Real-World Experience with 177Lu-PSMA-617 Radioligand Therapy After Food and Drug Administration Approval.

We report our initial real-world experience with 177Lu-PSMA-617 radioligand therapy. Methods: We performed a retrospective review of patients treated with 177Lu-PSMA-617. Pretreatment PSMA PET, laboratory findings, overall survival, a fall in prostate-specific antigen by 50% (PSA50), and toxicities were evaluated. Results: Ninety-nine patients were included. Sixty patients achieved a PSA50. Seven of 18 (39%) patients who did not meet the TheraP PSMA imaging criteria achieved a PSA50. Nineteen of 31 (61%) patients who did not meet the VISION laboratory criteria achieved a PSA50. Sixty-three patients had a delay or stoppage in therapy, which was due to a good response in 19 patients and progressive disease in 14 patients. Of 10 patients with a good response who restarted treatment, 9 subsequently achieved a PSA50 on retreatment. The most common toxicities were anemia (33%) and thrombocytopenia (21%). Conclusion: At our center, patients who did not meet the TheraP PSMA imaging criteria or the VISION laboratory criteria benefited from 177Lu-PSMA-617 radioligand therapy.

Initial Experience with 68Ga-FAP-2286 PET Imaging in Patients with Urothelial Cancer.

Improved imaging modalities are needed to accurately stage patients with muscle-invasive bladder cancer (MIBC) and metastatic urothelial carcinoma. Imaging with small-molecule ligands or inhibitors of fibroblast activation protein (FAP) is a promising modality that has demonstrated initial efficacy across a broad range of tumors. We present our experience with the novel FAP-peptide binder 68Ga-FAP-2286 in patients with MIBC. Methods: Patients with histopathologically confirmed bladder cancer who had either localized disease at diagnosis (localized cohort, n = 13) or known metastatic disease (metastatic cohort, n = 8) were imaged with 68Ga-FAP-2286 PET as part of a clinical trial (NCT04621435). The SUVmax of 68Ga-FAP-2286 PET-positive lesions and lesion size were documented. In patients who had available 18F-FDG PET performed within 45 d of 68Ga-FAP-2286 PET (n = 5), uptake on the 2 scans was compared. When there was a discrepancy between imaging modalities on retrospective review, biopsy of suggestive lesions was performed as the standard of care. Results: In the metastatic and localized cohorts, 36 and 18 68Ga-FAP-2286-avid lesions, respectively, were identified across multiple anatomic locations, including lymph nodes, visceral metastases, and bones. Fourteen of 36 lesions in the metastatic cohort and 14 of 18 lesions in the localized cohort were lymph nodes measuring less than 1 cm. Among lesions measuring less than 0.5 cm, 0.5-1 cm, and more than 1 cm, average SUVmax was 5.2 ± 2.6, 9.6 ± 3.7, and 13.0 ± 4.3, respectively, in the metastatic cohort and 10.5 ± 5.1, 10.8 ± 5.7, and 9.9 ± 5.4, respectively, in the localized cohort. Five patients had 18F-FDG PET available for comparison. The average SUVmax for lesions avid on 68Ga-FAP-2286 PET and 18F-FDG PET was 9.9 ± 3.4 versus 4.2 ± 1.9, respectively (n = 16 lesions). For 3 patients in the localized cohort, 68Ga-FAP-2286 PET informed clinical management, including identification of both false-positive findings on 18F-FDG PET and false-negative findings on conventional CT. Conclusion: 68Ga-FAP-2286 imaging is highly sensitive in patients with urothelial cancer and is effective in identifying metastatic lesions across a variety of anatomic sites, including subcentimeter lymph nodes that would not have raised suspicion on conventional scans. This novel imaging modality may inform clinical decision-making in patients with MIBC both by refining local nodal staging and by defining metastatic disease that would otherwise be undetectable on conventional imaging.

Diagnosis and management of neuroendocrine prostate cancer.

BACKGROUND: Although most patients with prostate cancer (PC) respond to initial androgen deprivation therapy (ADT), castration-resistant disease invariably develops. Progression to treatment-emergent neuroendocrine PC (t-NEPC) represents a unique mechanism of resistance to androgen receptor (AR)-targeted therapy in which lineage plasticity and neuroendocrine differentiation induce a phenotypic switch from an AR-driven adenocarcinoma to an AR-independent NEPC. t-NEPC is characterized by an aggressive clinical course, increased resistance to AR-targeted therapies, and a poor overall prognosis. METHODS: This review provides an overview of our current knowledge of NEPC, with a focus on the unmet needs, diagnosis, and clinical management of t-NEPC. RESULTS: Evidence extrapolated from the literature on small cell lung cancer or data from metastatic castration-resistant PC (mCRPC) cohorts enriched for t-NEPC suggests an increased sensitivity to platinum-based chemotherapy. However, optimal strategies for managing t-NEPC have not been established, and prospective clinical trial data are limited. Intertumoral heterogeneity within a given patient, as well as the lack of robust molecular or clinical biomarkers for early detection, often lead to delays in diagnosis and prolonged treatment with suboptimal strategies (i.e., conventional chemohormonal therapies for mCRPC), which may further contribute to poor outcomes. CONCLUSIONS: Recent advances in genomic and molecular classification of NEPC and the development of novel biomarkers may facilitate an early diagnosis, help to identify promising therapeutic targets, and improve the selection of patients most likely to benefit from NEPC-targeted therapies.

Single-dose 177Lu-PSMA-617 followed by maintenance pembrolizumab in patients with metastatic castration-resistant prostate cancer: an open-label, dose-expansion, phase 1 trial.

BACKGROUND: Checkpoint inhibitors have been shown to have limited activity in patients with metastatic castration-resistant prostate cancer. We aimed to determine whether a single dose of lutetium-177 [177Lu]-prostate-specific membrane antigen (PSMA)-617 (177Lu-PSMA-617) followed by maintenance pembrolizumab was safe and could induce durable clinical benefit. METHODS: We did an open-label, dose-expansion, phase 1 study at the University of California, San Francisco (San Fransisco, CA, USA). Eligible patients were men aged 18 years or older with progressive metastatic castration-resistant prostate cancer who had an Eastern Cooperative Oncology Group performance status of 0 or 1, had progression on one or more androgen signalling inhibitors, and at least three PSMA-avid lesions on 68Ga-PSMA-11 positron emission tomography. In part A, patients were enrolled sequentially to one of three schedules in which a single dose of 177Lu-PSMA-617 (7·4 GBq) was given intravenously 28 days before (schedule 1), concomitant with (schedule 2), or 21 days after (schedule 3) the start of maintenance intravenous pembrolizumab (200 mg every 3 weeks). In part B, 25 patients were enrolled using the recommended phase 2 schedule. The primary endpoint in part A was determination of the recommended phase 2 schedule, and in part B, the objective response rate. The analysis set included all patients who received at least one dose of pembrolizumab or 177Lu-PSMA-617. This study is registered with ClinicalTrials.gov, NCT03805594. FINDINGS: Between Aug 8, 2019 and May 7, 2022, 43 male patients were enrolled (n=18 part A [six patients per schedule]; n=25 part B), with a median follow-up of 16·5 months (IQR 12·2-21·9). Schedule 1 was selected as the recommended phase 2 schedule for part B, on the basis of safety and feasibility of administration observed in part A. In part B, 14 (56%; 95% CI 35-76) of 25 patients had a confirmed objective response. Two (5%) of 43 patients had a treatment-related adverse event of grade 3 or worse (grade 3 arthritis in schedule 2, grade 3 pneumonitis in schedule 3). One serious adverse event (one death due to aspiration pneumonia) and no treatment-related deaths were observed. INTERPRETATION: A single priming dose of 177Lu-PSMA-617 followed by pembrolizumab maintenance was safe and had encouraging preliminary activity in patients with metastatic castration-resistant prostate cancer. FUNDING: Prostate Cancer Foundation, National Cancer Institute, Novartis Pharmaceuticals, and Merck.

Impact of Squamous Histology on Clinical Outcomes and Molecular Profiling in Metastatic Urothelial Carcinoma Patients Treated With Immune Checkpoint Inhibitors or Enfortumab Vedotin.

INTRODUCTION: Urothelial carcinoma with squamous differentiation (UCS) is associated with increased resistance to chemotherapy, but outcomes associated with newer therapies approved in this space over the last 5 to 10 years are less well defined. We investigated clinical outcomes and molecular profiling of patients with UCS treated with an immune checkpoint inhibitor (ICI) and/or Enfortumab vedotin (EV). PATIENTS AND METHODS: We undertook a retrospective analysis of UC patients treated with ICI and/or EV. Objective response rate (ORR), progression free survival (PFS) and overall survival (OS) were compared between pure UC (pUC) and UCS using X2 and log-rank tests, respectively. Prevalence of the most commonly detected somatic alterations were also compared between the 2 histologic subgroups. RESULTS: A total of 160 patients (40 UCS, 120 pUC) were identified for this analysis. Among 151 patients treated with ICI (38 UCS, 113 pUC), UCS patients had a shorter mPFS (1.9 vs. 4.8 months, P < 0.01) and mOS (9.2 vs. 20.7 months, P < 0.01) compared to pUC. Among 37 patients treated with EV (12 UCS, 25 pUC), UCS patients had a lower ORR (17% vs. 70%, P < 0.01) and shorter mPFS (3.4 vs. 15.8 months, P < 0.01). UCS samples were enriched for CDKN2A, CDKN2B, PIK3CA, while pUC samples were enriched for ERBB2 alterations. CONCLUSION: In this single-center retrospective analysis, patients with UCS had a distinct somatic genomic profile relative to patients with pUC. Patients with UCS also had inferior outcomes to ICIs and EV compared to patients with pUC.

Somatic alterations of TP53 and MDM2 associated with response to enfortumab vedotin in patients with advanced urothelial cancer.

Background: Enfortumab vedotin (EV) is an antibody-drug conjugate approved for patients with treatment-refractory advanced urothelial carcinoma (aUC), however data on biomarkers of response is lacking. Methods: We retrospectively identified all aUC patients at our institution who received EV monotherapy and had next-generation sequencing (NGS) data available. Patients were considered responders if they had a complete response or partial response on restaging scans during treatment. Observed response rate (ORR) was evaluated by local investigator and compared between responders and non-responders using Chi-squared test. A univariable analysis was conducted using the Cox proportional hazard test to assess for associations between baseline characteristics and most common somatic alterations (in ≥10% of patients) with patient survival outcomes [progression-free survival (PFS) and overall survival (OS)]. Somatic alterations were then individually evaluated in separate multivariate models while accounting for patient and clinical characteristics using Cox regression models. Results: Among 29 patients treated with EV monotherapy, 27 had available NGS data. Median age was 70, 24 (83%) were men, 19 (62%) were Caucasian, 15 (52%) had pure urothelial histology and 22 (76%) had primary tumor in the bladder. ORR was 41%, and PFS and OS for the overall cohort were 5.1 months and 10.2 months. Responders were enriched among patients with TP53, KDM6A and MDM2 alterations. Patients with these alterations, as well as those with composite TP53/MDM2 alterations (alterations in either TP53 or MDM2), also had increased ORR with EV treatment compared to patients without these alterations. In the univariable analysis, baseline albumin level ≥ 3.0g/dL and presence of composite TP53/MDM2 alterations were associated with a prolonged OS. Baseline ECOG 0/1, TP53 alterations and TP53/MDM2 alterations were associated with a prolonged PFS. In the multivariable analysis, TP53 and TP53/MDM2 alterations were genomic markers predictive of improved PFS after accounting for the relevant clinical characteristics. Conclusion: In this single-center retrospective analysis of aUC patients treated with EV, presence of TP53 or MDM2 somatic alterations, lower ECOG PS scores (ECOG 0 or 1) and higher albumin levels (≥3 g/dL) were associated with improved outcomes with EV treatment. Prospective and external validation of these findings in larger cohorts is warranted.

Serial stereotactic body radiation therapy for oligometastatic prostate cancer detected by novel PET-based radiotracers.

BACKGROUND: Radiopharmaceuticals, including Ga-68-prostate specific membrane antigen (PSMA)-11 and F-18-Fluciclovine, are increasingly used to inform therapies for prostate cancer (CaP). Stereotactic body radiation therapy (SBRT) to PET-detected oligometastatic CaP has been shown to improve progression free survival (PFS) and delay androgen deprivation therapy (ADT) compared to observation. For men who subsequently develop oligorecurrent CaP, outcomes following second SBRT are unknown. METHODS: A retrospective cohort study was conducted. Eligibility criteria included patients with oligometastatic (1-5 lesions) CaP detected on PSMA or Fluciclovine PET who underwent 2 consecutive SBRT courses to tracer-avid sites. Data on stage, tracer type, concurrent systemic therapy, and prostate-specific antigen (PSA) responses for first SBRT (SBRT1) and second SBRT (SBRT2) were collected. Outcomes included PSA decline ≥50% (PSA50), PFS after SBRT2, and ADT initiation or intensification-free survival after SBRT2. Factors potentially associated with PSA50 after SBRT2 was evaluated with multivariable logistic regression. Factors potentially associated with PFS and ADT initiation/intensification-free survival after SBRT2 were evaluated with separate multivariable Cox proportional-hazards models. RESULTS: Twenty-five patients were identified. At SBRT2, oligorecurrence was detected on PSMA and Fluciclovine PET in 17 (68%) and 8 (32%) patients, respectively. Fifteen (60%) patients had castration-sensitive disease and 10 (40%) had castration-resistant disease. After SBRT2, 16 (64%) achieved a PSA50 response, median PFS was 11.0mo, and median ADT initiation/intensification-free survival was 23.2mo. On multivariable analysis, maximum percent change in PSA after SBRT1 (OR 0.94, 95%CI 0.88-0.99, P = 0.046) and concurrent change in systemic therapy (OR 21.61, 95%CI 1.12-417.9, P = 0.042) were associated with PSA50 responses after SBRT2. PSA50 response after SBRT1 was associated with improved PFS (HR 0.36, 95%CI 0.00-0.42, P = 0.008) and ADT initiation/intensification-free survival (HR 0.07, 95%CI 0.01-0.68, P = 0.021) after SBRT2. From SBRT1 to last follow-up (median 48 months), 7 (28%) patients remained ADT-free. CONCLUSIONS: Serial SBRT for oligometastatic CaP detected on PSMA or Fluciclovine PET is feasible and can achieve PSA declines, with or without systemic therapy. Degree of biochemical response to first SBRT warrants further study as a potential predictor of PSA response, PFS, and ADT initiation/intensification-free survival following a subsequent SBRT course. This preliminary evidence provides rationale for larger, prospective studies of this strategy.

PSMA PET Scan.

This JAMA Oncology Patient Page describes the PSMA PET scan, an imaging test used to detect prostate cancer throughout the body.

Association of the Time to Immune Checkpoint Inhibitor (ICI) Initiation and Outcomes With Second Line ICI in Patients With Advanced Urothelial Carcinoma.

BACKGROUND: Early progression on first-line (1L) platinum-based therapy or between therapy lines may be a surrogate of more aggressive disease and poor outcomes in advanced urothelial carcinoma (aUC), but its prognostic role regarding immune checkpoint inhibitor (ICI) response and survival is unclear. We hypothesized that shorter time until start of second-line (2L) ICI would be associated with worse outcomes in aUC. PATIENTS AND METHODS: We performed a retrospective multi-institution cohort study in patients with aUC treated with 1L platinum-based chemotherapy, who received 2L ICI. Patients receiving switch maintenance ICI were excluded. We defined time to 2L ICI therapy as the time between the start of 1L platinum-based chemotherapy to the start of 2L ICI and categorized patients a priori into 1 of 3 groups: less than 3 months versus 3-6 months versus more than 6 months. We calculated overall response rate (ORR) with 2L ICI, progression-free survival (PFS) and overall survival (OS) from the start of 2L ICI. ORR was compared among the 3 groups using multivariable logistic regression, and PFS, OS using cox regression. Multivariable models were adjusted for known prognostic factors. RESULTS: We included 215, 215, and 219 patients in the ORR, PFS, and OS analyses, respectively, after exclusions. ORR difference did not reach statistical significance between patients with less than 3 months versus 3-6 months versus more than 6 months to 2L ICI. However, PFS (HR 1.64; 95% CI 1.02-2.63) and OS (HR 1.77; 95% CI 1.10-2.84) was shorter among those with time to 2L ICI less than 3 months compared to those who initiated 2L ICI more than 6 months. CONCLUSION: Among patients with aUC treated with 2L ICI, time to 2L ICI less than 3 months was associated with lower, but not significantly different ORR, but shorter PFS and OS compared to 2L ICI more than 6 months. This highlights potential cross resistance mechanisms between ICI and platinum-based chemotherapy.

Association Between Sites of Metastasis and Outcomes With Immune Checkpoint Inhibitors in Advanced Urothelial Carcinoma.

BACKGROUND: Sites of metastasis have prognostic significance in advanced urothelial carcinoma (aUC), but more information is needed regarding outcomes based on metastatic sites in patients treated with immune checkpoint inhibitors (ICI). We hypothesized that presence of liver/bone metastases would be associated with worse outcomes with ICI. METHODS: We identified a retrospective cohort of patients with aUC across 26 institutions, collecting demographics, clinicopathological, treatment, and outcomes information. Outcomes were compared with logistic (observed response rate; ORR) and Cox (progression-free survival; PFS, overall survival; OS) regression between patients with/without metastasis beyond lymph nodes (LN) and those with/without bone/liver/lung metastasis. Analysis was stratified by 1st or 2nd+ line. RESULTS: We identified 917 ICI-treated patients: in the 1st line, bone/liver metastases were associated with shorter PFS (Hazard ratio; HR: 1.65 and 2.54), OS (HR: 1.60 and 2.35, respectively) and lower ORR (OR: 0.48 and 0.31). In the 2nd+ line, bone/liver metastases were associated with shorter PFS (HR: 1.71 and 1.62), OS (HR: 1.76 and 1.56) and, for bone-only metastases, lower ORR (OR: 0.29). In the 1st line, LN-confined metastasis was associated with longer PFS (HR: 0.53), OS (HR:0.49) and higher ORR (OR: 2.97). In the 2nd+ line, LN-confined metastasis was associated with longer PFS (HR: 0.47), OS (HR: 0.54), and higher ORR (OR: 2.79); all associations were significant. CONCLUSION: Bone and/or liver metastases were associated with worse, while LN-confined metastases were associated with better outcomes in patients with aUC receiving ICI. These findings in a large population treated outside clinical trials corroborate data from trial subset analyses.

A Phase Ib/II Study of the CDK4/6 Inhibitor Ribociclib in Combination with Docetaxel plus Prednisone in Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: Ribociclib, a CDK4/6 inhibitor, demonstrates preclinical antitumor activity in combination with taxanes. We evaluated the safety and efficacy of ribociclib plus docetaxel in a phase Ib/II study in metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: Patients had chemotherapy-naïve mCRPC with progression on ≥ 1 androgen receptor signaling inhibitor (ARSI). The phase II primary endpoint was 6-month radiographic progression-free survival (rPFS) rate, with an alternative hypothesis of 55% versus 35% historical control. Circulating tumor cells (CTC) were collected at baseline and genomically profiled. RESULT: Forty-three patients were enrolled (N = 30 in phase II). Two dose-limiting toxicities were observed (grade 4 neutropenia and febrile neutropenia). The recommended phase II dose (RP2D) and schedule was docetaxel 60 mg/m2 every 21 days plus ribociclib 400 mg/day on days 1-4 and 8-15 with filgrastim on days 5-7. At the RP2D, neutropenia was the most common grade ≥ 3 adverse event (37%); however, no cases of febrile neutropenia were observed. The primary endpoint was met; the 6-month rPFS rate was 65.8% [95% confidence interval (CI): 50.6%-85.5%; P = 0.005] and median rPFS was 8.1 months (95% CI, 6.0-10.0 months). Thirty-two percent of evaluable patients achieved a PSA50 response. Nonamplified MYC in baseline CTCs was associated with longer rPFS (P = 0.052). CONCLUSIONS: The combination of intermittent ribociclib plus every-3-weeks docetaxel demonstrated acceptable toxicity and encouraging efficacy in ARSI-pretreated mCRPC. Genomic profiling of CTCs may enrich for those most likely to derive benefit. Further evaluation in a randomized clinical trial is warranted.

Response and Outcomes to Immune Checkpoint Inhibitors in Advanced Urothelial Cancer Based on Prior Intravesical Bacillus Calmette-Guerin.

BACKGROUND: Immune checkpoint inhibitors (ICI) improve overall survival (OS) in patients with locally advanced, unresectable, or metastatic urothelial carcinoma (aUC), but response rates can be modest. We compared outcomes between patients with and without prior intravesical Bacillus Calmette-Guerin (BCG), who received ICI for aUC, hypothesizing that prior intravesical BCG would be associated with worse outcomes. PATIENTS AND METHODS: We performed a retrospective cohort study across 25 institutions in US and Europe. We compared observed response rate (ORR) using logistic regression; progression-free survival (PFS) and OS using Kaplan-Meier and Cox proportional hazards. Analyses were stratified by treatment line (first line/salvage) and included multivariable models adjusting for known prognostic factors. RESULTS: A total of 1026 patients with aUC were identified; 614, 617, and 638 were included in ORR, OS, PFS analyses, respectively. Overall, 150 pts had history of prior intravesical BCG treatment. ORR to ICI was similar between those with and without prior intravesical BCG exposure in both first line and salvage settings (adjusted odds radios 0.55 [P= .08] and 1.65 [P= .12]). OS (adjusted hazard ratios 1.05 [P= .79] and 1.13 [P= .49]) and PFS (adjusted hazard ratios 1.12 [P= .55] and 0.87 [P= .39]) were similar between those with and without intravesical BCG exposure in first line and salvage settings. CONCLUSION: Prior intravesical BCG was not associated with differences in response and survival in patients with aUC treated with ICI. Limitations include retrospective nature, lack of randomization, presence of selection and confounding biases. This study provides important preliminary data that prior intravesical BCG exposure may not impact ICI efficacy in aUC.

Association of prior local therapy and outcomes with programmed-death ligand-1 inhibitors in advanced urothelial cancer.

OBJECTIVES: To compare clinical outcomes with programmed-death ligand-1 immune checkpoint inhibitors (ICIs) in patients with advanced urothelial carcinoma (aUC) who have vs have not undergone radical surgery (RS) or radiation therapy (RT) prior to developing metastatic disease. PATIENTS AND METHODS: We performed a retrospective cohort study collecting clinicopathological, treatment and outcomes data for patients with aUC receiving ICIs across 25 institutions. We compared outcomes (observed response rate [ORR], progression-free survival [PFS], overall survival [OS]) between patients with vs without prior RS, and by type of prior locoregional treatment (RS vs RT vs no locoregional treatment). Patients with de novo advanced disease were excluded. Analysis was stratified by treatment line (first-line and second-line or greater [second-plus line]). Logistic regression was used to compare ORR, while Kaplan-Meier analysis and Cox regression were used for PFS and OS. Multivariable models were adjusted for known prognostic factors. RESULTS: We included 562 patients (first-line: 342 and second-plus line: 220). There was no difference in outcomes based on prior locoregional treatment among those treated with first-line ICIs. In the second-plus-line setting, prior RS was associated with higher ORR (adjusted odds ratio 2.61, 95% confidence interval [CI]1.19-5.74]), longer OS (adjusted hazard ratio [aHR] 0.61, 95% CI 0.42-0.88) and PFS (aHR 0.63, 95% CI 0.45-0.89) vs no prior RS. This association remained significant when type of prior locoregional treatment (RS and RT) was modelled separately. CONCLUSION: Prior RS before developing advanced disease was associated with better outcomes in patients with aUC treated with ICIs in the second-plus-line but not in the first-line setting. While further validation is needed, our findings could have implications for prognostic estimates in clinical discussions and benchmarking for clinical trials. Limitations include the study's retrospective nature, lack of randomization, and possible selection and confounding biases.

Prostate-specific membrane antigen (PSMA)-based imaging in localized and advanced prostate cancer: a narrative review.

Combined molecular and morphologic imaging modalities have emerged in recent years as an alternative to conventional imaging in prostate cancer (PC). In particular, novel prostate-specific membrane antigen (PSMA) radiotracers have demonstrated increased sensitivity and specificity for the initial staging of men with clinically localized PC, as well as for PC detection in the setting of biochemical recurrence (BCR). Molecular imaging is increasingly used to guide treatment decisions in these patients-though its impact on survival has yet to be established. Improved PC detection in men with BCR has also helped to identify a subset of patients with oligometastatic disease. The optimal management of oligometastatic PC and the role of metastasis-directed therapies (MDT) are the subjects of ongoing studies. In comparison to clinically localized or biochemically recurrent PC, the role of molecular imaging in men with advanced disease is less established. In metastatic castration-resistant PC (mCRPC), PSMA-based imaging has primarily been investigated as a companion diagnostic tool to predict and monitor response to PSMA-targeted radioligand therapy (RLT). More recent efforts have focused on using molecular imaging to monitor treatment response to conventional chemohormonal therapies. However, despite promising early results, several barriers remain to the widespread use of PSMA-based imaging in metastatic PC: temporary flares in PSMA uptake have been described in a subset of patients after initiation of therapy, and the underlying mechanism and clinical implications of this phenomenon are still poorly understood. Furthermore, whereas PSMA is invariably expressed in hormone-sensitive PC, loss of PSMA expression is increasingly recognized in a subset of mCRPC patients with aggressive disease. Although this may limit the use of PSMA-based imaging as a standalone modality in advanced PC, loss of PSMA uptake may also provide non-invasive and clinically relevant molecular insight on patients' underlying tumor biology.

TERT promoter mutations and other prognostic factors in patients with advanced urothelial carcinoma treated with an immune checkpoint inhibitor.

BACKGROUND: Immune checkpoint inhibitors (ICI) can achieve durable responses in a subset of patients with locally advanced or metastatic urothelial carcinoma (aUC). The use of tumor genomic profiling in clinical practice may help suggest biomarkers to identify patients most likely to benefit from ICI. METHODS: We undertook a retrospective analysis of patients treated with an ICI for aUC at a large academic medical center. Patient clinical and histopathological variables were collected. Responses to treatment were assessed for all patients with at least one post-baseline scan or clear evidence of clinical progression following treatment start. Genomic profiling information was also collected for patients when available. Associations between patient clinical/genomic characteristics and objective response were assessed by logistic regression; associations between the characteristics and progression-free survival (PFS) and overall survival (OS) were examined by Cox regression. Multivariable analyses were performed to identify independent prognostic factors. RESULTS: We identified 119 aUC patients treated with an ICI from December 2014 to January 2020. Genomic profiling was available for 78 patients. Overall response rate to ICI was 29%, and median OS (mOS) was 13.4 months. Favorable performance status at the start of therapy was associated with improved OS (HR 0.46, p=0.025) after accounting for other covariates. Similarly, the presence of a TERT promoter mutation was an independent predictor of improved PFS (HR 0.38, p=0.012) and OS (HR 0.32, p=0.037) among patients who had genomic profiling available. Patients with both a favorable performance status and a TERT promoter mutation had a particularly good prognosis with mOS of 21.1 months as compared with 7.5 months in all other patients (p=0.03). CONCLUSIONS: The presence of a TERT promoter mutation was an independent predictor of improved OS in a cohort of aUC patients treated with an ICI who had genomic data available. Most of the clinical and laboratory variables previously shown to be prognostic in aUC patients treated with chemotherapy did not have prognostic value among patients treated with an ICI. Genomic profiling may provide important prognostic information and affect clinical decision making in this patient population. Validation of these findings in prospective patient cohorts is needed.

Immune checkpoint inhibitors in advanced upper and lower tract urothelial carcinoma: a comparison of outcomes.

OBJECTIVES: To compare clinical outcomes between patients with locally advanced (unresectable) or metastatic urothelial carcinoma (aUC) in the upper and lower urinary tract receiving immune checkpoint inhibitors (ICIs). PATIENTS AND METHODS: We performed a retrospective cohort study collecting clinicopathological, treatment, and outcome data for patients with aUC receiving ICIs from 2013 to 2020 across 24 institutions. We compared the objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) between patients with upper and lower tract UC (UTUC, LTUC). Uni- and multivariable logistic and Cox regression were used to assess the effect of UTUC on ORR, OS, and PFS. Subgroup analyses were performed stratified based on histology (pure, mixed) and line of treatment (first line, subsequent line). RESULTS: Out of a total of 746 eligible patients, 707, 717, and 738 were included in the ORR, OS, and PFS analyses, respectively. Our results did not contradict the hypothesis that patients with UTUC and LTUC had similar ORRs (24% vs 28%; adjusted odds ratio [aOR] 0.73, 95% confidence interval [CI] 0.43-1.24), OS (median 9.8 vs 9.6 months; adjusted hazard ratio [aHR] 0.93, 95% CI 0.73-1.19), and PFS (median 4.3 vs 4.1 months; aHR 1.01, 95% CI 0.81-1.27). Patients with mixed-histology UTUC had a significantly lower ORR and shorter PFS vs mixed-histology LTUC (aOR 0.20, 95% CI 0.05-0.91 and aHR 1.66, 95% CI 1.06-2.59), respectively). CONCLUSION: Overall, patients with UTUC and LTUC receiving ICIs have comparable treatment response and outcomes. Subgroup analyses based on histology showed that those with mixed-histology UTUC had a lower ORR and shorter PFS compared to mixed-histology LTUC. Further studies and evaluation of molecular biomarkers can help refine patient selection for immunotherapy.

A New Prognostic Model in Patients with Advanced Urothelial Carcinoma Treated with First-line Immune Checkpoint Inhibitors.

BACKGROUND: While immune checkpoint inhibitors (ICIs) are approved in the first-line (1L) setting for cisplatin-unfit patients with programmed death-ligand 1 (PD-L1)-high tumors or for platinum (cisplatin/carboplatin)-unfit patients, response rates remain modest and outcomes vary with no clinically useful biomarkers (except for PD-L1). OBJECTIVE: We aimed to develop a prognostic model for overall survival (OS) in patients receiving 1L ICIs for advanced urothelial cancer (aUC) in a multicenter cohort study. DESIGN, SETTING, AND PARTICIPANTS: Patients treated with 1L ICIs for aUC across 24 institutions and five countries (in the USA and Europe) outside clinical trials were included in this study. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We used a stepwise, hypothesis-driven approach using clinician-selected covariates to develop a new risk score for patients receiving ICIs in the 1L setting. Demographics, clinicopathologic data, treatment patterns, and OS were collected uniformly. Univariate Cox regression was performed on 18 covariates hypothesized to be associated with OS based on published data. Variables were retained for multivariate analysis (MVA) if they correlated with OS (p < 0.2) and were included in the final model if p < 0.05 on MVA. Retained covariates were assigned points based on the beta coefficient to create a risk score. Stratified median OS and C-statistic were calculated. RESULTS AND LIMITATIONS: Among 984 patients, 357 with a mean age of 71 yr were included in the analysis, 27% were female, 68% had pure UC, and 13% had upper tract UC. Eastern Cooperative Oncology Group performance status ≥2, albumin <3.5 g/dl, neutrophil:lymphocyte ratio >5, and liver metastases were significant prognostic factors on MVA and were included in the risk score. C index for new 1L risk score was 0.68 (95% confidence interval 0.65-0.71). Limitations include retrospective nature and lack of external validation. CONCLUSIONS: We developed a new 1L ICI risk score for OS based on data from patients with aUC treated with ICIs in the USA and Europe outside of clinical trials. The score components highlight readily available factors related to tumor biology and treatment response. External validation is being pursued. PATIENT SUMMARY: With multiple new treatments under development and approved for advanced urothelial carcinoma, it can be difficult to identify the best treatment sequence for each patient. The risk score may help inform treatment discussions and estimate outcomes in patients treated with first-line immune checkpoint inhibitors, while it can also impact clinical trial design and endpoints. TAKE HOME MESSAGE: A new risk score was developed for advanced urothelial carcinoma treated with first-line immune checkpoint inhibitors. The score assigned Eastern Cooperative Oncology Group performance status ≥2, albumin <3.5 g/dl, neutrophil:lymphocyte ratio >5, and liver metastases each one point, with a higher score being associated with worse overall survival.

Periprocedural Bridging in Patients with Venous Thromboembolism: A Systematic Review.

BACKGROUND: Vitamin K antagonists (VKA) are the most widely used anticoagulants, and bridging is commonly administered during periprocedural VKA interruption. Given the unclear benefits and risks of periprocedural bridging in patients with previous venous thromboembolism, we aimed to assess recurrent venous thromboembolism and bleeding outcomes with and without bridging in this population. METHODS: We performed a systematic review searching the PubMed and Embase databases from inception to December 7, 2017 for randomized and nonrandomized studies that included adults with previous venous thromboembolism requiring VKA interruption to undergo an elective procedure, and that reported venous thromboembolism or bleeding outcomes. Quality of evidence was graded by consensus. RESULTS: We included 28 cohort studies (20 being single-arm cohorts) with, overall, 6915 procedures for analysis. In 27 studies reporting perioperative venous thromboembolism outcomes, the pooled incidence of recurrent venous thromboembolism with bridging was 0.7% (95% confidence interval [CI], 0.4%-1.2%) and 0.5% (95% CI, 0.3%-0.8%) without bridging. Eighteen studies reported major or nonmajor bleeding outcomes. The pooled incidence of any bleeding was 3.9% (95% CI, 2.0%-7.4%) with bridging and 0.4% (95% CI, 0.1%-1.7%) without bridging. In bridged patients at high thromboembolic risk, the pooled incidence for venous thromboembolism was 0.8% (95% CI, 0.3%-2.5%) and 7.5% (95% CI, 3.1%-17.4%) for any bleeding. Quality of available evidence was very low, primarily due to a high risk of bias of included studies. CONCLUSIONS: Periprocedural bridging increases the risk of bleeding compared with VKA interruption without bridging, without a significant difference in periprocedural venous thromboembolism rates.