Moore, Cassandra N.

Abstract Introduction: Attending to survivorship including distress in the contexts of social drivers (SDH) is critical but lacking. In response, this novel research on Black CaP survivors (CaPS) aims to measure SDH distresses and assess utility of a digital intervention to inform survivorship studies, practice and outcomes. Method: Informed by the Science of Survivorship, and our pilot study with multisectoral stakeholders, we assessed SDH and acceptability/utility of a digital Survivorship Care (SC) Toolkit. SCToolkit is a digitized whole-person care with guidance from multisectoral stakeholders e.g., clinicians and survivors. SCToolkit includes: ASCO informed treatment summary template for diagnostics, treatments, side effects, care team, genetics, and comorbidities, and patient active guide on survivorship concerns, provider communication, health advisories, survivorship care booklet, SDH FINDHELP resource, and survivorship videos. SCToolkit was delivered via survivors’ personal REDCap file, and can be uploaded to their EMR patient portal for easy-to-use survivorship roadmap accessible on smartphones, laptops, and computers. Motivational Interviewing was provided via Zoom to facilitate digital efficacy and SCToolkit use. Descriptive analyses were conducted using SAS. Citation Format: Kimlin Ashing, Floyd Willis, Christopher Williams, John McCall, Gaole Song, Douglas Adu-Fokuo, Erika Galdamez, Fornati Bedell, Cassandra N. Moore, EWAN COBRAN, Che Ngufor, Kathleen J. Yost, Timethia J. Bonner, Getachew Dagne, Arnold Merriweather, Ernest T. Kaninjing, Rotimi Oladapo, Roxana S. Dronca, Folakemi T. Odedina. Examining contextual distress and utility of a digital survivorship care toolkit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 880.

Abstract Introduction: This ongoing study investigates the impact of vitamin D deficiency on the immune response to prostate cancer (CaP) in Black patients and its potential contribution to CaP disparities. The study also evaluates differences in immune function, including p53 and CaP associated antibody levels, in Black men with localized versus metastatic CaP. Methodology: Eligible patients with a history of localized or metastatic CaP are enrolled following informed consent (in person or remote). At baseline, blood is collected for calcium and vitamin D3 levels, and for immune testing. Patients who participate in the screening portion of the trial and are found to have vitamin D3 levels <30 ng/mL are prescribed oral vitamin D3 (2000 IU daily) and asked to record adherence in a medication diary. Follow-up includes a 4-week check-in and end-of-treatment labs at 8 weeks for calcium, vitamin D3 levels, and immune re-testing. Virtual consults occur after baseline and at 8 weeks. Quality of life is measured at baseline and EOT follow-up using the CDC HRQOL–4. The study began accruing patients in December 2021. In an attempt to accelerate patient accrual, the protocol was amended to become one of Mayo Clinic’s first fully decentralized clinical trials. Newly integrated components included at-home and community-based blood collection (outside of Mayo Clinic southern sites) and continued virtual engagement. These changes were designed to reduce barriers linked to social determinants of health (SDOH) and expand participation among medically underserved populations. This is a report on the impact of clinical trial DCT. Results: From December 2021 to September 2023 (pre-DCT), 24 patients were enrolled from 66 patients who participated in the screening portion for the trial (mean accrual: 1.09/month; SD: 1.15). Following the DCT amendment, enrollment rose to 102 patients from 213 screened (mean: 4.86/month; SD: 3.12) through June 2025. Of 126 enrolled patients, 119 (94.4%) returned medication diaries, with only 6 non-returns occurring post-DCT. QOL measures were completed by approximately 75% of participants. Importantly, 90 of 126 participants (71%) were enrolled from outside Jacksonville, FL or Scottsdale/Phoenix, AZ, indicating successful national expansion. A total of 111 patients failed the screening due to baseline vitamin D levels >30 ng/ml. The total number of protocol deviations increased post-DCT (60 from 10/23–6/25 vs. 14 from 12/21–9/23), there was no change in the number of protocol deviations per enrolled patients. Minor documentation and study timeline deviations were the most common in both periods. Conclusions: The successful implementation of a fully decentralized model was associated with a marked increase in the accrual of underserved patients and allows the completion of critical clinical trials that address important cancer care disparities without impacting protocol integrity. Clinical trial DCT can potentially reduce SDOH-related barriers and improve representation of underserved populations in research. Citation Format: Sandra Casanova Leyva, Kim M. Barbel Johnson, Tufia Haddad, Lydia Mercado, Trevanne Matthews Hew, Cassandra Moore, Gerardo Colon-Otero, Devina Joshi, Roselyn Heduvor. Feasibility of an interventional clinical trial addressing prostate cancer disparities in Black men by decentralization (DCT): A potential solution to disparities in clinical trial participation [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr C064.

Abstract Introduction: Advances in treatment have led to significant increases in survival rates, with over 90% of men diagnosed with prostate cancer (CaP) living at least five years. However, surviving cancer and its treatment often weigh a hefty survivorship burden. Men from the at-risk, vulnerable populations have the greatest burden. This study aims to understand distress among Black CaP survivors (CaPS) who bear the heaviest CaP burden. Method: We conducted key informant interviews with Motivational Interviewing techniques to collect CaPS demographic information, medical history, and multilevel distress evaluation. Descriptive analyses were conducted using SAS. Results: A total of 22 CaPS (aged from 48 to 72) were involved in the study. The majority of CaPS were African American (90.9%) and were diagnosed with stage 2 (31.8%) or stage 3 (36.4%). Over half of them (68.2%) were treated by surgery; most CaPS (90.9%) experienced side effects from prostate cancer treatments. CaPS reported distress in the following domains: Emotional well-being (e.g., Feeling sad, depressed or anxious, mental health) – 40.9%, Death of someone very close to you (e.g., family) – 36.4%, Alcohol use in close family – 36.4%, Experiences of discrimination or racism – 36.4%, Healthcare costs and coverage (e.g., medication, medical services, copay, insurance premium) – 31.8%, Loneliness and isolation – 27.3%, Serious injury/illness in close family (e.g., being a caregiver) – 27.3%, Money and finance – 22.7%, Using telehealth (e.g., using a smartphone or tablet for telephone or over the computer, clinic visit, patient portal, completing online forms, virtual classes) – 22.7%, Marriage, romantic relationships – 22.7%. Discussion: Black CaP survivors (CaPS) who bear the heaviest CaP burden are considered a priority population for research and care. These CaPS identified that their psychological distress was related to both familial and socioeconomic issues. The most endorsed life-stresses included emotional wellbeing, experiences of discrimination/racism, loneliness and isolation, healthcare cost/finance, family health, personal relationship, and telehealth use. The distress data as measured by the life-stress scale are invaluable in better documenting and addressing distress in interventions responsive to specific priority communities. Our novel findings suggest the relevance of grief and loss for these men. 36% reported death of someone close, and 27% indicated distress due to loneliness and isolation. Though the sample size was small, the distress data obtained may inform the science and practice of whole-person survivorship that consider distress emphasizing emotional wellbeing. The study is ongoing, and this abstract presents preliminary results; further muti-variate analyses will be conducted for the conference presentation. Citation Format: Kimlin Ashing, Floyd Willis, Chris Williams, John Mccall, Gaole Song, Fornati Bedell, Cassandra Moore, Ewan Cobran, Che Ngufor, Timethia Bonner, Getachew Dagne, Arnold Merriweather, Ernie Kaninjing, Rotimi Oladapo, Roxana Dronca, Fullwood Dottington, Folakemi Odedina. Whole person survivorship: Multilevel distress in prostate cancer survivors from priority communities [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A024.

Abstract In the US and globally, Black men experience the highest prostate cancer burden among all racial and ethnic groups, underscoring the urgent need for research to guide the development and implementation of culturally tailored strategies aimed at reducing disparities and improving outcomes. In response, the Inclusive Cancer Care Research Equity (iCCaRE) Consortium was created to advance health equity and reduce disparities in prostate cancer. Importantly, a Survivorship Care Plan (SCP) is recommended to educate and empower patients, enabling them to be better informed about their cancer diagnosis, treatment, and survivorship care recommendations. To date, there is no SCP targeted to Black prostate cancer survivors (CaPS) who have the greatest disparities with the poorest survivorship outcomes (ACS F&F; AACR HD Report; Fullwood, 2024). Therefore, we aimed to develop a SCP tailored for Black men. Addressing the unique needs of Black men require a genuine bidirectional relationship between scientist and the community rooted in community engaged research (CER). The SCP was first informed by the literature (Bonner, 2024) and the ASCO template (canceradvocacy.org). With input from the iCCaRE leadership and the Partnership Engagement Services (PES) Core, the Whole Person SCP better responds to the informational, clinical and quality of life needs of Black Prostate Cancer survivors. Based on CER, we included 22 diverse, Black CaPs to further guide and tailor the iCCaRE. Our findings indicate that the iCCaRE Survivorship Care Plan (SCP) enhanced the ASCO template by incorporating and expanding several unique domains, including family history, care team contacts, follow-up and surveillance, symptoms, quality of life, survivor concerns, major comorbidities, health advisories, and culturally relevant resources, creating a comprehensive, whole-person SCP tailored specifically for Black men. It is crucial to continue to improve support for clinical research and advocate for Black men and their communities to reduce prostate cancer burden. Prostate cancer also needs to include incidence, mortality, and disparities for Black men to raise awareness of scarcely studied field of Black men and prostate cancer survivorship. Citation Format: Kimlin Tam Ashing, Timethia Bonner, Ewan K. Cobran, Folakemi Odedina, Aj Merriweather, Ernie Kaninjing, Floyd Willis, Cassandra Moore, Joanne Oliver, Fornati Bedell, John McCall. Advancing health equity and reducing disparities in prostate cancer in Black men: iCCaRE [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 994.

Abstract Background: Second generation androgen receptor signaling inhibitors (ARSIs), such as abiraterone, have demonstrated improved survival in metastatic castration-resistant prostate cancer (mCRPC) patients, however, acquired resistance to these agents often arises. Novel and alternative therapies are needed to combat the ARSI resistant tumor. In the last two decades patient-derived xenograft (PDX) and PDX organoids have become pivotal models in anticancer drug development and biomarker discovery due to their ability to faithfully recapitulate the complex and heterogeneous tumor biology. Methods: We analyzed RNAseq data from mCRPC patients and corresponding PDX models (PROMOTE study, NCT #01953640) and employed L1000 Chem Perturbation down/up signatures database to find candidate drugs to overcome abiraterone resistance by reverse signature search. We then performed proliferation assay using 49 compounds in three PROMOTE-PDX organoid models (2 abiraterone-resistant and 1 abiraterone-sensitive) using our semi high-throughput drug screening platform. Results: Overall, we identified a total of 32 compounds with IC50<10µM in at least one of the models, among which, 5 agents are active in all three models and 5 in at least two of the models. (Table 1). Within active compounds we find selective kinase inhibitors (BRAF, JAK2, AKT, FLT3) and histone deacetylase inhibitors (belinostat and pracinostat). Particularly interesting are two drugs that are only active in the abiraterone resistant setting but not the sensitive PDX. Conclusions: In summary, we leveraged RNAseq data from mCRPC patients and PDX models and performed a high-throughput drug screen in PDX-derived organoid models to identify potential drugs that could overcome abiraterone-resistance in lethal advanced prostate cancer. These data highlight potential drug combinations or subsequent therapeutic strategies for these patients. Citation Format: Irene Marín-Goñi, Huanyao Gao, Joachim L. Petit, Shreya Indulkar, Adam M. Kase, Cassandra N. Moore, Krishna R. Kalari, Michael T. Barrett, Richard Weinshilboum, Winston Tan, John A. Copland, Liewei Wang. Overcoming resistance in mCRPC: drug discovery using PDX models and high-throughput drug screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5658.

132 Background: Distant metastasis at the time of prostate cancer (PCa) diagnosis is associated with increased morbidity and mortality. This study aimed to assess the impact of sociodemographic characteristics on distant metastasis at the time of PCa diagnosis. Methods: The Surveillance Epidemiology and End Results (SEER) database (2000-2021), including PCa patients from 17 registries, was queried. Patients with late-stage diagnosis (LSD) were defined as those who were initially diagnosed with stage IV disease, indicating distant metastasis. Sociodemographic predictors included race, ethnicity, age, marital status, residential status, and median household income. Multicollinearity was assessed using variance inflation factors (VIF). Univariable logistic regression was performed to identify significant predictors of LSD, which were further analyzed in multivariable logistic regression using a maximum likelihood estimation approach. Odds ratios with 95% confidence intervals (CI) were computed with a p-value of <0.05 indicating a statistically significant association. Results: Of the 1,089,736 PCa patients diagnosed, 64,983 (6%) had an LSD. The majority were white (80%), non-Hispanic/Latino (HL) (91%), aged ≥65 years (60%), married (75%), residents in metropolitan areas (88%), and had an annual house income of ≥$70,000 (70%). Multivariable logistic regression identified Black (OR: 1.24; 95%CI: 1.22-1.27), Asian or Pacific Islander (1.35; 1.30-1.40), and American Indian/Alaska Native (1.70; 1.53-1.89) to have higher odds of LSD compared to White patients (Table). In addition, HL ethnicity compared to non-HL (OR: 1.45; 95% CI: 1.42-1.49), age ≥65 compared to <65 (1.68; 1.65-1.71), unmarried status compared to married (1.88; 1.85-1.91), residency in non-metropolitan areas compared to metropolitan (1.10; 1.07-1.12), and household income <$70,000 compared to ≥$70,000 (1.03; 1.01-1.05) had a significant association with LSD. Conclusions: Older, non-White (Black, Asian/Pacific Islander, American Indian/Alaska Native), Hispanic/Latino, unmarried men, residents of non-metropolitan areas, or those with lower annual household incomes have higher odds of late-stage diagnosis. Interventions targeting early detection in these at-risk groups may improve prostate cancer outcomes in the US. Variable Odds Ratio (95% CI) p-value Race (Black vs White) 1.24 (1.22-1.27) <0.01 Race (Asian or Pacific Islander vs White) 1.35 (1.31-1.40) <0.01 Race (American Indian/Alaska Native vs White) 1.70 (1.53-1.89) <0.01 Ethnicity (Hispanic/Latino vs non-/Hispanic/Latino) 1.45 (1.42-1.49) <0.01 Age (≥65 vs <65) 1.68 (1.65-1.71) <0.01 Marital status (unmarried vs married) 1.88 (1.85-1.91) <0.01 Residence status (non-metropolitan vs metropolitan) 1.10 (1.07-1.12) <0.01 Household income (<$70,000 vs ≥$70,000) 1.03 (1.01-1.05) <0.01

Abstract Intro: Compared to white men, Black men bear the highest burden of prostate cancer, experiencing a higher incidence and mortality rate, and poorer survivorship outcomes. Although prioritized, survivorship and quality of life (QOL) are under-studied in the fight against prostate cancer disparities. To address this issue, clinicians, researchers, and community advocates have formed the Inclusive Cancer Care Research Equity (iCCaRE) Consortium for Black Men. iCCaRE’s goal is to advance the science and practice of survivorship focused on the needs of Black men and their loved ones affected by prostate cancer. Methods: We developed a survivorship care plan (SCP) tailored to the whole person's needs. IRB-approved qualitative methods to preliminarily gain evaluation and guidance on the SCP. The SCP presented content in the following areas: diagnosis and treatment, follow-up care/surveillance, family history, care team, major co-morbidities, symptoms and quality of life, survivorship concerns, and health advisories. Results: 23 Black prostate cancer survivors (PCS) participated and provided feedback on the SCP Mean age was 64 years. PCS diagnosed between 2018-2023 between stages 1-4. The Majority of PCS were provided information for follow-up and side effects. But none had received a comprehensive SCP All agreed that the SCP would contribute to enhancing cancer knowledge, patient activation, and shared decision, and their QOL, if the SCP was obtained. A survivor noted “having inspirational quotes throughout the SCP is important”. An unforeseen consequence to the interviews was the emotional release for the men, justifying the need for the SCP and an expansion of its scope. Domains that the men wanted more contents were social support, sexuality, masculinity, and maintaining a healthy lifestyle. All PCS understood the value of having trusted family and friends to bear the burden of the disease despite some not having a solid support system. PCS emphasized the role of family support stating, “my wife and children helped me stay positive”. Another critical lifestyle component that survivors mentioned was their sexuality and how it directly reflects their masculinity. Although PCS adapted to other forms of intimacy like couples’ activities and stronger communication with their partners, majority of men struggle with adapting to their sexual performance. A quote by a survivor encompasses the mindset expressed by many of the men fear “Like a track star in his prime who can’t run anymore”. Erectile Dysfunction can lead to fear and anxiety among survivors, ultimately affecting QOL. Lastly, PCS wanted more options to stay fit and healthy. Further research and resources are needed to address survivor concerns in this area. Discussion: Overall, PCS have acknowledged that the SCP can assist them in these areas of concern, but more research is required. Life after prostate cancer treatment is an ongoing process; while some survivors cope better than others, it is evident a need for more information and guidance is not being provided to all those affected. Citation Format: James Morrison, Kimlin Ashing, Gaole Song, John McCall, Timethia J. Bonner, Che Ngufor, Getachew A. Dagne, Arnold Merriweather, Ewan Cobran, Cassandra N. Moore, Fornati Bedell, Rotimi Oladapo, Floyd B. Willis, JoAnne S. Oliver, Ernie Kaninjing, Roxana Dronca, Folakemi T. Odedina. iCCaRE qualitative interviews for Black prostate cancer survivors and quality of life [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C042.

TPS5108 Background: Penile cancer is a devastating malignancy that affects just over 2000 patients per year in the United States and approximately 40,000 worldwide. Metastatic or unresectable penile cancer is rapidly fatal in most cases and there are few effective systemic therapy options.1 There is an urgent need for alternatives to chemotherapy such as immunotherapy or targeted therapy. Enfortumab vedotin (EV) is an antibody-drug conjugate targeting nectin-4 protein on the tumor cell surface and having efficacy in treatment of metastatic urothelial carcinoma.2 Recent studies have demonstrated frequent and strong expression of nectin-4 in penile squamous cell carcinoma (PSCC).3,4 In this setting, Mayo Clinic is leading a phase II trial of EV for advanced PSCC, currently in progress. Methods: This single arm, open-label, two-stage, phase II trial evaluates best overall response rate (BRR) to EV in patients with PSCC regional lymph node involvement or distant metastatic (M1) disease. Participants may have had any prior systemic therapy or be treatment naïve. Previously untreated patients must be ineligible for or have refused surgery or radiotherapy, have N2-N3 disease and are ineligible for or have refused neoadjuvant chemotherapy, or have clinical evidence of M1 disease. Participants will receive treatment with EV until disease progression, withdrawal, death, or limiting toxicity. Participants will receive EV 1.25 mg/kg intravenous on days 1, 8, and 15 of a 28-day cycle, with tumor assessment performed at 8-week intervals. The primary endpoint is the combined BRR of partial and complete responses (whether confirmed or unconfirmed) according to RECIST 1.1. Secondary endpoints are confirmed response rate, duration of response, progression-free survival, overall survival, adverse events, and BRR in HPV related and unrelated subgroups. Stage 1 will consist of 15 participants, and if there are 2 or more responses will proceed to Stage 2 with an additional 10 participants. The trial opened to enrollment in December 2023, and is active at Mayo Clinic sites in Minnesota, Arizona, and Florida. Clinical trial information: Funding and drug supplied by Astellas Pharma Global Development, Inc./Seagen Inc. NCT06104618. 1. Chahoud J, et al., Curr Opin Urol. 2022 Jan 1;32(1):8-16. 2. Powles T, et al. N Engl J Med. 2021 Mar 25;384(12):1125-1135. 3. Tekin B, et al. Hum Pathol. 2023 Dec;142:42-50. 4. Grass GD, et al. Eur Urol Open Sci. 2023 Jan 10;49:1-5. Clinical trial information: NCT06104618 .

Abstract Black men hold the highest prostate cancer burden among all ethnicities; thus, there is an urgent need for research to inform the development and implementation of a culturally tailored intervention to reduce disparities and improve outcomes. In response, the Inclusive Cancer Care Research Equity (iCCaRE) Consortium was created to advance health equity and reduce disparities in prostate cancer. Addressing the unique needs of Black men require a genuine bidirectional relationship between scientist and the community. In the Black community, faith-based organizations are respected institutions advocating for health equity and justice. Given their vital role as community health gatekeepers, the iCCaRE Consortium partners with faith-based organizations. Rooted in community engaged research (CER), we conducted an environmental scan through stakeholder meetings to discuss the prevailing challenges and opportunities to meet the needs of the Black community along the prostate cancer care continuum. iCCaRE investigators including Partnership Engagement Services (PES) core partnered with faith-based organizations to ensure and advance community responsive cancer prevention. Together, with our faith-based leaders (N=18), we identified gaps including issues associated with the care continuum from screening to diagnosis and from treatment to survivorship; disparities according to health coverage and social determinants of health, and best practices to assist patients including care coordination, patient navigation, digital innovations, and programs offered by patient advocacy organizations. In response to the needs of the community and the strengths of faith-based organization, we prioritized our initial focus on increasing community prostate cancer literacy and activation using co-design educational infographics for both traditional and technology-based communication platforms. The infographics provided evidence-based facts about prostate cancer burden in the Black community; and using a call to action approach, we emphasized the importance of taking action for life saving screening, prevention and healthy lifestyle. Taking action in prostate cancer symptom recognition, survivorship care, and quality care. Also, co-designed infographics were created for clinical studies and biospecimen awareness and participation and the importance of advocacy and equitable care. Another component incorporated face to face trainings and presentations to enhance their knowledge of cancer screening tools, epidemiology of prostate cancer, and pathways to care. This presentation highlighted the first step towards community based intervention development, implementation and dissemination towards equity and justice for prostate cancer prevention and patient/survivor improvements for Black men. Citation Format: James C. Morrison, Kimlin T. Ashing, Gaole Song, Timethia J. Bonner, Che Ngufor, Getachew Dagne, Arnold Merriweather, John McCall, Ewan Cobran, Cassandra N. Moore, Fornati Bedell, Rotimi Oladapo, Floyd B. Willis, Runcie Chidebe Chidebe, Noreen A. Stephenson, JoAnne S. Oliver, Vinessa Gordon, Folakemi Odedina. iCCaRE engagement of faith-based organizations to co-create and co-disseminate infographics addressing disparities in prostate cancer literacy and clinical and biospecimen studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 808.

173 Background: The data for combining PARPi and ARPi in mCRPC have shown conflicting results. Here, we report a quantitative summary of benefits by clinically meaningful subgroups (HRR mutation status, BRCA mutation status) to guide the use of PARPi and ARPi combination in mCRPC setting. Methods: MEDLINE, EMBASE, and CENTRAL were systematically searched from each database’s inception through September 7, 2023. Phase III studies comparing PARPi + ARPi with ARPi + placebo in mCRPC were included. Radiographic progression-free survival (rPFS) and overall survival (OS) in patient subgroups based on HRR and BRCA mutation status were assessed. Hazard ratios for rPFS and OS with 95% CI were collected at the level of each trial, and a random-effects meta-analysis was conducted using an inverse variance approach. Subgroup differences were assessed and p-value of interaction <0.1 was considered statistically significant. Results: The literature search identified 4976 studies from which 3 trials (11 references) – TALAPRO2, PROpel and MAGNITUDE met the inclusion criteria. A total of 2254 participants were eligible for analysis. PARPi + ARPi prolonged rPFS in patients with HRR mutations (HR: 0.55, 95%CI: 0.38-0.78) as well as in patients without HRR mutations (HR: 0.74, 95%CI: 0.63-0.88). There is no evidence of treatment interaction by HRR mutation status (p = 0.14). In patients harboring HRR mutations, improved rPFS was observed in those with BRCA mutations (HR: 0.28, 95%CI: 0.13-0.62) as well as those without BRCA mutations (HR: 0.72, 95%CI: 0.59-0.87). However, there is evidence that patients with BRCA mutations derived greater rPFS benefit as compared to patients without BRCA mutations (p =0.02). PARPi + ARPi showed no significant improvement in overall survival either in patients with HRR mutations (HR: 0.79, 95%CI: 0.59-1.05) or in patients without HRR mutations (HR: 0.92, 95%CI: 0.74-1.14). Conclusions: Genomic testing for HRR genes is mandatory to guide clinical decision making in mCRPC patients. Patients harboring BRCA mutations are most likely to derive clinically meaningful benefit from combination PARPi + ARPi treatment. [Table: see text]