Darolutamide and Survival in Metastatic, Hormone-Sensitive Prostate Cancer.

BACKGROUND: Darolutamide is a potent androgen-receptor inhibitor that has been associated with increased overall survival among patients with nonmetastatic, castration-resistant prostate cancer. Whether a combination of darolutamide, androgen-deprivation therapy, and docetaxel would increase survival among patients with metastatic, hormone-sensitive prostate cancer is unknown. METHODS: In this international, phase 3 trial, we randomly assigned patients with metastatic, hormone-sensitive prostate cancer in a 1:1 ratio to receive darolutamide (at a dose of 600 mg [two 300-mg tablets] twice daily) or matching placebo, both in combination with androgen-deprivation therapy and docetaxel. The primary end point was overall survival. RESULTS: The primary analysis involved 1306 patients (651 in the darolutamide group and 655 in the placebo group); 86.1% of the patients had disease that was metastatic at the time of the initial diagnosis. At the data cutoff date for the primary analysis (October 25, 2021), the risk of death was significantly lower, by 32.5%, in the darolutamide group than in the placebo group (hazard ratio 0.68; 95% confidence interval, 0.57 to 0.80; P<0.001). Darolutamide was also associated with consistent benefits with respect to the secondary end points and prespecified subgroups. Adverse events were similar in the two groups, and the incidences of the most common adverse events (occurring in ≥10% of the patients) were highest during the overlapping docetaxel treatment period in both groups. The frequency of grade 3 or 4 adverse events was 66.1% in the darolutamide group and 63.5% in the placebo group; neutropenia was the most common grade 3 or 4 adverse event (in 33.7% and 34.2%, respectively). CONCLUSIONS: In this trial involving patients with metastatic, hormone-sensitive prostate cancer, overall survival was significantly longer with the combination of darolutamide, androgen-deprivation therapy, and docetaxel than with placebo plus androgen-deprivation therapy and docetaxel, and the addition of darolutamide led to improvement in key secondary end points. The frequency of adverse events was similar in the two groups. (Funded by Bayer and Orion Pharma; ARASENS ClinicalTrials.gov number, NCT02799602.).

Natural course of metastatic castration-resistant prostate cancer in the era of intensified androgen deprivation therapy in the hormone-sensitive setting.

BACKGROUND: Androgen deprivation therapy (ADT) intensification (ADTi) (i.e., ADT with androgen receptor pathway inhibitor or docetaxel, or both) has significantly improved survival outcomes of patients with metastatic hormone-sensitive prostate cancer (mHSPC). However, the impact of prior ADTi in the mHSPC setting on the disease presentation and survival outcomes in metastatic castration-resistant prostate cancer (mCRPC) is not well characterized. In this study, our objective was to compare the disease characteristics and survival outcomes of patients with new mCRPC with respect to receipt of intensified or nonintensified ADT in the mHSPC setting. METHODS: In this institutional review board-approved retrospective study, eligibility criteria were as follows: patients diagnosed with mCRPC, treated with an approved first-line mCRPC therapy, and who received either intensified or nonintensified ADT in the mHSPC setting. Progression-free survival (PFS) was defined from the start of first-line therapy for mCRPC to progression per Prostate Cancer Working Group 2 criteria or death, and overall survival (OS) was defined from the start of first-line therapy for mCRPC to death or censored at the last follow-up. A multivariable analysis using the Cox proportional hazards model was used, adjusting for potential confounders. RESULTS: Patients (n = 387) treated between March 20, 2008, and August 18, 2022, were eligible and included: 283 received nonintensified ADT, whereas 104 were treated with ADTi. At mCRPC diagnosis, patients in the ADTi group were significantly younger, had more visceral metastasis, lower baseline prostate-specific antigen (all p < 0.01), and lower hemoglobin (p = 0.027). Furthermore, they had significantly shorter PFS (median 4.8 vs. 8.4 months, adjusted hazard ratio [HR]: 1.46, 95% confidence interval [95% CI]: 1.07-2, p = 0.017) and OS (median 21.3 vs. 33.1 months, adjusted HR: 1.53, 95% CI: 1.06-2.21, p = 0.022) compared to patients in the nonintensified ADT group. CONCLUSION: Patients treated with ADTi in the mHSPC setting and experiencing disease progression to mCRPC had more aggressive disease features of mCRPC (characterized by a higher number of poor prognostic factors at mCRPC presentation). They also had shorter PFS on first-line mCRPC treatment and shorter OS after the onset of mCRPC compared to those not receiving ADTi in the mHSPC setting. Upon external validation, these findings may impact patient counseling, prognostication, treatment selection, and design of future clinical trials in the mCRPC setting. There remains an unmet need to develop novel life-prolonging therapies with new mechanisms of action to improve mCRPC prognosis in the current era.

Phase 2 trial of tremelimumab in patients with metastatic urothelial cancer previously treated with programmed death 1/programmed death ligand 1 blockade.

INTRODUCTION: Programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) blockade has changed the landscape of treatment for metastatic urothelial cancer, but single-agent cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade in metastatic urothelial cancer has been underexplored. A prior phase 2 trial of tremelimumab in PD-1/PD-L1-blockade naive patients with metastatic urothelial cancer revealed activity comparable to that observed with PD-1/PD-L1 blockade raising the hypothesis that these classes of immune checkpoint inhibitors might be non-cross-resistant. METHODS: The current phase 2 trial treated patients with PD-1/PD-L1 blockade-resistant metastatic urothelial cancer with single-agent tremelimumab (750 mg intravenously every 28 days for up to 7 cycles). The primary end point was objective response rate. RESULTS: Twenty-six patients were enrolled and 24 patients were evaluable for response. The objective response rate was 8.3%, composed of a total of two partial responses that lasted 10.9 and 24.0 months. Stable disease was observed in another 20.8% of patients, with a median duration of stable disease of 5.4 months. Diarrhea occurred in 15 patients (58%), elevated hepatic transaminases occurred in seven patients (27%), and adrenal insufficiency occurred in two patients (8%); one patient died after experiencing immune-related hepatitis. CONCLUSIONS: High dose CTLA-4 blockade in patients with PD-1/PD-L1-resistant metastatic urothelial cancer has modest activity and is associated with treatment-related toxicity similar to prior reports.

Cabozantinib with immune checkpoint inhibitor versus cabozantinib monotherapy in patients with metastatic clear cell renal cell carcinoma progressing after prior immune checkpoint inhibitor.

INTRODUCTION: Rechallenge with antibodies targeting programmed cell death protein-1 or its ligand (PD-1/L1) after discontinuation or disease progression in solid tumors following a prior PD-1/L1 treatment is often practiced in clinic. This study aimed to investigate if adding PD-1/L1 inhibitors to cabozantinib, the most used second-line treatment in real-world patients with metastatic clear cell renal cell carcinoma (mccRCC), offers additional benefits. METHODS: Using de-identified patient-level data from a large real-world US-based database, patients diagnosed with mccRCC, who received any PD-1/L1-based combination in first-line (1L) setting, followed by second-line (2L) therapy with either cabozantinib alone or in combination with PD-1/L1 inhibitors were included. Patients given a cabozantinib-containing regimen in 1L were excluded. The study end points were real-world time to next therapy (rwTTNT) and real-world overall survival (rwOS) by 2L. RESULTS: Of 12,285 patients with metastatic renal cell carcinoma in the data set, 348 patients met eligibility and were included in the analysis. After propensity score matching weighting, cabozantinib with PD-1/L1 inhibitors versus cabozantinib (ref.) had similar rwTTNT and rwOS in the 2L setting. Hazard ratios and 95% confidence interval (CI) for rwTTNT and rwOS are 0.74 (95% CI, 0.49-1.12) and 1.15 (95% CI, 0.73-1.79), respectively. CONCLUSION: In this study, the results align with the phase 3 CONTACT-03 trial results, which showed no additional benefit of adding PD-L1 inhibitor to cabozantinib compared to cabozantinib alone in 2L following PD-1/L1-based therapies in 1L. These results from real-world patients strengthen the evidence regarding the futility of rechallenge with PD-1/L1 inhibitors.

A Phase II Study of Rucaparib Monotherapy in Nonmetastatic, Hormone-Sensitive Prostate Cancer Demonstrating "BRCAness" Genotype (ROAR).

BACKGROUND: Both germline and somatic BReast CAncer gene (BRCA) mutations are poor prognostic markers in men with localized or metastatic prostate cancer. For instance, men with these mutations often are diagnosed with prostate cancer earlier and develop metastatic disease earlier compared with those who do not harbor similar mutations. Patients with germline alterations typically have more advanced disease and shorter overall survival (Castro E, Goh C, Olmos D, et al. Germline BRCA mutations are associated with higher risk of nodal involvement, distant metastasis, and poor survival outcomes in prostate cancer. J Clin Oncol. 2013;31(14):1748-1757. doi:10.1200/JCO.2012.43.1882). The risk of disease progression to metastatic disease is significant in patients with this genotype of prostate cancer. The percentage of patients free from metastatic disease was 90%, 72%, and 50%, respectively, compared with 97%, 94%, and 84% at 3, 5, and 10 years for patients with intact DNA repair (P < .001) (Castro E, Goh C, Leongamornlert D, et al. Effect of BRCA mutations on metastatic relapse and cause-specific survival after radical treatment for localised prostate cancer. Eur Urol. 2015;68(2):186-193. doi: 10.1016/j.eururo.2014.10.022). DNA damage repair non-BRCA mutations include alterations in genes such as ATM, CHEK2, PALB2, and RAD51. While less common than BRCA mutations, they have emerged as significant prognostic markers in prostate cancer. These BRCAness mutations are associated with a higher risk of aggressive disease and poorer survival outcomes. Given the debilitating physical and psychological side effects of androgen deprivation therapy (ADT) in relatively younger men with prostate cancer, delaying ADT in these men may be an attractive strategy. Given the proven efficacy of polyadenosine diphosphate-ribose polymerase (PARP) inhibitors in the castration-resistant prostate cancersetting, PARP inhibitor monotherapy in a nonmetastatic castration-sensitive (nmCSPC) setting has the potential to delay metastasis and delay the onset of ADT related symptoms. METHODS: This is a single-arm, single-center, open-label, phase II trial to assess the efficacy of rucaparib in patients with high-risk biochemically recurrent (BCR) nmHSPC, which was defined as PSA doubling time of <9 months, demonstrating a "BRCAness" genotype (BRCA1/2 and other homologous recombination repair mutations). A total of 15 patients were intended to be enrolled, with an expected enrollment duration of 12 months. Patients were given rucaparib 600 mg orally twice daily and were allowed to remain on study treatment until PSA progression defined by Prostate Cancer Working Group 3, with 2 years of follow-up after study treatment. We anticipated a total of 2-3 years until completion of the clinical trial. The primary endpoint was to assess the PSA progression-free survival (PSA-PFS). The secondary endpoints of the study were safety, the proportion of patients with a PSA 50% response (PSA 50), and an undetectable PSA. A 4-week treatment duration comprised one cycle. RESULTS: The study started enrolling in June 2019 and was prematurely terminated in June 2022 after the accrual of 7 patients because of changing standard of care treatments with the introduction of next-generation scans, eg, prostate-specific membrane antigen positron emission tomography (PSMA-PET). Seven patients were enrolled in the study with the following pathogenic alterations: ATM (n = 3), BRCA2 (n = 2), BRCA1 (n = 1), BRIP1 (n = 1), and RAD51 (n = 1). The median duration of follow-up was 18 months. A median of 20 cycles (range 4-42) was completed, median PSA-PFS was 35.37 months (95% CI, 0-85.11 months). In total, 2 patients achieved PSA50; both also achieved nadir PSA as undetectable. Grade ≥ 3 adverse events (AEs) were anemia and rash (in 1 patient each). No dose-limiting toxicities or severe AEs were seen. CONCLUSION: Rucaparib demonstrated acceptable toxicity and efficacy signal as an ADT-sparing approach in patients with biochemically recurrent nonmetastatic prostate cancer. It is currently challenging to understand the optimal value of systemic therapy in this disease setting due to the rapidly changing standard of care. Additionally, there are relatively few patients with BRCAness who present with nonmetastatic hormone-sensitive prostate cancer (ClinicalTrials.gov Identifier: NCT03533946).

Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease.

BACKGROUND: Patients with von Hippel-Lindau (VHL) disease have a high incidence of renal cell carcinoma owing to VHL gene inactivation and constitutive activation of the transcription factor hypoxia-inducible factor 2α (HIF-2α). METHODS: In this phase 2, open-label, single-group trial, we investigated the efficacy and safety of the HIF-2α inhibitor belzutifan (MK-6482, previously called PT2977), administered orally at a dose of 120 mg daily, in patients with renal cell carcinoma associated with VHL disease. The primary end point was objective response (complete or partial response) as measured according to the Response Evaluation Criteria in Solid Tumors, version 1.1, by an independent central radiology review committee. We also assessed responses to belzutifan in patients with non-renal cell carcinoma neoplasms and the safety of belzutifan. RESULTS: After a median follow-up of 21.8 months (range, 20.2 to 30.1), the percentage of patients with renal cell carcinoma who had an objective response was 49% (95% confidence interval, 36 to 62). Responses were also observed in patients with pancreatic lesions (47 of 61 patients [77%]) and central nervous system hemangioblastomas (15 of 50 patients [30%]). Among the 16 eyes that could be evaluated in 12 patients with retinal hemangioblastomas at baseline, all (100%) were graded as showing improvement. The most common adverse events were anemia (in 90% of the patients) and fatigue (in 66%). Seven patients discontinued treatment: four patients voluntarily discontinued, one discontinued owing to a treatment-related adverse event (grade 1 dizziness), one discontinued because of disease progression as assessed by the investigator, and one patient died (of acute toxic effects of fentanyl). CONCLUSIONS: Belzutifan was associated with predominantly grade 1 and 2 adverse events and showed activity in patients with renal cell carcinomas and non-renal cell carcinoma neoplasms associated with VHL disease. (Funded by Merck Sharp and Dohme and others; MK-6482-004 ClinicalTrials.gov number, NCT03401788.).

Oral Hypoxia-Inducible Factor 2α Inhibitor Belzutifan in Ocular von Hippel-Lindau Disease: Subgroup Analysis of the Single-Arm Phase 2 LITESPARK-004 Study.

PURPOSE: To report the efficacy of the oral hypoxia-inducible factor 2α inhibitor belzutifan in participants with von Hippel-Lindau disease-associated retinal hemangioblastomas in the LITESPARK-004 study. DESIGN: Subgroup analysis of the phase 2, single-arm, open-label LITESPARK-004 study. PARTICIPANTS: Adults with 1 or more von Hippel-Lindau disease-associated measurable renal cell carcinoma tumors not requiring immediate surgical intervention were eligible. METHODS: Participants received oral belzutifan 120 mg once daily until disease progression or unacceptable treatment-related toxicity. MAIN OUTCOME MEASURES: Efficacy of belzutifan in retinal hemangioblastomas was a secondary end point, measured as response (improved, stable, or progressed) by independent reading center-certified graders based on color fundus imaging performed every 12 weeks using the investigator's preferred imaging standards. Additional assessments, where available, included OCT and ultra-widefield fluorescein angiography. RESULTS: Among 61 participants in LITESPARK-004, 12 had 1 or more evaluable active retinal hemangioblastomas in 16 eyes at baseline per independent reading center. As of April 1, 2022, the median follow-up for participants with ocular von Hippel-Lindau disease at baseline was 37.3 months. All 16 eyes were graded as improved, with a response rate of 100.0% (95% confidence interval, 79.4%-100%). No new retinal hemangioblastomas or ocular disease progression were reported as of data cutoff date. Eight participants underwent additional multimodal eye assessments performed at the National Institutes of Health study site. Among this subgroup, 10 of 24 hemangioblastomas in 8 eyes of 6 participants measured 500 µm or more in greatest linear dimension at baseline and were analyzed further. All 10 hemangioblastomas had a mean area reduction of 15% or more by month 12 and of 30% or more by month 24. CONCLUSIONS: Belzutifan showed promising activity against ocular von Hippel-Lindau disease, including capacity to control retinal hemangioblastomas, with effects sustained for more than 2 years while treatment is ongoing. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Creatine supplementation and resistance training to preserve muscle mass and attenuate cancer progression (CREATINE-52): a protocol for a double-blind randomized controlled trial.

BACKGROUND: Muscle mass is important for metastatic prostate cancer survival and quality of life (QoL). The backbone of treatment for men with metastatic castration sensitive prostate cancer (mCSPC) is androgen deprivation therapy (ADT) with an androgen signaling inhibitor. ADT is an effective cancer treatment, but it facilitates significant declines in muscle mass and adverse health outcomes important to mCSPC survivors, such as fatigue, and reductions in physical function, independence, insulin sensitivity, and QoL. In non-metastatic CSPC survivors, resistance training (RT) preserves muscle mass and improves these related health outcomes, but the biggest barrier to RT in CSPC survivors of all stages is fatigue. Creatine monohydrate supplementation coupled with RT (Cr + RT) may address this barrier since creatine plays a critical role in energy metabolism. Cr + RT in cancer-free older adults and other clinical populations improves muscle mass and related health outcomes. Evidence also suggests that creatine supplementation can complement cancer treatment. Thus, Cr + RT is a strategy that addresses gaps in survivorship needs of people with mCSPC. The purpose of this parallel, double-blind randomized controlled trial is to test the effects of 52-weeks of Cr + RT compared with placebo (PLA) and RT (PLA + RT) on muscle mass, other related health outcomes, and markers of cancer progression. METHODS: We will carry out this trial with our team's established, effective, home-based, telehealth RT program in 200 mCSPC survivors receiving ADT, and evaluate outcomes at baseline, 24-, and 52-weeks. RT will occur twice weekly with elastic resistance bands, and an established creatine supplementation protocol will be used for supplementation delivery. Our approach addresses a major facilitator to RT in mCSPC survivors, a home-based RT program, while utilizing a supervised model for safety. DISCUSSION: Findings will improve delivery of comprehensive survivorship care by providing a multicomponent, patient-centered lifestyle strategy to preserve muscle mass, improve health outcomes, and complement cancer treatment (NCT06112990).

Impact of androgen receptor alterations on cell-free DNA genomic profiling on survival outcomes in metastatic castration-resistant prostate cancer.

BACKGROUND: Androgen receptor (AR) gene alterations, as detected by circulating tumor cell-free DNA (cfDNA) genomic profiling, have been shown to emerge after a variable duration of androgen signaling inhibition. AR alterations were associated with inferior outcomes on treatment with androgen receptor pathway inhibitors (ARPI) in the first line metastatic castration-resistant prostate cancer (mCRPC) setting in a phase 2 trial. Here in, we assessed the impact of these AR alterations on survival outcomes in a real-world patient population of mCRPC experiencing disease progression on an ARPI. METHODS: In this IRB-approved retrospective study, consecutively seen patients with a confirmed diagnosis of mCRPC, with disease progression on a treatment with ARPIs in the first line mCRPC setting, with no prior exposure to an ARPI in the castration sensitive setting, and with available cfDNA profiling from a CLIA certified laboratory were included. Patients were categorized based on AR status: wild-type (ARwt ) or alteration-positive (AR+ ). The objective was to correlate overall survival (OS) after disease progression on the first-line ARPI with the presence or absence of AR alterations. Kaplan-Meier and Cox Regression Tests were used as implemented in R-Studio (v.4.2). RESULTS: A total of 137 mCRPC patients were eligible: 69 with ARwt versus 68 with AR+ . The median OS posttreatment with the first ARPI was significantly higher for ARwt than AR+ patients (30.1 vs. 15.2 mos; p < 0.001). Of 108 patients who received a subsequent line of therapy, 63 received an alternate ARPI (AR+ 39 vs. 24 ARwt ), while 20 received a taxane-based therapy (11 AR+ vs. 9 ARwt ). Among patients receiving an alternate ARPI, AR+ had numerically shorter OS (16.8 vs. 30.4 mos, p = 0.1). Among patients receiving taxane-based regimens, the OS was not significantly different between AR+ and ARwt (14.5 vs. 10.1 mos, p = 0.18). CONCLUSION: In this real-world study, mCRPC patients with AR alterations on cfDNA had inferior OS after disease progression on the first ARPI, compared to those who did not, and may impact outcomes on a subsequent ARPI but not on subsequent taxane-based therapy received. By providing survival estimates for patients with or without AR alterations, our data may aid in patient counseling, prognostication, treatment decision, and for designing future clinical trials in this setting.

Phase I Trial of Combination Therapy With Avelumab and Cabozantinib in Patients With Newly Diagnosed Metastatic Clear Cell Renal Cell Carcinoma.

BACKGROUND: Combination immunotherapy is now considered the standard first-line therapy for patients with metastatic clear cell renal cell carcinoma (mccRCC) after multiple clinical trials demonstrated improved overall survival compared with single-agent tyrosine kinase inhibitors. Cabozantinib modulates critical components of the immune system, such as decreasing regulatory T cells and increasing T-effector cell populations, and is approved for the treatment of mRCC. Avelumab is a human IgG1 monoclonal antibody that binds to programmed death-ligand 1 protein and inhibits the interaction with PD-1. This phase I trial assessed the safety and clinical activity of avelumab and cabozantinib combination therapy in mccRCC. METHODS: This study was a phase I, 3+3 dose escalation clinical trial. The primary endpoint was the safety and identification of the recommended phase II dose (RP2D). Secondary endpoints included objective response rate (ORR) and radiographic progression-free survival (rPFS). There were 3 dose cohorts: cabozantinib 20, 40, and 60 mg/day, each combined with avelumab (10 mg/kg intravenously every 2 weeks). An additional 3 patients were included in the final dose cohort as a confirmation of the RP2D. No dose modifications were allowed for avelumab, but dose delays were permitted. Both dose reductions and holds were allowed for cabozantinib. Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, was used to determine ORR, and treatment beyond progression was allowed. RESULTS: Twelve patients with newly diagnosed mccRCC were enrolled from July 2018 until March 2020. Three patients were enrolled in the 20 and 40 mg cohorts each, and 6 were enrolled in the 60 mg cohort. The International Metastatic RCC Database Consortium (IMDC) risk categories for these patients were: 4 patients (favorable risk), 6 patients (intermediate risk), and 2 patients (poor risk). No dose-limiting toxicities (DLTs) were observed in any cohort. Six patients developed serious adverse events related to study treatment after the DLT window period. Immune-related adverse events (iRAEs) were reported in 11 patients; fatigue and diarrhea were the most common (each with n = 4, 33.3%), followed by maculopapular rash and hand-foot syndrome (each with n = 3, 25%). Dose reductions were required in 5 of 6 patients in the cabozantinib 60 mg cohort after the DLT period. One patient discontinued avelumab due to irAE (nephritis), while none discontinued cabozantinib due to toxicity. The ORR was 50%, with one complete response (CR) and 5 partial responses (PR). The disease control rate (CR + PR + stable disease) was noted in 92% of the patients. Radiological PFS survival rate at 6 and 12 months was reported in 67.7% and 33.5% of patients, respectively. CONCLUSION: Combination therapy with avelumab and cabozantinib is safe and showed preliminary clinical activity in mccRCC. Even though the DLT was not met in any of the 3 cohorts, the recommended RP2D dose for the combination is cabozantinib 40 mg/day due to a high incidence of grade 2 toxicity for cabozantinib 60 mg/day after the DLT period. (ClinicalTrials.gov Identifier: NCT03200587).

Papillary Renal Cell Carcinoma: A Review of Prospective Clinical Trials.

OPINION STATEMENT: PRCC is a unique histologic entity compared to other forms of renal cell carcinoma, harboring distinct molecular drivers. The WHO 2022 classification is further emphasizing the molecular biology by making molecular classifications of PRCC subclassifications and discontinuing the morphologic type 1 and type 2 classification system. We agree with this functional classification system and encourage all future clinical trials to only include patients with similar diagnosis instead of conducting basket trials (including all nccRCC together) which limits the scientific value of those conclusions. Based on recent disease-specific clinical trial (S1500, PAPMET), the current standard of care for patients with treatment naïve PRCC is cabozantinib. Prospective clinical trials clearly establish that immune checkpoint inhibitor therapy has meaningful activity in PRCC. The data to date include only single-arm clinical trials of combination immune therapy. Despite the positive and encouraging results, we need validation through randomized studies because of the overestimation of effect size seen in single-arm trials. These randomized trials are currently underway and enrolling. We strongly encourage all physicians to support these studies and enroll patients with PRCC to these trials in order to continue improving the standard of care.

Cabozantinib in combination with atezolizumab in patients with metastatic castration-resistant prostate cancer: results from an expansion cohort of a multicentre, open-label, phase 1b trial (COSMIC-021).

BACKGROUND: Patients with metastatic castration-resistant prostate cancer have few treatment options after novel hormonal therapy (eg, abiraterone or enzalutamide). We aimed to evaluate cabozantinib, a tyrosine kinase inhibitor with immunomodulatory properties, in combination with the PD-L1 inhibitor atezolizumab in metastatic castration-resistant prostate cancer. METHODS: COSMIC-021 is an ongoing, multicentre, open-label, phase 1b study with a dose-escalation stage followed by tumour-specific expansion stages. Expansion cohort 6 in metastatic castration-resistant prostate cancer was enrolled at 42 cancer research centres in France, Italy, the Netherlands, Spain, and the USA. Eligible patients were aged 18 years or older and had metastatic castration-resistant prostate cancer with radiographic soft tissue progression following treatment with either enzalutamide or abiraterone, or both; measurable soft tissue disease per Response Evaluation Criteria In Solid Tumours (RECIST) version 1.1; and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received oral cabozantinib 40 mg per day and intravenous atezolizumab 1200 mg once every 3 weeks. Study treatment continued until progressive disease or unacceptable toxicity. All enrolled patients were assessed for efficacy and safety. The primary endpoint was objective response rate per RECIST version 1.1 as assessed by the investigator. This study is registered with ClinicalTrials.gov, NCT03170960. FINDINGS: Between April 24, 2018, and Aug 31, 2020, 132 patients were enrolled and received at least one dose of study treatment. At data cutoff (Feb 19, 2021), median duration of follow-up was 15·2 months (IQR 9·6-21·7). Objective response rate was 23% (95% CI 17-32; 31 of 132 patients), with three (2%) confirmed complete responses and 28 (21%) confirmed partial responses. 72 (55%) of 132 patients had grade 3-4 treatment-related adverse events, with the most common being pulmonary embolism (11 [8%] patients), diarrhoea (nine [7%]), fatigue (nine [7%]), and hypertension (nine [7%]). There was one grade 5 treatment-related adverse event (dehydration). 74 (56%) of 132 patients had serious adverse events of any causality. 28 (21%) of 132 patients had treatment-related adverse events leading to discontinuation of either study drug. INTERPRETATION: Cabozantinib plus atezolizumab showed promising antitumour activity in patients with metastatic castration-resistant prostate cancer after novel hormonal therapy with an acceptable safety profile, supporting further evaluation of this combination. FUNDING: Exelixis.

Comprehensive Genomic Profiling of Cell-Free DNA in Men With Advanced Prostate Cancer: Differences in Genomic Landscape Based on Race.

Advanced prostate cancer (aPC) in Black men was reported to present with aggressive features and to be associated with poor prognosis. Herein, we compared the cell-free DNA (cfDNA) genomic landscape of aPC in Black vs White men. Patients (pts) with aPC from 6 academic institutions and available cfDNA comprehensive genomic profiling (CGP) were included. Association between mutated genes and race was evaluated using Barnard's test and a Probabilistic Graphical Model (PGM) machine learning approach. Analysis included 743 aPC pts (217 Black, 526 White) with available cfDNA CGP. The frequency of alterations in the androgen receptor gene was significantly higher in Black vs White men (55.3% vs 35% respectively, P < .001). Additionally, alterations in EGFR, MYC, FGFR1, and CTNNB1 were present at higher frequencies in Black men. PGM analysis and Barnard's test were concordant. Findings from the largest cohort of Black men with aPC undergoing cfDNA CGP may guide further drug development in these men.

Start of a New Era: Management of Non-Clear Cell Renal Cell Carcinoma in 2022.

PURPOSE OF REVIEW: Historically, kidney cancer was diagnosed as either clear cell renal carcinoma (ccRCC) or non-clear cell renal carcinoma (nccRCC). With further research into the pathophysiology of nccRCC, multiple distinct subtypes have emerged creating distinct diagnosis, such as papillary renal cell carcinoma (PRCC), chromophobe renal cell carcinoma (crRCC), or unclassified carcinoma (cRCC). Many other kidney cancer subtypes are now included in the WHO classification system. RECENT FINDINGS: The prognosis for each of the more frequently diagnosed types is discussed here along with treatment recommendations. The available clinical trial results and salient retrospective studies of each subtype are reviewed here to guide clinicians on the optimal treatment selection for patients with these rare histologic types or RCC. Many nccRCC types are now recognized and each has unique molecular drivers which are different than ccRCC. The optimal treatment strategy is different for each subtype. The prognosis also differs based on the histology.

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.

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.

Tumor Frameshift Mutation Proportion Predicts Response to Immunotherapy in Mismatch Repair-Deficient Prostate Cancer.

BACKGROUND: Genomic biomarkers that predict response to anti-PD1 therapy in prostate cancer are needed. Frameshift mutations are predicted to generate more neoantigens than missense mutations; therefore, we hypothesized that the number or proportion of tumor frameshift mutations would correlate with response to anti-PD1 therapy in prostate cancer. METHODS: To enrich for response to anti-PD1 therapy, we assembled a multicenter cohort of 65 men with mismatch repair-deficient (dMMR) prostate cancer. Patient characteristics and outcomes were determined by retrospective chart review. Clinical somatic DNA sequencing was used to determine tumor mutational burden (TMB), frameshift mutation burden, and frameshift mutation proportion (FSP), which were correlated to outcomes on anti-PD1 treatment. We subsequently used data from a clinical trial of pembrolizumab in patients with nonprostatic dMMR cancers of various histologies as a biomarker validation cohort. RESULTS: Nineteen of 65 patients with dMMR metastatic castration-resistant prostate cancer were treated with anti-PD1 therapy. The PSA50 response rate was 65%, and the median progression-free survival (PFS) was 24 (95% confidence interval 16-54) weeks. Tumor FSP, more than overall TMB, correlated most strongly with prolonged PFS and overall survival (OS) on anti-PD1 treatment and with density of CD8+ tumor-infiltrating lymphocytes. High FSP similarly identified patients with longer PFS as well as OS on anti-PD1 therapy in a validation cohort. CONCLUSION: Tumor FSP correlated with prolonged efficacy of anti-PD1 treatment among patients with dMMR cancers and may represent a new biomarker of immune checkpoint inhibitor sensitivity. IMPLICATIONS FOR PRACTICE: Given the modest efficacy of immune checkpoint inhibition (ICI) in unselected patients with advanced prostate cancer, biomarkers of ICI sensitivity are needed. To facilitate biomarker discovery, a cohort of patients with DNA mismatch repair-deficient (dMMR) prostate cancer was assembled, as these patients are enriched for responses to ICI. A high response rate to anti-PD1 therapy in these patients was observed; however, these responses were not durable in most patients. Notably, tumor frameshift mutation proportion (FSP) was identified as a novel biomarker that was associated with prolonged response to anti-PD1 therapy in this cohort. This finding was validated in a separate cohort of patients with nonprostatic dMMR cancers of various primary histologies. This works suggests that FSP predicts response to anti-PD1 therapy in dMMR cancers, which should be validated prospectively in larger independent cohorts.

Neuroendocrine differentiation in usual-type prostatic adenocarcinoma: Molecular characterization and clinical significance.

BACKGROUND: Small cell neuroendocrine (NE) carcinomas of the prostate classically lose androgen receptor (AR) expression, may harbor loss of the RB1, TP53, and PTEN tumor suppressor genes, and are associated with a poor prognosis. However usual-type adenocarcinomas may also contain areas of NE differentiation, and in this context the molecular features and biological significance are less certain. METHODS: We examined the molecular phenotype and oncologic outcomes of primary prostate adenocarcinomas with ≥5% NE differentiation (≥5% chromogranin A-positive NE cells in any given tumor spot on tissue microarray) using three independent study sets: a set of tumors with paneth cell-like NE differentiation (n = 26), a retrospective case-cohort of intermediate- and high-risk patients enriched for adverse outcomes (n = 267), and primary tumors from a retrospective series of men with eventual castration-resistant metastatic prostate cancer (CRPC) treated with abiraterone or enzalutamide (n = 55). RESULTS: Benign NE cells expressed significantly lower quantified AR levels compared with paired benign luminal cells (P < .001). Similarly, paneth-like NE carcinoma cells or carcinoma cells expressing chromogranin A expressed significantly lower quantified AR levels than paired non-NE carcinoma cells (P < .001). Quantified ERG protein expression, was also lower in chromogranin A-labeled adenocarcinoma cells compared with unlabeled cells (P < .001) and tumors with NE differentiation showed lower gene expression scores for AR activity compared with those without. Despite evidence of lower AR signaling, adenocarcinomas with NE differentiation did not differ by prevalence of TP53 missense mutations, or PTEN or RB1 loss, compared with those without NE differentiation. Finally, NE differentiation was not associated with time to metastasis in intermediate- and high-risk patients (P = .6 on multivariate analysis), nor with progression-free survival in patients with CRPC treated with abiraterone or enzalutamide (P = .9). CONCLUSION: NE differentiation in usual-type primary prostate adenocarcinoma is a molecularly and clinically distinct form of lineage plasticity from that occurring in small cell NE carcinoma.

A Phase I Study of Alpha-1,3-Galactosyltransferase-Expressing Allogeneic Renal Cell Carcinoma Immunotherapy in Patients with Refractory Metastatic Renal Cell Carcinoma.

LESSONS LEARNED: HyperAcute Renal immunotherapy was well tolerated and demonstrated antitumor activity in patients requiring salvage-line treatment for metastatic renal cell carcinoma (mRCC). HyperAcute Renal immunotherapy was safely administered with concomitant salvage-line treatments for mRCC, and it may be a candidate for inclusion in novel combinations for salvage treatment of mRCC because of its unique mechanism of action. BACKGROUND: HyperAcute Renal (HAR) immunotherapy exploits a naturally occurring barrier to xenotransplantation and zoonotic infections in humans to immunize patients against metastatic renal cell carcinoma (mRCC) cells. HAR consists of two allogeneic renal cancer cell lines genetically modified to express α(1,3)Gal, to which humans have an inherent pre-existing immunity. METHODS: Patients with refractory mRCC were eligible for this phase I dose-escalation trial. Concomitant treatment was permitted after the initial 2 months of HAR monotherapy. HAR was injected intradermally weekly for 4 weeks then biweekly for 20 weeks, totaling 14 immunizations. The primary endpoint was safety and determination of a maximum tolerated dose (MTD). RESULTS: Among 18 patients enrolled, two grade 3 adverse events (AEs) were attributed to HAR, lymphopenia and injection site reaction, and no grade 4/5 AEs occurred. The recommended phase II dose (RP2D) was 300 million cells. One patient had a partial response and eight patients had stable disease, for a disease control rate of 50% (9/18). Median overall survival with low-dose HAR was 14.2 months and was 25.3 months with high-dose HAR. CONCLUSION: In pretreated mRCC, HAR immunotherapy was well tolerated and demonstrated antitumor activity. HAR immunotherapy may be a candidate for inclusion in novel combinations for salvage treatment of mRCC.

Management of Nonmetastatic Castration-Resistant Prostate Cancer: Recent Advances and Future Direction.

OPINION STATEMENT: Nonmetastatic castration-resistant prostate cancer (nmCRPC) comprises a relatively narrow niche of advanced prostate cancer, but the treatment landscape for men with nmCRPC has drastically changed over the past year. Prior to the SPARTAN and PROSPER trials, men with nmCRPC were commonly treated with first-generation androgen receptor antagonists, such as bicalutamide or flutamide, or with estrogens or ketoconazole, none of which were associated with any proven survival benefit. The SPARTAN trial evaluated apalutamide versus placebo for men with nmCRPC and found that apalutamide significantly improved metastasis-free survival (MFS), the primary endpoint of this trial. Similarly, the PROSPER trial showed that enzalutamide significantly improved MFS compared with placebo for men with nmCRPC. In both trials, the data for overall survival was immature at the time of analysis. The SPARTAN and PROSPER trials led to the approval of apalutamide and enzalutamide, respectively, for men with nmCRPC. More recently, the phase 3 trial ARAMIS showed that darolutamide, a novel androgen receptor antagonist, also improves MFS compared with placebo for men with nmCRPC, and this trial is expected to garner regulatory approval for darolutamide in the nmCRPC setting. Novel imaging modalities are becoming more prevalent for the diagnostic evaluation of men with prostate cancer and are more sensitive than conventional bone or CT scans for detection of oligometastatic disease that previously was undetected. These modalities are likely to reduce the incidence and prevalence of nmCRPC in the near future. Ultimately, the treatment options for men with nmCRPC have significantly improved over the past 2 years.