptomatic patients with no known visceral metastases. In this narrative review, we summarize the treatment landscape for mCRPC, both from a historical and practical point of view, to understand the new potential of radium-223 as a treatment option in this setting.

Lutetium-177-PSMA-617 or cabazitaxel in metastatic prostate cancer: circulating tumor DNA analysis of the randomized phase 2 TheraP trial

The prostate-specific membrane antigen (PSMA)-targeted radioligand [¹⁷⁷Lu]Lu-PSMA-617 is a new standard treatment for metastatic castration-resistant prostate cancer (mCRPC), but predictive genomic biomarkers informing its rational use are unknown. We performed detailed dissection of prostate cancer driver genes across 290 serial plasma cell-free DNA samples from 180 molecular imaging-selected patients with mCRPC from the randomized TheraP trial of [¹⁷⁷Lu]Lu-PSMA-617 (n = 97) versus cabazitaxel chemotherapy (n = 83). The primary endpoint was PSA50 biochemical response, with secondary endpoints of progression-free survival (PFS) and overall survival (OS). In this post-hoc biomarker analysis, a low pretreatment circulating tumor DNA (ctDNA) fraction predicted a superior biochemical response (100% versus 58%, P = 0.0067) and PFS (median 14.7 versus 6.0 months; hazard ratio 0.12, P = 2.5 × 10-4) on [¹⁷⁷Lu]Lu-PSMA-617 independent of predictive PSMA-positron emission tomography imaging parameters, although this benefit did not extend to OS. Deleterious PTEN alterations were associated with worse PFS and OS on cabazitaxel, whereas ATM defects were observed in select patients with favorable [¹⁷⁷Lu]Lu-PSMA-617 outcomes. Comparing pretreatment and progression ctDNA revealed population flux but no evidence that alterations in individual mCRPC genes (or FOLH1) are dominant causes of acquired [¹⁷⁷Lu]Lu-PSMA-617 or cabazitaxel resistance. Our results nominate new candidate biomarkers for [¹⁷⁷Lu]Lu-PSMA-617 selection and ultimately expand the mCRPC predictive biomarker repertoire. We anticipate our ctDNA fraction-aware analytical framework will aid future precision management strategies for [¹⁷⁷Lu]Lu-PSMA-617 and other PSMA-targeted therapeutics. ClinicalTrials.gov identifier: NCT03392428 .

PSMA PET Imaging in the Management of Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Radioligand Therapy

Despite an evolving treatment landscape for people with metastatic castration-resistant prostate cancer, prognosis for this patient population remains poor. Prostate-specific membrane antigen positron emission tomography (PSMA PET) imaging may be used to identify patients with PSMA-positive (and no significant PSMA-negative) metastatic castration-resistant prostate cancer who could benefit from PSMA-targeted radioligand therapy. As the PSMA PET imaging and treatment landscape expands, there is a growing need for guidance and greater utilization of PSMA-targeted tracers and radioligand therapies to improve outcomes for patients with metastatic castration-resistant prostate cancer. This review discusses the current clinical considerations of PSMA PET, including the various imaging agents available and how best to identify patients eligible for PSMA PET imaging and subsequent PSMA-targeted radioligand therapy. This review also examines opportunities to mitigate discordant findings, as well as considerations around the standardization of reporting of PSMA PET imaging, key gaps in the evidence base, and guidance around the use of PSMA PET in clinical and research settings.

Direct Correlation of Tumor Absorbed Dose with Overall Survival in Metastatic Castration-Resistant Prostate Cancer Treated with 177Lu Prostate-Specific Membrane Antigen

In systemic radiopharmaceutical therapy, a direct dosimetric correlation between the tumor absorbed dose and overall survival, that is, Grays to months, has never been explicitly defined. This dosimetric analysis expounds this relationship in the context of metastatic castration-resistant prostate cancer treated with 177Lu prostate-specific membrane antigen (177Lu-PSMA). Methods: The average tumor absorbed dose per unit of administered activity from the first to sixth treatments was extrapolated from population data. This was used to calculate the cumulative tumor absorbed doses above the response threshold for 2 empiric randomized 177Lu-PSMA clinical trials (VISION and TheraP). This was correlated to the difference in overall survival between these 2 trials to derive the tumor absorbed dose-survival relationship. This result was used to calculate the overall survival for a hypothetical optimized first strike in the context of personalized predictive dosimetry. Results: The tumor absorbed dose-survival relationship is calculated to be approximately 1 mo of overall survival per 1 Gy above the response threshold. An optimized first strike can double the overall survival compared with empiric regimens, delivers a higher cumulative tumor absorbed dose in fewer treatments, and avoids futile whole-body irradiation. Overall survival is proportional to the area bounded by the tumor absorbed dose curve and the response threshold absorbed dose curve. This suggests that, in addition to an optimized first strike, overall survival may also be improved by the concurrent administration of other systemic agents that modify tumor radiobiology to lower the response threshold, such as radiosensitization. Conclusion: Dosimetric evidence advocates for personalized prescription based on predictive dosimetry to optimize overall survival by exploiting radiobiologic synergy between the first strike and tumor radiosensitization.

Cost-utility analysis of 177Lu-PSMA-617 radioligand therapy in second-line and third-line treatment for metastatic castration-resistant prostate cancer (mCRPC) in Germany

PURPOSE

To evaluate the cost-effectiveness of 177Lu-PSMA-617 radioligand therapy (PRLT) in metastatic castration-resistant prostate cancer (mCRPC) in Germany by comparing (I) PRLT plus standard-of-care (SoC) versus SoC alone as third-line treatment and (II) PRLT versus second-line cabazitaxel chemotherapy.

METHODS

Cohort state-transition models were developed with (I) four health states (treatment, stable after treatment, progression, death) and (II) six health states (treatment, stable after treatment, third-line treatment after progression, stable after third-line treatment, next progression, death). Transition probabilities were derived from the VISION and TheraP trials, and quality-of-life data from the VISION and CARD trials. Costs were derived from statutory health insurance claims data (2019-2022). Models simulated a five-year horizon with one-month cycles, applying within-cycle correction and a 3% discount rate. Sensitivity analyses addressed uncertainty.

RESULTS

For Model I, PRLT plus SoC compared to SoC incurred incremental costs of €27,200 per patient, with a gain of 0.39 quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER) of €69,418 per QALY gained. In Model II, PRLT plus SoC compared to cabazitaxel achieved incremental savings of €1,460 per patient and a QALY gain of 0.11, making it the dominant option.

CONCLUSION

Although Germany lacks an explicit willingness-to-pay threshold for interpreting the ICER of Model I, it falls within the range of other reimbursed cancer therapies. This suggests PRLT is cost-effective as second- or third-line treatment for mCRPC. Between 2019 and 2022, hospitals mainly used self-produced 177Lu-PSMA-617, which was less costly than the product now commercially available, limiting the generalizability of our findings.

[225Ac]Ac-PSMA for the treatment of metastatic castration-resistant prostate cancer: A systematic review and meta-analysis

BACKGROUND

Approximately 10%-20% of prostate cancers progress to metastatic and castration-resistant forms (mCRPC). Radioligand (RLT) therapy with [177Lu]Lu-prostate-specific membrane antigen (PSMA) is an approved treatment for metastasized mCRPC. Moreover, Actinium-225 (225Ac), an alpha-emitter isotope, has also been used to label PSMA and, recently, to treat mCRPC patients with encouraging results. However, robust clinical data on [225Ac]Ac-PSMA therapy and its comparison with [177Lu]Lu-PSMA are still limited. Our aim was to evaluate the role of [225Ac]Ac-PSMA in treating mCRPC and compare it with conventional [177Lu]Lu-PSMA therapy.

METHODS

A systematic search was performed in PubMed, Web of Science, Scopus and the Cochrane Register of Controlled Trials from June 2023 to January 2024. This work was conducted in accordance with PRISMA guidelines.

RESULTS

After screening and study selection according to PRISMA guidelines, 11 studies were included, 9 of which focused on [225Ac]Ac-PSMA only and two on tandem therapy ([225Ac]Ac-PSMA/[177Lu]Lu-PSMA). Overall, the pooled proportion of PSA decline in patients was .85 (95% CI: .79-.91, p < .001); patients pretreated with [177Lu]Lu-PSMA achieved a pooled proportion of PSA decline of .90 (95% CI: .82-.97, p < .001). In patients treated with tandem therapy, PSA decline was observed in approximately 90% of them, while PSA response rates above 50% ranged from 53.3% to 65%. Xerostomia was the most frequently reported side effect, along with anaemia, thrombocytopenia and nephrotoxicity.

CONCLUSIONS

Overall, the main results of our study showed that [225Ac]Ac-PSMA-617 had a significant therapeutic effect on mCRPC with an acceptable toxicity level. The latter, however, appears greater than with [177Lu]Lu-PSMA-617. In future studies, an adequate analysis of the incidence of side effects associated with [225Ac]Ac-PSMA should be performed to evaluate the role of cumulative toxicity of earlier treatments and the higher frailty of heavily pretreated patients.

Lutetium-177 PSMA radioligand therapy in taxan-naive first- and second-line metastatic castration resistant prostate cancer after first-line ARPI therapy

PURPOSE

Lutetium-177 Prostate-specific membrane antigen (Lu-PSMA) radioligand therapy is EMA-approved for metastatic castration resistant prostate cancer (mCRPC) after androgen receptor pathway inhibition (ARPI) and taxan-based chemotherapy. However, its effect in taxan-naïve patients is under current investigation.

METHODS

We relied on the FRAMCAP database to elaborate Lu-PSMA therapy outcomes of progression-free (PFS) and overall (OS) in taxan-naïve mCRPC patients after previous ARPI treatment. Comparison was made against current standard of care with ARPI or docetaxel, irrespective of the previous used staging modality.

RESULTS

Of 269 patients, 11% received Lu-PSMA in first/second-line mCRPC vs. 57% ARPI vs. 33% docetaxel. Mostly no significant baseline differences between Lu-PSMA and ARPI patients were observed, while Lu-PSMA patients were significantly older, received less systematic treatments and ECOG1-2 proportions were higher, relative to docetaxel patients. In PFS (13.3 vs. 8.2 months, hazard ratio [HR]: 0.70, p = 0.16) and OS analyses (68.9 vs. 39.1 months, HR: 0.64, p = 0.2), Lu-PSMA was numerically more favorable than ARPI. In additional multivariable Cox regression models, Lu-PSMA was significant better regarding PFS and OS, relative to ARPI (both p < 0.05). Compared to docetaxel, also significant better PFS (13.3 vs. 8.1 months, HR: 0.46) and OS (68.9 vs. 27.3 months, HR: 0.34, both p < 0.01) was observed for Lu-PSMA treatment. The OS advantage was also observed after multivariable adjustment (p < 0.01).

CONCLUSION

This retrospective single-center study including a substantial proportion of patients with treatment preference for Lu-PSMA suggests that Lu-PSMA therapy provides significantly more favorable PFS and OS outcomes in taxan-naïve mCRPC patients after previous ARPI treatment, relative to ARPI or docetaxel treatment and may be considered as an early mCRPC treatment option.

Expanding horizons in theragnostics: from oncology to multidisciplinary applications

Theragnostics is the integration of treatment and diagnosis, involving a drug or technology that combines diagnostic imaging with targeted therapy. This approach utilizes imaging to identify specific biological targets, which are then used to deliver therapeutic effects for the benefit of patients. The effectiveness and potential of theragnostics in improving patient outcomes are supported by significant clinical trials and technological innovations. Theragnostics has demonstrated its capacity to deliver targeted and real-time interventions, making it adaptable to diverse clinical domains. Its applications range from visualizing and eradicating tumors to addressing complex neurological disorders and cardiovascular diseases. The integration of nanomaterials and advancements in molecular biology further enhance the capabilities of theragnostics, promising a future where treatments are highly personalized, and diseases are understood and managed at a molecular level previously unattainable. Our comprehensive overview focuses on the current advancements in theragnostics applications across different disease domains. We highlight the role of molecular imaging technologies, such as PET/CT scans, in early diagnosis and treatment. Additionally, we explore the potential of chemokines as molecular imaging targets in systemic inflammatory diseases and central nervous system pathologies. In conclusion, the progression of theragnostics represents a transformative phase in medical practice, providing new avenues for precise treatment and improved patient outcomes. Its multidisciplinary nature and continuous innovation have the potential to profoundly impact the future of medical research and clinical practice, as well as revolutionizing the treatment and management of a wide array of diseases.

Treatment Landscape of Prostate Cancer in the Era of PSMA Radiopharmaceutical Therapy

The treatment landscape of prostate cancer is quite complex because of the many therapeutic options available in different disease settings (hormonal treatments, chemotherapy, poly(adenosine diphosphate ribose) polymerase inhibitors, radiopharmaceutical therapy). Since in most cases we do not have comparative studies between these different agents, the best therapeutic sequence in patients with prostate cancer remains unsolved. In this review, we describe the different systemic therapeutic options available in each disease setting from localized disease to metastatic castration-resistant disease. We also indicate when to use each of these therapeutic options in the therapeutic sequence on the basis of the results of the available studies. A special focus of this review is the place of prostate-specific membrane antigen radiopharmaceutical therapy in the treatment algorithms.

Role of PSMA PET/CT in imaging and management of prostate cancer

PURPOSE OF REVIEW

In the era of precision medicine, the introduction of FDA-approved prostate-specific membrane antigen (PSMA) targeting tracers has revolutionized prostate cancer imaging. These tracers enable functional positron emission tomography (PET) imaging, allowing for precise identification of the location and extent of prostate cancer spread. This review serves as a practical guide for multidisciplinary teams caring for prostate cancer patients, outlining the current approved uses of PET imaging with PSMA tracers and exploring its future applications.

RECENT FINDINGS

PSMA PET/CT has become a reliable modality for initial staging in patients with intermediate-to-high risk prostate cancer, restaging in cases of biochemical recurrence and further clarifying disease status among patients with conventional imaging based nonmetastatic castrate resistant prostate cancer and metastatic prostate cancer. Additionally, it has promising roles in selecting patients for radioligand therapy, monitoring treatment response, and guiding therapeutic decision-making.

SUMMARY

PSMA PET/CT is currently a crucial imaging tool used at key stages of prostate cancer management, with ongoing research exploring its potential for additional clinical applications.

Impact of PSMA-PET/CT on Radiotherapy Decisions: Is There a Clinical Benefit?

Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA-PET/CT) has emerged as a game-changing imaging modality in prostate cancer, offering superior sensitivity and specificity compared to conventional imaging techniques. Its increasing adoption has significantly influenced radiotherapy decision-making, yet its true clinical impact remains under investigation. This narrative review explores the role of PSMA-PET/CT in guiding radiotherapy decisions across different clinical scenarios, from primary treatment planning to biochemical recurrence and oligometastatic disease. We assess its impact on target delineation, treatment modifications, and overall patient management while addressing existing knowledge gaps.

Systemic treatment options for metastatic castration resistant prostate cancer: A living systematic review

Background

Optimal treatment selection for metastatic castration resistant prostate cancer (mCRPC) remains challenging due to evolving standards of care in castration sensitive setting.

Purpose

To synthesize and appraise evidence on systemic therapy for mCRPC patients stratified by prior therapy and HRR alterations informing a clinical practice guideline.

Data Sources

MEDLINE and EMBASE (inception to 5 March 2025) using living search.

Study Selection

Randomized clinical trials assessing systemic therapy in mCRPC.

Data Extraction

Primary outcomes assessed were progression free survival (PFS) and overall survival (OS).

Data Synthesis

This report of the living systematic review (LSR) includes 143 trials with 17,523 patients (59 phase III/IV trials, 8,941 patients; 84 phase II, 8,582 patients). In the setting of prior androgen deprivation therapy (ADT) alone or ADT+docetaxel, treatment benefit was observed with poly (ADP-ribose) polymerase inhibitors (PARPi) in combination with androgen receptor pathway inhibitors (ARPI) for BRCA+ subgroup. In the setting of prior ADT+ARPI or ADT+ARPI+docetaxel, treatment benefit was observed with PARPi monotherapy for BRCA+ subgroup. Treatment benefit with PARPi may be observed for select non-BRCA homologous recombination repair (HRR) alterations (CDK12, PALB2). Treatment benefit was observed with abiraterone, enzalutamide, cabazitaxel, docetaxel (if no prior docetaxel), and Lu177 (if PSMA+) for patients without HRR alterations.

Limitations

Study-level data and indirectness in evidence.

Conclusion

Findings from the current LSR suggest that optimal treatment for mCRPC should be individualized based on prior therapy and HRR alterations. Current evidence favors PARPi alone (ARPI exposed) or in combination with ARPI (ARPI naïve) for patients with BRCA alterations, while ARPI alone, chemotherapy, and Lu177 remain potential options for patients without HRR alterations.

E-Urea-K-Based PSMA Imaging Served as an Alternative in Assessing Tumor Neovascularization via Targeting CD31

To reveal the natural correlation between prostate-specific membrane antigen (PSMA) imaging and tumor neovascularization in prostate cancer and further explore E-urea-K-based PSMA-targeted (EK-PSMA) imaging as a potential indicator of tumor neovascularization, the 22Rv1 mouse models were established and underwent 99mTc-HYNIC-ALUG SPECT/CT. Pearson correlation analysis was applied to assess the relationship between tumor tracer uptake and tumor characteristics, including size, glucose metabolism, and cell phenotypes (e.g., Ki-67, VEGF, CD31, and PSMA). Then, molecular docking further identified the key factors of EK-PSMA imaging, specifically related to tumor neovascularization. Finally, animal models with positive and negative PSMA expression (22Rv1, LNCaP, U87, SAOS-2, A549, and ACHN) were subjected to antibody-targeted blockade to verify the role of these key factors in EK-PSMA imaging. The Pearson's r values of tracer uptake correlated with CD31 and tumor size were 0.82 and 0.99, respectively (P < 0.05), and the correlations of tracer uptake with SUVmax, SUVmean, Ki-67, VEGF, and PSMA expressions were 0.47, 0.20, 0.69, -0.65, and 0.20, respectively (all P > 0.05). Molecular docking confirmed the affinity of E-urea-K to PSMA (two sites, binding scores, -5.4 kcal/mol and -6.0 kcal/mol) and CD31 (one site, binding score, -5.1 kcal/mol). The blockade of the CD31 antibody partially reduced the 99mTc-HYNIC-ALUG uptake in five other types of tumors (paired t test, P = 0.0478). The Pearson's r value of CD31 staining and tracer uptake prior to the antibody blockade was 0.84 (P < 0.05). Additionally, when removing the PSMA-positive models (22Rv1 and LNCaP), the Pearson's r value of CD31 staining and tracer uptake prior to the antibody blockade was 0.99 (P < 0.05). Thus, CD31 was found to be a mutual target of EK-PSMA imaging; therefore, EK-PSMA imaging provides a viable assessment option for tumor neovascularization, especially for PSMA-negative tumors.

When You Get to the Fork in the Road, Take It: The Challenges in Managing Patients With Advanced Prostate Cancer

As is the case with most solid tumors, the heterogeneity of the disease biology of prostate cancer presents clinicians managing this disease with daily challenges. However, in contrast to other common cancers such as breast, lung, and colorectal cancers, there are unique challenges in prostate cancer management, including the variety of clinicians who manage aspects of the disease (urologists, medical oncologist, radiation oncologists) and the striking absence of prospective comparative data to inform the optimal sequence of systemic therapy in patients with metastatic castration-resistant disease. The purpose of this review is to attempt to assist practicing oncologists with sorting through the myriad of prostate cancer disease subsets and the challenges in making therapeutic decisions in multiple data-free zones given the absence of level 1 comparative clinical trials in the metastatic hormone-sensitive and castration-resistant states.

Clinical Trial Protocol for LuCAB: A Phase I-II Trial Evaluating Cabazitaxel in Combination with [177Lu]Lu-PSMA-617 in Patients with Metastatic Castration-Resistant Prostate Cancer

[177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 is a standard treatment for patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel and an androgen receptor pathway inhibitor. However, for many, responses are short and progression is inevitable. Contributing factors to treatment resistance include molecular heterogeneity with variable PSMA expression, micrometastases that may not absorb sufficient radiation from 177Lu to result in cell death, and inherent or acquired radioresistance because of genomic alterations or the tumor microenvironment. Cabazitaxel is a radiosensitizer and may treat PSMA-negative disease that would otherwise evade targeting by [177Lu]Lu-PSMA-617. We hypothesize that the combination of [177Lu]Lu-PSMA-617 and cabazitaxel will be synergistic with an acceptable safety profile. Methods: This investigator-initiated phase I-II trial aims to evaluate the safety, tolerability, and preliminary efficacy of cabazitaxel and [177Lu]Lu-PSMA-617 in combination. Up to 38 patients with mCRPC will receive up to 6 doses of [177Lu]Lu-PSMA-617 administered intravenously every 6 wk at a fixed dose of 7.4 GBq. Cabazitaxel will be administered concurrently (dose range, 12.5-20 mg/m2) on day 2 and day 23 of each 6-wk cycle, with dose escalation determined using a traditional 3 + 3 design to establish the maximum tolerated or administered dose. Key eligibility criteria include a diagnosis of progressive mCRPC with PSMA-positive disease on PSMA PET/CT (SUVmax ≥ 15) and no sites of discordance on [18F]F-FDG PET/CT. Patients must have received prior docetaxel and an androgen receptor pathway inhibitor, have adequate bone marrow and organ function, and have an Eastern Cooperative Oncology Group performance status of 0 or 1. The primary objective is to assess for dose-limiting toxicities and determine the recommended phase II dose of cabazitaxel and [177Lu]Lu-PSMA-617 in combination. Secondary objectives include further safety evaluation through the measurement of the frequency and severity of adverse events, assessment of efficacy, and evaluation of changes in pain and health-related quality of life over the first 12 mo from treatment commencement. Plasma will be collected at baseline, during treatment, and at disease progression for circulating tumor DNA analysis, which will be correlated with clinical outcomes to identify potential biomarkers of treatment response or resistance. Conclusion: Enrollment commenced in August 2022, with anticipated completion in 2025.

Recommendations from the Galician Oncological Society and the Galician Society of Nuclear Medicine for the use of 177Lu-PSMA-617 radioligand-therapy in prostate cancer

Theragnostic is a type of precision medicine that uses molecules linked to radioactive isotopes for the diagnosis and treatment of diseases. In recent years, it has gained significant importance to treat neuroendocrine tumors and is currently being used in prostate cancer. Various radiopharmaceuticals have emerged for diagnosing and detecting lesions showing prostate-specific membrane antigen (PSMA) positivity on the Positron emission tomography/computed tomography scan, being the most widely used labeled with [68Ga] and [18F]. Its use as therapy in prostate cancer (PC) has been assessed in the VISION, TheraP, and PSMAfore clinical trials conducted with the radioligand [177Lu]Lu-PSMA-617, demonstrating significant antitumor activity. The aim of this article is to present practical recommendations, based on current available scientific evidence and on a multidisciplinary consensus, for the diagnosis and treatment with [177Lu]Lu-PSMA-617 in patients with PC.

A Meta-Analysis and Meta-Regression of the Efficacy, Toxicity, and Quality of Life Outcomes Following Prostate-Specific Membrane Antigen Radioligand Therapy Utilising Lutetium-177 and Actinium-225 in Metastatic Prostate Cancer

BACKGROUND AND OBJECTIVE

Management of metastatic prostate cancer (mPCa) presents significant challenges. In this systematic review, meta-analysis, and meta-regression, the efficacy, safety, and quality of life (QoL) outcomes of prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (PRLT) utilising lutetium-177 ([177Lu]Lu-PSMA) and actinium-225 ([225Ac]Ac-PSMA) were assessed.

METHODS

A detailed literature search across PubMed/Medline, EMBASE, Web of Science, Scopus, and Cochrane Library was conducted, culminating in the inclusion of 100 studies involving 8711 patients. Data on prostate-specific antigen (PSA) responses, toxicity profiles, and QoL and survival outcomes were analysed. Proportional meta-analyses and meta-regression analyses were performed.

KEY FINDINGS AND LIMITATIONS

The estimated proportion of patients with PSA decline ≥50% was 0.49 for [177Lu]Lu-PSMA and 0.60 for [225Ac]Ac-PSMA in mPCa, particularly metastatic castration-resistant prostate cancer. A meta-regression analysis indicated an association between the cumulative amount of administered activity and the proportion of PSA ≥50% decline. Positive PSA responses were observed alongside improved overall survival across both therapies. Our analyses also identified the key factors associated with PSA responses and survival outcomes, including baseline haemoglobin level, and the presence of visceral metastases. Although anaemia was commonly observed, with [177Lu]Lu-PSMA, severe toxicities were infrequent. Improved QoL was observed following [177Lu]Lu-PSMA therapy, whereas it remained stable following the second cycle of [225Ac]Ac-PSMA treatment. Heterogeneity across studies for PSA responses and toxicity profiles is a limitation.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our findings suggest an association between PRLT and reductions in PSA levels, as well as associations with enhanced survival outcomes in mPCa. Furthermore, our analysis shows a low incidence of severe toxicity associated with this treatment. These observations highlight the important role of PRLT in the management of mPCa.

Integrating Prostate Specific Membrane Antigen-PET into Clinical Practice for Prostate Cancer

Prostate surface membrane antigen (PSMA)-PET imaging has significantly shaped the clinical management of prostate cancer, from localized to metastatic disease. It outperforms conventional imaging in both primary staging and detecting recurrence. PSMA-PET incorporation into the clinical workflow can alter treatment decisions, though the impact of observed stage migration on patient outcomes has yet to be well-characterized. There is growing interest in using PSMA-PET to predict treatment response across all stages of prostate cancer, and to select patients for PSMA radioligand therapy. Use of PSMA-PET will continue to expand for clinical applications as its role becomes better defined through prospective studies.

Overall survival and quality of life with [177Lu]Lu-PSMA-617 plus enzalutamide versus enzalutamide alone in metastatic castration-resistant prostate cancer (ENZA-p): secondary outcomes from a multicentre, open-label, randomised, phase 2 trial

BACKGROUND

Interim analysis of the ENZA-p trial showed improved prostate-specific antigen (PSA) progression-free survival with the addition of lutetium-177 [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 to enzalutamide as first-line treatment of metastatic castration-resistant prostate cancer. Here, we report the secondary endpoints of overall survival and health-related quality of life (HRQOL) with longer follow-up.

METHODS

ENZA-p was a multicentre, open-label, randomised, phase 2 trial done at 15 hospitals in Australia. Participants were men aged 18 years or older who had not previously been treated with docetaxel or androgen receptor pathway inhibitors for metastatic castration-resistant prostate cancer, gallium-68 [68Ga]Ga PSMA-PET-CT-positive disease, an Eastern Cooperative Oncology Group performance status of 0-2, and at least two risk factors for early progression on enzalutamide. Participants were randomly assigned (1:1) by a centralised, web-based system using minimisation with a random component to stratify for study site, disease burden, early docetaxel, and previous treatment with abiraterone. Treatment was oral enzalutamide 160 mg daily alone or with adaptive-dosed (two or four doses) intravenous 7·5 GBq [177Lu]Lu-PSMA-617 every 6-8 weeks. The primary endpoint was prostate-specific antigen (PSA) progression-free survival, which has been previously reported. Overall survival, defined as the interval from the date of randomisation to date of death from any cause, or the date last known alive, and HRQOL were key secondary endpoints. HRQOL was assessed with the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) and the Patient Disease and Treatment Assessment Form. For HRQOL analyses, deterioration-free survival was measured from randomisation until the earliest occurrence of death, clinical progression, discontinuation of study treatment; or a worsening of 10 points or more from baseline in physical function, or in overall health and QOL. Analyses of these secondary endpoints were prespecified and are by intention to treat. The trial is registered with ClinicalTrials.gov, NCT04419402, and follow-up is complete.

FINDINGS

Between Aug 17, 2020, and July 26, 2022, 79 patients were randomly assigned to enzalutamide and 83 to enzalutamide plus [177Lu]Lu-PSMA-617. 96 deaths was reported after a median follow-up of 34 months (IQR 29-39): 53 (67%) in the enzalutamide group and 43 (52%) in the enzalutamide plus [177Lu]Lu-PSMA-617 group. Overall survival was longer in the enzalutamide plus [177Lu]Lu-PSMA-617 group than the enzalutamide group (median 34 months [95% CI 30-37] vs 26 months [23-31]; HR 0·55 [95% CI 0·36-0·84], log-rank p=0·0053). HRQOL was rated by 154 (95%) of 162 participants. Deterioration-free survival at 12 months and stratified log-rank p values favoured enzalutamide plus [177Lu]Lu-PSMA-617 for both physical function (median 10·64 months [95% CI 7·66-12·42] vs 3·42 months [3·19-7·89]; HR 0·51 [95% CI 0·36-0·72], log-rank p<0·0001) and overall health and QOL (8·71 months [6·41-11·56] vs 3·32 months [3·09-5·26]; HR 0·47 [95% CI 0·33-0·67], log-rank p=0·0001). Mean scores for pain until progression favoured enzalutamide plus [177Lu]Lu-PSMA-617 over enzalutamide (difference 7·3 [95% CI 1·6-12·9]; p=0·012). Mean scores for fatigue until progression favoured enzalutamide plus [177Lu]Lu-PSMA-617 over enzalutamide (difference 5·9 [95% CI 1·1-10·7]; p=0·016). The frequency of self-rated xerostomia was lower in the enzalutamide group than in the enzalutamide plus [177Lu]Lu-PSMA-617 group (43 [57%] of 75 vs 58 [74%] of 78; p=0·039), and scores were not significantly different between groups for all other domains. Grade 3-5 adverse events occurred in 35 (44%) of 79 patients in the enzalutamide group and 37 (46%) of 81 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group. No deaths were attributed to study treatment in either group.

INTERPRETATION

The addition of [177Lu] Lu-PSMA-617 to enzalutamide was associated with improved survival and some aspects of HRQOL in patients with high-risk metastatic castration-resistant prostate cancer. Our findings warrant phase 3 evaluation of adaptive-dosed [177Lu] Lu-PSMA-617 in combination with androgen receptor pathway inhibitors in people with metastatic prostate cancer.

FUNDING

The Prostate Cancer Research Alliance initiative (Movember and Australian Federal Government), St Vincent's Clinic Foundation, GenesisCare, RoyMorgan, AdAcAp (a Novartis company), and Astellas.

Re-Rechallenge 177 Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer : A Step Further

ABSTRACT

177 Lu-PSMA-617 radioligand therapy has been US Food and Drug Administration-approved safe and effective treatment modality for metastatic castration-resistant prostate cancer, usually administered in 4 to 6 cycles at 6 to 8 weeks apart. Many patients achieve partial response or stable disease with biochemical response after treatment. However, these effects are usually short-lived, and patients ultimately show disease progression after a median period of 6 to 9 months. Rechallenge therapy appears to be safe and effective treatment modality in such patients. We show the clinical efficacy and safety of re-rechallenge 177 Lu-PSMA radioligand therapy in a 64-year-old man with metastatic castration-resistant prostate cancer with disease progression on multiple lines of hormonal and chemotherapy treatment.

Management Based on Pretreatment PSMA PET of Patients with Localized High-Risk Prostate Cancer Part 2: Prediction of Recurrence-A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

For patients with prostate cancer (PCa), PSMA PET better diagnose metastases than conventional imaging. In a systematic review and meta-analysis (INPLASY register, 2024311004), we aimed to summarize findings with pretreatment PSMA PET in patients with PCa that was localized according to conventional imaging and summarize how pretreatment PSMA PET had influence on biochemical recurrence (BCR)-free survival and overall survival (OS).

METHODS

We searched for publications in Pubmed, Google Scholar, ClinicalTrials.gov, and reference lists between 2016 and February 2025. We summarized biochemical recurrence-free survival in Forest plots.

RESULTS

Nine publications reported 1908 patients and showed that pretreatment PSMA PET was associated with survival. Three publications reported that pretreatment PSMA PET gave better 3-5-year BCR-free survival than conventional imaging (74% versus 57%). Two publications reported PSMA PET-risk for 389 patients. Those with PSMA PET-low-risk lived 5 years longer often than those with PSMA PET high-risk (84% versus 20%).

CONCLUSIONS

Pretreatment PSMA PET is widely used in the real world. Pretreatment PSMA PET supports personalized treatment and may explain why pretreatment PSMA PET improved BCR-free survival and OS. It is believed that pretreatment PSMA PET may facilitate future progress in care of patients with high-risk PCa.

The Role of PSMA PET Parameters as Biomarkers for Response to PSMA-Targeted Radiopharmaceutical Therapy

Prostate-specific membrane antigen (PSMA) PET is a well-established imaging tool for the evaluation of primary and recurrent prostate cancer (PCa). 177Lu PSMA-targeted radiopharmaceutical therapy (RPT) enables direct delivery of β-radiation to PSMA-expressing PCa cells while minimizing damage to normal tissue. As PSMA RPT becomes more widely used, there is growing interest in evaluating the predictive and prognostic role of PSMA PET parameters to enable better patient selection and effectively monitor treatment response. The purpose of this paper is to review the role of PSMA PET parameters as biomarkers for PSMA RPT. Quantitative parameters on baseline PSMA PET can serve as prognostic biomarkers for overall survival and predictive biomarkers for prostate-specific antigen response. Alongside lesion-based assessments, changes in whole-body quantitative parameters from baseline to interim or end-of-treatment PSMA PET are prognostic for overall survival and progression-free survival in patients undergoing PSMA RPT. Changes in quantitative, whole-body PSMA PET parameters may better reflect changes in PCa following systemic therapy compared with individual lesion-based assessments. Further research is necessary in larger, prospective trials to characterize the role of PSMA PET parameters as prognostic biomarkers for progression-free survival and overall survival in metastatic castration-resistant PCa patients undergoing PSMA RPT.

Comparison of two alternative sequences with cabazitaxel and 177Lu-PSMA-617 in metastatic castration-resistant prostate cancer: A retrospective multicenter study (LuCaS)

BACKGROUND

Cabazitaxel and 177Lu-PSMA-617 have been shown to improve survival in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel and androgen receptor pathway inhibitors (ARPI). we aimed to evaluate the impact of sequencing cabazitaxel and 177Lu-PSMA-617 on survival outcomes in patients with mCRPC.

PATIENTS AND METHODS

This is a retrospective, multicenter, cohort study which included patients with mCRPC who received sequential treatment with 177Lu-PSMA-617 and cabazitaxel between January 2015 and December 2023. Primary outcome was progression-free survival-2 (PFS-2) RESULTS: A total of 68 patients with mCRPC who received sequential 177Lu-PSMA-617 and cabazitaxel were included in the study. The primary outcome, progression-free survival-2 (PFS-2), was similar in patients treated with 177Lu-PSMA-617 first (LU-CA) and those receiving cabazitaxel (CA-LU) first (10.8 and 11.7 months, respectively; p = 0.422). The median overall survival (OS) was also similar in the LU-CA and CA-LU groups (16.6 and 19.9 months, respectively; p = 0.917). The objective response rate (ORR) for 177Lu-PSMA-617 was 23.1 % when used first and 16.1 % after cabazitaxel. ORR for cabazitaxel was 25.6 % and 31.3 % when used as the first agent and when used after 177Lu-PSMA-617, respectively.

CONCLUSIONS

In conclusion, treatment sequencing between cabazitaxel and 177Lu-PSMA-617 did not significantly affect survival outcomes in patients with mCRPC. These findings suggest that both drugs can be effectively integrated into the mCRPC treatment paradigm without concerns about the effect of sequencing. However, prospective data are needed to optimize sequencing strategies and explore their impact on specific patient subgroups for more personalized care.

Development of [225Ac]Ac‑LNC1011 for targeted alpha-radionuclide therapy of prostate cancer

PURPOSE

Prostate-specific membrane antigen (PSMA) radioligand therapy (PRLT) has become a promising option for treating metastatic castration-resistant prostate cancer (mCRPC). Radioligands labelled with the 68Ga/177Lu theranostic pair have been most widely used in the clinic for diagnosis and therapy, respectively. This study aims to develop a novel PSMA-targeted radioligand, LNC1011, radiolabeled with alpha-emitter 225Ac, to optimise pharmacokinetic properties and assess its potential for targeted alpha therapy (TAT) in prostate cancer treatment.

METHODS

LNC1011 (Dan-PSMA) was synthesised based on a PSMA-binding ligand with the addition of a dansylated amino acid. Systematic radiochemical analyses were conducted to confirm the successful synthesis and radiolabelling of [225Ac]Ac-LNC1011. Cell uptake and competition binding assays were performed in PSMA-positive PC3-PIP tumour cells to evaluate the binding affinity and PSMA targeting specificity. The pharmacokinetics properties and tumour uptake were characterised by biodistribution studies using healthy mice and a PC3-PIP xenograft mouse model injected with [225Ac]Ac-LNC1011. Radioligand therapy studies and maximum tolerated dose (MTD) assays were conducted to systematically evaluate the therapeutic efficacy and the safety of [225Ac]Ac-LNC1011.

RESULTS

[225Ac]Ac-LNC1011 was successfully radiolabelled with high radiochemical purity (> 97%) and high stability within 96 h (radiochemical purity > 96%). The high binding affinity of LNC1011 (IC50 = 16.28 nM) to PSMA was comparable to that of PSMA-617 (IC50 = 27.93 nM). Biodistribution studies confirmed that [225Ac]Ac-LNC1011 had moderate blood elimination half-life (T1/2z = 13.4 ± 0.57 h), which was at an optimised level between [225Ac]Ac-PSMA-617 (T1/2z = 5.19 ± 0.12 h) and [225Ac]Ac-PSMA-EB-01 (T1/2z = 25.18 ± 2.78 h). In addition, high tumour uptake of [225Ac]Ac-LNC1011 was identified to be 38.28 ± 10.04%ID/g at 1 h post-injection. The specific uptake gradually increased and peaked at 24 h (80.57 ± 3.00%ID/g) and persisted at a high level up to 72 h post-injection (50.58 ± 5.37%ID/g). Targeted alpha therapy results showed the complete inhibition of PC3-PIP tumour growth after administration of a single dose of 1 µCi and 0.5 µCi of [225Ac]Ac-LNC1011 similar to 0.5 µCi [225Ac]Ac-PSMA-617. At the 0.1 µCi dose level, partial remission was observed for [225Ac]Ac-LNC1011, as recurrence was found 20 days after administration. In contrast, mice treated with 0.1 µCi [225Ac]Ac-PSMA-617 showed incomplete tumour inhibition under the same conditions.

CONCLUSION

[225Ac]Ac-LNC1011 was successfully radiolabelled with high radiochemical purity and stability. With significantly improved tumour uptake and retention over PSMA-617, [225Ac]Ac-LNC1011 showed significantly better therapeutic efficacy than [225Ac]Ac-PSMA-617 for targeted alpha therapy of prostate cancer.

Cabazitaxel versus abiraterone or enzalutamide for metastatic castration-resistant prostate cancer following docetaxel failure: a systematic review and meta-analysis

PURPOSE

Treatment for metastatic castration-resistant prostate cancer (mCRPC) includes chemotherapy and inhibition of the androgen receptor pathway. However, the optimal treatment sequence in this scenario is not yet fully understood. Therefore, we conducted a systematic review and meta-analysis comparing cabazitaxel versus abiraterone or enzalutamide for efficacy and safety outcomes as second-line therapy in mCRPC patients after docetaxel failure.

METHODS

We searched PubMed, Embase, and Cochrane databases for interventional studies comparing cabazitaxel versus abiraterone or enzalutamide for patients with mCRPC who have experienced treatment failure with docetaxel as their first-line therapy. We computed hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Eight studies, comprising 1,897 patients were included, of whom 548 (28.8%) received cabazitaxel. Mean follow-up time ranged from 3 to 16.4 months. Median age ranged from 68.1 to 73.9 years in the cabazitaxel group, and 68.0 to 73.1 years in the abiraterone or enzalutamide group. In our meta-analysis, cabazitaxel significantly improved progression-free survival (PFS) rates (HR 0.60; 95% CI 0.47-0.78; p < 0.001) compared to abiraterone or enzalutamide. There were no differences between groups in overall survival (HR 0.76; 95% CI 0.46-1.24; p = 0.27), therapy-related grade ≥ 3 adverse events (AEs) (OR 3.00; 95% CI 0.72-12.40; p = 0.12), and PSA decline ≥ 50% (OR 1.20; 95% CI 0.51-2.80; p = 0.67).

CONCLUSIONS

In this systematic review and meta-analysis of men with mCRPC after docetaxel failure, second-line therapy with cabazitaxel was associated with a longer PFS compared with abiraterone or enzalutamide, though without a significant difference in OS.

A Look to the Future: Potential Theranostic Applications in Head and Neck Tumors

Theranostics, the practice of using a diagnostic radiopharmaceutical to guide radiotherapy with a chemically identical (or nearly identical) therapeutic radiopharmaceutical, is an exciting new field under development within the auspices of nuclear medicine. We aim to provide a narrative review of the areas of theranostics use and development which are occurring specifically in the head and neck, with attention to the therapeutic use of existing diagnostically used radiotracers such as agents that target prostate-specific membrane antigen (PSMA) and somatostatin receptors (e.g., DOTATATE derivatives), as well as developing classes of radiotracers such as those targeting fibrinogen-activating protein (FAP) and carbonic anhydrase IX (CAIX), as well as new meta-iodo-benzylguanidine (MIBG) derivatives. Most of those agents are still at the preclinical or early clinical stages of development, but as this is an emerging field, we aim to both outline current progress and suggest future directions.

Validation of Prognostic and Predictive Models for Therapeutic Response in Patients Treated with [177Lu]Lu-PSMA-617 Versus Cabazitaxel for Metastatic Castration-resistant Prostate Cancer (TheraP): A Post Hoc Analysis from a Randomised, Open-label, Phase 2 Trial

BACKGROUND

Prognostic models have been developed using data from a multicentre noncomparative study to forecast the likelihood of a 50% reduction in prostate-specific antigen (PSA50), longer prostate-specific antigen (PSA) progression-free survival (PFS), and longer overall survival (OS) in patients with metastatic castration-resistant prostate cancer receiving [177Lu]Lu-PSMA radioligand therapy. The predictive utility of the models to identify patients likely to benefit most from [177Lu]Lu-PSMA compared with standard chemotherapy has not been established.

OBJECTIVE

To determine the predictive value of the models using data from the randomised, open-label, phase 2, TheraP trial (primary objective) and to evaluate the clinical net benefit of the PSA50 model (secondary objective).

DESIGN, SETTING, AND PARTICIPANTS

All 200 patients were randomised in the TheraP trial to receive [177Lu]Lu-PSMA-617 (n = 99) or cabazitaxel (n = 101) between February 2018 and September 2019.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Predictive performance was investigated by testing whether the association between the modelled outcome classifications (favourable vs unfavourable outcome) was different for patients randomised to [177Lu]Lu-PSMA versus cabazitaxel. The clinical benefit of the PSA50 model was evaluated using a decision curve analysis.

RESULTS AND LIMITATIONS

The probability of PSA50 in patients classified as having a favourable outcome was greater in the [177Lu]Lu-PSMA-617 group than in the cabazitaxel group (odds ratio 6.36 [95% confidence interval {CI} 1.69-30.80] vs 0.96 [95% CI 0.32-3.05]; p = 0.038 for treatment-by-model interaction). The PSA50 rate in patients with a favourable outcome for [177Lu]Lu-PSMA-617 versus cabazitaxel was 62/88 (70%) versus 31/85 (36%). The decision curve analysis indicated that the use of the PSA50 model had a clinical net benefit when the probability of a PSA response was ≥30%. The predictive performance of the models for PSA PFS and OS was not established (treatment-by-model interaction: p = 0.36 and p = 0.41, respectively).

CONCLUSIONS

A previously developed outcome classification model for PSA50 was demonstrated to be both predictive and prognostic for the outcome after [177Lu]Lu-PSMA-617 versus cabazitaxel, while the PSA PFS and OS models had purely prognostic value. The models may aid clinicians in defining strategies for patients with metastatic castration-resistant prostate cancer who failed first-line chemotherapy and are eligible for [177Lu]Lu-PSMA-617 and cabazitaxel.

PATIENT SUMMARY

In this report, we validated previously developed statistical models that can predict a response to Lu-PSMA radioligand therapy in patients with advanced prostate cancer. We found that the statistical models can predict patient survival, and aid in determining whether Lu-PSMA therapy or cabazitaxel yields a higher probability to achieve a serum prostate-specific antigen response.

Dual-Tracer 18 F-FDG and 68 Ga-PSMA PET/CT Imaging of Heterogeneous Phenotypes of Metastatic Castration-Resistant Prostate Cancer for Predicting Response to Novel Hormone Therapy

PURPOSE

This study evaluated interlesion heterogeneity in prostate cancer using dual-tracer imaging (PSMA and FDG) and explored its predictive value for novel hormone therapy (NHT).

PATIENTS AND METHODS

A total of 205 prostate cancer patients (23 biochemical recurrences, 68 metastatic castration-sensitive prostate cancers, 114 metastatic castration-resistant prostate cancers [mCRPC]) who underwent dual 18 F-FDG and 68 Ga-PSMA PET/CT imaging were retrospectively analyzed. Among them, 62 mCRPC patients received NHT. Patients were classified into 3 groups: PSMA+FDG-, PSMA+FDG+, and PSMA-FDG+. SUV ratio , the ratio of PSMA-SUV max to FDG-SUV max , was evaluated for its predictive value on progression-free survival (PFS).

RESULTS

The proportion of PSMA+FDG- patients decreased from biochemical recurrence to mCRPC stages, whereas FDG+ cases increased significantly ( P = 0.001). In the NHT cohort, group 3 (PSMA-FDG+) had significantly shorter median PFS than group 1 (133 vs 497 days; P = 0.027). In group 2, patients with a high SUV ratio had better median PFS than those with a low SUV ratio (368 vs 147 days; P = 0.031).

CONCLUSIONS

Dual-tracer imaging reveals interlesion heterogeneity in prostate cancer, and SUV ratio may help predict early response to NHT.

Management of Patients with Advanced Prostate Cancer. Report from the 2024 Advanced Prostate Cancer Consensus Conference (APCCC)

BACKGROUND AND OBJECTIVE

Innovations have improved outcomes in advanced prostate cancer (PC). Nonetheless, we continue to lack high-level evidence on a variety of topics that greatly impact daily practice. The 2024 Advanced Prostate Cancer Consensus Conference (APCCC) surveyed experts on key questions in clinical management in order to supplement evidence-based guidelines. Here we present voting results for questions from APCCC 2024.

METHODS

Before the conference, a panel of 120 international PC experts used a modified Delphi process to develop 183 multiple-choice consensus questions on eight different topics. Before the conference, these questions were administered via a web-based survey to the voting panel members ("panellists").

KEY FINDINGS AND LIMITATIONS

Consensus was a priori defined as ≥75% agreement, with strong consensus defined as ≥90% agreement. The voting results show varying degrees of consensus, as discussed in this article and detailed in the Supplementary material. These findings do not include a formal literature review or meta-analysis.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The voting results can help physicians and patients navigate controversial areas of clinical management for which high-level evidence is scant or conflicting. The findings can also help funders and policymakers in prioritising areas for future research. Diagnostic and treatment decisions should always be individualised on the basis of patient and cancer characteristics, and should incorporate current and emerging clinical evidence, guidelines, and logistic and economic factors. Enrolment in clinical trials is always strongly encouraged. Importantly, APCCC 2024 once again identified important gaps (areas of nonconsensus) that merit evaluation in specifically designed trials.

The Role of Nuclear Medicine in Imaging and Therapy of Prostate Cancer: The State of the Art

Prostate cancer (PCa) is the second most diagnosed cancer in men. In recent years, nuclear medicine has played an expanding role in diagnosing, staging, monitoring, and treating PCa. Specifically, the introduction of prostate-specific membrane antigen PET/computed tomography has significantly contributed to detecting locoregional and distant disease. Radioligand therapy, with its capacity to induce highly selective cytotoxic effects, is progressively being integrated into PCa therapy. The advent of novel therapeutic agents, additional indications, and a more comprehensive integration between nuclear imaging and therapy, represent the forefront of nuclear medicine in PCa.

Overview of selected completed prospective studies on PSMA-targeted radioligand therapy with [177Lu]Lu-PSMA-617 in metastatic castration-resistant prostate cancer

Theranostics in nuclear oncology combines diagnostic and therapeutic procedures using radiotracers to target tumor cells. Prostate-specific membrane antigen (PSMA) is a key target in metastatic prostate cancer, and the radioligand [177Lu]Lu-PSMA-617, which binds to PSMA, has shown promising results in treating metastatic castration-resistant prostate cancer (mCRPC), leading to its approval by the European Medicines Agency in 2022.In this narrative review, the current evidence of [177Lu]Lu-PSMA-617 in mCRPC was discussed in the context of selected studies and the joint EANM/SNMMI guidelines for Lutetium-177-labeled PSMA-targeted radioligand therapy.The use of [177Lu]Lu-PSMA-617 for post-chemotherapy mCRPC is supported by substantial evidence from the phase II TheraP and the phase III VISION trials, demonstrating its safety and efficacy. The theranostic approach identifies patients likely to benefit from [177Lu]Lu-PSMA-617, which is effective only in tumors with sufficient PSMA expression, as detected by PSMA-ligand PET/CT, which is also used for response assessment.The success of [177Lu]Lu-PSMA-617 in post-chemotherapy mCRPC patients has led to further ongoing studies evaluating its use earlier in the treatment sequence, prior to chemotherapy. To ensure beneficial treatment outcome, adequate patient selection and evaluation of imaging-based response through PSMA-ligand PET/CT is necessary. · Indications for [177Lu]Lu-PSMA-617 are based on the TheraP and VISION clinical trials.. · Adequate patient selection using PSMA-ligand PET/CT is essential for beneficial outcomes.. · Response evaluation is based on imaging, PSA levels, and the patient's clinical condition.. · Karimzadeh A, Lehnert W, Koehler D et al. Overview of selected completed prospective studies on PSMA-targeted radioligand therapy with [177Lu]Lu-PSMA-617 in metastatic castration-resistant prostate cancer. Rofo 2025; DOI 10.1055/a-2514-4523.

Vesicles Secreted by Renal Cell Carcinoma Cells Cause Vascular Endothelial Cells to Express PSMA and Drive Tumor Progression

Prostate-specific membrane antigen (PSMA) protein expression is induced during prostate cancer progression and metastasis. Recently, we reported that PSMA-positive vesicles released by prostate cancer cell lines enhanced vascular endothelial cell angiogenesis and that PSMA may be involved in tumor angiogenesis. Similarly, it is known that PSMA is upregulated in peritumoral vessels in renal cell carcinoma (RCC). In this study, we investigated the significance and molecular function of PSMA in RCC. PSMA immunohistochemical staining confirmed PSMA presence only in perinephric tumor vessels, and PSMA intensity was strongly correlated with recurrence rate and venous invasion. Spatial gene expression analysis revealed that FOLH1 expression, which codes PSMA, was upregulated in tumor blood vessels around renal cancer, and that angiogenesis-related pathways were enhanced. The 10,000 g pellet fraction of the renal cancer cell lines Caki1- and ACHN-conditioned medium (CM) induced PSMA positivity in human umbilical vein endothelial cells (HUVECs) and enhanced tube formation. Mass spectrometry indicated that the 10,000 g pellet fraction contained various kinds of growth factors, like GDF15 and MYDGF. RNA sequencing showed that supplementing HUVECs with RCC cell CM-enhanced angiogenesis-related signaling pathways. Conclusively, microvesicle components secreted by RCC cells transform vascular endothelial cells into PSMA-positive cells, enhancing angiogenesis.

PET-Based TheraP Eligibility and Outcomes of VISION-Eligible Patients with Metastatic Castration-Resistant Prostate Cancer Who Received 177Lu-PSMA-617: Importance of 18F-FDG-Avid Discordant Findings

The VISION and TheraP trials introduced different PET-based criteria for patient selection for treatment with 177Lu-PSMA-617 (LuPSMA). TheraP used a higher prostate-specific membrane antigen (PSMA) uptake threshold than VISION and required 18F-FDG PET to exclude patients with discordant findings. Although the screen-failed patients had shorter overall survival (OS) than those treated with LuPSMA, it remains unclear whether their outcomes might have been modified if they had been exposed to LuPSMA. In this study, we evaluated associations between the TheraP eligibility criteria and subgroups and the treatment outcomes of patients who were deemed suitable and treated on the basis of VISION criteria. Methods: Consecutive patients who were treated with LuPSMA and who underwent pretreatment PSMA and 18F-FDG PET were classified as TheraP-eligible (TheraP-E) and TheraP-ineligible (TheraP-I), the latter of which were subclassified as low PSMA or discordant. Odds ratios for an at least 50% decline in prostate-specific antigen (PSA50) were computed using logistic regression, and hazard ratios (HRs) for PSA progression-free survival (PSA-PFS) and OS were computed using Cox regressions. Multivariable analyses were adjusted for baseline imaging and clinical parameters. Results: Of 75 patients, 31 (41%) were deemed TheraP-I; of those, 24 were subclassified as having discordant disease. TheraP-I patients had a lower PSA50 rate than that of TheraP-E patients (28% vs. 67%; odds ratio, 0.19; 95% CI, 0.06-0.52; P = 0.002) and a higher risk of PSA progression (HR, 2.0; 95% CI, 1.2-3.3; P = 0.007). OS in the TheraP-I group was numerically shorter than in the TheraP-E group, but the comparison was only marginally significant (10.4 mo vs. not reached; HR, 1.9; 95% CI, 1.0-3.7; P = 0.054). TheraP-I patients with low PSMA had no significantly different risk of death (P = 0.9) from that of TheraP-E patients, but those with discordant findings had higher risk of death (HR, 2.3; 95% CI, 1.1-4.6; P = 0.02). Discordant disease remained prognostic for OS after adjusting for baseline imaging and clinical parameters (HR, 3.0; 95% CI, 1.3-6.8; P = 0.01). Conclusion: In VISION-eligible patients who were treated with LuPSMA, TheraP-I patients with discordant findings had lower PSA50, PSA-PFS, and OS. Our study suggests that the shorter OS of TheraP-I patients is mainly driven by the presence of discordant disease.

Defining the Position of [177Lu]Lu-PSMA Radioligand Therapy in the Treatment Landscape of Metastatic Castration-Resistant Prostate Cancer: A Meta-analysis of Clinical Trials

BACKGROUND

In recent years, theranostics has become a promising approach for treating metastatic castration-resistant prostate cancer (mCRPC), with trials investigating targeted radioligand therapy, particularly using prostate-specific membrane antigen labeled with lutetium-177 ([177Lu]Lu-PSMA). The proper position of [177Lu]Lu-PSMA in the therapeutic algorithm of mCRPC is yet to be identified.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a systematic review and meta-analysis of phase II/III randomized controlled trials to assess the efficacy of [177Lu]Lu-PSMA in treating mCRPC. Study endpoints included radiographic progression-free survival (rPFS), prostate-specific antigen-PFS, objective response rate, and overall survival.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Data were extracted according to the PRISMA statement. Summary hazard ratios (HRs) were calculated using random- or fixed-effects models. Statistical analyses were performed with RevMan software (v.5.2.3).

RESULTS

[177Lu]Lu-PSMA reduced the risk of rPFS (HR 0.55; 95% confidence interval [CI] 0.43-0.71; p < 0.00001) and prostate-specific antigen-PFS (HR 0.53; 95% CI 0.41-0.67; p < 0.00001), and improved the objective response rate compared with control therapies (response rate 3.55; 95% CI 1.91-6.60; p < 0.0001), whereas no significant cumulative effect on overall survival was documented (HR 0.92; 95% CI 0.65-1.31; p = 0.63). Notably, in a dedicated subanalysis, comparable effects on rPFS were observed when [177Lu]Lu-PSMA was compared with active therapy.

CONCLUSION

[177Lu]Lu-PSMA has a favorable impact on the radiographic and biochemical control of mCRPC and represents a potential treatment in a scenario where other valuable options are available. Further efforts are required to identify clinical and molecular markers necessary for proper patient stratification.

Intensification Approaches and Treatment Sequencing in Metastatic Castration-resistant Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Recently, research on treatment intensification has gathered momentum, and three novel therapy combinations were approved for metastatic castration-resistant prostate cancer (mCRPC). This systematic review summarizes the current and emerging evidence around intensified strategies for mCRPC and provides guidance for an ideal therapeutic sequencing.

METHODS

Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) guidelines were followed to perform this review. PubMed, EMBASE, Web of Science, Cochrane Library, ClinicalTrials.gov, and major international societies' online proceedings were searched comprehensively until May 15, 2024, for terms related to treatment intensification and sequencing for mCRPC.

KEY FINDINGS AND LIMITATIONS

Overall, 28 clinical trials and 24 ongoing studies of intensification treatments were included in this review. Algorithms of optimal sequencing of approved treatments for mCRPC were outlined according to the use of androgen receptor pathway inhibitors (ARPIs) with or without docetaxel for earlier disease states. In first line, poly(ADP-ribose) polymerase inhibitor + ARPI combinations improve radiographical progression-free survival (rPFS), particularly for those with BRCA1/2 alterations. The AKT inhibitor combination of ipatasertib + abiraterone extends rPFS in those with PTEN loss or PIK3CA/AKT1/PTEN alterations. In those with two or more risk factors for early progression on enzalutamide, radionuclide 177-Lu-PSMA-617 + enzalutamide prolongs progression-free survival. Ongoing research of intensified approaches for mCRPC, and available and potential predictive and prognostic biomarkers are discussed.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Recent approvals and ongoing investigations of single agents and intensification approaches will keep transforming the mCRPC treatment landscape. Improvement of patient profiling applying recognized genomic, molecular, and clinical predictive and prognostic indicators is fundamental to optimize sequential use of available therapies.

Current Clinical Applications of PSMA-PET for Prostate Cancer Diagnosis, Staging, and Treatment

Over the past decade, prostate-specific membrane antigen positron emission tomography (PSMA-PET) has revolutionized prostate cancer (PCa) imaging, offering greater sensitivity and specificity compared to conventional imaging modalities such as CT, MRI, and bone scintigraphy. PSMA-PET is particularly valuable in staging newly diagnosed patients with intermediate- and high-risk disease, detecting biochemical recurrence, and evaluating metastatic cases. By utilizing radiotracers that accumulate specifically in PSMA-expressing cells, even small metastases can be detected, offering a detailed assessment of cancer extent and enabling more targeted diagnostic evaluations. Among the most utilized radiotracers, [68Ga]- and [18F]-labeled PSMA tracers enable precise imaging even with low disease burden. This diagnostic precision also supports advanced therapeutic approaches, including metastasis-directed therapy for oligometastatic cases and systemic treatment options, such as radioligand therapy, which presents new treatment perspectives for metastatic, castration-resistant PCa. This review examines the evolution of PSMA-PET in the diagnostics and therapy of PCa while comparing the current recommendations from leading clinical guidelines. The integration of PSMA-PET into clinical practice has redefined the management of PCa, improving diagnostic accuracy and enabling personalized treatment strategies, while lacking prospective long-term outcome data. As PSMA-PET continues to expand in clinical application, this review highlights its significant advancements while critically addressing limitations to ensure balanced and evidence-based implementation in prostate cancer care.

Outcomes for Patients with Metastatic Castration-Resistant Prostate Cancer and Liver Metastasis Receiving [177Lu]Lu-PSMA-617

It is well known that patients with liver metastasis from metastatic castration-resistant prostate cancer have poor or only transient responses to many forms of systemic therapy. Data on outcomes after treatment with [177Lu]Lu-PSMA-617 (LuPSMA) are scarce. The VISION trial reports a hazard ratio for overall survival (OS) in the subgroup of patients with liver metastasis without disclosing the absolute duration of survival. Using real-world clinical data, we examined this important subgroup of patients, describing prostate-specific antigen (PSA) response and OS. Methods: A single-institution database was assembled to include all patients receiving LuPSMA at Mayo Clinic in Rochester, Minnesota, for whom treatment was initiated between March 2022 and March 2023. Baseline clinicopathologic and imaging characteristics were abstracted. Patients were then categorized by presence or absence of liver metastasis on pretreatment prostate-specific membrane antigen (PSMA) PET. PSA response and OS for the 2 groups (liver metastasis vs. no liver metastasis) were compared using χ2 testing and the Kaplan-Meier method, respectively. A multivariate Cox regression analysis was performed, including established prognostic factors. Finally, those with pretreatment circulating tumor DNA as determined in an 83-gene panel were assessed for the presence of pathogenic and likely pathogenic alterations. These findings were summarized using descriptive statistics and compared between the 2 cohorts using the Fisher exact test. Results: The overall cohort consisted of 273 patients, including 43 (15.75%) with liver metastasis on pretreatment PSMA PET/CT. The median number of cycles received was 3 (range, 1-6) for patients with liver metastasis and 5 (range, 1-6) for those without hepatic involvement. The 50% or greater reduction in PSA from baseline response rate was lower for those with liver metastasis than for those without (30.23% [13/43] vs 49.77% [106/213], P = 0.019). At a median follow-up of 10 mo (interquartile range, 9-13 mo), there was a significant difference in median OS (8.35 mo vs. not reached, P < 0.001). On multivariate analysis, the presence of liver metastasis was independently associated with shorter survival (hazard ratio, 4.06; P < 0.001). Conclusion: Our data suggest that the presence of liver metastasis predicts poorer outcomes in patients receiving LuPSMA treatment. Alternative and combination approaches should be explored to maximize the antitumor activity of radiopharmaceutical therapy in the liver.

Association of Declining Prostate-specific Antigen Levels with Clinical Outcomes in Patients with Metastatic Castration-resistant Prostate Cancer Receiving [177Lu]Lu-PSMA-617 in the Phase 3 VISION Trial

BACKGROUND AND OBJECTIVE

The prognostic value of declining prostate-specific antigen (PSA) levels is under investigation in patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) receiving PSMA-targeted radioligand therapy with [177Lu]Lu-PSMA-617 (177Lu-PSMA-617). This post hoc analysis of the phase 3 VISION trial aimed to evaluate associations between PSA decline and clinical and patient-reported outcomes in patients receiving 177Lu-PSMA-617.

METHODS

Of 831 enrolled patients with PSMA-positive progressive mCRPC treated previously with one or more androgen receptor pathway inhibitors and one to two taxanes, 551 were randomised to 177Lu-PSMA-617 plus protocol-permitted standard of care (SoC). Radiographic progression-free survival, overall survival, radiographic objective response rate, and patient-reported health-related quality of life (HRQoL) and pain were analysed in subgroups of patients categorised by the magnitude of unconfirmed PSA decline from baseline.

KEY FINDINGS AND LIMITATIONS

Patients randomised to 177Lu-PSMA-617 with the best PSA declines of ≥0-<50% (96/551 [17%]), ≥50-<90% (152/551 [28%]), and ≥90% (83/551 [15%]) up to and including week 12 had 61%, 72%, and 88% reduced risks of radiographic disease progression or death, and 51%, 70%, and 87% reduced risks of death, respectively, versus those with increased PSA levels (160/551 [29%]), based on hazard ratios in a multivariate Cox proportional hazard model. In patients with greater PSA declines, radiographic responses were more frequent and median time to worsening in HRQoL and pain scores were longer.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The magnitude of PSA decline was associated with improvement in clinical and patient-reported outcomes in patients with mCRPC receiving 177Lu-PSMA-617 plus SoC in VISION. PSA decline therefore appears to have a prognostic value during 177Lu-PSMA-617 treatment in this population.

PSMA Radiotheranostics in Prostate Cancer: Principles, Practice, and Future Prospects

Prostate cancer is a leading cause of cancer-related mortality in men, with metastatic castration-resistant prostate cancer presenting a substantial treatment challenge. The authors focuse on prostate-specific membrane antigen (PSMA) radiotheranostics, particularly lutetium 177 (177Lu)-PSMA radioligand therapy, as an emerging treatment modality for metastatic castration-resistant prostate cancer. The U.S. Food and Drug Administration approval of 177Lu-PSMA-617 marked a substantial advancement in the treatment paradigm of metastatic castration-resistant prostate cancer, based on the VISION trial that showed improved overall survival and quality of life compared with those for standard care. PSMA expression, assessed via PSMA PET, is crucial for patient selection and assessment of treatment eligibility. The authors discuss current practices, including therapy administration, dosing, and side effects, with a particular focus on eligibility criteria and the added value of posttherapy imaging. Response assessment criteria using PSMA PET are discussed, although these require further validation. The discussion of future directions highlights ongoing trials investigating PSMA targeting agents, the extension of radioligand therapy to earlier stages of prostate cancer, and combination therapies. This review underscores the role of PSMA radioligand therapy in the evolving landscape of prostate cancer treatment and its promise for improving patient outcomes. ©RSNA, 2024 Supplemental material is available for this article.

177 Lu-PSMA-617 Radioligand Therapy in Patient With Prostate Cancer Sciatic Nerve Metastasis

ABSTRACT

Patients with metastatic castration-resistant prostate cancer usually have lymph nodes and bone metastasis. We present a rare case of a 51-year-old patient with metastatic castration-resistant prostate cancer who complained of left truncated sciatica and diffuse bone pain and who was referred for 177 Lu-prostate-specific membrane antigen (PSMA) screening. Pretreatment 68 Ga-PSMA showed left sciatic nerve and multiple bone uptake. Patient underwent stereotactic radiotherapy on the sciatic nerve metastasis (30 Gy in 6 fractions of 5 Gy) before 7.4 GBq of 177 Lu-PSMA infusions. Left truncated sciatica disappeared after stereotactic radiotherapy. No additional toxicity was added to the sciatic nerve from 177 Lu-PSMA after stereotactic radiotherapy.

PSMA-Guided Imaging and Therapy of Advanced Adenoid Cystic Carcinomas and Other Salivary Gland Carcinomas

SGCs are rare malignancies, accounting for less than 1% of all head and neck cancers [...].