Treatment Outcomes in Patients With Metastatic Renal Cell Carcinoma With Sarcomatoid and/or Rhabdoid Dedifferentiation After Progression on Immune Checkpoint Therapy

BACKGROUND

Metastatic RCC with sarcomatoid and/or rhabdoid (S/R) dedifferentiation is an aggressive disease associated with improved response to immune checkpoint therapy (ICT). The outcomes of patients treated with VEGFR-targeted therapies (TT) following ICT progression have not been investigated.

PATIENTS AND METHODS

Retrospective review of 57 patients with sarcomatoid (S), rhabdoid (R), or sarcomatoid plus rhabdoid (S + R) dedifferentiation who received any TT after progression on ICT at an academic cancer center. Clinical endpoints of interest included time on TT, overall survival (OS) from initiation of TT, and objective response rate (ORR) by RECIST version 1.1. Multivariable models adjusted for epithelial histology, IMDC risk, prior VEGFR TT, and inclusion of cabozantinib in the post-ICT TT regimen.

RESULTS

29/57 patients had S dedifferentiation and 19 had R dedifferentiation. The most frequently used TT was cabozantinib (43.9%) followed by selective VEGFR TT (22.8%). The median time on TT was 6.4 months for all, 6.1 months for those with S dedifferentiation, 15.6 months for R dedifferentiation, and 6.1 months for S + R dedifferentiation. Median OS from initiation of TT was 24.9 months for the entire cohort, and the ORR was 20.0%. Patients with R dedifferentiation had significantly longer time on TT than those with S dedifferentiation (HR 0.44, 95% CI, 0.21-0.94). IMDC risk was associated with OS.

CONCLUSIONS

A subset of patients with S/R dedifferentiation derive clinical benefit from TT after they have progressive disease on ICT. Patients with R dedifferentiation appeared to derive more benefit from TT than those with S dedifferentiation.

Alcohol and drug use severity are independently associated with antiretroviral adherence in the current treatment era

Substance use in people with HIV (PWH) negatively impacts antiretroviral therapy (ART) adherence. However, less is known about this in the current treatment era and the impact of specific substances or severity of substance use. We examined the associations of alcohol, marijuana, and illicit drug use (methamphetamine/crystal, cocaine/crack, illicit opioids/heroin) and their severity of use with adherence using multivariable linear regression in adult PWH in care between 2016 and 2020 at 8 sites across the US. PWH completed assessments of alcohol use severity (AUDIT-C), drug use severity (modified ASSIST), and ART adherence (visual analogue scale). Among 9400 PWH, 16% reported current hazardous alcohol use, 31% current marijuana use, and 15% current use of ≥1 illicit drugs. In multivariable analysis, current methamphetamine/crystal use, particularly common among men who had sex with men, was associated with 10.1% lower mean ART adherence (p < 0.001) and 2.6% lower adherence per 5-point higher severity of use (ASSIST score) (p < 0.001). Current and more severe use of alcohol, marijuana, and other illicit drugs were also associated with lower adherence in a dose-dependent manner. In the current HIV treatment era, individualized substance use treatment, especially for methamphetamine/crystal, and ART adherence should be prioritized.

A Modular Trial of Androgen Signaling Inhibitor Combinations Testing a Risk-Adapted Strategy in Patients with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

To determine the efficacy and safety of risk-adapted combinations of androgen signaling inhibitors and inform disease classifiers for metastatic castration-resistant prostate cancers (mCRPC).

EXPERIMENTAL DESIGN

In a modular, randomized phase II trial, 192 men were treated with 8 weeks of abiraterone acetate, prednisone and apalutamide (AAPA; Module 1), then allocated to Modules 2 or 3 based on Satisfactory (≥50% PSA decline from baseline and <5 CTC/7.5 mL) versus Unsatisfactory status. Men in the former were randomized to continue AAPA alone (Module 2A) or with ipilimumab (Module 2B). Men in the latter had carboplatin+cabazitaxel added to AAPA (Module 3). Optional baseline biopsies were subject to correlative studies.

RESULTS

Median overall survival (from allocation) was 46.4 (95% CI 39.2, 68.2), 41.4 (95% CI 33.3, 49.9) and 18.7 (95% CI 14.3, 26.3) months in Modules 2A (n=64), 2B (n=64) and 3 (n=59) respectively. Toxicities were within expectations. Of 192 eligible patients, 154 (80.2%) underwent pre-treatment metastatic biopsies. The aggressive variant prostate cancer molecular profile (defects in ≥2 of p53, RB1, and PTEN) was associated with Unsatisfactory status. Exploratory analyses suggested SPP1+ and IGFBP2+ macrophages, druggable myeloid cell markers, and germline pathogenic mutations were enriched in the Unsatisfactory group.

CONCLUSIONS

Adding ipilimumab to AAPA did not improve outcomes in men with androgen responsive mCRPC. Despite the addition of carboplatin+cabazitaxel, men in the Unsatisfactory group had shortened survivals. Adaptive designs can enrich for biologically and clinically relevant disease subgroups, to contribute to the development of marker-informed, risk-adapted therapy strategies in men with prostate cancer.

Optimizing outcomes in men with prostate cancer: the cardiovascular event lowering (CaELo) pathways

INTRODUCTION

Risk of cardiovascular disease is higher among men with prostate cancer than men without, and prostate cancer treatments (especially those that are hormonally based) are associated with increased cardiovascular risk.

MATERIALS AND METHODS

An 11-member panel of urologic, medical, and radiation oncologists (along with a men's health specialist and an endocrinologist/preventive cardiologist) met to discuss current practices and challenges in the management of cardiovascular risk in prostate cancer patients who are taking androgen deprivation therapies (ADT) including LHRH analogues, alone and in combination with androgen-targeted therapies (ATTs).

RESULTS

The panel developed an assessment algorithm to categorize patients by risk and deploy a risk-adapted management strategy, in collaboration with other healthcare providers (the patient's healthcare "village"), with the goal of preventing as well as reducing cardiovascular events. The panel also developed a patient questionnaire for cardiovascular risk as well as a checklist to ensure that all aspects of cardiovascular disease risk reduction are completed and monitored.

CONCLUSIONS

Prostate cancer patients receiving ADT with or without ATT need to be more zealously assessed for prevention and aggressively managed to reduce cardiovascular events. This can and should include participation from the entire multidisciplinary healthcare team.

The association of body mass index with tumor aggression among men undergoing radical prostatectomy

OBJECTIVES

To evaluate the association of preoperative body mass index (BMI) on adverse pathology in peripheral (PZ) and transition zone (TZ) tumors at time of prostatectomy for localized prostate cancer.

METHODS

Clinical and pathologic characteristics were obtained from up to 100 consecutive prostatectomy patients from 10 prostate surgeons. BMI groups included normal (18.5-24.9), overweight (25-29.9) and obese (> 29.9). "Aggressive" pathology was defined as the presence of Grade Group (GG) 3 or higher and/or pT3a or higher. Pathologic characteristics were evaluated for association with BMI using univariate analyses. Our primary outcome was the association of BMI with adverse pathology, which was assessed using logistic regression accounting for patient age. We hypothesized that obese BMI would be associated with aggressive TZ tumor.

RESULTS

Among 923 patients, 140 (15%) were classified as "normal" BMI, 413 (45%) were "overweight", and 370 (40%) were "obese." 474 patients (51%) had aggressive PZ tumors while 102 (11%) had aggressive TZ tumors. "Obese" BMI was not associated with aggressive TZ tumor compared to normal weight. Increasing BMI group was associated with overall increased risk of aggressive PZ tumor (HR 1.56 [95CI 1.04-2.34]; P = 0.03). Among patients with GG1 or GG2, increasing BMI was associated with presence of pT3a or higher TZ tumor (P = 0.03).

CONCLUSIONS

Increased BMI is associated with adverse pathology in PZ tumors. TZ adverse pathology risk may be increased among obese men with GG1 or GG2 disease, which has implications for future studies assessing behavioral change among men whose tumors are actively monitored.

Phase I Study of ORIC-101, a Glucocorticoid Receptor Antagonist, in Combination with Enzalutamide in Patients with Metastatic Castration-resistant Prostate Cancer Progressing on Enzalutamide

PURPOSE

Increased glucocorticoid receptor (GR) signaling is a proposed compensatory mechanism of resistance to androgen receptor (AR) inhibition in metastatic castration-resistant prostate cancer (mCRPC). ORIC-101 is a potent and selective orally-bioavailable GR antagonist.

PATIENTS AND METHODS

Safety, pharmacokinetic/pharmacodynamic, and antitumor activity of ORIC-101 in combination with enzalutamide were studied in patients with mCRPC progressing on enzalutamide. ORIC-101 doses ranging from 80 to 240 mg once daily were tested in combination with enzalutamide 160 mg once daily. Pharmacokinetics/pharmacodynamics was assessed after a single dose and at steady state. Disease control rate (DCR) at 12 weeks was evaluated at the recommended phase 2 dose (RP2D).

RESULTS

A total of 41 patients were enrolled. There were no dose-limiting toxicities and the RP2D was selected as 240 mg of ORIC-101 and 160 mg of enzalutamide daily. At the RP2D, the most common treatment-related adverse events were fatigue (38.7%), nausea (29.0%), decreased appetite (19.4%), and constipation (12.9%). Pharmacokinetic/pharmacodynamic data confirmed ORIC-101 achieved exposures necessary for GR target engagement. Overall, for 31 patients treated at the RP2D, there was insufficient clinical benefit based on DCR (25.8%; 80% confidence interval: 15.65-38.52) which did not meet the prespecified target rate, leading to termination of the study. Exploratory subgroup analyses based on baseline GR expression, presence of AR resistance variants, and molecular features of aggressive variant prostate cancer suggested possible benefit in patients with high GR expression and no other resistance markers, although this would require confirmation.

CONCLUSIONS

Although the combination of ORIC-101 and enzalutamide demonstrated an acceptable tolerability profile, GR target inhibition with ORIC-101 did not produce clinical benefit in men with metastatic prostate cancer resistant to enzalutamide.

Differential Treatment Effects of Subgroup Analyses in Phase 3 Oncology Trials From 2004 to 2020

Importance

Subgroup analyses are often performed in oncology to investigate differential treatment effects and may even constitute the basis for regulatory approvals. Current understanding of the features, results, and quality of subgroup analyses is limited.

Objective

To evaluate forest plot interpretability and credibility of differential treatment effect claims among oncology trials.

Design, Setting, and Participants

This cross-sectional study included randomized phase 3 clinical oncology trials published prior to 2021. Trials were screened from ClinicalTrials.gov.

Main Outcomes and Measures

Missing visual elements in forest plots were defined as a missing point estimate or use of a linear x-axis scale for hazard and odds ratios. Multiplicity of testing control was recorded. Differential treatment effect claims were rated using the Instrument for Assessing the Credibility of Effect Modification Analyses. Linear and logistic regressions evaluated associations with outcomes.

Results

Among 785 trials, 379 studies (48%) enrolling 331 653 patients reported a subgroup analysis. The forest plots of 43% of trials (156 of 363) were missing visual elements impeding interpretability. While 4148 subgroup effects were evaluated, only 1 trial (0.3%) controlled for multiple testing. On average, trials that did not meet the primary end point conducted 2 more subgroup effect tests compared with trials meeting the primary end point (95% CI, 0.59-3.43 tests; P = .006). A total of 101 differential treatment effects were claimed across 15% of trials (55 of 379). Interaction testing was missing in 53% of trials (29 of 55) claiming differential treatment effects. Trials not meeting the primary end point were associated with greater odds of no interaction testing (odds ratio, 4.47; 95% CI, 1.42-15.55, P = .01). The credibility of differential treatment effect claims was rated as low or very low in 93% of cases (94 of 101).

Conclusions and Relevance

In this cross-sectional study of phase 3 oncology trials, nearly half of trials presented a subgroup analysis in their primary publication. However, forest plots of these subgroup analyses largely lacked essential features for interpretation, and most differential treatment effect claims were not supported. Oncology subgroup analyses should be interpreted with caution, and improvements to the quality of subgroup analyses are needed.

Venous Thromboembolism Among People With HIV: Design, Implementation, and Findings of a Centralized Adjudication System in Clinical Care Sites Across the United States

BACKGROUND

People with HIV (PWH) are at increased risk for venous thromboembolism (VTE). We conducted this study to characterize VTE including provoking factors among PWH in the current treatment era.

METHODS

We included PWH with VTE between 2010 and 2020 at 6 sites in the CFAR Network of Integrated Clinical Systems cohort. We ascertained for possible VTE using diagnosis, VTE-related imaging, and VTE-related procedure codes, followed by centralized adjudication of primary data by expert physician reviewers. We evaluated sensitivity and positive predictive value of VTE ascertainment approaches. VTEs were classified by type and anatomic location. Reviewers identified provoking factors such as hospitalizations, infections, and other potential predisposing factors such as smoking.

RESULTS

We identified 557 PWH with adjudicated VTE: 239 (43%) had pulmonary embolism with or without deep venous thrombosis, and 318 (57%) had deep venous thrombosis alone. Ascertainment with clinical diagnoses alone missed 6% of VTEs identified with multiple ascertainment approaches. DVTs not associated with intravenous lines were most often in the proximal lower extremities. Among PWH with VTE, common provoking factors included recent hospitalization (n = 134, 42%), infection (n = 133, 42%), and immobilization/bed rest (n = 78, 25%). Only 57 (10%) PWH had no provoking factor identified. Smoking (46%), HIV viremia (27%), and injection drug use (22%) were also common.

CONCLUSIONS

We conducted a robust adjudication process that demonstrated the benefits of multiple ascertainment approaches followed by adjudication. Provoked VTEs were more common than unprovoked events. Nontraditional and modifiable potential predisposing factors such as viremia and smoking were common.

Challenging the Prevailing Therapeutic Dogma for Prostate Cancer: The Case for an Overlap Syndrome

There is a need to understand what accounts for the modest impact of therapy on overall survival among men with potentially lethal prostate cancer. Given converging lines of evidence, we hypothesize that in a subset of men, prostate cancer is part of an "overlap syndrome" of age-related illnesses with shared biologic vulnerability.

Evaluating the Sick Quitting Hypothesis for Frailty Status and Reducing Alcohol Use Among People With HIV in a Longitudinal Clinical Cohort Study

ABSTRACT

"Sick quitting," a phenomenon describing reductions in alcohol consumption following poor health, may explain observations that alcohol appears protective for frailty risk. We examined associations between frailty and reductions in drinking frequency among people with HIV (PWH). At six Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) sites between January 2012 and August 2021, we assessed whether frailty, measured through validated modified frailty phenotype, precedes reductions in drinking frequency. We associated time-updated frailty with quitting and reducing frequency of any drinking and heavy episodic drinking (HED), adjusted for demographic and clinical characteristics in Cox models. Among 5,654 PWH reporting drinking, 60% reported >monthly drinking and 18% reported ≥monthly HED. Over an average of 5.4 years, frail PWH had greater probabilities of quitting (HR: 1.56, 95% confidence interval [95% CI] [1.13-2.15]) and reducing (HR: 1.35, 95% CI [1.13-1.62]) drinking frequency, as well as reducing HED frequency (HR: 1.58, 95% CI [1.20-2.09]) versus robust PWH. Sick quitting likely confounds the association between alcohol use and frailty risk, requiring investigation for control.

Monitoring Glucocorticoid Receptor in Plasma-derived Extracellular Vesicles as a Marker of Resistance to Androgen Receptor Signaling Inhibition in Prostate Cancer

Disease progression following androgen ablation was shown to be associated with upregulation of the glucocorticoid receptor (GR). Longitudinal monitoring of GR expression in circulating extracellular vesicles (EV) may reflect changes in the tumor cell and facilitates detection of acquired resistance. We utilized LNCaP, LREX cells and a patient-derived xenograft, MDA PDX 322-2-6a, for in vitro and in vivo experiments. Plasma-derived EVs were isolated from patients with localized high-risk prostate cancer undergoing androgen ablation. The mRNA levels of GR in EVs and their responsive genes were detected by transcriptome analysis, qRT-PCR and the protein levels by Western blot analysis. We detected changes in GR expression at mRNA and protein levels in EVs derived from LNCaP and LREX cells in in vitro studies. In in vivo experiments, LNCaP and the PDX MDA 322-2-6a-bearing mice were treated with enzalutamide. GR levels in plasma-derived EVs were increased only in those tumors that did not respond to enzalutamide. Treatment of mice bearing enzalutamide-resistant tumors with a GR inhibitor in combination with enzalutamide led to a transient pause in tumor growth in a subset of tumors and decreased GR levels intracellular and in plasma-derived EVs. In a subgroup of patients with high-risk localized prostate cancer treated with androgen signaling inhibition, GR was found upregulated in matching tissue and plasma EVs. These analyses showed that GR levels in plasma-derived EVs may be used for monitoring the transition of GR expression allowing for early detection of resistance to androgen ablation treatment.

SIGNIFICANCE

Longitudinal monitoring of GR expression in plasma-derived EVs from patients with prostate cancer treated with androgen signaling inhibitors facilitates early detection of acquisition of resistance to androgen receptor signaling inhibition in individual patients.

Safety and efficacy of immune checkpoint inhibitors in advanced penile cancer: report from the Global Society of Rare Genitourinary Tumors

BACKGROUND

Treatment options for penile squamous cell carcinoma are limited. We sought to investigate clinical outcomes and safety profiles of patients with penile squamous cell carcinoma receiving immune checkpoint inhibitors.

METHODS

This retrospective study included patients with locally advanced or metastatic penile squamous cell carcinoma receiving immune checkpoint inhibitors between 2015 and 2022 across 24 centers in the United States, Europe, and Asia. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Objective response rates were determined per Response Evaluation Criteria in Solid Tumours 1.1 criteria. Treatment-related adverse events were graded per the Common Terminology Criteria for Adverse Events, version 5.0. Two-sided statistical tests were used for comparisons.

RESULTS

Among 92 patients, 8 (8.7%) were Asian, 6 (6.5%) were Black, and 24 (29%) were Hispanic and/or Latinx. Median (interquartile range) age was 62 (53-70) years. In all, 83 (90%) had metastatic penile squamous cell carcinoma, and 74 (80%) had received at least second-line treatment. Most patients received pembrolizumab monotherapy (n = 26 [28%]), combination nivolumab-ipilimumab with or without multitargeted tyrosine kinase inhibitors (n = 23 [25%]), or nivolumab (n = 16 [17%]) or cemiplimab (n = 15 [16%]) monotherapies. Median overall and progression-free survival were 9.8 months (95% confidence interval = 7.7 to 12.8 months) and 3.2 months (95% confidence interval = 2.5 to 4.2 months), respectively. The objective response rate was 13% (n = 11/85) in the overall cohort and 35% (n = 7/20) in patients with lymph node-only metastases. Visceral metastases, Eastern Cooperative Oncology Group (ECOG) performance status of 1 or higher, and a higher neutrophil/lymphocyte ratio were associated with worse overall survival. Treatment-related adverse events occurred in 27 (29%) patients, and 9.8% (n = 9) of the events were grade 3 or higher.

CONCLUSIONS

Immune checkpoint inhibitors are active in a subset of patients with penile squamous cell carcinoma. Future translational studies are warranted to identify patients more likely to derive clinical benefit from immune checkpoint inhibitors.

Characterization of prostate cancer adrenal metastases: dependence upon androgen receptor signaling and steroid hormones

BACKGROUND

Prostate cancer (PCa) typically spreads to the bone, and this distribution is attributed to the central role of the microenvironment in progression. However, metastasis to the adrenal glands, while not as common, does occur. The biology that accounts for adrenal metastases may be attributed to the unique local steroid metabolome and co-clinical characterization may elucidate the role steroid biosynthesis plays in PCa progression.

METHODS

Three patients with metastatic PCa who had archived tumor tissue from an adrenalectomy were retrospectively identified, and one adrenal metastasis was developed into a xenograft (MDA-PCa-250). The adrenal metastases were characterized by performing somatic DNA whole exome sequencing (WES), RNA-Seq, immunohistochemistry (IHC), and steroid metabolite quantitation. The influence of steroid metabolites on adrenal metastasis cells and tumor growth was tested in vitro and in vivo.

RESULTS

Clinically, adrenalectomy was performed during castration-resistant oligometastatic disease, and two men experienced resensitization to leuprolide. Somatic DNA WES revealed heterogeneous alterations in tumor suppressor and DNA damage repair pathway genes. Adrenal metastases had active androgen receptor (AR) signaling by IHC, and RNA-Seq supported a potential role for adrenal androgen precursor metabolism in activating the AR. Steroid quantitation suggested the adrenal androgen precursors were converted into testosterone in these metastases, and stable isotope tracing of an organoid from MDA-PCa-250 confirmed the capability of adrenal metastases to biosynthesize testosterone from adrenal precursors. In vitro testing of a cell line derived from MDA-PCa-250 showed that testosterone and cortisol stimulated tumor cell growth. In vivo experiments demonstrated that MDA-PCa-250 grew in intact mice with circulating testosterone, but not in castrated mice.

CONCLUSIONS

PCa adrenal metastases depend upon AR signaling driven by androgen precursors, androstenedione and dehydroepiandrosterone, available in the microenvironment, despite the presence of heterogeneous somatic DNA alterations. Moreover, MDA-PCa-250 provides a preclinical model that can recapitulate the unique androgen-dependence of adrenal metastases.

CLINICAL TRIAL REGISTRATION

This study does not report the clinical results of a clinical trial, but it does use samples from a completed clinical trial that is registered with clinicaltrials.gov (NCT01254864).

The Influence of Obesity on Outcomes with Immune Checkpoint Blockade: Clinical Evidence and Potential Biological Mechanisms

Immune checkpoint blockade (ICB) is a mainstay of treatment for advanced cancer, yet tumor response and host toxicity are heterogenous in those patients who receive ICB. There is growing interest in understanding how host factors interact with tumor intrinsic properties and the tumor microenvironment to influence the therapeutic index with ICB. Obesity, defined by body mass index, is a host factor associated with improved outcomes in select cancers when treated with ICB. While the biological mechanism for this obesity paradox is not fully understood, pre-clinical and translational studies suggest obesity may potentially impact tumor metabolism, inflammation, and angiogenesis. Herein, we summarize clinical studies that support an obesity paradox with ICB, explore potential biological mechanisms that may account for the obesity paradox, and address methodological challenges to consider when studying obesity and treatment outcomes.

Tobacco Smoking and Pack-Years Are Associated With Frailty Among People With HIV

BACKGROUND

Tobacco smoking increases frailty risk among the general population and is common among people with HIV (PWH) who experience higher rates of frailty at younger ages than the general population.

METHODS

We identified 8608 PWH across 6 Centers for AIDS Research Network of Integrated Clinical Systems sites who completed ≥2 patient-reported outcome assessments, including a frailty phenotype measuring unintentional weight loss, poor mobility, fatigue, and inactivity, and scored 0-4. Smoking was measured as baseline pack-years and time-updated never, former, or current use with cigarettes/day. We used Cox models to associate smoking with risk of incident frailty (score ≥3) and deterioration (frailty score increase by ≥2 points), adjusted for demographics, antiretroviral medication, and time-updated CD4 count.

RESULTS

The mean follow-up of PWH was 5.3 years (median: 5.0), the mean age at baseline was 45 years, 15% were female, and 52% were non-White. At baseline, 60% reported current or former smoking. Current (HR: 1.79; 95% confidence interval: 1.54 to 2.08) and former (HR: 1.31; 95% confidence interval: 1.12 to 1.53) smoking were associated with higher incident frailty risk, as were higher pack-years. Current smoking (among younger PWH) and pack-years, but not former smoking, were associated with higher risk of deterioration.

CONCLUSIONS

Among PWH, smoking status and duration are associated with incident and worsening frailty.

Cardiometabolic healthcare for men with prostate cancer: an MD Anderson Cancer Center experience

BACKGROUND

Men diagnosed with prostate cancer are at risk for competing morbidity and mortality due to cardiometabolic disease given their advanced age at diagnosis, high prevalence of pre-existing risk factors, and receipt of systemic therapy that targets the androgen receptor (AR). Expert panels have stressed the importance of cardiometabolic risk assessment in the clinic and proposed evaluating key risks using consensus paradigms. Yet, there is a gap in real-world evidence for implementation of comprehensive cardiometabolic care for men with prostate cancer.

METHODS

This is a retrospective, descriptive study of patients with prostate cancer who were referred and evaluated in the Healthy Heart Program at MD Anderson Cancer Center, which was established to mitigate cardiometabolic risks in men with prostate cancer. Patients were seen by a cardiologist and exercise physiologist to evaluate and manage cardiometabolic risk factors, including blood pressure, cholesterol, blood glucose, tobacco use, and coronary artery disease, concurrent with management of their cancer by a medical oncologist.

RESULTS

From December 2018 through October 2021, the Healthy Heart Program enrolled 55 men with prostate cancer, out of which 35 had biochemical, locoregional recurrence or distant metastases, while all received at least a single dose of a luteinizing hormone-releasing hormone (LHRH) analog. Ninety-three percent of men were overweight or obese, and 51% had an intermediate or high risk of atherosclerotic cardiovascular disease at 10 years based on the pooled cohort equation. Most men had an overlap of two or more cardiometabolic diseases (84%), and 25% had an overlap of at least 4 cardiometabolic diseases. Although uncontrolled hypertension and hyperlipidemia were common among the cohort (45% and 26%, respectively), only 29% of men followed up with the clinic.

CONCLUSIONS

Men with prostate cancer have a high burden of concurrent cardiometabolic risk factors. At a tertiary cancer center, the Healthy Heart Program was implemented to address this need, yet the utility of the program was limited by poor follow-up possibly due to outside cardiometabolic care and inconvenient appointment logistics, a lack of cardiometabolic labs at the time of visits, and telemedicine visits.

Cytoreductive Nephrectomy for Patients with Metastatic Sarcomatoid and/or Rhabdoid Renal Cell Carcinoma Treated with Immune Checkpoint Therapy

BACKGROUND

Renal cell carcinoma (RCC) with sarcomatoid and/or rhabdoid (S/R) dedifferentiation is a highly aggressive tumor with a poor prognosis. Immune checkpoint therapy (ICT) has shown significant treatment efficacy in this subtype. There remains uncertainly regarding the role of cytoreductive nephrectomy (CN) for patients with metastatic RCC (mRCC) with S/R who received ICT.

OBJECTIVE

Here, we report the outcomes with ICT for patients with mRCC and S/R dedifferentiation by CN status.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review was conducted of 157 patients with sarcomatoid, rhabdoid, or sarcomatoid plus rhabdoid dedifferentiation who received an ICT-based regimen at two cancer centers.

INTERVENTION

CN performed at any time point; nephrectomy with curative intent was excluded.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

ICT treatment duration (TD) and overall survival (OS) from ICT initiation were recorded. To address the immortal time bias, a time-dependent Cox regression model was generated that accounted for confounders identified by a directed acyclic graph as well as a time-dependent nephrectomy variable.

RESULTS AND LIMITATIONS

A total of 118 patients underwent CN, and of them, 89 underwent upfront CN. The results did not contradict the supposition that CN does not improve ICT TD (hazard ratio [HR] 0.98, 95% confidence interval [CI] 0.65-1.47, p = 0.94) or OS from ICT initiation (HR 0.79, 95% CI 0.47-1.33, p = 0.37). In patients who underwent upfront CN compared with those who did not undergo CN, there was no association with ICT duration or OS (HR 0.61, 95% CI 0.35-1.06, p = 0.08). A detailed clinical summary of 49 patients with mRCC and rhabdoid dedifferentiation is provided.

CONCLUSIONS

In this multi-institutional cohort of mRCC with S/R dedifferentiation treated with ICT, CN was not significantly associated with improved TD or superior OS when accounting for the lead time bias. There appears to be a subset of patients who derive meaningful benefit from CN, so improved tools for stratification prior to CN are needed to optimize outcomes.

PATIENT SUMMARY

Immunotherapy has improved outcomes for patients with metastatic renal cell carcinoma (mRCC) who have sarcomatoid and/or rhabdoid (S/R) dedifferentiation, which is an aggressive and uncommon feature; yet, the utility of a nephrectomy in this setting is unclear. We found that nephrectomy did not significantly improve survival or time on immunotherapy for these patients with mRCC and S/R dedifferentiation; yet, there may be a subset of patients who benefit from this surgical approach.

Obesity and renal cell carcinoma: Biological mechanisms and perspectives

Obesity, defined by body mass index (BMI), is an established risk factor for specific renal cell carcinoma (RCC) subtypes such as clear cell RCC, the most common RCC histology. Many studies have identified an association between obesity and improved survival after diagnosis of RCC, a potential "obesity paradox." Clinically, there is uncertainty whether improved outcomes observed after diagnosis are driven by stage, type of treatment received, or artifacts of longitudinal changes in weight and body composition. The biological mechanisms underlying obesity's influence on RCC are not fully established, but multiomic and mechanistic studies suggest an impact on tumor metabolism, particularly fatty acid metabolism, angiogenesis, and peritumoral inflammation, which are known to be key biological hallmarks of clear cell RCC. Conversely, high-intensity exercise associated with increased muscle mass may be a risk factor for renal medullary carcinoma, a rare RCC subtype that predominantly occurs in individuals with sickle hemoglobinopathies. Herein, we highlight methodologic challenges associated with studying the influence of obesity on RCC and review the clinical evidence and potential underlying mechanisms associating RCC with BMI and body composition.

Development of Frail RISC-HIV: a Risk Score for Predicting Frailty Risk in the Short-term for Care of People with HIV

OBJECTIVE

Frailty is common among people with HIV (PWH), so we developed frail risk in the short-term for care (RISC)-HIV, a frailty prediction risk score for HIV clinical decision-making.

DESIGN

We followed PWH for up to 2 years to identify short-term predictors of becoming frail.

METHODS

We predicted frailty risk among PWH at seven HIV clinics across the United States. A modified self-reported Fried Phenotype captured frailty, including fatigue, weight loss, inactivity, and poor mobility. PWH without frailty were separated into training and validation sets and followed until becoming frail or 2 years. Bayesian Model Averaging (BMA) and five-fold-cross-validation Lasso regression selected predictors of frailty. Predictors were selected by BMA if they had a greater than 45% probability of being in the best model and by Lasso if they minimized mean squared error. We included age, sex, and variables selected by both BMA and Lasso in Frail RISC-HIV by associating incident frailty with each selected variable in Cox models. Frail RISC-HIV performance was assessed in the validation set by Harrell's C and lift plots.

RESULTS

Among 3170 PWH (training set), 7% developed frailty, whereas among 1510 PWH (validation set), 12% developed frailty. BMA and Lasso selected baseline frailty score, prescribed antidepressants, prescribed antiretroviral therapy, depressive symptomology, and current marijuana and illicit opioid use. Discrimination was acceptable in the validation set, with Harrell's C of 0.76 (95% confidence interval: 0.73-0.79) and sensitivity of 80% and specificity of 61% at a 5% frailty risk cutoff.

CONCLUSIONS

Frail RISC-HIV is a simple, easily implemented tool to assist in classifying PWH at risk for frailty in clinics.

Phase I study of sapanisertib with carboplatin and paclitaxel in mTOR pathway altered solid malignancies

Pre-clinically, the mTORC1/2 inhibitor sapanisertib restored sensitivity to platinums and enhanced paclitaxel-induced cancer cell killing. NCT03430882 enrolled patients with mTOR pathway aberrant tumors to receive sapanisertib, carboplatin and paclitaxel. Primary objective was safety and secondary objectives were clinical response and survival. One patient had a dose-limiting toxicity at dose level 4. There were no unanticipated toxicities. Grade 3-4 treatment-related adverse events included anemia (21%), neutropenia (21%), thrombocytopenia (10.5%), and transaminitis (5%). Of 17 patients evaluable for response, 2 and 11 patients achieved partial response and stable disease, respectively. Responders included a patient with unclassified renal cell carcinoma harboring EWSR1-POU5F1 fusion and a patient with castrate resistant prostate cancer harboring PTEN loss. Median progression free survival was 3.84 months. Sapanisertib in combination with carboplatin plus paclitaxel demonstrated a manageable safety profile, with preliminary antitumor activity observed in advanced malignancies harboring mTOR pathway alterations.

Cancer Cell-Extrinsic Roles for the Androgen Receptor in Prostate Cancer

Given the central role of the androgen receptor (AR) in prostate cancer cell biology, AR-targeted therapies have been the backbone of prostate cancer treatment for over 50 years. New data indicate that AR is expressed in additional cell types within the tumor microenvironment. Moreover, targeting AR for the treatment of prostate cancer has established side effects such as bone complications and an increased risk of developing cardiometabolic disease, indicating broader roles for AR. With the advent of novel technologies, such as single-cell approaches and advances in preclinical modeling, AR has been identified to have clinically significant functions in other cell types. In this mini-review, we describe new cancer cell-extrinsic roles for AR within the tumor microenvironment as well as systemic effects that collectively impact prostate cancer progression and patient outcomes.

Validity Properties of a Self-reported Modified Frailty Phenotype Among People With HIV in Clinical Care in the United States

ABSTRACT

Modifications to Fried's frailty phenotype (FFP) are common. We evaluated a self-reported modified frailty phenotype (Mod-FP) used among people with HIV (PWH). Among 522 PWH engaged in two longitudinal studies, we assessed validity of the four-item Mod-FP compared with the five-item FFP. We compared the phenotypes via receiver operator characteristic curves, agreement in classifying frailty, and criterion validity via association with having experienced falls. Mod-FP classified 8% of PWH as frail, whereas FFP classified 9%. The area under the receiver operator characteristic curve for Mod-FP classifying frailty was 0.93 (95% CI = 0.91-0.96). We observed kappa ranging from 0.64 (unweighted) to 0.75 (weighted) for categorizing frailty status. Both definitions found frailty associated with a greater odds of experiencing a fall; FFP estimated a slightly greater magnitude (i.e., OR) for the association than Mod-FP. The Mod-FP has good performance in measuring frailty among PWH and is reasonable to use when the gold standards of observed assessments (i.e., weakness and slowness) are not feasible.

Vaporized Nicotine (E-Cigarette) and Tobacco Smoking Among People With HIV: Use Patterns and Associations With Depression and Panic Symptoms

BACKGROUND

Vaporized nicotine (VN) use is increasing among people with HIV (PWH). We examined demographics, patterns of use, depression, and panic symptoms associated with VN and combustible cigarette (CC) use among PWH.

METHODS

We analyzed VN use among PWH in care at 7 US sites. PWH completed a set of patient-reported outcomes, including substance use and mental health. We categorized VN use as never vs. ever with the frequency of use (days/month) and CC use as never, former, or current. We used relative risk regression to associate VN and CC use, depression, and panic symptoms. Linear regression estimated each relationship with VN frequency. Models were adjusted for demographics.

RESULTS

Among 7431 PWH, 812 (11%) reported ever-using VN, and 264 (4%) reported daily use. Half (51%) of VN users concurrently used CC. VN users were more likely than those without use to be younger, to be White, and to report ever-using CC. PWH reporting former CC use reported ≥8.5 more days per month of VN use compared with never CC use [95% confidence interval (95% CI): 5.5 to 11.5 days/month] or current CC use (95% CI: 6.6 to 10.5 days/month). Depression (relative risk: 1.20 [95% CI: 1.02 to 1.42]) and panic disorder (1.71 [95% CI: 1.43 to 2.05]) were more common among PWH ever-using VN. Depression was common among PWH using VN (27%) and CC (22%), as was panic disorder (21% for VN and 16% for CC).

CONCLUSION

Our study elucidated demographic associations with VN use among PWH, revealed the overlap of VN and CC use, and associations with depression/panic symptoms, suggesting roles of VN in self-medication and CC substitution, warranting further longitudinal/qualitative research.

Immune Checkpoint Therapy Combinations in Adult Advanced MiT Family Translocation Renal Cell Carcinomas

BACKGROUND

There remains a paucity of data regarding the efficacy of immune checkpoint therapy (ICT) combinations ± vascular endothelial growth factor (VEGF) targeted therapy (TT) in translocation renal cell carcinoma (tRCC).

METHODS

This is a retrospective study of patients with advanced tRCC treated with ICT combinations at 11 centers in the US, France, and Belgium. Only cases with confirmed fluorescence in situ hybridization (FISH) were included. Objective response rates (ORR) and progression-free survival (PFS) were assessed by RECIST, and overall survival (OS) was estimated by Kaplan-Meier methods.

RESULTS

There were 29 patients identified with median age of 38 (21-70) years, and F:M ratio 0.9:1. FISH revealed TFE3 and TFEB translocations in 22 and 7 patients, respectively. Dual ICT and ICT + VEGF TT were used in 18 and 11 patients, respectively. Seventeen (59%) patients received ICT combinations as first-line therapy. ORR was 1/18 (5.5%) for dual ICT and 4/11 (36%) for ICT + VEGF TT. At a median follow-up of 12.9 months, median PFS was 2.8 and 5.4 months in the dual ICT and ICT + VEGF TT groups, respectively. Median OS from metastatic disease was 17.8 and 30.7 months in the dual ICT and ICT + VEGF TT groups, respectively.

CONCLUSION

In this retrospective study of advanced tRCC, limited response and survival were seen after frontline dual ICT combination therapy, while ICT + VEGF TT therapy offered some efficacy. Due to the heterogeneity of tRCC, insights into the biological underpinnings are necessary to develop more effective therapies.

Obesity Is Associated with Altered Tumor Metabolism in Metastatic Melanoma

PURPOSE

Overweight/obese (OW/OB) patients with metastatic melanoma unexpectedly have improved outcomes with immune checkpoint inhibitors (ICI) and BRAF-targeted therapies. The mechanism(s) underlying this association remain unclear, thus we assessed the integrated molecular, metabolic, and immune profile of tumors, as well as gut microbiome features, for associations with patient body mass index (BMI).

EXPERIMENTAL DESIGN

Associations between BMI [normal (NL < 25) or OW/OB (BMI ≥ 25)] and tumor or microbiome characteristics were examined in specimens from 782 patients with metastatic melanoma across 7 cohorts. DNA associations were evaluated in The Cancer Genome Atlas cohort. RNA sequencing from 4 cohorts (n = 357) was batch corrected and gene set enrichment analysis (GSEA) by BMI category was performed. Metabolic profiling was conducted in a subset of patients (x = 36) by LC/MS, and in flow-sorted melanoma tumor cells (x = 37) and patient-derived melanoma cell lines (x = 17) using the Seahorse XF assay. Gut microbiome features were examined in an independent cohort (n = 371).

RESULTS

DNA mutations and copy number variations were not associated with BMI. GSEA demonstrated that tumors from OW/OB patients were metabolically quiescent, with downregulation of oxidative phosphorylation and multiple other metabolic pathways. Direct metabolite analysis and functional metabolic profiling confirmed decreased central carbon metabolism in OW/OB metastatic melanoma tumors and patient-derived cell lines. The overall structure, diversity, and taxonomy of the fecal microbiome did not differ by BMI.

CONCLUSIONS

These findings suggest that the host metabolic phenotype influences melanoma metabolism and provide insight into the improved outcomes observed in OW/OB patients with metastatic melanoma treated with ICIs and targeted therapies. See related commentary by Smalley, p. 5.

Efficacy of Cabozantinib in Metastatic MiT Family Translocation Renal Cell Carcinomas

BACKGROUND

MiT family translocation renal cell carcinoma (TRCC) is a rare and aggressive subgroup of renal cell carcinoma harboring high expression of c-MET. While TRCC response rates to VEGF receptor tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors are limited, efficacy of cabozantinib (a VEGFR, MET, and AXL inhibitor) in this subgroup is unclear.

METHODS

We performed a multicenter, retrospective, international cohort study of patients with TRCC treated with cabozantinib. The main objectives were to estimate response rate according to RECIST 1.1 and to analyze progression-free survival (PFS) and overall survival (OS).

RESULTS

Fifty-two patients with metastatic TRCC treated in the participating centers and evaluable for response were included. Median age at metastatic diagnosis was 40 years (IQR 28.5-53). Patients' IMDC risk groups at diagnosis were favorable (9/52), intermediate (35/52), and poor (8/52). Eleven (21.2%) patients received cabozantinib as frontline therapy, 15 (28.8%) at second line, and 26 (50%) at third line and beyond. The proportion of patients who achieved an objective response was 17.3%, including 2 complete responses and 7 partial responses. For 26 (50%) patients, stable disease was the best response. With a median follow-up of 25.1 months (IQR 12.6-39), median PFS was 6.8 months (95%CI 4.6-16.3) and median OS was 18.3 months (95%CI 17.0-30.6). No difference of response was identified according to fusion transcript features.

CONCLUSION

This real-world study provides evidence of the activity of cabozantinib in TRCC, with more durable responses than those observed historically with other VEGFR-TKIs or ICIs.

External Validation of Association of Baseline Circulating Tumor Cell Counts with Survival Outcomes in Men with Metastatic Castration-Sensitive Prostate Cancer

Approximately 20% of men with metastatic castration-sensitive prostate cancer (mCSPC) progress within 1 year of treatment, and biomarkers to identify them up front are lacking. In a randomized phase III trial in men with mCSPC (SWOG S1216), higher baseline circulating tumor cells (CTCs) were prognostic of inferior outcomes. We aimed to validate these findings and interrogate corresponding tumor genomic profiles. Consecutively seen men with newly diagnosed mCSPC undergoing systemic therapy and baseline CTC enumeration by CellSearch assay were included. Gene alterations were determined by comprehensive genomic profiling of tumor tissue by Clinical Laboratory Improvement Amendments-certified lab. The relationship between categorized CTC counts and both progression-free survival (PFS) and overall survival (OS) was assessed in the context of Cox proportional hazards models, both unadjusted and adjusted for age, Gleason score, PSA at androgen-deprivation therapy initiation, disease volume, de novo status, treatment intensification, and number of altered genes. Overall, 103 patients were included in the analysis. On multivariate analysis high CTCs (≥ 5 vs. 0) were associated with poorer PFS [HR, 4.52; 95% confidence interval (CI), 1.84-11.11; P = 0.001) and OS (HR, 3.59; 95% CI, 0.95-13.57; P = 0.060). Patients with higher CTC counts had a greater number of altered genes and total number of alterations (all P < 0.02). In this article, for the first time, we externally validate the association of higher CTC counts with inferior survival outcomes in men with mCSPC and show a distinct associated tumor genomic landscape. These findings may improve prognostication, patient counseling, and treatment selection in men with mCSPC.

Associations between drug and alcohol use, smoking, and frailty among people with HIV across the United States in the current era of antiretroviral treatment

OBJECTIVE

To examine associations between frailty and drug, alcohol, and tobacco use among a large diverse cohort of people with HIV (PWH) in clinical care in the current era.

METHODS

PWH at 7 sites across the United States completed clinical assessments of patient-reported measures and outcomes between 2016 and 2019 as part of routine care including drug and alcohol use, smoking, and other domains. Frailty was assessed using 4 of the 5 components of the Fried frailty phenotype and PWH were categorized as not frail, pre-frail, or frail. Associations of substance use with frailty were assessed with multivariate Poisson regression.

RESULTS

Among 9336 PWH, 43% were not frail, 44% were prefrail, and 13% were frail. Frailty was more prevalent among women, older PWH, and those reporting current use of drugs or cigarettes. Current methamphetamine use (1.26: 95% CI 1.07-1.48), current (1.65: 95% CI 1.39-1.97) and former (1.21:95% CI 1.06-1.36) illicit opioid use, and former cocaine/crack use (1.17: 95% CI 1.01-1.35) were associated with greater risk of being frail in adjusted analyses. Current smoking was associated with a 61% higher risk of being frail vs. not frail (1.61: 95% CI 1.41-1.85) in adjusted analyses.

CONCLUSIONS

We found a high prevalence of prefrailty and frailty among a nationally distributed cohort of PWH in care. This study identified distinct risk factors that may be associated with frailty among PWH, many of which, such as cigarette smoking and drug use, are potentially modifiable.

The significance of sarcomatoid and rhabdoid dedifferentiation in renal cell carcinoma

Dedifferentiation in renal cell carcinoma (RCC), either sarcomatoid or rhabdoid, is an infrequent event that may occur heterogeneously in the setting of any RCC histology and is associated with poor outcomes. Sarcomatoid dedifferentiation is associated with inferior survival with angiogenesis targeted therapy and infrequent responses to cytotoxic chemotherapy. However, immune checkpoint therapy has significantly improved outcomes for patients with sarcomatoid dedifferentiation. Biologically, sarcomatoid dedifferentiation has increased programmed death-ligand 1 (PD-L1) expression and an inflamed tumor microenvironment, in addition to other distinct molecular alterations. Less is known about rhabdoid dedifferentiation from either a clinical, biological, or therapeutic perspective. In this focused review, we will discuss the prognostic implications, outcomes with systemic therapy, and underlying biology in RCC with either sarcomatoid or rhabdoid dedifferentiation present.

Missing the trees for the forest: most subgroup analyses using forest plots at the ASCO annual meeting are inconclusive

Background:

Oncologists often refer to forest plots to determine which patient subgroups may be more likely to benefit from a therapy tested in a randomized clinical trial (RCT). We sought to empirically determine the information content of subgroup comparisons from forest plots of RCTs.

Methods:

We assessed all forest plots from RCTs of therapeutic interventions presented orally at the American Society of Clinical Oncology Annual Meetings in 2020 and 2021. Subgroups were considered as showing evidence of treatment effect heterogeneity in forest plots when their confidence intervals (CIs) did not overlap with the vertical line corresponding to the main effect observed in the overall RCT cohort. Subgroups were considered as showing evidence of treatment effect homogeneity in forest plots when their CIs did not meaningfully differ, within 80–125% equivalence range, with the values compatible with the main effect. All other subgroups were considered as inconclusive.

Results:

A total of 99 forest plots were presented, and only 24.2% contained one or more subgroups suggestive of treatment effect heterogeneity. A total of 81 forest plots provided enough information to evaluate treatment effect heterogeneity and homogeneity. These 81 forest plots represented a total of 1344 individual subgroups, of which 57.2% were inconclusive, 41.1% showed evidence of treatment effect homogeneity, and 1.6% yielded evidence suggestive of treatment effect heterogeneity.

Conclusion:

The majority of subgroup comparisons were inconclusive in this empirical analysis of forest plots used in oncology RCTs. Different strategies should be considered to improve the estimation and representation of subgroup-specific effects.

First-Line Immuno-Oncology Combinations for Metastatic Clear Cell Renal Cell Carcinoma (mRCC): A Systematic Review of Phase III Clinical Trials

BACKGROUND: The introduction of immune checkpoint inhibitors rapidly changed treatment for patients with metastatic clear cell renal cell carcinoma (mRCC). First-line treatment now includes multiple immuno-oncology (IO) combinations that were approved over a short time period and were not directly compared in randomized clinical trials. Thus, clinicians face a challenge in individualizing first-line treatment to optimize clinical outcomes. OBJECTIVE: We sought to systematically review clinical outcomes for first-line IO combinations for patients with mRCC. METHODS: Literature reporting outcomes from phase III clinical trials that evaluated first-line IO combination therapies was identified through a search of the PubMed electronic database following PRISMA guidelines. Abstracts were screened to identify manuscripts that fit the search criteria, and then, a descriptive review was performed. RESULTS: Our literature search identified 2,229 abstracts that met the initial search criteria, and then, it was narrowed to 431 abstracts using filters for “clinical trial” and a “ten year” time window. After review of the abstracts, six manuscripts were selected for data extraction and subsequent review. CONCLUSION: When compared to sunitinib, four IO combinations improved overall survival as first-line treatment, and five improved progression free survival for patients with mRCC. These IO combination therapies have unique characteristics, so clinicians should take into account patient and cancer factors to individualize treatment recommendations.

Abstract P041: Initial results from a phase 1b study of ORIC-101, a glucocorticoid receptor antagonist, in combination with enzalutamide in patients with metastatic prostate cancer

Background: Upregulation of the glucocorticoid receptor (GR) is a potential mechanism of resistance to enzalutamide and other androgen receptor (AR) modulators in prostate cancer. Preclinical studies have demonstrated that GR activation can bypass enzalutamide-mediated AR inhibition and support prostate cancer cell growth. Overexpression of GR is associated with poor outcomes in castration-resistant prostate cancer patients (CRPC) treated with enzalutamide. ORIC-101 is a potent and selective orally bioavailable, small molecule antagonist of GR. Mechanistically, ORIC-101 inhibits GR transcriptional activity and blocks the pro-survival signals mediated by the activated nuclear hormone receptor. Methods: A modified interval 3+3 (i3+3) design was used to assess safety, pharmacokinetics (PK), and pharmacodynamics (PD) to select the Recommended Phase 2 Dose (RP2D) of ORIC-101 in combination with enzalutamide in patients with metastatic CRPC progressing on enzalutamide 160 mg, dosed once daily (NCT04033328). ORIC-101, at doses ranging from 80 to 240 mg once daily, given in a continuous dosing regimen, was added to enzalutamide at the time of disease progression. Plasma PK and PD biomarkers were assessed on multiple days and times before and after dosing. PD modulation in blood-derived peripheral blood mononuclear cells (PBMCs) was assessed by RT-qPCR for GR target genes. Antitumor activity was assessed by Prostate Cancer Clinical Trials Working Group 3 (PCWG3) and RECIST 1.1. Results: 10 patients were treated in 3 cohorts in the dose escalation portion of the study. ORIC-101 exposure increased with dose and no drug-drug interaction (DDI) was observed that necessitated reduction from the standard enzalutamide dose of 160 mg. No dose limiting toxicities were observed at any dose level. Based upon plasma exposure and PD modulation, the RP2D was established as 240 mg ORIC-101 plus 160 mg enzalutamide, both dosed once daily continuously in 28-day cycles. All adverse events (AEs) were Grade 1 or 2 with the most common (&gt;15%), treatment-related AEs being fatigue (40%), nausea (30%), constipation (20%), decreased appetite (20%), high aspartate aminotransferase (20%), high alkaline phosphatase (20%), and headache (20%). There were no Grade ≥3 treatment-related AEs. Biomarker data demonstrated ORIC-101 induced reduction in GR target gene expression in PBMCs, indicating PD modulation across dose levels of ORIC-101. Data will be updated at the time of the presentation. Conclusions: Preliminary evidence suggests that ORIC-101 effectively modulates GR and has an acceptable tolerability profile when combined with enzalutamide. Dose expansion is ongoing at the RP2D.

Citation Format: Wassim Abida, Neeraj Agarwal, Andrew W. Hahn, Neal Shore, Paul Sieber, Tanya Dorff, Mathew Rettig, Mathew Smith, Paul Monk, Rongda Xu, Ann Johnson, Anneleen Daemen, Edna Chow Maneval, Pratik S. Multani, Rupal Patel, Michael J. Morris. Initial results from a phase 1b study of ORIC-101, a glucocorticoid receptor antagonist, in combination with enzalutamide in patients with metastatic prostate cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P041.

Drug and alcohol use among people living with HIV in care in the United States by geographic region

Substance use in the U.S. varies by geographic region. Opioid prescribing practices and marijuana, heroin, and methamphetamine availability are evolving differently across regions. We examined self-reported substance use among people living with HIV (PLWH) in care at seven sites from 2017-2019 to understand current regional substance use patterns. We calculated the percentage and standardized percentage of PLWH reporting current drug use and at-risk and binge alcohol use by U.S. Census Bureau geographic region and examined associations in adjusted logistic regression analyses. Among 7,686 PLWH, marijuana use was the most prevalent drug (30%), followed by methamphetamine/crystal (8%), cocaine/crack (7%), and illicit opioids (3%). One-third reported binge alcohol use (32%). Differences in percent of current use by region were seen for marijuana (24-41%) and methamphetamine/crystal (2-15%), with more use in the West and Northeast, and binge alcohol use (26-40%). In adjusted analyses, PLWH in the Midwest were significantly less likely to use methamphetamine/crystal (aOR: 0.13;0.06-0.25) or illicit opioids (aOR:0.16;0.05-0.53), and PLWH in the Northeast were more likely to use cocaine/crack (aOR:1.59;1.16-2.17), compared to PLWH in the West. Understanding differences in substance use patterns in the current era, as policies continue to evolve, will enable more targeted interventions in clinical settings among PLWH.

An Evolving Role for AXL in Metastatic Renal Cell Carcinoma

High tumoral expression of AXL was associated with inferior response to anti-PD-1 therapy and increased tumoral programmed death ligand 1 (PD-L1) expression in patients with metastatic renal cell carcinoma, with particularly poor outcomes in those with high AXL and PD-L1. AXL expression has potential as a biomarker and therapeutic target.See related article by Terry et al., p. xxx.

Radium-223 plus Enzalutamide Versus Enzalutamide in Metastatic Castration-Refractory Prostate Cancer: Final Safety and Efficacy Results

LESSONS LEARNED

Long-term safety of radium-223 with enzalutamide was confirmed in this clinical trial. PSA-PFS2 was prolonged with the combination compared with enzalutamide alone.

BACKGROUND

Previously, we showed the combination of radium-223 and enzalutamide to be safe and associated with improved efficacy based on a concomitant decline in serum bone metabolism markers compared with enzalutamide alone in a phase II trial of men with metastatic castration-resistant prostate cancer (mCRPC) [1].

METHODS

Secondary endpoints were not included in our initial report, and we include them herein, after a median follow-up of 22 months. These objectives included long-term safety, prostate-specific antigen (PSA)-progression-free survival (PFS), and radiographic progression-free survival; PSA-PFS2 (time from start of protocol therapy to PSA progression on subsequent therapy); time to next therapy (TTNT); and overall survival (OS). Survival analysis and log-rank tests were performed using the R statistical package v.4.0.2 (https://www.r-project.org). Statistical significance was defined as p < .05.

RESULTS

Of 47 patients (median age, 68 years), 35 received the combination and 12 enzalutamide alone. After a median follow-up of 22 months, final safety results did not show any increase in fractures or other adverse events in the combination arm. PSA-PFS2 was significantly improved, and other efficacy parameters were numerically improved in the combination over the enzalutamide arm.

CONCLUSION

The combination of enzalutamide and radium-223 was found to be safe and associated with promising efficacy in men with mCRPC. These hypothesis-generating results portend well for the ongoing phase III PEACE III trial in this setting.

Validation of Prognostic Scores in Patients With Metastatic Urothelial Cancer Enrolling in Phase I Targeted Therapy or Next Generation Immunotherapy Trials

INTRODUCTION

Enrolling patients with metastatic urothelial carcinoma (mUC) in phase I trials provides an opportunity to identify biological drug activity. Developing prognostic scores may aid in patient selection for phase 1 trials.

PATIENTS AND METHODS

We analyzed records of patients with mUC who participated in targeted therapy and immunotherapy phase I clinical trials at MD Anderson Cancer Center (MDACC). The Bellmunt and Bajorin scores were calculated as bladder cancer-specific prognostic scores. The Royal Marsden Hospital (RMH) and MDACC scores were calculated as phase I prognostic scores. Hazard ratios (HR) were calculated using the Cox proportional hazard model. The prognostic value of the Bellmunt, Bajorin, RMH, and MDACC scores were assessed using the Likelihood ratio (LR) χ2 test and the c-index.

RESULTS

Between 2015 and 2019, 43 patients were enrolled in phase I trials and 12 were enrolled in >I trial leading to a total of 57 trial participants (TPs). Ninty-seven percent of TPs received prior platinum therapy and 60% received a prior checkpoint inhibitor. Median overall survival (OS) and progression-free survival (PFS) were significantly shorter with increasing Bajorin, RMH, or MDACC scores, but not with increasing Bellmunt score. The RMH (c-index=0.658, LR χ2=11.8, P=.008) and MDACC scores (c-index =0.66, LR χ2=12.76, P=.01) outperformed the Bajorin score (c-index=0.522, LR χ2=1.22, P=.5) and the Bellmunt score (c-index=0.537, LR χ2=0.36, P=.9) in predicting overall survivalover. The Bajorin, RMH, and MDACC scores, but not the Bellmunt score, were also predictive of progression-free survival (PFS)prog. The RMH and MDACC scores again outperformed the Bajorin scoreand the Bellmunt score for predicting PFS.

CONCLUSION

The RMH and MDACC phase I prognostic scores accurately predicted survival in patients with mUC and outperformed the bladder cancer-specific scores at time of enrollment on phase 1 clinical trials. The RMH and MDACC scores could optimize selection of patients with mUC for phase I clinical trials.

Identification of Somatic Gene Signatures in Circulating Cell-Free DNA Associated with Disease Progression in Metastatic Prostate Cancer by a Novel Machine Learning Platform

PURPOSE

Progression from metastatic castration-sensitive prostate cancer (mCSPC) to a castration-resistant (mCRPC) state heralds the lethal phenotype of prostate cancer. Identifying genomic alterations associated with mCRPC may help find new targets for drug development. In the majority of patients, obtaining a tumor biopsy is challenging because of the predominance of bone-only metastasis. In this study, we hypothesize that machine learning (ML) algorithms can identify clinically relevant patterns of genomic alterations (GAs) that distinguish mCRPC from mCSPC, as assessed by next-generation sequencing (NGS) of circulating cell-free DNA (cfDNA).

EXPERIMENTAL DESIGN

Retrospective clinical data from men with metastatic prostate cancer were collected. Men with NGS of cfDNA performed at a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory at time of diagnosis of mCSPC or mCRPC were included. A combination of supervised and unsupervised ML algorithms was used to obtain biologically interpretable, potentially actionable insights into genomic signatures that distinguish mCRPC from mCSPC.

RESULTS

GAs that distinguish patients with mCRPC (n = 187) from patients with mCSPC (n = 154) (positive predictive value = 94%, specificity = 91%) were identified using supervised ML algorithms. These GAs, primarily amplifications, corresponded to androgen receptor, Mitogen-activated protein kinase (MAPK) signaling, Phosphoinositide 3-kinase (PI3K) signaling, G1/S cell cycle, and receptor tyrosine kinases. We also identified recurrent patterns of gene- and pathway-level alterations associated with mCRPC by using Bayesian networks, an unsupervised machine learning algorithm.

CONCLUSION

These results provide clinical evidence that progression from mCSPC to mCRPC is associated with stereotyped concomitant gain-of-function aberrations in these pathways. Furthermore, detection of these aberrations in cfDNA may overcome the challenges associated with obtaining tumor bone biopsies and allow contemporary investigation of combinatorial therapies that target these aberrations.

IMPLICATIONS FOR PRACTICE

The progression from castration-sensitive to castration-resistant prostate cancer is characterized by worse prognosis and there is a pressing need for targeted drugs to prevent or delay this transition. This study used machine learning algorithms to examine the cell-free DNA of patients to identify alterations to specific pathways and genes associated with progression. Detection of these alterations in cell-free DNA may overcome the challenges associated with obtaining tumor bone biopsies and allow contemporary investigation of combinatorial therapies that target these aberrations.

Abstract LB208: Obesity is associated with lower tumor oxidative phosphorylation (OXPhos) in metastatic melanoma (MM)

Immune checkpoint inhibitors (ICI) and BRAF targeted therapies improve overall survival (OS) for patients (pts) with MM, but treatment responses are heterogeneous. Recent data strongly implicates host factors in response and resistance to these agents. We and others have shown that overweight/obese BMI [OW/OB: body mass index (BMI≥25)] is associated with improved OS with both ICI and BRAF targeted therapies in MM pts. The biologic basis for this association is unknown. Thus, we examined the molecular and immune correlates of BMI in MM. In melanoma TCGA regionally metastatic specimens with available BMI (n=202), BMI was not associated with DNA mutations or copy number variations, nor with protein expression. To assess for associations with gene expression, we performed a gene set enrichment analysis (GSEA) on pooled data for cohorts of MM patients with RNAseq and BMI data (TCGA, n=202; MDACC, n=61; MIA, n=68; UCLA, n=26). Following batch correction, GSEA identified downregulation of OXPHOS and adipogenesis in tumors from OW/OB pts compared to normal (NL) BMI (BMI&lt;25). Mass spectrometry of 36 MM specimens from the TCGA cohort confirmed downregulation of the TCA cycle intermediates citrate (p=0.01) and succinate (p&lt;0.05) in OW/OB MM. Immunohistochemistry for key immune cell populations and checkpoints in the MIA and MDACC cohorts did not identify significant differences by BMI, consistent with the lack of difference in inflammatory pathways by gene expression. Finally, we evaluated associations of BMI with gut microbiome features in MM pts (n=272). OW/OB was associated with lower microbial alpha diversity vs. NL BMI (p=0.02), but no significant differences were observed in the composition of individual species. As increased microbiome diversity has been associated with improved outcomes with ICI in MM, this finding supports that changes in the microbiome are unlikely to explain the improved outcomes seen with ICI in OW/OB pts. In sum, our findings suggest that host energy balance influences tumor metabolism in MM, with downregulation of OXPHOS in MM from OB/OW pts, which may influence outcomes with targeted and immune therapies. These hypothesis generating findings suggest one possible mechanism underlying the obesity paradox observed in MM pts.

Citation Format: Andrew W. Hahn, Mingchu Xu, Jun Li, Lauren E. Haydu, M.A. Wadud Khan, Tuba N. Gide, Alexander M. Menzies, Courtney W. Hudgens, Theodore S. Nowicki, Jeffrey E. Gershenwald, Antoni Ribas, Michael T. Tetzlaff, Alexander J. Lazar, James Willmott, Jennifer Wargo, Andrew Futreal, Jianhua Zhang, Michael A. Davies, Jennifer L. McQuade. Obesity is associated with lower tumor oxidative phosphorylation (OXPhos) in metastatic melanoma (MM) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB208.

Lenvatinib with or Without Everolimus in Patients with Metastatic Renal Cell Carcinoma After Immune Checkpoint Inhibitors and Vascular Endothelial Growth Factor Receptor-Tyrosine Kinase Inhibitor Therapies

INTRODUCTION

Lenvatinib (Len) plus everolimus (Eve) is an approved therapy for metastatic renal cell carcinoma (mRCC) after first-line vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs), but limited data exist on the efficacy of Len ± Eve after progression on immune checkpoint inhibitors (ICIs) and VEGFR-TKIs.

METHODS

We retrospectively reviewed the records of patients with mRCC at our institution who were treated with Len ± Eve after ICI and VEGFR-TKI. A blinded radiologist assessed objective response as defined by RECIST version 1.1. Descriptive statistics and the Kaplan-Meier method were used.

RESULTS

Fifty-five patients were included in the analysis. Of these patients, 81.8% had clear-cell histology (ccRCC), and 76.4% had International Metastatic RCC Database Consortium intermediate-risk disease. Median number of prior therapies was four (range, 2-10); all patients had prior ICIs and VEGFR-TKIs, and 80% were previously treated with ICI and at least two VEGFR-TKIs, including cabozantinib. One patient (1.8%) achieved a complete response, and 11 patients (20.0%) achieved a partial response, for an overall response rate (ORR) of 21.8%; 35 patients (63.6%) achieved stable disease. In all patients, median progression-free survival (PFS) was 6.2 months (95% confidence interval [CI], 4.8-9.4) and median overall survival (OS) was 12.1 months (95% CI, 8.8-16.0). In patients with ccRCC, ORR was 24.4%, PFS was 7.1 months (95% CI, 5.0-10.5), and OS was 11.7 months (95% CI, 7.9-16.1). 50.9% of patients required dose reductions and 7.3% discontinued treatment because of toxicity.

CONCLUSION

Len ± Eve demonstrated meaningful clinical activity and tolerability in heavily pretreated patients with mRCC after disease progression with prior ICIs and VEGFR-TKIs.

IMPLICATIONS FOR PRACTICE

As the therapeutic landscape for patients with metastatic renal cell carcinoma continues to evolve, this single-center, retrospective review highlights the real-world efficacy of lenvatinib with or without everolimus in heavily pretreated patients. This article supports the use of lenvatinib with or without everolimus as a viable salvage strategy for patients whose disease progresses after treatment with immune checkpoint inhibitors and vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapies, including cabozantinib.

Molecular Profiling of Metastatic Bladder Cancer Early-Phase Clinical Trial Participants Predicts Patient Outcomes

Prognosis for patients with metastatic bladder carcinoma (mBC) remains limited and in need of novel therapies. We retrospectively analyzed medical records of 43 patients with platinum-refractory metastatic bladder cancer (mBC) who participated in one or more phase I trials of various investigational therapies. Patients' tumors or circulating tumor DNA were analyzed by next-generation sequencing. The median progression-free survival was 4.2 months, the median overall survival was 9.6 months, and the overall response rate was 17.5%. TP53, ERBB2, PI3KCA, FGFR3, and ARID1A alterations were detected in 66%, 29%, 27%, 24%, and 22% of all patients, respectively. Alterations in FGFR3 were almost mutually exclusive of TP53. More than half (64%) of patients with an FGFR alt received an FGFR inhibitor, 67% of which achieved disease control. Among patients with urothelial carcinoma histology, those harboring a TP53 alteration had a shorter median progression-free survival (PFS) compared with those whose tumors carry wild-type TP53. The reverse relationship was observed in patients harboring an FGFR alteration. IMPLICATIONS: Patients with platinum-refractory mBC derive clinical benefit from participating in early-phase clinical trials and their survival outcomes correlate with the genetic profile of the tumor. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/3/395/F1.large.jpg.

Validation of prognostic scoring systems for patients with metastatic renal cell carcinoma enrolled in phase I clinical trials

BACKGROUND

For patients with metastatic renal cell carcinoma (mRCC) who progress on standard-of-care therapies, there is an unmet need for novel treatments. Phase I clinical trials are designed to test the safety, toxicity and optimal dosing of novel agents. Herein, we analysed the outcomes of patients with mRCC enrolled in phase I trials and assess the utility of prognostic scores.

METHODS

Patients with all histologies of mRCC were included if they received treatment on a phase I clinical trial at MD Anderson Cancer Center (MDACC). Survival outcomes were calculated using Cox proportional hazard model. Prognostic value of the International Metastatic RCC Database Consortium (IMDC), Royal Marsden Hospital (RMH) and MDACC scores was assessed using the likelihood ratio (LR) χ² test and the c-index.

RESULTS

Among 82 patients with mRCC who received treatment, 21 patients participated in more than one trial, resulting in 106 trial participants (TP). Median prior therapies was two. For all TPs, median overall survival (OS) was 31.2 months, progression-free survival (PFS) was 5.9 months and objective response rate was 22%. Median OS and PFS were significantly shorter with increasing IMDC, RMH and MDACC scores. The RMH and MDACC scores outperformed the IMDC score for predicting OS (RMH LR χ²=8.64; MDACC LR χ²=7.74; IMDC LR χ²=2.36) and PFS (RMH LR χ²=17.5; MDACC LR χ²=20.3; IMDC LR χ²=4.28).

CONCLUSIONS

The RMH and MDACC prognostic scores can be used to predict OS for patients with mRCC in phase I trials and may guide patient selection. Patients with mRCC should be considered for phase I trials.

Circulating-tumor DNA as predictor of enzalutamide response post-abiraterone treatment in metastatic castration-resistant prostate cancer

BACKGROUND

The crossover from abiraterone acetate (AA) to enzalutamide (ENZA) is a frequent approach in clinical practice. Our aim was to explore the role of genomic alterations as putative biomarkers of response to sequential AA followed by ENZA in mCRPC and their association with clinical outcomes.

PATIENTS AND METHODS

This was a multi-center, retrospective analysis of mCRPC patients with circulating-tumor DNA (ctDNA) post-AA and prior to ENZA treatment. Objectives of this analysis were to assess PSA response, time to PSA progression (TTP) and overall survival (OS) in mCRPC patients treated with ENZA following progression on AA with respect to genomic aberrations detected by ctDNA.

RESULTS

A total of 28 patients with mCRPC were identified. Median time between AA and ENZA was 3.1 months and median initial PSA prior to ENZA was 35.0 ng/mL. Nine patients (32.1%) achieved PSA responses to ENZA. Most patients (79.0%) achieved confirmed PSA progression with median TTP of 1.6 months (95% CI, 0.7-2.4). Somatic alterations in AR genes were detected in 36.0% of patients with other common alterations detected including 39.0% TP53, 11.0% DNA repair, and 11.0% PTEN. A lack of AR alterations was associated with better PSA response to ENZA (p = 0.04).

CONCLUSION

While lack of AR alterations in ctDNA was associated with more favorable outcomes, the present dataset is insufficient to recommend the use of ctDNA to impact clinical decision-making in this setting. Further understanding of the implications of the genomic phenotype in ctDNA of castration-resistant tumors and the potential therapeutic implications is required.

Association of SPOP Mutations with Outcomes in Men with De Novo Metastatic Castration-sensitive Prostate Cancer

Recently, mutations in speckle-type pox virus and zinc finger protein (SPOP) gene (mutant SPOP [mtSPOP]) have been associated with improved outcomes to abiraterone in the castration-resistant setting. We hypothesized that mtSPOP would be associated with improved outcomes to systemic therapy in men with de novo metastatic castration-sensitive prostate cancer (d-mCSPC). Retrospective data of newly diagnosed d-mCSPC patients were collected from four institutions. Eligibility criteria included standard androgen deprivation therapy without intensification, and SPOP mutational status (mtSPOP or wild-type SPOP [wtSPOP]) determination by targeted next-generation sequencing from tumor biopsies. A total of 121 men (25 mtSPOP [21%] and 96 wtSPOP [79%]) were included. After adjusting for covariates, mtSPOP was significantly associated with better median progression-free survival (35 vs 13 mo; adjusted hazard ratio [HR] 0.47; p =  0.016) and overall survival (97 vs 69 mo; adjusted HR 0.32; p =  0.027), with similar HR and p value on the univariate analysis. These findings, upon external validation, may assist with counseling and prognostication in the clinic, and inform the design of future clinical trials in this setting. PATIENT SUMMARY: : Presence of tumor mutation in speckle-type pox virus and zinc finger protein (SPOP) gene was associated with improved survival outcomes in men with de novo metastatic castration-sensitive prostate cancer receiving standard androgen deprivation therapy.

Phase I clinical trials as a therapeutic option for patients with metastatic renal cell carcinoma (mRCC)

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Background: Immune checkpoint inhibitors, multi-kinase VEGF agents, and mTOR inhibitors are approved for mRCC. Due to the overlapping mechanisms of action of the twelve approved therapies for mRCC, select patients are referred for phase I clinical trials after progression on multiple lines of treatment. We sought to evaluate the efficacy of phase I trials in patients with mRCC. Methods: Patients with all histologies of mRCC were included if they received treatment on a phase I clinical trial at MD Anderson Cancer Center. Baseline clinical characteristics and outcomes data were retrospectively collected. The historical control was a study of 1112 patients with mRCC who received third-line treatment in the IMDC database (PMID: 27318422). Time to event endpoints were calculated using Kaplan-Meier methods. Hazard ratios (HR) were calculated using the Cox proportional hazard model. Results: Between 2014 and 2019, there were 106 cases where 82 patients with mRCC were enrolled in a phase I clinical trials (40 unique trials). 30% (32/108) of the cases were in patients with non-clear cell RCC (nccRCC), and the most prevalent nccRCC histologies were papillary (n = 7) and renal medullary carcinoma (n = 7). The median number of prior systemic therapies was 2 (range 0-9). Across the entire cohort, median PFS was 5.9 months (m), median OS was 31.2 m, and the ORR was 23% (Table). In patients who received at least two prior lines of therapy (n = 70), the median PFS was 4.8 m and median OS was 24.9 m. In patients with metastatic nccRCC, median OS, PFS, and ORR were numerically lower, but statistically did not contradict the supposition that these outcomes did not differ from ccRCC (Table). Conclusions: In the largest pooled phase I clinical trial experience for patients with mRCC, phase I trials may have therapeutic value when compared to historical controls, where median PFS was 3.9 m, median OS was 12.4 m, and ORR was 10.5%. Patients with all histologies of mRCC may derive clinical benefit from phase I clinical trials, yet patients with ccRCC had numerically better outcomes. Patients with mRCC should be considered for phase I clinical trials. [Table: see text]

Genomic alterations associated with the progression from castration-sensitive to castration-resistant metastatic prostate cancer based on machine learning analysis of cell-free DNA genomic profile

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Background: Metastatic castration-sensitive prostate cancer (mCSPC) eventually progresses to metastatic castration-resistant prostate cancer (mCRPC), which has few treatment options and carries a poor prognosis. We hypothesize that there are specific genomic alterations (GAs) associated with the progression from mCSPC to mCRPC. Methods: Patients (Pts) with mCSPC and mCRPC undergoing next-generation sequencing of cell-free DNA by a CLIA certified lab (G360, Guardant Health Inc., Redwood City, CA) as a part of routine care were retrospectively identified. Principal components analysis, an unsupervised ML algorithm, was used for data exploration and visualization. A combination of feature selection and supervised machine learning classification algorithms were used to identify genes associated with mCRPC. Gene Ontology enrichment analysis was used to identify pathways enriched for mCRPC-associated GAs. Patterns of mCRPC-associated GAs at a gene- and pathway-level were identified by Bayesian networks fitted using an exact structure learning algorithm. Results: 154 Pts with mCSPC and 187 Pts with mCRPC were included. A set of 16 GAs that robustly distinguished mCRPC from mCSPC (PPV = 94%, specificity = 91%) using supervised machine learning algorithms. These GAs, primarily amplifications, corresponded to AR, MAPK signaling, PI3K signaling, G1/S cell cycle, and receptor tyrosine kinases (RTKs). Positive statistical dependencies were observed between genes in these pathways. At a pathway-level, the presence of G1/S GAs in mCRPC samples increased the likelihood of harboring GAs in RTK, MAPK, and PI3K signaling. Limitations: The retrospective nature of our study means that unknown exposures could act as confounding variables, however this is representative of real-world clinical settings. Although the strength of this study is inclusion of clinically annotated patient samples, the limitation is that patients with mCSPC and mCRPC were unmatched. Conclusions: These results provide evidence that progression from mCSPC to mCRPC is associated with stereotyped concomitant gain-of-function in the RTK, PI3K, MAPK, and G1/S pathways in addition to AR. Upon external validation, these hypothesis generating data may warrant further investigation into combinatorial therapies that target these pathways.

Outcomes and the impact of genomic characteristics on patients with metastatic urothelial carcinoma enrolled in early phase trials

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Background: With the recent approvals of checkpoint inhibitors (CPIs), a fibroblast growth factor receptor (FGFR) inhibitor, and an antibody-drug conjugate, patients with platinum-refractory metastatic urothelial carcinoma (mUC) have several treatment options available. However, many patients with platinum-refractory mUC need novel therapies after progressing on current therapies. We assessed the role of early phase trials in treatment of mUC and the impact of genomic alterations on their outcomes. Methods: We retrospectively analyzed medical records of patients with mUC who received an investigational therapy at the phase 1 clinic and had CLIA-certified clinical next generation sequencing. Clinical parameters and mutations were abstracted. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier methods. Hazard ratios (HR) were calculated using the Cox proportional hazard model. Results: Among the 57 pts enrolled in 41 unique phase 1 trials between 2015 and 2019, 16% (9/57) had variant histology: neuroendocrine carcinoma (n = 3) and urachal carcinoma (n = 6). Median age was 64. Majority were males (72%). 97% received prior platinum therapy and 60% had received prior CPI therapy. Across the pure urothelial carcinoma cohort (n = 48), median PFS was 4.2 months (m), median OS was 9.8 m, and the overall response rate (ORR) was 19%. TP53, FGFR, TERT, and ARID1A alterations (alt) were detected in 54%, 41%, 21% and 17% of UC patients, respectively. Patients harboring a TP53 alt, compared to no alt, had a shorter median PFS of 3.2m vs 9.6 m (HR = 2.738 [1.247 - 6.011], p = 0.0121). On the contrary, median PFS was longer in FGFR alt, compared to no alt, 6.3m vs 3.2m (HR = 0.4662 [0.224 - 0.971], p = 0.0415). Of note, 64% of FGFR alt patients were treated under an early phase FGFR targeting trial. Median OS was numerically longer in FGFR alt and shorter in TP53 alt but did not reach statistical significance (table). Conclusions: Patients with mUC may derive clinical benefit from enrollment in phase I clinical trials. Patients with TP53 alterations had numerically worse outcomes. Patients with mUC should be considered for an FGFR targeting therapy in the setting of an FGFR alteration. [Table: see text]

Pathogenic Germline DNA Repair Gene and HOXB13 Mutations in Men With Metastatic Prostate Cancer

PURPOSE

Germline mutations in DNA repair (DR) genes and susceptibility genes CDKN2A and HOXB13 have previously been associated with prostate cancer (PC) incidence and/or progression. However, the role and prevalence of this class of mutations in metastatic PC (mPC) are not fully understood.

PATIENTS AND METHODS

To evaluate the frequency of pathogenic/likely pathogenic germline variants (PVs/LPVs) in men with mPC, this study sequenced 38 DR genes, CDKN2A, and HOXB13 in a predominantly white cohort of 317 patients with mPC. A PC registry at the University of Utah was used for patient sample acquisition and retrospective clinical data collection. Deep target sequencing allowed for germline and copy number variant analyses. Validated PVs/LPVs were integrated with clinical and demographic data for statistical correlation analyses.

RESULTS

All pathogenic variants were found in men self-reported as white, with a carrier frequency of 8.5% (DR genes, 7.3%; CDKN2A/HOXB13, 1.2%). Consistent with previous reports, mutations were most frequently identified in the breast cancer susceptibility gene BRCA2. It was also found that 50% of identified PVs/LPVs were categorized as founder mutations with European origins. Correlation analyses did not support a trend toward more advanced or earlier-onset disease in comparisons between carriers and noncarriers of deleterious DR or HOXB13 G84E mutations.

CONCLUSION

These findings demonstrate a lower prevalence of germline PVs/LPVs in an unselected, predominantly white mPC cohort than previously reported, which may have implications for the design of clinical trials testing targeted therapies. Larger studies in broad and diverse populations are needed to more accurately define the prevalence of germline mutations in men with mPC.