Enzalutamide Monotherapy in the EMBARK Trial Should Be Practice-changing and Existing Data Suggest How to Mitigate Toxicity.

Data from the EMBARK trial demonstrate the potential of enzalutamide monotherapy as an effective treatment for biochemically recurrent prostate cancer (BCR) without the side effects of testosterone-lowering therapy. Unfortunately, concerns about gynecomastia and how to manage this treatment-related toxicity have diminished enthusiasm. Existing data may offer an alternative scheduling strategy for enzalutamide monotherapy in BCR.

Biochemically recurrent prostate cancer in the era of EMBARK and PSMA PET imaging: everything has changed, except the patients.

PURPOSE OF REVIEW: Patients with biochemically recurrent prostate cancer (BCR) after unsuccessful curative therapies frequently have an indolent and asymptomatic disease course for years. There are no prospective data showing that treating BCR improves overall survival despite new imaging strategies and emerging therapeutic data. Managing BCR requires a unique perspective in oncology that balances toxicities and disease kinetics. RECENT FINDINGS: Prostate specific membrane antigen (PSMA) imaging is now widely available and can define subclinical disease in patients with BCR who otherwise have negative CT and bone scans, but limited data exists showing that treating PSMA-positive disease has long term impact. A phase 3 trial demonstrated that the androgen receptor pathway inhibitor enzalutamide either alone or with androgen deprivation therapy (ADT) was superior in delaying metastasis, relative to ADT alone. Survival benefits from this study remain unknown. SUMMARY: BCR is a heterogeneous population where overtreatment may present greater risk to patients than a disease course that is often indolent. Management of BCR should be individualized based on disease kinetics. Given the unique biology of BCR, future therapeutic research should emphasize an approach that alters disease trajectory without accompanying side effects and should explore options beyond ADT-based strategies.

Stem cell dynamics and cellular heterogeneity across lineage subtypes of castrate-resistant prostate cancer.

To resist lineage-dependent therapies such as androgen receptor inhibition, prostate luminal epithelial adenocarcinoma cells often adopt a stem-like state resulting in lineage plasticity and phenotypic heterogeneity. Castrate-resistant prostate adenocarcinoma can transition to neuroendocrine (NE) and occasionally to amphicrine, co-expressed luminal and NE, phenotypes. We developed castrate-resistant prostate cancer (CRPC) patient-derived organoid models that preserve heterogeneity of the originating tumor, including an amphicrine model displaying a range of luminal and NE phenotypes. To gain biological insight and to identify potential treatment targets within heterogeneous tumor cell populations, we assessed the lineage hierarchy and molecular characteristics of various CRPC tumor subpopulations. Transcriptionally similar stem/progenitor (St/Pr) cells were identified for all lineage populations. Lineage tracing in amphicrine CRPC showed that heterogeneity originated from distinct subclones of infrequent St/Pr cells that produced mainly quiescent differentiated amphicrine progeny. By contrast, adenocarcinoma CRPC progeny originated from St/Pr cells and self-renewing differentiated luminal cells. Neuroendocrine prostate cancer (NEPC) was composed almost exclusively of self-renewing St/Pr cells. Amphicrine subpopulations were enriched for secretory luminal, mesenchymal, and enzalutamide treatment persistent signatures that characterize clinical progression. Finally, the amphicrine St/Pr subpopulation was specifically depleted with an AURKA inhibitor, which blocked tumor growth. These data illuminate distinct stem cell (SC) characteristics for subtype-specific CRPC in addition to demonstrating a context for targeting differentiation-competent prostate SCs.

Restaging With Prostate-Specific Membrane Antigen Imaging in Metastatic Castration-Resistant Prostate Cancer: When Seeing More Is Detrimental to Care.

#PSMA is amazing new tech but is using it to expedite the call of disease progression helping #ProstateCancer patients?

Localized high-risk prostate cancer harbors an androgen receptor low subpopulation susceptible to HER2 inhibition.

Patients diagnosed with localized high-risk prostate cancer have higher rates of recurrence, and the introduction of neoadjuvant intensive hormonal therapies seeks to treat occult micrometastatic disease by their addition to definitive treatment. Sufficient profiling of baseline disease has remained a challenge in enabling the in-depth assessment of phenotypes associated with exceptional vs. poor pathologic responses after treatment. In this study, we report comprehensive and integrative gene expression profiling of 37 locally advanced prostate tumors prior to six months of androgen deprivation therapy (ADT) plus the androgen receptor (AR) inhibitor enzalutamide prior to radical prostatectomy. A robust transcriptional program associated with HER2 activity was positively associated with poor outcome and opposed AR activity, even after adjusting for common genomic alterations in prostate cancer including PTEN loss and expression of the TMPRSS2:ERG fusion. Patients experiencing exceptional pathologic responses demonstrated lower levels of HER2 and phospho-HER2 by immunohistochemistry of biopsy tissues. The inverse correlation of AR and HER2 activity was found to be a universal feature of all aggressive prostate tumors, validated by transcriptional profiling an external cohort of 121 patients and immunostaining of tumors from 84 additional patients. Importantly, the AR activity-low, HER2 activity-high cells that resist ADT are a pre-existing subset of cells that can be targeted by HER2 inhibition alone or in combination with enzalutamide. In summary, we show that prostate tumors adopt an AR activity-low prior to antiandrogen exposure that can be exploited by treatment with HER2 inhibitors.

Increasing diversity in clinical trials: demographic trends at the National Cancer Institute, 2005-2020.

BACKGROUND: We described participant demographics for National Cancer Institute (NCI) clinical trials at the clinical center (NCI-CC participants) of the National Institutes of Health to identify enrollment disparities. METHODS: We analyzed NCI-CC data from 2005 to 2020, calculated enrollment fractions, compared with the US cancer population represented by the Surveillance, Epidemiology, and End Results cancer incidence data (2018) and the Cancer in North America database (2018), and compared further with clinical trial disparities data from the NCI Community Oncology Research Program and National Clinical Trials Network (2005-2019), and from ClinicalTrials.gov (2003-2016). RESULTS: NCI-CC (38 531 participants) had higher enrollment fractions for older adults (8.5%), male (5.6%), non-Hispanic (5.1%), and Black or African American (5.3%) participants; lower women proportion across race and ethnicity; and fewer female sex-specific cancer (6.8%) than male sex-specific cancer (11.7%) participants. NCI-CC had lower median age than Surveillance, Epidemiology, and End Results (54.0 vs 65.4); more Black or African American participants (12.0% vs 11.1%); and fewer women (41.7% vs 49.5%), White (76.1% vs 80.5%), Asian or Pacific Islander (4.6% vs 6.0%), American Indian or Alaska Native (0.3% vs 0.5%), and Hispanic participants (7.1% vs 13%). NCI-CC had more Black or African American and Asian or Pacific Islander participants; fewer Hispanic participants than the NCI Community Oncology Research Program and National Clinical Trials Network; more Black or African American and Hispanic participants; fewer Asian or Pacific Islander participants than ClinicalTrials.gov data. Improvement was noted for NCI-CC (older adults, Black or African American, Asian or Pacific Islander, Hispanic participants). CONCLUSION: We found lower representation of older adults, women, Asian or Pacific Islander, American Indian or Alaska Native, and Hispanic participants vs the US cancer population and higher representation of Black or African American vs US cancer population and oncology clinical trials. Multifaceted efforts are underway to reduce disparities in cancer clinical trials at the NCI-CC.

Comparison of Large Language Models in Answering Immuno-Oncology Questions: A Cross-Sectional Study.

BACKGROUND: The capability of large language models (LLMs) to understand and generate human-readable text has prompted the investigation of their potential as educational and management tools for patients with cancer and healthcare providers. MATERIALS AND METHODS: We conducted a cross-sectional study aimed at evaluating the ability of ChatGPT-4, ChatGPT-3.5, and Google Bard to answer questions related to 4 domains of immuno-oncology (Mechanisms, Indications, Toxicities, and Prognosis). We generated 60 open-ended questions (15 for each section). Questions were manually submitted to LLMs, and responses were collected on June 30, 2023. Two reviewers evaluated the answers independently. RESULTS: ChatGPT-4 and ChatGPT-3.5 answered all questions, whereas Google Bard answered only 53.3% (P < .0001). The number of questions with reproducible answers was higher for ChatGPT-4 (95%) and ChatGPT3.5 (88.3%) than for Google Bard (50%) (P < .0001). In terms of accuracy, the number of answers deemed fully correct were 75.4%, 58.5%, and 43.8% for ChatGPT-4, ChatGPT-3.5, and Google Bard, respectively (P = .03). Furthermore, the number of responses deemed highly relevant was 71.9%, 77.4%, and 43.8% for ChatGPT-4, ChatGPT-3.5, and Google Bard, respectively (P = .04). Regarding readability, the number of highly readable was higher for ChatGPT-4 and ChatGPT-3.5 (98.1%) and (100%) compared to Google Bard (87.5%) (P = .02). CONCLUSION: ChatGPT-4 and ChatGPT-3.5 are potentially powerful tools in immuno-oncology, whereas Google Bard demonstrated relatively poorer performance. However, the risk of inaccuracy or incompleteness in the responses was evident in all 3 LLMs, highlighting the importance of expert-driven verification of the outputs returned by these technologies.

Comparison of Large Language Models in Answering Immuno-Oncology Questions: A Cross-Sectional Study.

Background: The capability of large language models (LLMs) to understand and generate human-readable text has prompted the investigation of their potential as educational and management tools for cancer patients and healthcare providers. Materials and Methods: We conducted a cross-sectional study aimed at evaluating the ability of ChatGPT-4, ChatGPT-3.5, and Google Bard to answer questions related to four domains of immuno-oncology (Mechanisms, Indications, Toxicities, and Prognosis). We generated 60 open-ended questions (15 for each section). Questions were manually submitted to LLMs, and responses were collected on June 30th, 2023. Two reviewers evaluated the answers independently. Results: ChatGPT-4 and ChatGPT-3.5 answered all questions, whereas Google Bard answered only 53.3% (p <0.0001). The number of questions with reproducible answers was higher for ChatGPT-4 (95%) and ChatGPT3.5 (88.3%) than for Google Bard (50%) (p <0.0001). In terms of accuracy, the number of answers deemed fully correct were 75.4%, 58.5%, and 43.8% for ChatGPT-4, ChatGPT-3.5, and Google Bard, respectively (p = 0.03). Furthermore, the number of responses deemed highly relevant was 71.9%, 77.4%, and 43.8% for ChatGPT-4, ChatGPT-3.5, and Google Bard, respectively (p = 0.04). Regarding readability, the number of highly readable was higher for ChatGPT-4 and ChatGPT-3.5 (98.1%) and (100%) compared to Google Bard (87.5%) (p = 0.02). Conclusion: ChatGPT-4 and ChatGPT-3.5 are potentially powerful tools in immuno-oncology, whereas Google Bard demonstrated relatively poorer performance. However, the risk of inaccuracy or incompleteness in the responses was evident in all three LLMs, highlighting the importance of expert-driven verification of the outputs returned by these technologies.

Quantitative Analysis of Serial Positron Emission Tomography Imaging in Men with Metastatic Castration-resistant Prostate Cancer Treated with Enzalutamide.

BACKGROUND: The emergence of positron emission tomography (PET) in prostate cancer is impacting clinical practice, but little is known about PET imaging as a tool to determine treatment failure in metastatic castration-resistant prostate cancer (mCRPC). OBJECTIVE: To evaluate PET imaging dynamics in mCRPC patients on enzalutamide with stable computed tomography (CT) and technetium-99m (Tc99) bone scans. DESIGN, SETTING, AND PARTICIPANTS: All patients were on treatment with enzalutamide for first-line mCRPC in a clinical trial at the National Cancer Institute (Bethesda, MD, USA). A volunteer sample had serial 18F-sodium fluoride (NaF) PET in parallel with CT and Tc99. Regions of interest (ROIs) on NaF were analyzed quantitatively for response. INTERVENTION: Patients were randomized to enzalutamide with/without a cancer immunotherapy, Prostvac. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: A post hoc, descriptive analysis was performed comparing the changes seen on CT and Tc99 as per RECIST 1.1 with NaF PET scans including the use of a quantitative analysis. RESULTS AND LIMITATIONS: Eighteen mCRPC patients had 67 NaF scans. A total of 233 ROIs resolved after treatment, 52 (22%) of which eventually retuned while on therapy. In all, 394 new ROIs were seen, but 112(28%) resolved subsequently. Of 18 patients, 14 had new ROIs that ultimately resolved after appearing. Many patients experienced progression in a minority of lesions, and one patient with radiation intervention to oligoprogression had a remarkable response. This study is limited by its small number of patients and post hoc nature. CONCLUSIONS: These data highlight the dynamic nature of NaF PET in mCRPC patients treated with enzalutamide, where not all new findings were ultimately related to disease progression. This analysis also provides a potential strategy to identify and intervene in oligoprogression in prostate cancer. PATIENT SUMMARY: In this small analysis of patients with prostate cancer on enzalutamide, changes on 18F-sodium fluoride positron emission tomography (PET) imaging were not always associated with treatment failure. Caution may be indicated when using PET imaging to determine whether new therapy is needed.

Applications of large language models in cancer care: current evidence and future perspectives.

The development of large language models (LLMs) is a recent success in the field of generative artificial intelligence (AI). They are computer models able to perform a wide range of natural language processing tasks, including content generation, question answering, or language translation. In recent months, a growing number of studies aimed to assess their potential applications in the field of medicine, including cancer care. In this mini review, we described the present published evidence for using LLMs in oncology. All the available studies assessed ChatGPT, an advanced language model developed by OpenAI, alone or compared to other LLMs, such as Google Bard, Chatsonic, and Perplexity. Although ChatGPT could provide adequate information on the screening or the management of specific solid tumors, it also demonstrated a significant error rate and a tendency toward providing obsolete data. Therefore, an accurate, expert-driven verification process remains mandatory to avoid the potential for misinformation and incorrect evidence. Overall, although this new generative AI-based technology has the potential to revolutionize the field of medicine, including that of cancer care, it will be necessary to develop rules to guide the application of these tools to maximize benefits and minimize risks.

Efficacy and safety of PARP inhibitors in metastatic castration-resistant prostate cancer: A systematic review and meta-analysis of clinical trials.

INTRODUCTION: PARP inhibitors (PARPi) are a standard-of-care (SoC) treatment option for patients with metastatic castration-resistant prostate cancer (mCRPC). Several clinical trials have shown the potential of combining PARPi with other anticancer agents. Therefore, we conducted a systematic review and meta-analysis to comprehensively evaluate the efficacy and safety of PARPi in patients with metastatic prostate cancer. METHODS: MEDLINE, Cochrane CENTRAL, EMBASE, CINAHL, and Web of Science were searched on March 22nd, 2023, for phase 2 or 3 clinical trials. Efficacy (progression-free survival [PFS], overall survival [OS], PSA decline >50% [PSA50], and objective response rate [ORR]) and safety outcomes were assessed in the included studies. RESULTS: Seventeen clinical trials (PARPi monotherapy [n = 7], PARPi + androgen-receptor signaling inhibitors [ARSI] [n = 6], and PARPi + immune checkpoint inhibitors [ICI] [n = 4]) were included in the quantitative analyses. PARPi monotherapy improved radiographic PFS and OS over SoC in mCRPC patients with alterations in BRCA1 or BRCA2 genes but not in those with alterations in the ATM gene. Higher rates of PSA50 and ORR were reported in participants treated with PARPi + ARSI than in single-agent PARPi or PARPi + ICI. Although the rate of high-grade adverse events was similar across all groups, treatment discontinuation was higher in patients treated with PARPi-based combinations than PARPi monotherapy. CONCLUSION: The efficacy of PARPi is not uniform across mCRPC patients with alterations in DNA damage repair genes, and optimal patient selection remains a clinical challenge. No unexpected safety signals for this class of agents emerged from this analysis.

Flutamide With or Without PROSTVAC in Non-metastatic Castration Resistant (M0) Prostate Cancer.

BACKGROUND: Before 2018, there was no standard of care for non-metastatic (M0) castration resistant prostate cancer nmCRPC. Androgen receptor antagonists (ARAs) were commonly used sequentially nmCRPC. METHODS: This was a multicenter, randomized clinical trial comparing the ARA flutamide+/-PROSTVAC, a pox viral vaccine targeting PSA that includes T-cell co-stimulatory molecules. Eligible men had negative CT and Tc99 bone scans, and rising PSA on ADT. Previous treatment with ARA was a stratification factor. Patients were also evaluated for antigen-specific immune responses using intracellular cytokine staining. RESULTS: Thirty-three patients randomized to flutamide and 31 to flutamide+vaccine. The median age was 71.8 and 69.8 years, respectively. The median time to treatment failure after a median potential follow-up of 46.7 months was, 4.5 months (range 2-70) for flutamide alone vs. 6.9 months (2.5-40; P = .38) with flutamide+vaccine. Seven patients in each arm had a >50% PSA response. Antigen-specific responses were similar in both arms (58% of patients in flutamide alone and 56% in flutamide+vaccine). The treatments were well tolerated. The most common side effect > grade 2 was injection site reaction seen in 29/31 vaccine patients which were self-limiting. CONCLUSION: The combination of flutamide+PROSTVAC did not improve outcomes in men with nmCRPC compared with flutamide alone. (ClinicalTrials.gov Identifier: NCT00450463).

Relugolix in Clinical Practice: The Best Route for All?

Androgen deprivation therapy (ADT) has been a mainstay of prostate cancer treatment for decades. Relugolix was FDA-approved in 2020 and is currently the only ADT option via an oral route. While the opportunity to use an oral medication for this indication has some advantages, a balanced discussion is required to understand in what clinical settings this agent truly has benefit over long-acting injectable formulations of ADT. Furthermore, patient preference, compliance, financial toxicity, and perhaps most importantly, pharmacologic characteristics must be considered.

Emerging treatment options for prostate cancer.

INTRODUCTION: Prostate cancer treatment has rapidly evolved in the past few years. Androgen deprivation therapy has been the backbone of treatment for locally advanced and metastatic prostate cancer, but incremental benefits in survival have been shown by adding androgen-receptor pathway inhibitors (ARPI) across various spectrums of disease state. In addition, docetaxel chemotherapy remains the first-line chemotherapy regimen available with survival benefits shown with triplet therapy in those who are chemotherapy eligible. However, disease progression remains inevitable and novel agents such as radioligand therapy with lutetium have shown improvement in survival. AREAS COVERED: This review discusses the pivotal trials that led to the U.S. FDA approval of agents utilized in metastatic prostate cancer and explores the use of novel agents including prostate-specific membrane antigen-targeting agents, radioligands, cell-based therapy, chimeric antigen receptor T-cell, BiTE, and antibody drug conjugates. EXPERT OPINION: Treatment landscape for metastatic castrate-resistant prostate cancer (mCRPC) has evolved beyond additional agents with ARPI and/or docetaxel, including other treatments with sipuleucel-T, radium, cabazitaxel, PARP inhibitors, and lutetium, which have specific indications and roles in sequencing. Novel therapies remain critically needed after progression from lutetium.

First-line pembrolizumab plus androgen deprivation therapy for locally advanced microsatellite instability-high prostate cancer in a patient with Muir-Torre syndrome: A case report.

The risks of development of colorectal and endometrial cancers in individuals with Lynch syndrome (LS) are well known and have been widely studied. In recent years, the potential association of other malignancies, including prostate cancer, with LS has been considered. Decision-making regarding screening for prostate cancer in the generalized population can be complicated; accounting for the possibility of a higher risk of cancer conferred by a potential genetic predisposition confounds the creation of salient guidelines even further. Although tissue-agnostic treatment approvals have been granted to several immune checkpoint inhibitors (ICIs) for their use in the treatment of subsets of patients whose tumors exhibit high levels of microsatellite instability or high tumor mutational burden, a paucity of data exists regarding the use of ICIs in the first line treatment of patients with locally advanced prostate cancer harboring these features. A significant reduction in tumor volume in response to the combination of immune checkpoint inhibition and androgen deprivation therapy is described in this report of a male with Muir-Torre syndrome who was found to have locally advanced adenocarcinoma of the prostate. While anecdotal, the anti-tumor activity of this combination of therapy is notable and calls attention to the importance of considering further investigation of the use of immune checkpoint blockade as a primary therapeutic option in patients with localized prostate cancer.

Avelumab in Men With Metastatic Castration-Resistant Prostate Cancer, Enriched for Patients Treated Previously With a Therapeutic Cancer Vaccine.

Therapeutic cancer vaccines including sipuleucel- T , a prostatic acid phosphatase (PAP) targeted vaccine that improves survival in metastatic castration-resistant prostate cancer (mCRPC), can produce immune responses that translate to clinical benefit. The effects of sequential checkpoint inhibitors after therapeutic vaccine on immune responses are unknown. Avelumab is an anti-programmed death ligand-1 monoclonal antibody evaluated in patients with mCRPC in the JAVELIN solid tumor phase 1 trial expansion cohort, enriched for patients with a previous therapeutic prostate cancer-targeted vaccine. mCRPC patients received intravenous avelumab 10 mg/kg every 2 weeks with imaging every 6 weeks. Peripheral blood T-cell responses to PAP and to PA2024, the peptide containing PAP utilized by the vaccine, were evaluated pre and posttreatment. Eighteen patients enrolled, and previous treatments included abiraterone or enzalutamide in 14 (78%), therapeutic cancer vaccine in 14 (78%), and chemotherapy in 4 (22%). Avelumab had a manageable safety profile. There were no sustained prostate specific antigen decreases. Of 17 patients evaluable for best overall response by RECISTv1.1, 12 had stable disease (SD) and 5 had progressive disease. Seven patients had SD for >24 weeks posttreatment. Fourteen patients had previously received therapeutic cancer vaccines. Eleven (79%) had SD as the best overall response. Of these 14 patients, 9 had previously received sipuleucel T . Analysis of antigen-specific T-cell responses pre and postavelumab treatment did not demonstrate changes in interferon-γ production or proliferation in response to PAP or PA2024. This unplanned analysis does not support the use of sequential therapeutic cancer vaccine therapy followed by programmed death ligand-1 inhibition in mCRPC.

A Phase I Single-Arm Study of Biweekly NHS-IL12 in Patients With Metastatic Solid Tumors.

BACKGROUND: NHS-IL12 is a first-in-class, recombinant fusion protein composed of the human monoclonal antibody NHS76 (binds exposed DNA/histones at sites of intratumoral necrosis) fused to 2 IL-12 heterodimers. The maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of NHS-IL12 monotherapy given subcutaneously (SC) every 4 weeks was previously reported. The study was expanded to include a high-exposure cohort with NHS-IL12 SC every 2 weeks (q2w). METHODS: This single-arm, phase I trial evaluated NHS-IL12 12 µg/kg SC q2w or 16.8µg/kg SC q2w in patients with metastatic solid tumors. The primary endpoint was safety. RESULTS: Using a 3+3 design, 13 patients with advanced cancer were enrolled and 12 were dose-limiting toxicity (DLT) evaluable. There was 1 DLT (Grade 3 aspartate transaminase/alanine transaminase [AST/ALT] elevation). Other grade 3 toxicities included: flu-like symptoms 1/13 (8%), decreased absolute lymphocyte count (ALC) 1/13 (8%), decreased white blood cell count (WBC) 1/13 (8%), but most adverse events reported were low grade and self-limiting grade. Fifty percent of evaluable patients (6/12) experienced stable disease (SD) with 42% (5/12) developing progressive disease (PD) at the first restaging. CONCLUSION: Biweekly NHS-IL12 was well tolerated in this small phase I study. Additional studies incorporating NHS-IL12 with other immunomodulating agents are underway. (ClinicalTrials.gov Identifier: NCT01417546).