Riaz, Anum

116 Background: The impact of socioeconomic status on genitourinary (GU) cancer mortality in the United States (US) is unclear. Hence, we evaluated the association of the socioeconomic status with GU cancer mortality across the US counties. Methods: County-level age-adjusted mortality rates (AAMR) per 100,000 person-years (PY) for populations diagnosed with GU cancers were abstracted from the wide-ranging online data for epidemiological research (WONDER) database. The agency for toxic substances and disease registry (ATSDR) was queried to obtain county-level social vulnerability indices from 2014-2018. Percentile ranking scores (PRS: ranging from 0-1) were computed for each US county and further categorized into quartiles (Q: 1st: 0-0.25 [least vulnerable]; 4th: 0.75-1.00 [most vulnerable]). AAMRs were then linked with quartile rankings. A population-weighted, Poisson regression analysis was conducted to compute rate ratios (RR) of AAMRs between 4th and 1st Q with the corresponding 95% confidence intervals (CI). Results: A total 3142 US counties were included in this analysis. The AAMR for GU cancers was 22.6 overall deaths (OD) and 4.20 premature deaths (PD; defined as death at age <65 years) per 100,000 PY. GU cancer-related mortality increased in a stepwise fashion from the 1st Q to the 4th Q (OD: 21.6 vs 24.1; PD: 3.48 vs 5.19). In terms of OD by specific GU cancers, significantly higher AAMRs were observed in the 4th Q compared to the 1st Q for patients with prostate cancer (RR; 1.19 [95% CI;1.14-1.24]), and renal cell carcinoma (RCC; 1.12 [1.04-1.21]) but not for those with lower urothelial tract cancers (0.92 [0.87-0.96]). Among subgroups, non-Hispanic Blacks (1.19 [1.07-1.33]), and Hispanics (1.28 [1.08-1.51]) with prostate cancer and men with RCC (1.11; 1.03-1.19) in the 4th Q experienced significantly higher overall mortality when compared to those in the 1st Q. With regards to PD, significantly higher AAMRs were observed in the 4th Q vs 1st Q for patients with prostate cancer (1.54 [1.34-1.77]), and RCC (1.28 [1.12-1.45]). Consistently, men with RCC in the 4th Q also experienced higher premature mortality when compared to the 1st Q. Sparsity of mortality data among different ethnic/racial subgroups across the US counties precluded any formal assessment of disparity by specific GU cancers. A sensitivity analysis, conducted using the weighted linear regression approach, showed consistent results. Conclusions: Population level data suggest that socially vulnerable populations, especially Non-Hispanic Black and Hispanic men with prostate cancer, and men with renal cell carcinoma may be at an increased risk of cancer-related mortality. Hence, there is a dire need to address this mortality gap across different socioeconomic subgroups to ensure health-care equity. Investigations at the patient level are required to further ascertain these findings.

23 Background: Identification of factors associated with enrollment disparities in clinical trials can narrow cancer care inequities. Funding source can influence minority representation in clinical trials. Therefore, we aimed to assess the impact of funding sources on enrollment disparities in colorectal (CRC) clinical trials. Methods: CRC phase II/III randomized controlled trial (RCTs) identified through MEDLINE and EMBASE from each database’s inception through 2022 were considered eligible. Trial level enrollment incidence ratios (EIR) were computed; defined as the ratio of trial proportions of a gender, age, or racial/ethnic subgroup category and the global incidence in the corresponding gender/age subgroup (from the global burden of disease database), or the US-population-based incidence in the corresponding racial/ethnic subgroup (from SEER 21 database). EIRs were then meta-analyzed using a random-effects model for each funding source category (US- government, industry, others). Temporal trends were analyzed using a univariate meta-regression. Results: Using data from 287 RCTs, women were significantly under-represented in the industry sponsored trials (EIR: 0.85 [95% CI: 0.83 - 0.88]) but not in US-government sponsored trials (0.92 [0.84-1.00]). A total of 87 RCTs reported age proportions; older adults (above 65 years) were significantly under-represented in the industry sponsored (0.84 [0.74-0.96]) and as well as in US-government sponsored CRC trials (0.52 [0.44-0.61]). Only 56 and 15 trials reported race and ethnicity, respectively. Limited data on racial/ethnic enrollment revealed significant under-representation of Black (0.45 [0.36 -0.57]) and Hispanic (0.45 [0.31-0.66]) patients across industry sponsored CRC trials. In contrast, no significant disparity was observed in the inclusion of Asian race in the industry sponsored trials. The number of US-government sponsored trials reporting racial/ethnic subgroups were small ( < 10) which precluded any meaningful statistics. Trends show that the representation of women has improved ( P: 0.02) while the representation of Black ( P: 0.007) and Hispanic patients ( P: 0.04) has worsened over the last three decades in industry sponsored CRC trials. Conclusions: The reporting of race/ethnicity is suboptimal in CRC trials especially in those sponsored by US government. Older adults may be under-represented regardless of funding source. Women, Blacks and Hispanics may be under-represented in industry sponsored CRC clinical trials. While representation of women appears to be improving, representation of Black and Hispanic patients has worsened in industry sponsored CRC clinical trials over the last three decades.

ImportanceProstate cancer (PCa) is marked by disparities in clinical outcomes by race, ethnicity, and age. Equitable enrollment in clinical trials is fundamental to promoting health equity.ObjectiveTo evaluate disparities in the inclusion of racial and ethnic minority groups and older adults across PCa clinical trials.Data SourcesMEDLINE, Embase, and ClinicalTrials.gov were searched to identify primary trial reports from each database's inception through February 2021. Global incidence in age subgroups and US population-based incidence in racial and ethnic subgroups were acquired from the Global Burden of Disease and Surveillance, Epidemiology, and End Results 21 incidence databases respectively.Study SelectionAll phase 2/3 randomized PCa clinical trials were eligible for age disparity analyses. Trials recruiting exclusively from the US were eligible for primary racial and ethnic disparity analyses.Data Extraction and SynthesisThis study was reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data were pooled using a random-effects model.Main Outcomes and MeasuresEnrollment incidence ratios (EIRs), trial proportions (TPs) of participants 65 years or older or members of a racial and ethnic subgroup divided by global incidence in the corresponding age group, or US population–based incidence in the corresponding racial and ethnic subgroup, were calculated. Meta-regression was used to explore associations between trial characteristics and EIRs and trends in EIRs during the past 3 decades.ResultsOf 9552 participants among trials reporting race, 954 (10.8%) were African American/Black, 80 (1.5%) were Asian/Pacific Islander, and 8518 (78.5) were White. Of 65 US trials, 45 (69.2%) reported race and only 9 (13.8%) reported data on all 5 US racial categories. Of 286 global trials, 75 (26.2%) reported the enrollment proportion of older adults. Outcomes by race and age were reported in 2 (3.1%) and 41 (15.0%) trials, respectively. Black (EIR, 0.70; 95% CI, 0.59-0.83) and Hispanic (EIR, 0.70; 95% CI, 0.59-0.83) patients were significantly underrepresented in US trials. There was no disparity in older adult representation (TP, 21 143 [71.1%]; EIR, 1.00; 95% CI, 0.95-1.05). The representation of Black patients was lower in larger trials (meta-regression coefficient, −0.06; 95% CI, −0.10 to −0.02; P = .002).Conclusions and RelevanceThe results of this meta-analysis suggest that Black and Hispanic men are underrepresented in trials compared with their share of PCa incidence. The representation of Black patients has consistently remained low during the past 2 decades.

5083 Background: ARASENS and PEACE-1 trials suggests treatment intensification with novel hormonal therapy (NHT) in addition to androgen deprivation therapy (ADT) and docetaxel (DOC) provides survival benefit as compared to DOC+ADT in patients with metastatic castration sensitive prostate cancer (mCSPC). However, the performance of triplet therapy as compared to NHT+ADT remains unexplored. Methods: MEDLINE, EMBASE and recent conference proceedings were searched to include phase III trials evaluating triplet therapy in patients with mCSPC and reporting treatment effects in subgroup of patients with and without docetaxel. Outcomes included overall survival (OS) and radiographic progression free survival (rPFS). Precomputed hazard ratios (HRs) and confidence intervals (CIs) from non-randomized subgroup comparisons were pooled after logarithmic transformation using inverse-variance weighting approach. A DerSimonian-Laird random-effects meta-analysis was then performed to assess subgroup differences. Interaction between subgroups was assessed using P-value of heterogeneity. Mixed treatment comparisons were computed using a fixed-effect model within the frequentist framework using subgroup effect estimates from eligible trials. Results: This meta-analysis included five clinical trials (ARASENS, PEACE-1, ENZAMET, ARCHES and TITAN) with a total of 5804 patients (docetaxel: 2836; no docetaxel: 2836). Subgroup analysis showed statistically significant difference between treatment effects in patients who received docetaxel (NHT + DOC + ADT; HR: 0.74; 95% CI: 0.66-0.84; I2: 0%) and those who did not (NHT + ADT; HR: 0.61; 95% CI: 0.53-0.70; I2: 0%) for OS (p-value of interaction: 0.04). However, no statistically significant interaction was observed in terms of rPFS (p-value: 0.46). Mixed treatment comparisons showed improved OS with NHT + DOC + ADT (HR: 0.74; 95% CI: 0.66-0.84) as compared to DOC + ADT, but not when compared to NHT + ADT (HR: 0.97; 95% CI: 0.78-1.20). NHT + ADT significantly improved OS compared to DOC + ADT (HR: 0.77; 95% CI: 0.64-0.92). Consistently, significant rPFS improvement was observed with NHT + DOC + ADT when compared DOC + ADT (HR: 0.49; 95% CI: 0.42-0.57) but not when compared to NHT + ADT (HR: 0.82; 0.65-1.04). NHT + ADT was observed to improve rPFS compared to DOC + ADT (HR: 0.60; 95% CI: 0.50-0.72). Conclusions: This exploratory and hypothesis generating analysis suggests that addition of docetaxel (triplet therapy) may not delay progression or prolong survival compared to NHT-based doublets. These findings provide direction for future clinical trials in this space and suggest an equipoise to the question of how triplet regimens compare with NHT-doublets. The results should be interpreted with caution as this analysis does not account for potential confounding relationships such as volume of disease.

136 Background: Intensification of initial treatment of in patients with metastatic castration-sensitive prostate cancer (mCSPC) with androgen pathway inhibition (API) in addition to docetaxel (DOC) and androgen deprivation therapy (ADT) has shown promise to improve clinical outcomes. Thus, we synthesize the data from modern clinical trials to estimate overall estimates of progression and survival outcomes. Methods: A systematic search of electronic databases (MEDLINE and EMBASE) was conducted to include phase III randomized controlled trials (RCTs) evaluating triplet therapy (API+DOC+ADT) against doublet therapy (DOC+ADT) in mCSPC. Outcomes of interest included overall survival (OS) and radiographic progression-free survival (rPFS). A DerSimonian-Laird random-effects meta-analysis was performed to pool precomputed hazard ratios (HRs) and confidence intervals (CIs) after logarithmic transformation using inverse-variance weighting approach. Cochran’s Q statistical test was used to assess statistically significant heterogeneity not explained by chance, while I2 statistical test was used to quantify the total observed variability, due to between-study heterogeneity. I2 values >50% indicated substantial heterogeneity. A summary of findings table was constructed to translate relative estimates to absolute risks. Results: A total of 1,531 patients in four RCTs with direct comparative data between triplet and doublet therapies, were included in this meta-analysis. PEACE-1 was the only RCT directly assessing this question (AAP+DOC+ADT). ENZA+DOC+ADT was evaluated as a subgroup in two RCTs (ENZAMET; ARCHES), APA+DOC+ADT was evaluated as a subgroup in one (TITAN). To be able to pool studies, the relative efficacy of control arm in ENZAMET (first generation bicalutamide + ADT) was considered equivalent to ADT based on prior literature. A total of 672 rPFS events were observed (34%; 261 events in triplet therapy, 54%; 411 events in doublet therapy). The difference was statistically significant (HR: 0.49; 95% CI: 0.42-0.58; I2: 0%). Similarly, 469 OS events were observed (28%; 217 events in triplet therapy, 33%; 252 events in doublet therapy). The difference was statistically significant (HR: 0.80; 95% CI: 0.67-0.96; I2: 0%). The summary of findings is outlined in the table. Conclusions: The results of this meta-analysis support an improvement in rPFS and OS in favor of triplet therapy over doublet therapy for mCRPC. However, comparative effectiveness of different triplet regimens may be different and needs further exploration.[Table: see text]

26 Background: The underrepresentation of minority populations in clinical trials negatively impacts cancer and widens inequities. We aimed to quantify the enrollment disparities in prostate cancer (PC) clinical trials over the last three decades. Methods: MEDLINE and Embase were searched to identify primary reports of prostate cancer RCTs (1989-2020). Data for trial characteristics, the proportion of trials reporting race, ethnicity and age, and the proportion of patients by race, ethnicity and age enrolled in trials were summarized using descriptive statistics. Enrollment incidence ratios (EIR), which compare trial enrollment against global estimates of incidence in age-related subgroups (acquired from the Global Burden of Disease database) and U.S. population-based estimates of racial/ethnic subgroups (acquired from the SEER 18 incidence database) were calculated. Individual trial EIRs were pooled using random-effects meta-analyses to account for the substantial heterogeneity between trials. Multivariable meta-regression was used to explore associations between key trial characteristics and EIR. Annual percentage changes (APC) over the last three decades in enrollment disparities were analyzed using the Joinpoint Regression Analysis. Results: 281 trials from 1989 to 2020 with 99,588 patients were included in this analysis. 107 trials reported race (38%), of which only 25 trials (9%) reported data on all 5 U.S. racial categories (Black, White, Asian, Pacific Islander and Native American. 255 (91%) trials reported mean or median but only 71 trials (25%) specifically reported the enrollment proportion of older adults (age > 65 years). Clinical outcomes by race and age were reported in 9 (8%) and 37 (14%) trials, respectively. Results from meta-analyses showed that Black patients (summary EIR: 0.42 [95% CI: 0.35 - 0.51]), Hispanics (summary EIR: 0.50 [95% CI: 0.37 - 0.68]) and older adults (summary EIR: 0.95 [95% CI: 0.91 - 0.99]) were underrepresented in trials relative to their population estimates. Significantly fewer Black participants (EIR for Black patients = 0.42, EIR for White patients = 0.99; p < 0.0001), Hispanic participants (EIR for Hispanics = 0.50, EIR for non-Hispanics = 1.00; p = 0.001) and older adults (EIR for older adults = 0.95, EIR for younger adults = 1.06; p = 0.037) were enrolled. Representation of Black patients decreased significantly from 1989-2019 (APC: -4.25), while Hispanic representation increased significantly from 2000-2020 (APC: 5.89). Meta-regression showed Black patients were particularly underrepresented in larger-size trials (p < 0.0001). Conclusions: Black representation in PC clinical trials is less than 50% of their expected share based on cancer incidence and it has consistently decreased over last three decades, contributing to the disparities experienced by the population.

PURPOSE Multiple large clinical trials have investigated adjuvant tyrosine kinase inhibitors (TKIs) to reduce the risk of cancer recurrence and progression to metastasis in high-risk renal cell carcinoma. We sought to maintain living and interactive evidence on this topic, until a high level of certainty is reached for key clinical outcomes such that further updates become unnecessary and unlikely to change clinical practice. METHODS We created a living interactive evidence synthesis platform to maintain a continuously updated meta-analysis on TKI monotherapy in adjuvant renal cell carcinoma. We implemented an automated search strategy with weekly updates to identify randomized phase 2 and 3 clinical trials. Study selection, appraisal, and data extraction were done in duplicate. Cumulative meta-analysis was performed using Analyzer Module in Living Interactive Evidence platform. For each outcome (overall survival [OS], disease-free survival [DFS], and all-cause and treatment-related adverse events), we assessed certainty of evidence using GRADE approach and conducted trial sequential analysis. RESULTS This final update includes five randomized trials including recently updated data from PROTECT trial. Meta-analysis shows that adjuvant TKI monotherapy offers no benefit in OS (hazard ratio, 1.01; 95% CI, 0.91 to 1.12, high certainty) or DFS (hazard ratio, 0.92; 95% CI, 0.86 to 1.00, high certainty) and significantly increases adverse event risk. Lack of benefit was consistent across subgroups including highest-risk patients (test for subgroup differences: P = .32). Optimal information size criteria were met, and there was high certainty of evidence for lack of DFS and OS benefit for adjuvant TKIs. CONCLUSION There is no guidance on when to stop maintaining a living review. In this example, we used trial sequential analysis and high certainty of evidence (future clinical trials unlikely to change current conclusions) as a benchmark to conclude a living review in view of convincing evidence.

5583 Background: FDA has approved three novel AAs [Apalutamide(A), Darolutamide(D) and Enzalutamide(E)] in combination with Androgen deprivation therapy ( ADT) for treatment of (nmCRPC) patients (pts). We report the cost-effectiveness of these drugs from the US perspective to help facilitate the choice of these agents for clinical practice. Methods: A life time Markov state-transition model was constructed with three health states (Metastasis-Free Survival[MFS], Metastatic disease, and Death) to compare cost-effectiveness of AA therapies for treatment of nmCRPC based on US healthcare payer perspective. A network meta-analysis of MFS and OS was conducted due to the lack of head to head trials. An approximation of the original individual-level patient time-to-event data were derived from digitized Kaplan-Meier curves for OS and MFS. Weibull distributions was selected as the best fitted model fitted and extrapolated as per the NICE decision support unit recommendations. Medication costs were based on wholesale acquisition cost. Adverse event (AE) grades 3/4 management costs were incorporated in the model. Discount rate of 3% per year was applied to costs and effects. Life years (LYs) and quality adjusted life years (QALYs) for each treatment as well as the incremental cost effectiveness (ICER) and cost utility (ICUR) ratios were estimated. Base case analyses (BCA) and probabilistic sensitivity analyses (PSA) were estimated. Results: The table summarizes the results form BCA analyses. A+ADT offers best gain in LYs (8.37yrs) and QALYs (5.30 yrs) but at higher cost. Conclusions: Apalutamide was associated with gains in LYs and QALYs traded off with higher lifetime cost relative to other AA alternatives. ADT was associated with lower gains in LYs and QALYs traded off with lower lifetime cost relative to other alternatives. Based on a $150,000/QALY threshold pay off, A+ADT is likely more cost effective compared to E+ADT or ADT alone; while E+ ADT may be more cost effective compared to D+ ADT. [Table: see text]

335 Background: Network meta-analysis can provide useful evidence for relative efficacy and toxicity of different treatment options in absence of head-to-head trials. Previously, we reported no difference in efficacy between Apalutamide (APA) and Enzalutamide (ENZA). In this analysis, we provide updated indirect comparisons of all FDA approved agents (APA,ENZA, Darolutamide(DARO) for the treatment of M0CRPC with rapid PSA doubling time. Methods: MEDLINE, EMBASE and Cochrane Library were searched to identify relevant clinical trials. Hazard ratios (HR) and 95% confidence interval (CI) for Metastasis Free Survival (MFS), Overall Survival (OS) and data on grade 3 or higher AEs were abstracted. Bayesian network meta-analysis was conducted using WinBUGS 1.4.3 software (MRC Biostatistics Unit, Cambridge, UK) to perform an indirect comparisons. Risk for bias was assessed using the Cochrane Collaboration’s tool. Results: Three RCTs (SPARTAN, PROSPER and ARAMIS) compared APA, ENZA and DARO respectively in combination with ADT to ADT alone. A total of 4117 patients were included in efficacy analysis (2694 received novel hormonal agents and 1423 received ADT and placebo). There were no statistically significant differences in MFS (HR 0.97, 95% CrI 0.74 - 1.30) between APA and ENZA; however, both APA 0.69 (95% CI 0.52 -0.92) and ENZA 0.71 (95% CrI 0.53, 0.92) significantly improved MFS as compared to DARO. There were no statistically significant differences in OS between these drugs. DARO had fewer grade 3 or higher adverse events of fatigue (HR 0.09, 95% CrI 0.01 – 0.51) compared to ENZA. However other common adverse events such as hypertension, falls, coronary artery disease/myocardial infarction and diarrhea were not significantly different between treatment groups. There was low risk of bias amongst included studies. Conclusions: APNA and ENZA provide significant improved in MFS as compared to DARO in patients with M0CRPC. The drugs have similar toxicity profile except that DARO was associated with lower incidence of fatigue compared to ENZA. Cost effective analysis of these drugs will be reported separately.

e13119 Background: Tyrosine kinase inhibitors (TKIs) are routinely used in the treatment of metastatic RCC and Sunitinib is approved for the use in adjuvant setting. Arterial thromboembolic events (ATEs) have been described with these agents, although the overall risk remains unclear. We did a systematic review and meta-analysis to determine the incidence associated with the use of FDA approved TKIs used in treatment of RCC. Methods: PubMed, EMBASE, Cochrane Central and Scopus databases were searched to identify phase 2 and 3 RCTs of TKI therapy in RCC. Trials were included if they reported ATEs defined as arterial thrombosis, cerebral ischemia or infarction, myocardial ischemia and myocardial infarction. The DerSimonian-Laird random effects meta-analysis was performed using CMAv3 software to derive pooled estimates of incidence rates of ATEs with its 95% confidence interval (CI). I2 statistic was computed to express the percentage of the total observed variability due to study heterogeneity. Risk for bias was assessed using the Cochrane Collaboration’s tool. Results: 1755 studies retrieved in the initial search, and 13 phase 2 and 3 clinical trials (n = 4983) were included in the quantitative analysis. The trials had open label design which can potentially result in bias. Risk of bias was low in all other domains. TKIs used for the treatment of RCC included sunitinib (n = 2632), sorafenib (n = 981), cabozantinib (n = 78), pazopanib (n = 844), axitinib (n = 189) and tivozanib (n = 259). The incidence of ATEs with the use of TKIs was 2.9% (95% CI: 2-3%). Cabozantinib was associated with the highest rate of ATEs (11.5%, 95% CI: 6-21%), followed by sunitinib (2.6%, 95% CI:2-3%) pazopanib (2.6%, 95% CI:2-4%) and axitinib (2.1%, 95% CI: 1-6%). The TKI with lowest event rate of ATE was tivozanib (0.8%, 95% CI:0.2-3%). Conclusions: The use of TKIs is associated with increased risk of developing ATEs. Clinicians should be aware of the possibility of increased ATEs and counsel the patients about this increased risk to enhance the process of informed decision making.