Citations

6559 Background: Recent findings that Black and Hispanic patients were significantly underrepresented in industry-sponsored prostate cancer trials warrant a detailed investigation across cancer types to assess the association between funding source and enrollment disparities. Methods: Phase II/III clinical trials in prostate, breast, colorectal, and lung cancers reporting age, gender, race/ethnicity, and reporting NIH or industry as the funding source were considered eligible for inclusion. For age, and gender analysis, all trials were considered eligible. For race/ethnicity analysis, trials recruiting from the United States (US) were considered eligible. Enrollment-incidence ratios (EIR) comparing trial proportion from age/gender or racial/ethnic subgroups against global cancer incidence in the corresponding group (from Global Burden of Disease) or US-population-based incidence in the corresponding racial/ethnic subgroup (from SEER 22), were computed. Trial-level EIRs were pooled using a random-effects model and subsequently stratified by funding source. A univariate meta-regression was conducted to assess the temporal changes in EIR by each funding category. Results: Of 42,390 studies initially identified, 2234 trials (1989-2021) met the eligibility criteria. Regarding age, 361 (16%) trials reported age categories by 65 years threshold. Of 698 trials recruiting from the US, 498 (71%) reported race, and 198 (28%) reported ethnicity. Regarding representation, older adults were under-represented (EIR: 0.66; 95% CI: 0.62-0.70) in the industry but not in NIH-sponsored clinical trials (0.79; 0.62-1.00). Regarding gender, no significant disparity was observed regarding the enrollment of men and women in colorectal and lung cancer clinical trials. In terms of race, there was a greater under-representation of Black patients in industry sponsored trials (0.29; 0.26-0.32) as compared to NIH-sponsored clinical trials (0.65; 0.57-0.74) [Pint <0.01]. Asian patients were significantly overrepresented in industry sponsored trials (3.17; 2.69-3.74) but not in NIH sponsored clinical trials (1.43; 0.85-2.41) [Pint <0.01]. Hispanic patients were significantly under-represented in both, industry (0.27; 0.22-0.34) and NIH-sponsored clinical trials (0.35; 0.22-0.55) [Pint 0.32]. Secondary analyses including trials recruiting exclusively from the US, and analyses by specific cancer types showed consistent results. Recruitment of older adults, men, and Black patients is decreasing over time. Conclusions: There is a consistent under-representation of older adults in industry-sponsored, and of Black and Hispanic patients in both industry-sponsored and NIH-sponsored clinical trials. The under-representation of Black patients is likely to be greater in industry-sponsored trials, which has worsened over the last three decades.

695 Background: Recent results from COSMIC 313 trial and updated findings from other contemporary trials have added to the existing body of evidence for 1L mRCC. Therefore, we present the most up-to-date results from our living, interactive systematic review (LISR) to facilitate the choice of optimal therapy in 1L mRCC setting. Methods: This LISR and network meta-analysis is maintained using a novel living evidence synthesis (LIvE) framework. The framework facilitates the identification of new or updated studies using an automated ‘living’ search which is followed by screening and extraction in a semi-automated fashion within a machine learning assisted graphical user interface. Relevant data is parsed and analyzed to compute mixed treatment comparisons and certainty of evidence is adjudicated using a rule-based algorithm. Detailed methods have been published before (PMID: 33824031). Results: As of October 1st 2022, this LISR includes 16 clinical trials (30 references). Mixed treatment comparisons showed statistically significant PFS benefit with lenvatinib-pembrolizumab (LenPem; rank 1) when compared to cabozantinib-nivolumab (CabNivo; rank 3; hazard ratio [HR]: 0.69, 95% confidence interval: 0.52-0.93), CaboNivo-ipilimumab (CaboNivoIpi; rank 4; HR: 0.62; 0.43-0.89), avelumab-axitinib (AveAxi; rank 5; HR: 0.56; 0.43-0.75), PemAxi (rank 6; HR: 0.55; 0.42-0.72), atezolizumab-bevacizumab (AteBev; rank 7; HR: 0.46; 0.35-0.59), and NivoIpi (rank 8; HR: 0.45; 0.35-0.59). No significant differences were observed between CaboNivoIpi and other combination therapies for PFS improvement. Similarly, for OS, LenPem (rank 1), PemAxi (rank 2) and CaboNivo (rank 3) were ranked as potentially more efficacious treatment options than other counterparts. However, no statistically significant difference was observed for OS benefit with mixed treatment comparisons. The odds of achieving an ORR were higher with LenPem (rank 1; odds ratio [OR]: 2.44; 1.43-4.17), and CaboNivo (rank 2; OR: 1.77; 1.04-3.03) when compared to CaboNivoIpi (rank 6). NivoIpi (rank 1), LenPem (rank 2), CaboNivoIpi (rank 3) were ranked potentially as more efficacious treatments for achieving a CR. In terms of grade 3 or higher treatment related adverse events, NivoIpi (rank 3) was ranked as potentially the safest option among other combinations while CaboNivoIpi (rank 12), LenPem (rank 11), and CaboNivo (rank 10) were more likely to increase the risk of toxicity compared to most other treatments. Conclusions: Triplet combination of CaboNivoIpi may not provide additional survival benefit compared to other immunotherapy combinations and may increase toxicity. Patient-level considerations such as treatment toxicity, and quality of life should be factored in when opting intensified 1L therapies in mRCC patients.

40 Background: Previously we have reported enrollment disparities in PCa clinical trials. Funding source can influence minority representation in clinical trials. Hence, we aimed to evaluate the impact of source of funding on enrollment disparities in PCa clinical trials. Methods: MEDLINE and EMBASE were searched to identify phase II/III PCa trials. All relevant trials reporting age by 65 years were considered eligible for inclusion. Trials recruiting from the United States (US) were considered eligible for analysis by race and ethnicity. The trial proportions of age, or racial/ethnic subgroup category and the global incidence in the corresponding 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) were used to compute enrollment incidence ratio (EIR) at each trial. EIRs with corresponding 95% confidence intervals (CI) were then meta-analyzed using a random-effects model and stratified by sources of funding (industry, US-government, and others [academic and non-US govt]). A univariate meta-regression was conducted to assess the temporal changes in EIR by each funding category. Results: Of 127 trials recruiting from the US, 89 (70%) reported race, and 35 (27%) reported ethnicity. Among those, 57 (64%), 14 (16%), and 18 (20%) trials reported industry, US-government, and other sources of funding, respectively. Of those reporting ethnicity, 23 (66%), 4 (11%), and 8 (23%) trials reported industry, US-government, and other sources of funding, respectively. Among the 287 eligible trials, 49 trials (17%) reported age by 65 years. Of those, 36 (73%), 6 (12%), and 7 (13%) reported industry, US-government, and other sources of funding, respectively. In terms of racial/ethnic enrollment, Black patients were significantly under-represented in industry funded trials (0.33; 0.27-0.41). No significant disparity was observed in US-government funded trials (0.75: 0.57-1.00). The P-value of interaction was <0.0001. Hispanics were significantly under-represented in industry funded clinical trials (0.56; 0.43-0.74). The number of US-government funded trials reporting Hispanics were small (<10) which precluded any meaningful statistics. No significant disparity was observed in terms of older adults (EIR: 1.00; 95% CI: 0.95; 1.05) overall and by funding sources. Black patients’ representation in industry funded PCa trials has significantly decreased over the last three decades. No significant change was observed in US-government funded PCa trials over the last three decades (P:0.004). Conclusions: Black and Hispanic men with PCa are likely to be under-represented in industry sponsored clinical trials. Black patients’ representation in industry sponsored trials has declined over time, thus widening the cancer-care inequities in these patients.

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.

Objective: To report the preliminary safety, tolerability, and cerebral spinal fluid (CSF) sampling utility of serial injections of concentrated intraventricular nicardipine (IVN) in the treatment of aneurysmal subarachnoid hemorrhage (aSAH). Methods: We report the clinical, radiographic, and laboratory safety and tolerability data of a retrospective case series from a single academic medical center. All patients with aSAH developed vasospasm despite enteral nimodipine and received serial injections of concentrated IVN (2.5 mg/mL). CSF injection safety, tolerability, and utility are defined and reported. Results: A total of 59 doses of concentrated IVN were administered to three patients with poor-grade SAH. In Case 1, a 33-year-old man with modified Fisher scale (mFS) grade 4 and Hunt-Hess scale (HH) score 4 received 26 doses; in Case 2, a 36-year-old woman with mFS grade 4 and HH score 5 received 13 doses; and in Case 3, a 70-year-old woman with mFS grade 3 and HH score 4 received 20 doses. No major safety or tolerability events occurred. Two patients were discharged to a rehabilitation facility, and one died after discharge from the hospital. Conclusions: A concentrated 4 mg IVN dose (2.5 mg/mL) in a 1.6 mL injection appears relatively safe and tolerable and potentially offers a second-line strategy for treating refractory vasospasm in poor-grade SAH without compromising intracranial pressure or cerebral perfusion pressure.

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.

4594 Background: Cisplatin based neoadjuvant chemotherapy (NAC) followed by definitive therapy improves survival in patients with muscle invasive bladder cancer (MIBC). However, the clinical benefit of NAC might vary with the choice of definitive therapy. Therefore, we assessed the absolute benefit of NAC followed by radical cystectomy or radical radiotherapy separately using the totality of evidence. Methods: MEDLINE and EMBASE were systematically searched to identify randomized trials assessing cisplatin based neoadjuvant chemotherapy followed by either radical cystectomy or definitive radiotherapy in patients with MIBC. Outcomes of interest included overall survival (OS) and disease-free survival (DFS). Treatment effects were expressed as hazard ratios (HR) with 95% confidence interval (CI). Incidence rate ratios were calculated to estimate time to event outcomes for trials not reporting HR. A random-effects DerSimonian-Laird meta-analysis was conducted. Absolute effects were then obtained using baseline risks from the control arm of RCTs. Results: Of 4887 studies identified, 13 trials with 2529 patients were included in this meta-analysis. Most trials included patients with T2-4 and N0 patients and only 3 trials included patients with node positive disease. Total of 180 (47%) DFS events were observed with NAC+RC compared to 213 (56%) events in RC alone (HR: 0.72; 95% CI: 0.59-0.89) and 346 (58%) OS events were observed with NAC+ RC compared to 385 (52%) events in RC alone (HR: 0.80; 95% CI: 0.69-0.92). Total of 186 (70%) DFS events were observed with NAC + radiotherapy compared to 205 (71%) events in radiotherapy alone (HR: 0.91; 95% CI: 0.74-1.12) and 263 (58%) OS events were observed with NAC+ radiotherapy compared to 294 (61%) events in radiotherapy alone (HR:0.93; 95% CI: 0.79-1.08). Conclusions: The choice of definitive therapy after cisplatin-based NAC impacts survival in patients with MIBC. RC after NAC improved DFS (114 fewer events per 1000 events) and OS (76 fewer per 1000 events) whereas radiotherapy after NAC showed no survival benefit. [Table: see text]

518 Background: Cisplatin (C) based neoadjuvant chemotherapy (NAC) has been the mainstay treatment for muscle invasive bladder cancer (MIBC). However, the optimal choice of NAC is not well-established. We therefore conducted a network-meta-analysis (NMA) to assess comparative efficacy of different treatment options. Methods: Several electronic databases (MEDLINE, and EMBASE) and conference proceedings were systematically used to identify randomized trials evaluating first-line treatments in neoadjuvant MIBC. Outcomes of interest included overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and pathologic complete response (pCR). DerSimonian-Laird random-effects meta-analysis was used to compute direct comparisons between NAC and local therapy (LT) only. Fixed effect NMA was conducted within the frequentist framework for mixed treatment comparisons. P-scores were used to assess relative treatment rankings. All statistical analyses were conducted in R (v 4.1.1). Results: This systematic review included 23 trials (25 references) with a total of 5313 patients with 10 unique treatments. Direct comparisons showed significant benefit in PFS (HR: 0.82; 95% CI: 0.71-0.94), and in OS (HR: 0.85; 95% CI: 0.78-0.92) with NAC when compared to LT only. However, the likelihood of achieving an objective response (RR: 1.18; 95% CI: 0.72-1.95: I2: 85%) or CR (RR: 1.51; 95% CI: 0.87-2.61; I2: 79%) was not different between the two arms. Data available in 15 trials contributed to the network for PFS outcome while only eight trials contributed to OS outcome. Mixed treatment comparisons showed significantly improved PFS with nintedanib-gemcitabine-cisplatin (NinGC; HR: 0.42; 95% CI: 0.20-0.87) and dose-dense-methotrexate-vinblastine-doxorubicin-cisplatin (ddMVAC; HR: 0.61; 95% CI: 0.43-0.88) compared to LT only. Consistent benefit was observed when NinGC (HR: 0.48; 95% CI: 0.24-0.97) and ddMVAC (HR: 0.70; 95% CI: 0.51-0.96) were compared to GC only. However, no significant differences were observed between NinGC (rank 1) and ddMVAC (rank 2) or among other mixed treatment comparisons. Similarly, OS was significantly improved with NinGC (rank 1) relative to MVAC (HR: 0.41; 95% CI: 0.17-0.97), MVC (HR: 0.37; 95% CI: 0.16-0.88), MC (HR: 0.38; 95% CI: 0.16-0.92), AC (HR: 0.36; 95% CI: 0.15-0.91), and GC (HR: 0.39; 95% CI: 0.17-0.90). While similar results were observed with ddMVAC (rank 2) when compared to MVC (HR: 0.63; 95% CI: 0.42-0.94), MC (HR: 0.64; 95% CI: 0.42-0.98), and GC (HR: 0.66; 95% CI: 0.47-0.92), no significant differences were observed with ddMVAC when compared to MVAC (HR: 0.62; 95% CI: 0.38-1.01) and NinGC (HR: 1.70; 95% CI: 0.69-4.19). Conclusions: Current evidence shows improved PFS and OS with the use of neoadjuvant ddMVAC and Nin-GC in patients with MIBC relative to other treatment options.

132 Background: Treatment landscape for metastatic castration-sensitive prostate cancer (mCSPC) is rapidly evolving. Recent updates of relevant trials and presentation of PEACE-1 results warranted mixed treatment comparisons to inform the choice of treatment in mCSPC. Methods: MEDLINE and EMBASE, along with conference proceedings were searched using a systematic search strategy to identify relevant abstracts and full-text publications of phase II/III randomized controlled trials (RCTs) assessing first-line treatment options in mCSPC. Outcomes of interest included overall survival (OS), radiographic progression-free survival (rPFS), and grade ≥3 adverse events (AEs). Direct comparisons were made using DerSimonian-Laird random-effects meta-analysis. Fixed-effect frequentist NMA was conducted to compute network estimates using a multivariate meta-regression approach. Relative treatment rankings were assessed in congruency with direct estimates using P-scores. Secondary NMAs were conducted in several substrata (young, and old; Gleason score < 8 and ≥8; performance status 0 and 1-2, low and high volume of disease). Results: This NMA included nine trials (23 references) with nine unique treatments. rPFS was improved with abiraterone acetate and prednisone-docetaxel-androgen deprivation therapy combination (AAP-D-ADT; rank 1) when compared against most treatment options including AAP-ADT (HR: 0.58, 95% CI: 0.44-0.76; rank 5), apalutamide (APA)-ADT (HR: 0.63, 95% CI: 0.46-0.87; rank 4), TAK-ADT (HR: 0.55, 95% CI: 0.36-0.84; rank 6), and enzalutamide(E)-AAP-ADT (HR: 0.70, 95% CI: 0.51-0.97; rank 3), however no significant differences were observed between AAP-D-ADT, and E+ADT (rank 2). Improved OS was observed with AAP-D-ADT (HR: 0.75, 95% CI: 0.59-0.95; rank 2), E-AAP-ADT (HR: 0.68; 95% CI: 0.48-0.97; rank 1), and AAP-ADT (HR: 0.82, 95% CI: 0.70-0.96; rank 3) compared to D+ADT (rank 6). However, most of the mixed treatment comparisons were statistically insignificant in terms of OS. Similarly, in patients with high volume of disease, AAP+D+ADT (rank 1) was observed to significantly improve rPFS compared to AAP-ADT, APA-ADT, E-ADT, and D-ADT; however, no significant differences were observed among treatment comparisons with regards to OS improvement. E+ADT (rank 1) improved rPFS compared to other treatment in low volume disease but was not different for OS. No significant differences were observed among different treatment options when compared across prespecified subgroups. Moreover, AAP+D+ADT was ranked as the least safe with significantly increased risk of grade 3 AEs relative to other treatments. Conclusions: Current NMA suggests that triplet therapy options were ranked as most likely to improve rPFS and OS at the cost of increased toxicity. Doublet combinations may still be preferred for older patients with low volume of disease.