Citations

e17059 Background: It is unclear if patients with different HRR gene-mutated mCRPC derive consistent benefit from treatment with PARPi and API combination. Approval labels for PARPi+API are inconsistent across regulatory bodies in the US (Food and Drug Administration, FDA) and Europe (European Medical Agency, EMA), adding to confusion among practicing clinicians. Therefore, we aimed to assess the differential efficacy of PARP+API therapy by different genes using up-to-date trial evidence. Methods: We maintain a living meta-analysis on mCRPC treatments that is updated when new data becomes available. Here, we report data from phase III randomized control trials (RCTs) assessing PARPi+API in 1L mCRPC. The outcomes of interest included radiographic progression-free survival (rPFS) and overall survival (OS). Hazard ratios (HR) for rPFS and OS by different genes were summarized using random effects meta-analysis via inverse variance approach. Results: We have screened 27376 references since the inception of this living review. Here, we report data from three trials (15 references) with a total of 1618 patients. Frequently reported HRR gene mutations in the included trials were BRCA2 (35%), ATM (21%), CDK12 (12.2%), CHEK2 (12.2%), BRCA1 (4.6%), and PALB2 (3.4%). In terms of rPFS, statistical benefit was observed in BRCA (0.28; 95% CI: 0.13-0.59) and CDK12 (0.58; 95% CI: 0.35-0.95) subgroups, whereas no statistically significant benefit was seen in PALB2 (0.53; 95% CI: 0.21-1.32), ATM (0.93; 95% CI, 0.57-1.53), and CHEK2 (0.92; 95% CI: 0.53-1.61) subgroups. For OS, benefit was observed in BRCA (0.47; 95%CI: 0.31-0.71) subgroup. While not statistically significant, a signal of meaningful OS benefit was observed in PALB2 (0.33; 95%CI: 0.10-1.16) but no OS benefit was observed in ATM (0.97; 95% CI: 0.57-1.67), CDK12 (0.80; 95% CI: 0.36-1.78), and CHEK2 (0.81; 95% CI: 0.37-1.75) subgroups. Conclusions: Current results show that mCRPC patients with BRCA and CDK12 alterations had delayed disease progression with PARPi+API as 1L therapy. BRCA mutations are also associated with improved OS, while patients with CHEK2 and ATM derived no significant benefit with PARPi+API combination. [Table: see text]

e16619 Background: Should patients (pts) with MIBC receive aIO given the DFS benefit seen in AMBASSADOR and CheckMate 274 trials is an important clinical question. Thus, we aimed to quantify the magnitude of absolute benefit across different subgroups to aid clinicians in shared decision-making with their patients. Methods: Phase III trials evaluating aIO as compared to observation or placebo (obs/plac) in pts with MIBC were considered eligible. Outcomes of interest included DFS and OS. Pre-specified subgroups included disease location, PDL1 status, neoadjuvant chemotherapy (NAC) receipt, and tumor and nodal (TN) staging. Pairwise comparisons were made using a DerSimonian-Lairds (DL) random-effects meta-analysis. Stratified baseline risks (obtained from clinical trials) and relative effect estimates were used to estimate corresponding intervention risks (CIRs). The difference in CIRs and baseline risk was calculated to present absolute risk differences (ARDs) in each subgroup category. Results: Analysis included three trials with 2220 pts (pembrolizumab, nivolumab, and atezolizumab assessed in each). No significant difference was observed in OS with aIO compared to obs/plac (hazard ratio: 0.91; 0.76-1.09). However, aIO significantly improved DFS compared to obs/plac (0.76; 0.64-0.91) in the overall population. In pts with bladder/lower tract disease, aIO improved DFS compared to obs/plac (0.72; 0.56-0.92); however, no significant difference was observed in DFS in pts with upper tract disease. There was a statistically significant effect modification by disease location (p: 0.01). Adjuvant IO significantly improved DFS in PDL1- (0.78; 0.64-0.94) but not in PDL1+ pts (0.75; 0.52-1.08). Likewise, aIO significantly improved DFS in pts who received NAC (0.69; 0.53-0.90) but not in pts who did not receive NAC (0.89; 0.75-1.05). In terms of TN staging, aIO improved DFS in T2-3N0 (0.73; 0.57-0.94), T4N0 (0.76; 0.61-0.95), and in T2-4N1 patients (0.75; 0.59-0.95). No statistically significant modifications were observed among these subgroups. Stratified ARDs for DFS by each subgroup are outlined (Table). Conclusions: When delayed disease progression is a vital consideration, a risk-adapted strategy for the optimal patient selection to receive aIO should be considered. Disease location (lower tract/bladder), node positivity, and receipt of NAC emerged as groups likely to derive greater benefit with aIO. [Table: see text]

e16579 Background: Recent results from EV 302 and CheckMate 901 have transformed the treatment landscape of untreated locally advanced/metastatic urothelial cancer (Ia/mUC). Here, we present the most up-to-date evidence of comparative efficacy and safety of first line (1L) treatment options in Ia/mUC with emphasis on Enfortumab vedotin (EV)-pembrolizumab (P) and gemcitabine (Gem)-cisplatin (Cis)-nivolumab (N). Methods: This living systematic review used the living interactive evidence (LIvE) synthesis framework. Full-text and abstract publications of phase II/III randomized clinical trials comparing 1L immunotherapy combined with chemotherapy (IO+C) or immunotherapy alone (IO) regimens with platinum-based chemotherapy (Plat) in Ia/mUC were included. Outcomes of interest included overall survival (OS), progression-free survival (PFS) and treatment-related grade 3 or greater adverse events (≥G3 TRAE). Mixed treatment comparisons were made using network meta-analysis. P-scores were computed to assess relative treatment rankings. Results: A total of 5 trials (8 references) with 4,749 patients and 9 unique treatments were included. EV-P and Gem-Cis-N were ranked first and second in terms of OS and PFS improvement. EV-P improved OS compared to Gem-Cis-N (HR: 0.60; 0.45-0.81), Gem-Plat-atezolizumab(A) (0.55; 0.42-0.72), durvalumab(D)- tremelimumab(T) (0.55; 0.42-0.72), Gem-Plat-P (0.55; 0.42-0.72), P (0.51; 0.39-0.68), D (0.47; 0.36-0.63), A (0.48; 0.36-0.63) and Gem-Plat (0.47; 0.38-0.58). EV-P also improved PFS compared to Gem-Cis-N (0.63; 0.48-0.82), Gem-Plat-A (0.55; 0.43-0.69), D-T (0.42; 0.33-0.53), Gem-Plat-P (0.58; 0.45-0.74), P (0.34; 0.26-0.44), D (0.35; 0.27-0.44) and Gem-Plat (0.45; 0.38- 0.54). For ≥G3 TRAE, A was ranked first with the lowest adverse events compared to others. EV-P (rank 5) had significantly fewer events compared to Gem-Plat, Gem-Plat-A, Gem-Cis-N and Gem-Plat-P. Gem-Cis-N was ranked last with significantly greater events compared to A, P, D, D-T, Gem-Plat, EV-P, and Gem-Plat-A (Table with ranks [p-scores]). Conclusions: Current evidence suggests that patients with untreated la/mUC experience improved survival and slower disease progression with EV-P when compared to other contemporary options. Gem-Cis-N may be a reasonable alternative in patients who are cisplatin-eligible. Cost and access to these treatments are crucial and should be considered to facilitate shared decision making. [Table: see text]

98 Background: The risk of secondary primary malignancies (SPM) among the survivors of GU cancer is not well-established. In this study, we attempt to describe the patterns of SPMs in patients diagnosed with GU cancers. Methods: The Surveillance, Epidemiology, and End Results (SEER) database (SEER*Stat 8.4.2) was searched to obtain data on the incidence of SPM in adult patients (age >18 years) diagnosed with GU cancers, including prostate, renal, and bladder cancer. Standardized incidence ratios (SIRs) with a 95% confidence interval (CI) were calculated. SIR was defined as the observed SPMS from each category divided by the expected number of SPMs in the age-matched US population for the same period. The data was further stratified by age (<50y, 50-70y, >70y), race (White, Black, Asian/Pacific Islander), ethnicity (Hispanic, non-Hispanic), chemotherapy, and radiotherapy exposure. Results: A total of 1,041,217 patients were included in this analysis. In patients diagnosed with GU cancer, the incidence of overall SPM was 11%. Particularly, patients with GU cancers were observed to have a high incidence of Endocrine system SPM (1.52; 1.45-1.59), and urinary system SPM (1.51; 1.49-1.53) These results were consistent by different sociodemographic groups. In patients diagnosed with prostate cancer, the incidence of thyroid SPM was increased (1.31; 1.23-1.39). Particularly, prostate cancer patients treated with radiation therapy had increased incidence rates of SPM in the peritoneum, omentum and mesentery (1.57; 0.79-2.81) and urinary bladder (1.36;1.32-1.40) was higher as compared to those with no exposure to radiation therapy (1.11;1.08-1.13 and 1.03;1-1.06 respectively). Bladder cancer patients had an overall increased incidence of SPM in the esophagus (1.21; 1.08-1.35), lung, bronchus, trachea, and other respiratory organs (1.97;1.92-2.01), prostate (3.50;3.4-3.6) and kidney (1.86;1.76-1.97). A higher incidence of renal pelvis, ureter and other urinary organ SPM (11.08;10.48-11.07) was also notable in this population. Similarly, kidney cancer patients had a higher incidence of the endocrine system (3.00;2.74-3.27), prostate (1.24;1.2-1.29) and bladder 1.78;1.68-1.79 SPMs. Conclusions: This population-based study shows an increased risk of SPM development in GU cancer survivors compared to the general population. Clinicians should keep a high index of suspicion for SPMs and initiate appropriate workups at early warning signs.

93 Background: The treatment paradigm for mCSPC patients has rapidly evolved over the last few years with the emergence of triplet therapy and prognostication by volume of disease. However, the health economic implications of triplet therapy by disease volume remain unclear. Methods: A Markov model where patients transitioned between the progression-free, progression and death states was developed. State utilities were derived from the LATITUDE trial. Point probabilities for overall survival, progression-free survival, grade ≥ 3 and 5 toxicities were obtained from the eligible mCSPC phase III clinical trials. Medicare Advantage and commercial total paid amounts (2022 US$) of treatments were obtained from OptumLabs Data Warehouse. Costs and disutilities of adverse events were derived from published literature. Half-cycle corrected costs and utilities were accrued monthly over a 20-year lifetime horizon and were discounted at 3%. Monte Carlo simulation was used to calculate incremental cost-effectiveness ratios (ICERs). A willingness-to-pay (WTP) threshold of US$100,000 was used. Results: In terms of Medicare Advantage payer’s perspective (Table), docetaxel (D)+ADT was observed to provide additional 0.068 QALYs compared to ADT at an ICER of US$16,544 per QALY in high volume disease. Compared to D+ADT, abiraterone (AAP) triplet provided additional 1.03 QALYs at US$56,641 per QALY. Compared to AAP triplet, apalutamide (APA)+ADT provided additional 0.048 QALYs at US$5,846,248 per QALY in high volume disease. In low volume disease, D+ADT provided 0.45 more QALYs at US$20,690 per QALY compared to ADT alone. Compared to D+ADT, AAP triplet provided an additional 1.51 QALYS at US$44,267 per QALY. In terms of total paid commercial costs, AAP triplet provided an additional 1.19 QALYs compared to ADT at US$91,952 per QALY in high volume disease. In low volume, D+ADT provided additional 0.38 QALYs at US$22,058 per QALY compared to ADT. Compared to D+ADT, AAP triplet provided a 0.97 QALY gain at US$105,958 per QALY. Compared to AAP triplet, darolutamide (DARO) triplet provided a 0.47 QALY at US$689,196 per QALY. Compared to DARO triplet, APA+ADT provided an additional 0.49 QALYs at an ICER of US$971,389 per QALY. All other treatments (not reported here) were dominated. Conclusions: At the selected WTP of US$100,000 per QALY, AAP triplet therapy was most likely the cost-effective strategy in overall mCSPC population particularly in patients with high volume disease. However, these results should be interpreted with careful accounting for timing of metastases. [Table: see text]

643 Background: The FDA approval of enfortumab (EV) and pembrolizumab (Pembro) combination therapy as a first-line treatment for cisplatin-ineligible patients with locally advanced/metastatic urothelial carcinoma (la/mUC) was based on the EV-103 trial. We aim to assess the clinical response rate of this combination therapy in our institution's patients with locally advanced and metastatic UC. Methods: This retrospective cohort study included 20 patients diagnosed with locally advanced/metastatic UC(la/mUC) who were treated with EV-Pembro combination for at least 2 cycles, from June 2022 to August 2023 at the Mayo Clinic. Patients who were treatment naïve or who progressed one or more lines of therapy were included in the study cohort. Main outcome of interest included imaging-based best overall response rate in terms of complete (CR) and partial (PR) response, stable disease (SD), and progressive disease (PD). Results: Out of 20 patients, the number of males and females were 16 (80%) and 4 (20%) respectively; the median age was 77 years (IQR: 51-92). 3 (15%) of patients had involvement of upper urinary tract disease along with bladder cancer. The common sites of visceral metastasis at the time of initial presentation include liver 2(10%), lung 6(30%) and lymph nodes12(60%). Common toxicities of this regimen included rash, pruritis, peripheral neuropathy, fatigue, transaminitis, dysgeusia, and diarrhea. The treatment was stopped in 10 (50%) patients due to completion of planned therapy (achieved CR or proceeded with resection of residual disease) (30%), 5 patients due to progression (50%), 1 patient due to therapy side effects (10%) and in 1 patient due to death (10%). The objective response was 45% (N =9); 5 (25%) had PR, and 4 (20%) had CR. A total of 2 (10%) had SD while 2 (10%) experienced PD. Histological correlation with clinical benefit is shown in the table. Conclusions: EV-Pembro combination therapy shows promising responses in patients who have progressed after previous lines of therapy, consistent with previously published data on EV 201 in small cohorts. However, ongoing expansion of this cohort and data from larger studies will help further elucidate survival benefits and their correlation with genetic testing. [Table: see text]

639 Background: Immunotherapy combined with chemotherapy (IO/C) as the first-line management of locally advanced or metastatic urothelial carcinoma (LA/mUC) has been investigated in multiple trials with conflicting outcomes. Therefore, we conducted a meta-analysis of available trials to compare objective response rates (ORR) of this combination regimen, both in overall and in cisplatin-ineligible populations. Methods: EMABSE and MEDLINE were searched from 2000 through July 20th, 2023, to identify phase II and III clinical trials assessing IO, C or both in LA/mUC. Main outcome of interest was objective response rates (ORR) as defined in the included trials. An inverse variance random-effects meta-analysis was performed to estimate pooled ORR using the restricted maximum likelihood estimation method. Subgroup differences were assessed among IO/C, IO alone, and C alone. The threshold for statistical significance was established at 0.1. Results: Of 5975 citations identified, a total of 26 trials with a total of 4,628 participants were included in this systematic review. In the overall group, the ORR in IO/C trials (5 trials, 1,236 patients) was 44.70% (95% CI: 21.88%- 70.0%). In IO trials (7 trials, 2,189 patients), ORR was 23.68% (19.55%- 28.36%) and in C trials (26 trials, 4,628 patients) was 43.46% (37.43%-49.68%]). In the cisplatin-ineligible group, the ORR in IO/C trials (2 trials, 240 patients) was 60.06% (33.38%-81.86%), in IO trials (6 trials, 1,103 patients) was 26.15% (23.01%; 29.56%), and in C trials (8 trials, 767 patients) was 42.45% (35.67%-49.52%). In terms of subgroup differences, the difference in ORR was statistically significant between IO/C and IO trials (p= 0.0844) and between IO and chemotherapy trials (p< 0.0001) in the overall population. Similarly, we found a statistically significant difference in ORR between IO/C and IO (p= 0.0108) and between IO and chemotherapy trials (p< 0.0001) in the cisplatin-ineligible population. No statistically significant differences were observed between IO/C and C alone. Conclusions: First-line IO/C may achieve a better objective response compared to IO alone in patients diagnosed with locally advanced/metastatic UC. Although, there appears to be a trend of greater benefit with IO/C compared to C alone, the difference was not statistically significant. The results will be updated as soon data from new trials (CheckMate 901 and EV 302) becomes available which could offer new insights. [Table: see text]

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]

Background Janus kinase inhibitors are actively investigated for treating various hematological, rheumatological, gastrointestinal and dermatological indications. Thus, we have initiated a living systematic review to define the toxicity profile of JAKi agents. Here, we report an up-to-date assessment of toxicity profile of JAKi in patients with myelofibrosis. Methods MEDLINE, EMBASE and CENTRAL were systematically searched from each database's inception through June 13, 2023, to identify phase I/II/III clinical trials assessing JAKi in myelofibrosis reporting adverse events. The main outcomes of interest included incidence rates of all-cause and treatment-related grade ≥ 3, grade 5 and all-grade AEs of interest (infections, hematological, gastrointestinal, and cardiovascular adverse events). Incidence rates (incidence per 100-person-years) for AEs of interest were calculated at the level of each trial. A random-effects meta-analysis was conducted to pool the incidence rates of AEs using an inverse-variance approach. Results The literature search identified 2044 studies from which 28 clinical trials (33 references) met the inclusion criteria - 4 (14%) trials were phase I, 4 (14%) trials were phase I/II, 13 (46%) trials were phase II, and 7 (25%) trials were phase III. A total of 4505 participants received JAKi and were eligible for analysis. All-cause and treatment-related hematological toxicities were reported in 28 (100%) and 18 (64%) trials, all-cause and treatment-related gastrointestinal toxicities were reported in 28 (100%) and 18 (64%) trials, all-cause and treatment-related cardiovascular toxicities were reported in 20 (71%) and 12 (43%) trials whereas all-cause and treatment-related infections were reported in 26 (93%) and 14 (50%) trials, respectively. The incidence rate per 100-person years for all-cause and treatment related adverse events of interest are summarized in Table 1a and 1b respectively. For treatment-related AEs, the incidence of grade ≥ 3 diarrhea with JAKi is 8.50 (95% CI: 5.34-13.53) events per 100-person years. The incidence of treatment-related grade ≥ 3 anemia and thrombocytopenia is 39.40 (95% CI: 25.57-60.71) and 29.25 (95% CI: 20.12-42.51) events per 100-person years respectively. The incidence of treatment-related grade 5 diarrhea with JAKi is 2.15 (95% CI: 1.07-4.29) events per 100-person years whereas the incidence of treatment-related grade 5 anemia and thrombocytopenia is 2.03 (95% CI: 1.04-3.97) and 2.01 (95% CI: 1.02-3.93) events per 100-person years respectively. For all-cause AEs, the incidence of grade ≥ 3 nausea, vomiting and diarrhea with JAKi is 1.72 (95% CI: 0.97-3.05), 3.56 (95% CI: 1.92-6.61) and 5.29 (95% CI: 3.48-8.04) events per 100-person years respectively. The incidence of all-cause grade ≥ 3 infections with JAKi is 4.38 (95% CI: 1.95-9.83) events per 100-person years whereas the incidence of all-cause grade ≥ 3 respiratory tract infections with JAKi is 4.21 (95% CI: 2.41-7.36) events per 100-person years. The incidence of all-cause grade ≥ 3 anemia, neutrophil decrease and thrombocytopenia is 46.83 (95% CI: 32.68-67.11), 29.11 (95% CI: 14.86-57.02) and 34.39 (95% CI: 23.82-49.64) events per 100-person years respectively. Moreover, the incidence of all-cause grade 5 nausea, vomiting and diarrhea with JAKi is 1.25 (95% CI: 0.72-2.18), 2.01 (95% CI: 1.08-3.74) and 1.60 (95% CI: 0.94-2.72) events per 100-person years respectively. In addition, the incidence of all-cause grade 5 infections and infestations is 3.71 (95% CI: 1.96-7.04) events per 100-person years with the incidence of grade 5 respiratory tract infections being 1.66 (95%CI: 0.89-3.10) events per 100-person years. Furthermore, the incidence of all-cause grade 5 anemia, neutrophil decrease and thrombocytopenia is 2.10 (95% CI: 1.26-3.52), 3.00 (95% CI: 1.25-7.21) and 1.95 (95% CI: 1.15-3.33) events per 100-person years respectively. Conclusions This report of living systematic review provides the best current evidence on toxicity profile of JAKi in patients with myelofibrosis. Current evidence suggests an overall higher incidence of all grade and grade ≥ 3 treatment related gastrointestinal adverse events in patients receiving JAKi. This living review will be updated as soon as new data becomes available.