Prostate-specific Membrane Antigen Positron Emission Tomography-detected Disease Extent and Overall Survival of Patients with High-risk Nonmetastatic Castration-resistant Prostate Cancer: An International Multicenter Retrospective Study.

Previously, we demonstrated that prostate-specific membrane antigen positron emission tomography (PSMA-PET) revealed distant metastases in 109/200 patients (39% distant nodes, 24% bone, and 6% visceral organ) with nonmetastatic castration-resistant prostate cancer (nmCRPC) and high-risk features (International Society of Urological Pathology score ≥4 and/or prostate-specific antigen doubling time ≤10 mo) without metastases by conventional imaging. However, the impact of disease extent determined by PSMA-PET on patient outcomes is unknown. We followed these 200 patients for a median of 43 mo after PSMA-PET and retrospectively assessed the association between patient characteristics, PSMA-PET findings, treatment management, and outcomes using a Kaplan-Meier model and Cox multivariable regressions. Among assessed disease characteristics, polymetastatic disease (five or more distant lesions on PET) was independently associated with shorter overall survival (OS; median 61 mo vs not reached; hazard ratio [95% confidence interval], 1.81 [1.00-3.27]; p = 0.050) and time to new metastases (median 38 vs 60 mo; 1.80 [1.10-2.96]; p = 0.019), and initial pN1 status with shorter OS (55 mo vs not reached; 1.94 [1.12-3.37]; p = 0.019). Following PSMA-PET, locoregional salvage therapies were used most commonly in no/local disease (58%), and androgen receptor signaling inhibitors were used in distant metastatic disease (51%). PSMA-PET provides additional risk stratification for patients with nmCRPC. Polymetastatic disease (five or more distant lesions) is associated with worse outcomes. PATIENT SUMMARY: A novel sensitive imaging technology, called prostate-specific membrane antigen positron emission tomography (PSMA-PET), allows doctors to detect the spread of prostate cancer, known as distant metastases, earlier and more accurately than in the past. In our study, PSMA-PET detected none to many metastases in patients who were considered free of distant metastasis by conventional imaging. These findings predicted outcomes and were used to select appropriate treatment.

Pharmacogenetic and clinical risk factors for bevacizumab-related gastrointestinal hemorrhage in prostate cancer patients treated on CALGB 90401 (Alliance).

The objective of this study was to discover clinical and pharmacogenetic factors associated with bevacizumab-related gastrointestinal hemorrhage in Cancer and Leukemia Group B (Alliance) 90401. Patients with metastatic castration-resistant prostate cancer received docetaxel and prednisone ± bevacizumab. Patients were genotyped using Illumina HumanHap610-Quad and assessed using cause-specific risk for association between single nucleotide polymorphisms (SNPs) and gastrointestinal hemorrhage. In 1008 patients, grade 2 or higher gastrointestinal hemorrhage occurred in 9.5% and 3.8% of bevacizumab (n = 503) and placebo (n = 505) treated patients, respectively. Bevacizumab (P < 0.001) and age (P = 0.002) were associated with gastrointestinal hemorrhage. In 616 genetically estimated Europeans (n = 314 bevacizumab and n = 302 placebo treated patients), grade 2 or higher gastrointestinal hemorrhage occurred in 9.6% and 2.0% of patients, respectively. One SNP (rs1478947; HR 6.26; 95% CI 3.19-12.28; P = 9.40 × 10-8) surpassed Bonferroni-corrected significance. Grade 2 or higher gastrointestinal hemorrhage rate was 33.3% and 6.2% in bevacizumab-treated patients with the AA/AG and GG genotypes, versus 2.9% and 1.9% in the placebo arm, respectively. Prospective validation of these findings and functional analyses are needed to better understand the genetic contribution to treatment-related gastrointestinal hemorrhage.

Immune Modulation with RANKL Blockade through Denosumab Treatment in Patients with Cancer.

Denosumab is a fully human mAb that binds receptor activator of NFκB ligand (RANKL). It is routinely administered to patients with cancer to reduce the incidence of new bone metastasis. RANK-RANKL interactions regulate bone turnover by controlling osteoclast recruitment, development, and activity. However, these interactions also can regulate immune cells including dendritic cells and medullary thymic epithelial cells. Inhibition of the latter results in reduced thymic negative selection of T cells and could enhance the generation of tumor-specific T cells. We examined whether administering denosumab could modify modulate circulating immune cells in patients with cancer. Blood was collected from 23 patients with prostate cancer and 3 patients with renal cell carcinoma, all of whom had advanced disease and were receiving denosumab, prior to and during denosumab treatment. Using high-dimensional mass cytometry, we found that denosumab treatment by itself induced modest effects on circulating immune cell frequency and activation. We also found minimal changes in the circulating T-cell repertoire and the frequency of new thymic emigrants with denosumab treatment. However, when we stratified patients by whether they were receiving chemotherapy and/or steroids, patients receiving these concomitant treatments showed significantly greater immune modulation, including an increase in the frequency of natural killer cells early and classical monocytes later. We also saw broad induction of CTLA-4 and TIM3 expression in circulating lymphocytes and some monocyte populations. These findings suggest that denosumab treatment by itself has modest immunomodulatory effects, but when combined with conventional cancer treatments, can lead to the induction of immunologic checkpoints. See related Spotlight by Nasrollahi and Davar, p. 383.

Apalutamide efficacy, safety and wellbeing in older patients with advanced prostate cancer from Phase 3 randomised clinical studies TITAN and SPARTAN.

BACKGROUND: Apalutamide plus androgen-deprivation therapy (ADT) improved outcomes in metastatic castration-sensitive prostate cancer (mCSPC) and non-metastatic castration-resistant PC (nmCRPC) in the Phase 3 randomised TITAN and SPARTAN studies, respectively, and maintained health-related quality of life (HRQoL). Apalutamide treatment effect by patient age requires assessment. METHODS: Post-hoc analysis assessed patients receiving 240 mg/day apalutamide (525 TITAN and 806 SPARTAN) or placebo (527 TITAN and 401 SPARTAN) with ongoing ADT, stratified by age groups. Prostate-specific antigen declines, radiographic progression-free survival, metastasis-free survival, overall survival (OS), HRQoL and safety were assessed using descriptive statistics, Kaplan-Meier method, Cox proportional-hazards model and mixed-effects model for repeated measures. RESULTS: Hazard ratios (95% confidence intervals) generally favoured apalutamide plus ADT versus ADT alone across all endpoints regardless of age; e.g., OS values were 0.57 (0.40-0.80), 0.70 (0.54-0.91) and 0.74 (0.40-1.39) (TITAN) and 0.39 (0.19-0.78), 0.89 (0.69-1.16) and 0.81 (0.58-1.15) (SPARTAN) in patients aged <65, 65-79 and ≥80 years. Regardless of age, apalutamide also maintained HRQoL and was tolerated well with a potential trend in rates of adverse events increasing with age. Limitations include post-hoc nature and variability in sample size of age groups. CONCLUSIONS: Apalutamide plus ADT was an effective and well-tolerated option maintaining HRQoL in patients with mCSPC and nmCRPC regardless of age. CLINICAL TRIAL REGISTRATION: TITAN (NCT02489318); SPARTAN (NCT01946204).

Post Hoc Analysis of Rapid and Deep Prostate-specific Antigen Decline and Patient-reported Health-related Quality of Life in SPARTAN and TITAN Patients with Advanced Prostate Cancer.

BACKGROUND: Adding apalutamide to androgen-deprivation therapy (ADT) resulted in a rapid (at 3- and 6-mo treatment) and deep prostate-specific antigen (PSA) decline (to ≤0.2 ng/ml or ≥90% from baseline), improved overall survival, reduced risk of disease progression, and prolonged health-related quality of life (HRQoL) in nonmetastatic castration-resistant prostate cancer (nmCRPC) in SPARTAN and metastatic castration-sensitive PC (mCSPC) in TITAN. OBJECTIVE: To evaluate the association of a rapid, deep PSA decline at 3 and 6 mo achieved with the addition of apalutamide to ADT with patient-reported outcomes (PROs) in SPARTAN and TITAN. DESIGN, SETTING, AND PARTICIPANTS: A post hoc analysis of SPARTAN and TITAN PRO data was performed. INTERVENTION: Apalutamide versus placebo plus concurrent ADT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PROs were assessed using Functional Assessment of Cancer Therapy-Prostate (FACT-P; SPARTAN and TITAN), Brief Pain Inventory-Short Form (BPI-SF; TITAN), and Brief Fatigue Inventory (BFI; TITAN) at baseline, prespecified cycles during treatment, and after progression for ≤1 yr. The association between a deep PSA decline at landmark 3 or 6 mo of apalutamide and the time to worsening of PROs was assessed using the Kaplan-Meier methodology and Cox proportional-hazard modeling. RESULTS AND LIMITATIONS: Among 806 SPARTAN and 525 TITAN apalutamide-treated patients, the median treatment duration was 32.9 and 39.3 mo, respectively. Patients achieving a deep PSA decline at 3 mo had longer time to worsening in FACT-P total, FACT-P physical well-being, BPI-SF worst pain intensity, or BFI worst fatigue intensity. The 6-mo PSA decline results were similar. Limitations of patient characteristics in clinical studies should be considered. CONCLUSIONS: Attaining a deep and rapid PSA decline at 3 mo with apalutamide plus ADT was associated with longer preservation of overall HRQoL and physical well-being in nmCRPC and mCSPC. PATIENT SUMMARY: Quality of life is maintained in individuals with advanced prostate cancer who achieve a deep prostate-specific antigen decline at 3 mo of apalutamide plus drugs that lower male sex hormones.

The Genomic and Epigenomic Landscape of Double-Negative Metastatic Prostate Cancer.

Systemic targeted therapy in prostate cancer is primarily focused on ablating androgen signaling. Androgen deprivation therapy and second-generation androgen receptor (AR)-targeted therapy selectively favor the development of treatment-resistant subtypes of metastatic castration-resistant prostate cancer (mCRPC), defined by AR and neuroendocrine (NE) markers. Molecular drivers of double-negative (AR-/NE-) mCRPC are poorly defined. In this study, we comprehensively characterized treatment-emergent mCRPC by integrating matched RNA sequencing, whole-genome sequencing, and whole-genome bisulfite sequencing from 210 tumors. AR-/NE- tumors were clinically and molecularly distinct from other mCRPC subtypes, with the shortest survival, amplification of the chromatin remodeler CHD7, and PTEN loss. Methylation changes in CHD7 candidate enhancers were linked to elevated CHD7 expression in AR-/NE+ tumors. Genome-wide methylation analysis nominated Krüppel-like factor 5 (KLF5) as a driver of the AR-/NE- phenotype, and KLF5 activity was linked to RB1 loss. These observations reveal the aggressiveness of AR-/NE- mCRPC and could facilitate the identification of therapeutic targets in this highly aggressive disease. SIGNIFICANCE: Comprehensive characterization of the five subtypes of metastatic castration-resistant prostate cancer identified transcription factors that drive each subtype and showed that the double-negative subtype has the worst prognosis.

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.

External Validation of a Prognostic Model of Overall Survival in Men With Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: We have previously developed and externally validated a prognostic model of overall survival (OS) in men with metastatic, castration-resistant prostate cancer (mCRPC) treated with docetaxel. We sought to externally validate this model in a broader group of men with docetaxel-naïve mCRPC and in specific subgroups (White, Black, Asian patients, different age groups, and specific treatments) and to classify patients into validated two and three prognostic risk groupings on the basis of the model. METHODS: Data from 8,083 docetaxel-naïve mCRPC men randomly assigned on seven phase III trials were used to validate the prognostic model of OS. We assessed the predictive performance of the model by computing the time-dependent area under the receiver operating characteristic curve (tAUC) and validated the two-risk (low and high) and three-risk prognostic groups (low, intermediate, and high). RESULTS: The tAUC was 0.74 (95% CI, 0.73 to 0.75), and when adjusting for the first-line androgen receptor (AR) inhibitor trial status, the tAUC was 0.75 (95% CI, 0.74 to 0.76). Similar results were observed by the different racial, age, and treatment subgroups. In patients enrolled on first-line AR inhibitor trials, the median OS (months) in the low-, intermediate-, and high-prognostic risk groups were 43.3 (95% CI, 40.7 to 45.8), 27.7 (95% CI, 25.8 to 31.3), and 15.4 (95% CI, 14.0 to 17.9), respectively. Compared with the low-risk prognostic group, the hazard ratios for the high- and intermediate-risk groups were 4.3 (95% CI, 3.6 to 5.1; P < .0001) and 1.9 (95% CI, 1.7 to 2.1; P < .0001). CONCLUSION: This prognostic model for OS in docetaxel-naïve men with mCRPC has been validated using data from seven trials and yields similar results overall and across race, age, and different treatment classes. The prognostic risk groups are robust and can be used to identify groups of patients for enrichment designs and for stratification in randomized clinical trials.

Niraparib and Abiraterone Acetate for Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: Metastatic castration-resistant prostate cancer (mCRPC) remains a lethal disease with current standard-of-care therapies. Homologous recombination repair (HRR) gene alterations, including BRCA1/2 alterations, can sensitize cancer cells to poly (ADP-ribose) polymerase inhibition, which may improve outcomes in treatment-naïve mCRPC when combined with androgen receptor signaling inhibition. METHODS: MAGNITUDE (ClinicalTrials.gov identifier: NCT03748641) is a phase III, randomized, double-blinded study that evaluates niraparib and abiraterone acetate plus prednisone (niraparib + AAP) in patients with (HRR+, n = 423) or without (HRR-, n = 247) HRR-associated gene alterations, as prospectively determined by tissue/plasma-based assays. Patients were assigned 1:1 to receive niraparib + AAP or placebo + AAP. The primary end point, radiographic progression-free survival (rPFS) assessed by central review, was evaluated first in the BRCA1/2 subgroup and then in the full HRR+ cohort, with secondary end points analyzed for the full HRR+ cohort if rPFS was statistically significant. A futility analysis was preplanned in the HRR- cohort. RESULTS: Median rPFS in the BRCA1/2 subgroup was significantly longer in the niraparib + AAP group compared with the placebo + AAP group (16.6 v 10.9 months; hazard ratio [HR], 0.53; 95% CI, 0.36 to 0.79; P = .001). In the overall HRR+ cohort, rPFS was significantly longer in the niraparib + AAP group compared with the placebo + AAP group (16.5 v 13.7 months; HR, 0.73; 95% CI, 0.56 to 0.96; P = .022). These findings were supported by improvement in the secondary end points of time to symptomatic progression and time to initiation of cytotoxic chemotherapy. In the HRR- cohort, futility was declared per the prespecified criteria. Treatment with niraparib + AAP was tolerable, with anemia and hypertension as the most reported grade ≥ 3 adverse events. CONCLUSION: Combination treatment with niraparib + AAP significantly lengthened rPFS in patients with HRR+ mCRPC compared with standard-of-care AAP.[Media: see text].

Randomized Phase III Study of Enzalutamide Compared With Enzalutamide Plus Abiraterone for Metastatic Castration-Resistant Prostate Cancer (Alliance A031201 Trial).

PURPOSE: Enzalutamide and abiraterone both target androgen receptor signaling but via different mechanisms. The mechanism of action of one drug may counteract the resistance pathways of the other. We sought to determine whether the addition of abiraterone acetate and prednisone (AAP) to enzalutamide prolongs overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) in the first-line setting. PATIENTS AND METHODS: Men with untreated mCRPC were randomly assigned (1:1) to receive first-line enzalutamide with or without AAP. The primary end point was OS. Toxicity, prostate-specific antigen declines, pharmacokinetics, and radiographic progression-free survival (rPFS) were also examined. Data were analyzed using an intent-to-treat approach. The Kaplan-Meier estimate and the stratified log-rank statistic were used to compare OS between treatments. RESULTS: In total, 1,311 patients were randomly assigned: 657 to enzalutamide and 654 to enzalutamide plus AAP. OS was not statistically different between the two arms (median, 32.7 [95% CI, 30.5 to 35.4] months for enzalutamide v 34.2 [95% CI, 31.4 to 37.3] months for enzalutamide and AAP; hazard ratio [HR], 0.89; one-sided P = .03; boundary nominal significance level = .02). rPFS was longer in the combination arm (median rPFS, 21.3 [95% CI, 19.4 to 22.9] months for enzalutamide v 24.3 [95% CI, 22.3 to 26.7] months for enzalutamide and AAP; HR, 0.86; two-sided P = .02). However, pharmacokinetic clearance of abiraterone was 2.2- to 2.9-fold higher when administered with enzalutamide, compared with clearance values for abiraterone alone. CONCLUSION: The addition of AAP to enzalutamide for first-line treatment of mCRPC was not associated with a statistically significant benefit in OS. Drug-drug interactions between the two agents resulting in increased abiraterone clearance may partly account for this result, although these interactions did not prevent the combination regimen from having more nonhematologic toxicity.

Implementation of a Telehealth Genetic Testing Station to Deliver Germline Testing for Men With Prostate Cancer.

PURPOSE: Germline testing for men with prostate cancer (PCa) poses numerous implementation barriers. Alternative models of care delivery are emerging, but implementation outcomes are understudied. We evaluated implementation outcomes of a hybrid oncologist- and genetic counselor-delivered model called the genetic testing station (GTS) created to streamline testing and increase access. METHODS: A prospective, single-institution, cohort study of men with PCa referred to the GTS from October 14, 2019, to October 14, 2021, was conducted. Using the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework, we described patients referred to GTS (Reach), the association of GTS with germline testing completion rates within 60 days of a new oncology appointment in a pre- versus post-GTS multivariable logistic regression (Effectiveness), Adoption, Implementation, and Maintenance. Because GTS transitioned from an on-site to remote service during the COVID-19 pandemic, we also compared outcomes for embedded versus remote GTS. RESULTS: Overall, 713 patients were referred to and eligible for GTS, and 592 (83%) patients completed germline testing. Seventy-six (13%) patients had ≥ 1 pathogenic variant. Post-GTS was independently associated with higher odds of completing testing within 60 days than pre-GTS (odds ratio, 8.97; 95% CI, 2.71 to 29.75; P < .001). Black race was independently associated with lower odds of testing completion compared with White race (odds ratio, 0.35; 95% CI, 0.13 to 0.96; P = .042). There was no difference in test completion rates or patient-reported decisional conflict for embedded versus remote GTS. GTS has been adopted by 31 oncology providers across four clinics, and implementation fidelity was high with low patient loss to follow-up, but staffing costs are a sustainability concern. CONCLUSION: GTS is a feasible, effective model for high-volume germline testing in men with PCa, both in person and using telehealth. GTS does not eliminate racial disparities in germline testing access.

Quality of life for men with metastatic castrate-resistant prostate cancer participating in an aerobic and resistance exercise pilot intervention.

BACKGROUND: Following a prostate cancer diagnosis, disease and treatment-related symptoms may result in diminished quality of life (QoL). Whether exercise improves QoL in men with metastatic castrate-resistant prostate cancer (mCRPC) is not fully understood. METHODS: We conducted a 3-arm pilot randomized controlled trial to assess the feasibility, acceptability, safety, and efficacy of a 12-week remotely monitored exercise program among men with mCRPC. Here we report qualitative changes in QoL, consistent with the guidelines for pilot trials. Men were randomized to control, aerobic exercise, or resistance exercise. Exercise prescriptions were based on baseline cardiorespiratory and strength assessments. QoL outcomes were evaluated using self-reported questionnaires (e.g., QLQ-C30, PROMIS Fatigue, Pittsburgh Sleep Quality Index (PSQI), EPIC-26) collected at baseline and 12 weeks. RESULTS: A total of 25 men were randomized (10 control, 8 aerobic, 7 resistance). Men were predominately white (76%) with a median age of 71 years (range: 51-84) and 10.5 years (range: 0.9-26.3) post prostate cancer diagnosis. The men reported poor sleep quality and high levels of fatigue at enrollment. Other baseline QoL metrics were relatively high. Compared to the controls at 12 weeks, the resistance arm reported some improvements in social function and urinary irritative/obstruction symptoms while the aerobic arm reported some improvements in social function and urinary incontinence, yet worsening nausea/vomiting. Compared to the resistance arm, the aerobic arm reported worse urinary irritative/obstruction symptoms and self-rated QoL, yet some improvements in emotional function, insomnia, and diarrhea. CONCLUSIONS: The 3-month exercise intervention pilot appeared to have modest effects on QoL among mCRPC survivors on ADT. Given the feasibility, acceptability, and safety demonstrated in prior analyses, evaluation of the effect of the intervention on QoL in a larger sample and for extended duration may still be 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.

Assessing Unique Risk Factors for COVID-19 Complications Among Cancer Patients: A Multi-ethnic Cohort Study.

A myriad of organ-specific complications have been observed with COVID-19. While racial/ethnic minorities have been disproportionately burdened by this disease, our understanding of the unique risk factors for complications among a diverse population of cancer patients remains limited. This is a multi-institutional, multi-ethnic cohort study evaluating COVID-19 complications among cancer patients. Patients with an invasive cancer diagnosis and confirmed SARS-CoV-2 infection were identified from March to November 2020. Demographic and clinical data were obtained and a multivariate logistic regression was employed to evaluate the impact of demographic and clinical factors on COVID-19 complications. The study endpoints were evaluated independently and included any complication, sepsis, pulmonary complications and cardiac complications. A total of 303 patients were evaluated, of whom 48% were male, 79% had solid tumors, and 42% were Hispanic/Latinx (Hispanic). Malignant hematologic cancers were associated with a higher risk of sepsis (OR 3.93 (95% CI 1.58-9.81)). Male patients had a higher risk of sepsis (OR 4.42 (95% CI 1.63-11.96)) and cardiac complications (OR 2.02 (95% CI 1.05-3.89)). Hispanic patients had a higher odds of any complication (OR 2.31 (95% CI 1.18-4.51)) and other race was associated with a higher odds of cardiac complications (OR 2.41 (95% CI 1.01-5.73)). Clinically, fever, cough, and ≥2 co-morbidities were independently significantly associated with any complication. This analysis evaluated covariates that can significantly predict a myriad of complications among a multi-ethnic cohort of cancer patients. The conclusions drawn from this analysis elucidate a mechanistic understanding of differential illness severity from COVID-19.

Immunotherapeutic Targeting and PET Imaging of DLL3 in Small-Cell Neuroendocrine Prostate Cancer.

Effective treatments for de novo and treatment-emergent small-cell/neuroendocrine (t-SCNC) prostate cancer represent an unmet need for this disease. Using metastatic biopsies from patients with advanced cancer, we demonstrate that delta-like ligand 3 (DLL3) is expressed in de novo and t-SCNC and is associated with reduced survival. We develop a PET agent, [89Zr]-DFO-DLL3-scFv, that detects DLL3 levels in mouse SCNC models. In multiple patient-derived xenograft models, AMG 757 (tarlatamab), a half-life-extended bispecific T-cell engager (BiTE) immunotherapy that redirects CD3-positive T cells to kill DLL3-expressing cells, exhibited potent and durable antitumor activity. Late relapsing tumors after AMG 757 treatment exhibited lower DLL3 levels, suggesting antigen loss as a resistance mechanism, particularly in tumors with heterogeneous DLL3 expression. These findings have been translated into an ongoing clinical trial of AMG 757 in de novo and t-SCNC, with a confirmed objective partial response in a patient with histologically confirmed SCNC. Overall, these results identify DLL3 as a therapeutic target in SCNC and demonstrate that DLL3-targeted BiTE immunotherapy has significant antitumor activity in this aggressive prostate cancer subtype. SIGNIFICANCE: The preclinical and clinical evaluation of DLL3-directed immunotherapy, AMG 757, and development of a PET radiotracer for noninvasive DLL3 detection demonstrate the potential of targeting DLL3 in SCNC prostate cancer.

Clinical characteristics associated with falls in patients with non-metastatic castration-resistant prostate cancer treated with apalutamide.

BACKGROUND: The phase III SPARTAN study demonstrated that apalutamide significantly improves metastasis-free survival and overall survival vs. placebo in patients with non-metastatic castration-resistant prostate cancer (nmCRPC). However, patients receiving apalutamide experienced falls more frequently vs. those receiving placebo (15.6% vs. 9.0%). METHODS: 806 patients with nmCRPC randomized to apalutamide in SPARTAN and treated with apalutamide in addition to ongoing androgen deprivation therapy (ADT) were included in this post-hoc analysis investigating clinical variables associated with a subsequent fall. Time to a fall was assessed with Cox proportional-hazards models adjusted for baseline characteristics and time-varying factors. Statistical inference was based on final multivariable models. RESULTS: Falls were reported for 125/803 (15.6%) patients treated with apalutamide and ADT. Most falls were grade 1 or 2 and did not require hospitalization. Median time from randomization to first fall was 9.2 months (range 0.1-25.3 months). In the final multivariable model of both baseline and after-baseline covariates, baseline patient characteristics (older age, poor Eastern Cooperative Oncology Group performance status, history of neuropathy, and α-blocker use before study treatment) remained significantly associated with fall; after-baseline clinical characteristics significantly associated with time to fall were development of neuropathy, arthralgia, and weight loss before fall. CONCLUSIONS: This analysis identified risk factors for fall among nmCRPC patients treated with apalutamide. Clinical management can minimize these identified risks while enhancing patient outcomes. Preventive interventions should be considered when the identified baseline conditions and post-treatment neuropathy, arthralgia, or weight decrease are present, to reduce risk of fall. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01946204.

Cancer Research in 2030: A unique strategic planning process at a comprehensive cancer center.

Following the successful renewal of its Cancer Center Support Grant (CCSG), leadership of the UCSF Helen Diller Comprehensive Cancer Center (HDFCCC) began a strategic planning process. The motivation was to think about where cancer research was going in the future; and with this vision to define a general scientific direction, mission, and priorities. HDFCCC Leadership began discussions about a new strategic plan in early 2018. From these meetings, the theme of "Cancer Research in 2030" arose: that is, what will cancer research look like in 2030? This forward-looking focus was intended to encourage creativity unconfined by a particular institutional structure or grant mechanism. Focusing on the science paved the way for an innovative, actionable, and motivating strategic planning process. Here, we describe the three-phase process, and the various groups involved across the HDFCCC and UCSF. We present the unique framework based on a cells-to-society model and an individual experience perspective, which led to the development of a logic model and ongoing implementation of tactics and tracking progress. We believe that sharing this process and its results will be of value to cancer centers and cancer researchers across the network of NCI comprehensive cancer centers, and cancer research centers in general.