Citations

e24078 Background: The addition of anti-CD38 mAbs, daratumumab and isatuximab, to standard anti-myeloma regimens have drawn scrutiny towards long-term safety concerns, including the risk of SPMs. ICARIA-MM study reported SPMs in 3.9% patients (pts.) in the Isatuximab, pomalidomide and dexamethasone (Isa-Pd) arm compared to 0.7% in the Pd arm. We hypothesized that exposure to anti-CD38 mAbs could potentially increase risk of SPMs due to prolonged immunosuppression. An assessment of this association is warranted, given the improved life expectancy and growing prevalence of pts. with MM. Methods: We performed a meta-analysis on data obtained from RCTs published between January 2005 and April 2022 that compared anti-CD38 mAb-based regimens to other standard anti-myeloma regimens (control) in pts. with newly diagnosed or relapsed/refractory (r/r) MM. Total number of SPMs (including categories) were extracted for pts. in both groups. Malignant melanomas were included under solid SPM category. Binary outcome data were analyzed using fixed-effect Peto method. Treatment effect estimates were expressed as odds ratio (OR) and 95% confidence interval (CI). I2 > 50% indicated substantial heterogeneity. Results: 10 RCTs involving 4980 pts. were included, with 2824 (57%) and 2156 (43%) pts. randomized to the anti-CD38 mAb and control arms, respectively (Table). Overall, 191 and 112 SPMs were reported in the anti-CD38 mAb and control arms, respectively. At a median follow-up of 35.3 months, anti-CD38 mAb exposure was associated with an increased risk of developing SPMs compared to control (6.8% vs. 5.2%; OR: 1.53 [95% CI: 1.20-1.95]; I2= 0%). Non-melanoma cutaneous cancers were the most common, and higher in the anti-CD38 mAb vs. control arms (92 versus 47; OR: 1.77 [95% CI: 1.25-2.51]; I2= 0%). The increase in solid cancers (including melanoma) (OR: 1.28 [95% CI: 0.85-1.95]) and hematologic SPMs (OR: 1.86; [95% CI: 0.81-4.27] was not significant. On sensitivity analysis, the total number of SPMs were higher in the anti-CD38 mAb arm vs. control arm, regardless of the presence of immunomodulatory drugs in combination regimen. Conclusions: This meta-analysis shows an increased risk of SPMs in pts. with MM exposed to daratumumab or isatuximab, particularly that of non-invasive cutaneous tumors. This association should be further investigated in real-world settings using large databases. [Table: see text]

6636 Background: Equitable regional enrollment in clinical trials is critical to addressing global inequities in health care outcomes. Therefore, we quantified disparities in regional recruitment in global cancer trials. Methods: Phase II/III clinical trials in prostate (PC), breast (BC), colorectal (CRC) and lung cancer (LC), and reporting regional recruitment were identified from Medline. Global regions were defined as North-(NA) and South- America (SA), Europe (EU), Africa (AF), Asia (AS), and Australia (AU). For multi-regional trials, enrollment incidence ratios (EIR) which compare region-wise trial enrollment against global estimates of region-wise specific cancer incidence obtained from Global Burden of Disease 2019 database. Trial-level EIRs were pooled using random-effects meta-analysis. A pooled EIR of < 1.0 indicates underrepresentation of a particular region in clinical trial enrollment compared to the actual burden of the specific cancer in that region. Statistical analyses were conducted in R v4.1.2. Results: Of the total 2125 trials identified, 1681 (79.1%) trials with 691,800 participants reported information regarding regional recruitment. Among those, only 1400 (65.9%) trials reported proportions of patients from pre-defined regions. A total of 1231 (57.9%) trials were single-regional recruiting patients from EU (589; 47.8%), NA (329; 26.7%), AS (295; 23.9%), AU (10; 0.8%), AF (4; 0.3%), and SA (4; 0.3%). There was significant underrepresentation of patients from AS (EIR: 0.47; 95% CI: 0.41-0.54) in cancer clinical trials. This was consistent across different cancers: PC (0.49; 0.35-0.71), BC (0.63; 0.43-0.94), CRC (0.63; 0.43-0.94), LC (0.39; 0.30-0.50). Similarly, there is a trend of under-representation of patients from AF (0.67; 0.43-1.04). Consistently, patients from were under-represented in PC (0.43; 0.24-0.77) and LC (0.26; 0.09-0.79) trials. Patients from NA (1.27; 1.08-1.51), EU (1.64; 1.57-1.72), and AU (5.41; 3.90-7.51) were significantly over-represented in multi-regional cancer clinical trials. The results are provided in table. Conclusions: There is suboptimal reporting of region-wise enrollment in cancer clinical trials. Representation of Africa and Asia in cancer clinical trials appears to be less than their expected share based on their burden of cancer incidence. [Table: see text]

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.

6557 Background: Trials that inadequately include underrepresented minority (URM) populations widen inequities in cancer care. We assessed reporting patterns, representation, and trends of URM representation in breast cancer (BC) trials. Methods: We analyzed all phase 2/3 trials for age disparity and trials recruiting from the US for racial/ethnic disparity amongst BC RCTs (1990-2021). Enrollment-incidence ratios (EIR), which compare trial proportions (TP) from age subgroups against global estimates of incidence in the corresponding age group (from Global Burden of Disease) and racial/ethnic subgroups against US-population-based incidence in the corresponding racial/ethnic group (from SEER 22), were calculated. Individual-trial EIRs were pooled using random-effects meta-analyses. EIRs of <0.80 indicated meaningful underrepresentation, while EIRs >1.20 indicated meaningful overrepresentation. Meta-regression was used to explore associations between key trial characteristics and EIR, and trends in EIR over the last three decades. Results: Of 842 global trials with 490,657 participants, 232 (27.6%) reported the number of participants in specific age strata and 144 (17.1%) reported outcomes by age. Only 60 trials recruited exclusively from the US. Of these, 41 (68.3%) reported race and 24 (40.0%) reported ethnicity, and 2 (3.3%) analyzed outcomes by race. Older adults aged ≥65 years (TP: 24.3%; EIR: 0.53 [95% CI: 0.47-0.60]) and Hispanic women (TP: 5.3%; 0.54; 0.40-0.75) were underrepresented across global trials and US-only trials respectively. Black women were significantly underrepresented in trials that led to FDA approval (0.38; 0.25-0.58) but not in US-only trials. Stratified analysis by BC subtype (with subtype-specific population incidence) showed underrepresentation of Black women in US-only trials for HER2+ BC (0.66; 0.47-0.93), Hispanic women in ER+ BC (0.42; 0.20-0.90), Asians in triple-negative BC (0.24; 0.11-0.53), and older women in HER2+ BC (0.35; 0.31-0.40) and triple-negative BC (0.36; 0.29-0.45). From 1990-2021, the representation of older women declined significantly (meta-regression coefficient for EIR: -0.4 per 10 years), while Black and Hispanic representation showed no significant change. Black (p = 0.02) and Hispanic representation (p = 0.05) worsened significantly in larger trials. Conclusions: Published reports of BC trials do not consistently report the inclusion of URM. Older and Hispanic women were consistently underrepresented, whereas Black women were underrepresented in large, practice-changing trials. [Table: see text]

5088 Background: Previous evidence suggests that there may be no additional benefit of triplet therapy in low volume disease based on limited data. Therefore, we investigated the efficacy of triplet therapy as compared to docetaxel (D) and androgen pathway inhibitor (API) doublets by volume of disease using the most up to date results from the ARASENS trial. Methods: Phase III randomized controlled trials (RCTs) assessing treatment intensification with API, and/or D in patients with mCSPC were included. Precomputed hazard ratios (HR) with 95% confidence intervals (CI) for OS were pooled using an inverse-variance approach. A DerSimonian-Laird random-effects meta-analysis was conducted to assess the efficacy of triplet therapy compared to D doublet therapy. P-value of interaction was computed to assess difference between high (HV) and low volume (LV) disease subgroups (Pint <0.1 - statistical significance). Additionally mixed treatment comparisons were computed using network meta-analysis (NMA) to assess the comparative effectiveness of triplet therapy compared to API doublets by volume of disease. Results: Pairwise meta-analysis included a total of 3 RCTs (ARASENS, PEACE-1, ENZAMET) with 2518 patients (HV: 1820; LV: 698) as shown. In patients with HV disease, 385 (43%) and 484 (53%) deaths were observed with triplet therapy, and D doublet, respectively. Triplet therapy significantly improved OS as compared to D doublet in HV (HR: 0.73; 95% CI: 0.64-0.84). In patients with LV disease, 73 (20%) and 94 (28%) deaths were observed with triplet therapy, and D doublet, respectively. Triplet therapy significantly improved OS as compared to D doublet in LV (HR: 0.71; 95% CI: 0.52-0.97). There was no statistically significant interaction by volume of disease for triplet therapy vs. D doublet (Pint: 0.86). NMA including 10 clinical trials and over 11500 patients updated as of 13th Feb 2023 showed that in HV mCSPC, triplet therapy was ranked as potentially the most efficacious treatment option and may improve OS compared to API doublet therapy (HR: 0.83; 95% CI: 0.66-1.03). In LV mCSPC, API doublet therapy was ranked as potentially the most efficacious treatment followed by triplet therapy. There was no significant difference between triplet therapy and API doublet therapy (HR: 1.12; 95% CI: 0.74-1.12). Conclusions: These results underscore that triplet therapy may be preferred in mCSPC patients with HV disease whereas API doublet therapy may be preferred in LV disease. [Table: see text]

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.

694 Background: The treatment landscape of localized renal cell carcinoma (RCC) is rapidly evolving. Recent trials have demonstrated contrasting efficacy with adjuvant immunotherapy. Therefore, we sought to assess the mixed treatment comparisons among different adjuvant treatment options using updated data from trials and quantified the absolute effect with these treatments stratified by risk categories. Methods: This living network meta-analysis was conducted using the living interactive evidence (LIvE) synthesis framework. We used stratified baseline risks of disease progression from observational data and at 5, 10, 15 years from the Leibovich risk stratification system (based on risk scores ranging from 0 to ≥15). Corresponding intervention risks were then approximated using relative effect estimates (from NMA) and baseline risks. The difference between CIRs and baseline risks were calculated to present absolute risk differences in each risk category. Results: This NMA included eight RCTs with 8480 participants and seven unique treatment options. Pembrolizumab (pembro; rank 1) was associated with improved disease-free survival (DFS) when compared to atezolizumab (atezo; rank 6; hazard ratio: 0.68; 0.49;0.93), and nivolumab-ipilimumab (nivoipi; rank 5; 0.68; 0.48-0.97). However, no statistically significant difference was observed between pembro and atezo for overall survival (0.53; 0.28-1.01). Survival data for nivoIpi was not reported. No new statistically significant differences were observed since last update. The absolute benefit of atezo and nivoipi was minimal with higher T and N patients (Table). The results were similar with increasing Leibovich risk scores. Conclusions: Current evidence favors the use of a risk adapted approach when offering adjuvant immunotherapy. Adjuvant pembrolizumab remains a preferred treatment in patients with RCC who underwent nephrectomy. [Table: see text]

692 Background: Sarcomatoid mRCC exhibits poor prognosis and limited response to vascular endothelial growth factor pathway inhibition. Therefore, we assessed the efficacy of ICI combination therapy in this patient population using data from contemporary trials. Methods: MEDLINE and EMBASE were searched to identify phase III randomized controlled trials (RCTs) comparing the efficacy of ICI combinations with sunitinib monotherapy in patients with sarcomatoid mRCC. Patient important outcomes of interest included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and complete response (CR). Precomputed hazard ratios (HR) with 95% confidence intervals (CI) for survival outcomes and binary outcome data for response rates (expressed as relative risk [RR] were meta-analyzed using a DerSimonian-Lairds random-effects method. Mixed treatment comparisons among different ICI combinations were made using a network-meta-analysis within the Bayesian framework. The surface under the cumulative ranking curves (SUCRA) were computed to assess the relative treatment rankings. Results: Six RCTs with a total of 618 patients were considered eligible for inclusion. ICI combination therapy was significantly associated with improved OS (HR: 0.56; 95% CI: 0.43-0.72) and PFS (HR: 0.50; 0.40-0.62), increased ORR (RR: 2.42; 1.92-3.06), and CR (RR: 4.23; 2.00-8.93) when compared to sunitinib in patients with sarcomatoid mRCC (Table). The results were consistent with Hartung-Knapp adjustment. Mixed treatment comparisons using current data revealed no statistically significant differences among different ICI combinations. However, the combination of nivolumab-ipilimumab was consistently ranked higher (rank 2 for OS, ORR, and CR) and may potentially be more efficacious than other counterparts. Conclusions: Current evidence suggests improved survival, delayed disease progression and increased response rates with the use of ICI combination therapy in patients with sarcomatoid mRCC. [Table: see text]

531 Background: Neoadjuvant cisplatin-based chemotherapy (NAC) is established in the management of MIBC. Pathologic complete response (pCR, ypT0N0) and downstaging (<ypT2N0) are associated with long term survival in patients with MIBC. Several trials have evaluated neoadjuvant immunotherapy (NAI) and chemoimmunotherapy (NACI) for MIBC. We aimed to conduct a meta-analysis of available trials to compare the incidence of pathological response with NAC, NAI and NACI in MIBC patients undergoing radical cystectomy. Methods: Phase II/III clinical trials assessing neoadjuvant systemic therapies (NAC, NAI, or NACI) in patients with MIBC undergoing radical cystectomy were identified through a systematic search of MEDLINE and EMBASE. Outcomes of interest included pCR and pathological downstaging. A DerSimonian and Laird random-effect meta-analysis was conducted to estimate pooled incidence of events using the Freeman-Tukey transformation. Clopper-Pearson method was used to estimate the associated 95% confidence intervals (CI). Results: Of the 5357 records initially identified, 28 trials with a total of 2138 patients were considered eligible for inclusion. Neoadjuvant chemotherapy was assessed in 15 trials (1535 patients), NAI in 5 (288 patients), and NACI in 8 (315 patients). The pooled incidence of patients experiencing a pCR was 30.91% (95% CI: 26.54%-35.45%) with NAC, 30.92% (23.22%-39.14%) with NAI, and 42.25% (36.6%-48.0%) with NACI. The difference in pCR among these therapies was statistically significant (p <0.05). Similarly, the pooled incidence of achieving pathological downstaging was 40.91% (34.26%-47.72%) with NAC, 38.84% (26.73%-51.64%) with NAI, and 62.88% (57.22%-68.39%) with NACI. Consistently, there was statistically significant effect modification by the choice of neoadjuvant systemic therapy (p <0.01). The results were consistent across different clinically important subgroups (Table). Conclusions: NACI may achieve better pCR and pathological downstaging than NAC and NAI alone in MIBC patients which may potentially be associated with long-term survival. Definitive data from phase III trials are pending. [Table: see text]

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.