e16216 Background: Patients with advanced unresectable BTC have a poor prognosis, and treatment options are limited and with variable response rates. Nivolumab (NIVO), a PD-1 inhibitor, has shown its effectiveness against multiple cancer types and has been tested as a therapeutic option in diverse settings and associations. Methods: We performed a systematic review and single arm meta-analysis of clinical trials of NIVO monotherapy or combined therapy in advanced unresectable BTC. PubMed, Embase, and Cochrane database were searched for clinical trials published up to May 1, 2023. Data were extracted from published reports and quality assessment was performed per Cochrane recommendations. The primary endpoints of interest were objective response rate (ORR = CR+PR) and disease control (DC = SD or better response) per RECIST v1.1, at any period of the trial. Results: Out of 80 database results, 6 clinical trials and 358 patients were included, all were using some form of NIVO therapy. Overall, NIVO and associations present an ORR = 13% (95% CI 0.08-0.16, I² = 23%, p = 0.26) and DC = 39% (95% CI 0.27-0.51, I² = 69%, p < 0.05). NIVO monotherapy present an ORR = 6% (95% CI 0.02-0.10, I² = 36%, p = 0.19) and DC = 28% (95% CI 0.04-0.51, I² = 87%, p < 0.001) while NIVO + ipilimumab association show an ORR = 11% (95% CI 0.004-0.22, I² = 76%, p < 0.05) and DC = 37% (95% CI 0.24-0.49, I² = 28%, p = 0.23). NIVO + gencitabine + cisplatin association trials reported an ORR within 13-18% and DC around 32%. This data suggests that associations of NIVO present higher efficacy in the treatment of BTC and should be considered among the first choices of therapy, however drug adverse effects tolerability might play an important part in the individualized patient care. Conclusions: There are marked limitations to the applicability of these findings in clinical practice, therefore a cautionary approach to this data is recommended, given their overall low statistical power, heterogenous study design, and tolerability to adverse effects. New trials of NIVO + associations with better standardized outcomes and comparative arms for different associations and populations will help to better clarify the effects of NIVO in the treatment of advanced unresectable BTC. [Table: see text]

4532 Background: CheckMate 67T (NCT04810078), a multicenter, randomized, open-label, phase 3 study, evaluated pharmacokinetics and objective response rate (ORR) noninferiority of NIVO SC vs IV in previously treated patients with advanced/metastatic ccRCC. Noninferiority endpoints of exposure (time-averaged serum concentration over the first 28 days and trough serum concentration at steady state) and efficacy (ORR by BICR) were met. Safety was comparable in the SC vs IV arms. NIVO-related immunogenicity was as expected for SC administration and further assessments did not identify apparent clinically meaningful impact. This report focuses on additional safety analyses and PROs. Methods: Patients were randomized 1:1 to NIVO SC 1200 mg + recombinant human hyaluronidase PH20 Q4W (n = 248) or NIVO IV 3 mg/kg Q2W (n = 247). Eligibility criteria were previously reported. Safety analyses were performed for all-causality adverse events (AEs) across weight categories (< 50 kg, ≥ 50 kg–< 70 kg, ≥ 70–< 90 kg, ≥ 90 kg–< 110 kg, and ≥ 110 kg). The onset, management, and resolution of treatment-related select AEs were studied; duration and grade of local site reactions and the effect of immunogenicity on local site reactions were reported. PROs were assessed using the Functional Assessment of Chronic Illness Therapy (FACIT) GP5 item. Results: The overall AE incidence rates in the SC arm were generally comparable to or lower than in the IV arm across weight categories, but limited by small sample sizes in the < 50 kg and ≥110 kg subgroups. Across the treatment-related select AE categories, most events were manageable with established algorithms and resolved with immune-modulating medications. Local site reactions were mild to moderate with a median duration of 2.0 and 0.01 days in the SC and the IV arms, respectively; most resolved without treatment. The proportion of patients with a local site reaction of any grade was 8.1% in the SC arm and 2.0% in the IV arm. In patients testing NIVO-specific anti-drug antibody (ADA)-positive, 15.2% of patients in the SC arm reported a local site reaction, but all were grade 1–2 and most resolved without treatment. No hypersensitivity/infusion reaction select AEs were reported in ADA-positive patients in either arm. A majority of patients in SC and IV arms reported minimal bother by treatment side effects in their FACIT GP5 scores. Conclusions: The safety profile of SC was consistent with IV, supporting the use of NIVO SC as an option improving patient experience. This aligns with patient preference for SC administration over IV. Analyses based on weight and ADA subgroups were consistent with the known NIVO safety profile. Toxicity was manageable with immune-modulating medications. FACIT GP5 scores indicated no bother by treatment side effects. Clinical trial information: NCT04810078 .

4509 Background: In the CheckMate 901 trial, combination nivolumab (NIVO) + gemcitabine-cisplatin (GC) demonstrated significant improvements in overall survival (OS) and progression-free survival (PFS) with compelling objective response rates (ORR; 57.6% with NIVO+GC vs 43.1% with GC alone) and deep, durable complete responses (CR; 21.7% with NIVO+GC vs 11.8% with GC alone) in patients (pts) with previously untreated unresectable or metastatic urothelial carcinoma (mUC). Lymph node (LN)-only metastatic disease is a favorable prognostic factor in pts with mUC and a subset of pts achieve durable disease-free, treatment-free survival with GC +/- surgical consolidation. We conducted a post hoc analysis to characterize the subset of pts with CR, with further analysis of pts with LN-only mUC. Methods: In the global, open-label, randomized, phase 3 CheckMate 901 (NCT03036098) trial, cisplatin-eligible pts received NIVO 360 mg + GC every 3 wk for ≤6 cycles followed by NIVO 480 mg every 4 wk until disease progression/unacceptable toxicity or up to a maximum of 2 yrs, or GC every 3 wk for ≤6 cycles. Primary endpoints were OS and PFS by blinded independent central review (BICR). ORR per BICR and safety were exploratory endpoints. These post hoc analyses evaluated treatment outcomes in complete responders and in pts with LN-only disease. Results: Of the 608 pts randomized, 102 (16.8%) achieved a CR. Baseline disease characteristics of these pts are shown in the Table. As pts with LN-only mUC were enriched in the CR group, additional analysis of this subgroup was performed. Of all randomized pts, 54 treated with NIVO+GC and 56 treated with GC had LN-only mUC. In these pts, the ORR and CR rate was 81.5% (95% CI 68.6-90.7) and 63.0% versus 64.3% (50.4-76.6%) and 33.9% for NIVO+GC and GC, respectively. Median OS (95% CI) in LN-only pts was 46.3 (24.0-NE) mos with NIVO+GC vs 24.9 (21.4-29.9) with GC (HR, 0.58, 95% CI 0.34-1.00), and median PFS (95% CI) was 30.5 (9.6-NE) mos with NIVO+GC vs 8.8 (7.5-10.9) mos with GC (HR 0.38, 95% CI 0.22-0.66). Conclusions: NIVO+GC generated deep responses in CheckMate 901 with a fixed duration of chemotherapy and up to 2 years NIVO. Exploratory characterization of pts with CR identified a group of pts enriched with LN-only disease.In pts with LN-only mUC, NIVO+GC induced durable disease control and clinically meaningful improvements in OS and PFS vs GC alone. These results provide additional support for NIVO plus cisplatin-based chemo as a first-line treatment option for pts with mUC. Clinical trial information: NCT03036098 . [Table: see text]

4569 Background: Although PD-1 blockade is active in varied mUC treatment settings, predicting response and overcoming resistance remain unmet needs. We hypothesized that immunosuppressive M-MDSCs (CD14+Lin-/HLA-DRlow/-) and TCR dynamics in tumors and blood may correlate with outcomes from NIVO in pts with platinum-refractory mUC (NCT02553642). Methods: 69 pts with mUC were treated with NIVO 240mg intravenously every 2 weeks (wks). Pre-treatment peripheral M-MDSCs among lineage-negative CD14+ monocytes (%) were estimated by flow cytometry using an algorithm that calculates MDSC frequencies based on HLA-DR mean fluorescence intensity (Kitano et al. 2014). High throughput DNA sequencing of the CDR3 region of the TCR beta chain was performed on baseline tumors (N = 57) and pre and post-treatment (wk 2) peripheral blood mononuclear cells using Adaptive Immunosequencing (Adaptive Biotechnologies). M-MDSC levels and TCR metrics were correlated with clinical outcomes: complete or partial response (CR, PR) vs. stable or progressive disease (SD, PD) by RECIST 1.1, clinical benefit (CR + PR + SD), and progression-free and overall survival (PFS, OS). Groups were compared using Wilcoxon signed rank (paired), Wilcoxon rank sum tests (unpaired), and log-rank tests (time-to-event). Cox proportional hazards and logistic regression models were used to analyze binary and time-to-event outcomes, respectively. Results: Higher pre-treatment M-MDSCs were associated with worse PFS and OS univariably (PFS HR 1.07; 95% CI, 1.01-1.14; p = 0.025; OS HR 1.07; 95% CI, 1.00-1.14; p = 0.038), and after adjustment for liver disease and PD-L1 at baseline (PFS HR 1.12; 95% CI, 1.04-1.21, p = 0.004; OS HR 1.11; 95% CI, 1.03-1.20, p = 0.010). Baseline M-MDSCs did not significantly differ between responders and non-responders, but were significantly lower in patients with clinical benefit (median 12.8 [IQR: 10.7-15.9] vs. median 15.6 [IQR: 13.5-18.3]; p = 0.039), and remained significantly associated after adjustment for PD-L1 score in a multivariable model (OR 0.82; 95% CI, 0.67-0.97; p = 0.037). A higher number of tumor-associated clones in the blood (BTACs) at baseline was associated with response (p = 0.049). Overall, BTACs significantly increased at wk 2 (p < 0.001), and wk 2 values were associated with response (p = 0.003). PFS also significantly differed between BTAC high (high: > median 2,012 clones) and low groups at wk 2, with improved PFS in the high group (log-rank p = 0.026). OS rate for the BTAC high group was 34% vs. 16% for the low group at wk 2, but this did not achieve significance (p = 0.098). Conclusions: Peripheral M-MDSCs may promote resistance to PD-1 blockade in pts with mUC. NIVO stimulated tumor-specific TCR clones in the blood, which correlated with improved response and outcomes. Clinical trial information: NCT02553642 .

e16552 Background: Recent drug approvals in the 1L treatment (tx) setting have expanded options for pts with la/mUC. It is important to understand the economic burden of these novel therapies within the current tx landscape. This study estimated first-year cost of care in the US from a Medicare and commercial payer perspective for pts with la/mUC treated with the following 1L tx: enfortumab vedotin (EV) + pembrolizumab (PEM) in platinum-eligible pts, nivolumab (NIV) + platinum-based chemotherapy (PBC) in cisplatin-eligible pts, and 1L PBC with or without avelumab (AVE) 1L maintenance (1LM). Methods: A cost of care model was developed to estimate direct medical care costs in the first year of tx with EV + PEM, NIV + PBC, and PBC with and without AVE 1LM in pts with la/mUC who are eligible for 1L PBC; pts treated with NIV + PBC were eligible for cisplatin. The latest available costs (2023 USD)—including drug acquisition and administration, disease management, adverse event (AE) management, and subsequent therapy (second-line or later line) costs—were calculated based on tx duration, progression-free survival, overall survival, and AE incidence with various therapies. Efficacy and safety data were sourced from key published trials (EV-302, CheckMate-901, JAVELIN Bladder 100) and product prescribing information. Results: Estimated first-year costs per treated pt are shown in the Table. Cost per treated pt was estimated to range between $56,952 to $438,660 and $90,918 to $457,390 for Medicare and commercial payers, respectively, with the highest cost for EV+PEM and the lowest for PBC only. Drug acquisition costs in the 1L represented the majority of the costs except PBC, for which subsequent tx and administration costs represented the largest cost component. Conclusions: Costs per treated pt were lower for PBC with AVE 1LM than for EV+PEM and NIV+PBC. As value-based oncology care is becoming increasingly important in the US, comprehensive understanding of costs across different tx options and sequences can facilitate informed tx choice. [Table: see text]

4507 Background: Immunotherapy regimens can be associated with prolonged disease control after treatment discontinuation without the need for further anticancer therapy. An integrated, comprehensive partitioned survival analysis describes how patients spend overall survival (OS) time, on/off treatment, with/without toxicity. Previous analysis of first-line (1L) nivolumab (NIVO) + ipilimumab (IPI) for aRCC in CheckMate 214 showed treatment-free survival (TFS) twice as long vs sunitinib (SUN). TFS and survival states for immune checkpoint inhibitor plus tyrosine kinase inhibitor (TKI) combination are of interest. Methods: Overall, 651 patients (pts) with aRCC were randomized to receive 1L NIVO + cabozantinib (CABO) or SUN in the CheckMate 9ER trial; treatment continued until progression or intolerance, NIVO for at most 24 months. Minimum follow-up was 4 years. We partitioned area under the Kaplan–Meier (KM) OS curve into 3 survival states, defined from randomization: time on 1L protocol therapy, TFS, and survival after subsequent systemic therapy (second line [2L]) initiation. TFS and protocol therapy were subdivided as mean times with/without reported grade 2+ treatment-related adverse events (TRAEs). Areas under and between KM curves were estimated by 48-month restricted mean times to event. Bootstrapped 95% CIs for between-group differences are reported. Results: At 4 years post randomization, KM estimates of OS were 49.2% vs 40.2% of pts assigned to NIVO+CABO vs SUN, respectively; 17.6% vs 4.7% of pts were surviving treatment-free, and 15.8% vs 8.2% were continuing on 1L protocol therapy. Over the 48-month period since randomization (Table), the mean TFS (95% CI) was 2.4 (0.8–3.9) months longer after treatment with NIVO+CABO than SUN. At least half of TFS was spent with toxicity in both treatment groups, resulting in difference in mean TFS (95% CI) without toxicity of 0.7 (−0.4 to 1.8) month. The NIVO+CABO group spent a mean (95% CI) of 8.5 (6.2–10.8) months more survival time on 1L protocol therapy, whereas the SUN group spent a mean (95% CI) of 6.5 (4.4–8.6) months more survival time after 2L therapy initiation. Conclusions: Over the 4-year period since initiation of 1L therapy for aRCC, the longer OS achieved with NIVO+CABO was accompanied by 1.5 times longer mean time surviving treatment-free before 2L therapy compared with SUN, a smaller difference than seen for NIVO + IPI vs SUN. [Table: see text]

12140 Background: Immune checkpoint inhibitors (ICIs) have dramatically improved outcomes of patients (pts) with metastatic renal cell carcinoma (mRCC). Unfortunately, adverse events (AEs) can limit treatment efficacy and worsen patient outcomes. Recently, a germline IL7 SNP (rs16906115) was identified as a potential biomarker for prediction of irAEs. We aimed to characterize the association between a germline IL7 SNP (rs16906115) and AEs in a prospective clinical trial of patients with mRCC treated with nivolumab (NIVO) or everolimus (EVE). Methods: Whole-exome sequencing (WES) data of tumor and peripheral blood samples from CheckMate 025 (NCT01668784) were used to infer somatic alterations using the Cancer Genome Analysis pipeline, as well as SNP carrier status using the STITCH pipeline. Within each treatment arm, time to incident adverse events (AEs) were compared between carriers (SNP+) and non-carriers (SNP-) via multivariable Cox regression, controlling for age, sex and sample purity, followed by a SNP´treatment interaction term in the whole cohort. Overall survival (OS) and progression-free survival (PFS) were also assessed. Finally, a recurrent event analysis for AEs was conducted using the Andersen-Gill model, controlling for the same variables. Results: In total, 382 pts were included (NIVO: n=189, EVE: n=193), among which 56 (14.7%) were SNP+. There were no differences in clinical and pathological characteristics between SNP+ and SNP-, except for sex (SNP+ 16.1% vs. SNP- 30.1% females, P=0.046). Similarly, no differences in somatic alterations, including single nucleotide and copy number variants were seen between SNP+ and SNP-. SNP carrier status had no effect on OS nor PFS in both treatment arms (all P≥0.47). Regarding AEs, 63 pts (33.3%) in the NIVO arm experienced at least 1 grade 2+ AE, compared to 78 pts (40.4%) in the EVE arm. The most common types of grade 2+ AEs were cutaneous (21.0%), hepatobiliary (16.8%) and endocrine (15.8%) in the NIVO arm, and respiratory (30.1%), cutaneous (22.3%) and gastrointestinal (19.4%) in the EVE arm. The rate of grade 2+ AEs was significantly higher in SNP+ vs. SNP- in the NIVO arm (HR=2.91[1.48-5.72]), but not in the EVE arm (HR=0.63[0.3-1.29], SNP´treatment Pinteraction=0.002). The rate of recurrent grade 2+ AEs was also significantly higher in SNP+ vs. SNP- in the NIVO arm (HR=3.43[1.83-6.43]), whereas a trend for fewer recurrent grade 2+ AEs was seen in SNP+ vs. SNP- in the EVE arm (HR=0.46[0.17-1.25], SNP´treatment Pinteraction=0.0005). Conclusions: The IL7 SNP (rs16906115) is associated with significantly higher rates of grade 2+ AEs, including recurrent events, in pts with mRCC treated with NIVO but not with EVE, with no effect on survival outcomes. These results affirm the SNP’s predictive potential as a biomarker for irAEs to guide therapeutic decisions in pts treated with ICIs.

e21501 Background: Programmed death-1 (PD-1) receptor inhibitors significantly increase survival rates for advanced melanoma, yet first-line PD-1 inhibitor therapy shows limited overall response rates (32.6%) and progression-free survival (4.6 months). Relatimab (RELA) was recently approved for the treatment of metastatic and unresectable stage III to IV melanoma in combination with nivolumab (NIVO). RELATIVITY-047 showed an ORR of 43% as a first-line treatment while RELATIVITY 020 showed an ORR of 9-12% in patients progressed on anti-PD-1 therapy. Although clinical trials have demonstrated NIVO-RELA provides benefit for patients with advanced melanoma, little is known about real-world treatment patterns and outcomes. Methods: We performed a retrospective review of all patients with stage III and IV melanoma treated with NIVO-RELA as first-(1L) or second-line or beyond (2L+) therapy at Inova Schar Cancer Institute between September 2021 to September 2023. Primary endpoints were overall response rate (ORR), complete response (CR), partial response (PR), stable disease (SD), and progression of disease (PD) which were evaluated using the RECIST v1.1 criteria. The Kaplan–Meier method was used to generate overall survival (OS) and progression free survival (PFS) median values. Results: Eighty-eight patients were followed for an average of 6.5 months following NIVO-RELA initiation. For 1L treated patients, ORR was 58% (21% PR, 37% CR). Median PFS was 11 months (95% CI 3.1-11). For 2L+ treated patients, ORR was 33% (14% PR, 19% CR). Median PFS was 9.8 months (95% CI 4.7-17.2). Subgroup analyses observed significantly different ORR between patients previously treated with versus without anti-CTLA4 therapy (29% v 44%; p = 0.017), patients treated with NIVO-RELA more than vs within 6 months from their last other therapy (50% v 27%; p = 0.004), and among patients with stage III vs stage IV disease (67% v 30%; p = 0.031) (Table 1). Conclusions: These real-world results support the use of NIVO + RELA in patients with advanced melanoma and emphasize the impressive efficacy of the drug combination in the IL and 2L+ settings compared to RELATIVITY-020 and 047. PFS and OS for 1L and 2L+ therapy with NIVO + RELA in this study aligned with or superposed results from previous trials. Further analyses with increased sample sizes and longer follow-up is warranted. [Table: see text]

TPS4609 Background: Efficacy outcomes for advanced RCC have improved with vascular endothelial growth factor receptor (VEGFR)-tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors (IO), and CABO has become an established treatment for both front-line and refractory, advanced RCC. However, most patients develop resistance to CABO. With each subsequent line of therapy, efficacy and survival benefits also shorten and treatment options become limited. It is thus important to explore ways to maximize each line of therapy. Methods: Based on previous studies suggesting 1) dose-dependent effect of VEGFR-TKIs with feasibility/efficacy of CABO dose escalation to 80mg and 2) immune-modulatory effects of CABO, we have designed a two-cohort phase 2 trial to salvage CABO response, either by escalating the dose of CABO to 80mg oral (PO) daily (cohort 1) or by combining CABO 40mg PO daily with NIVO 480mg intravenous (IV) every 4 weeks (cohort 2), based on investigator choice. Subjects will be treated until progression or unacceptable toxicity. Main inclusion criteria include progressive advanced RCC after prior CABO monotherapy for at least 6 months, able to tolerate CABO 60mg PO daily (cohort 1) and 40mg PO daily (cohort 2), radiographically measurable disease, ECOG < 2, and adequate end-organ function. Main exclusion criteria include prior treatment with concurrent CABO/NIVO, uncontrolled co-morbidities, uncontrolled HIV, and concurrent malignancy (excepting completely excised skin cancers and organ-confined Gleason 6 prostate cancer). Primary endpoint is progression free survival (PFS) with key secondary endpoints including overall response rate, disease control rate, duration of response, and overall survival. The null hypothesis of median PFS 3 months will be tested against an alternative hypothesis of median PFS 6 months. Assuming a 2-sided significance level of 10% and 80% power, and estimating 10% drop out, 18 patients per cohort (36 patients total) will be enrolled.Pharmacokinetics, circulating biomarkers, and pre-/post-biopsies are planned for tissue-based analyses. The study is open for enrollment (NCT05931393). Clinical trial information: NCT05931393 .

2O Health-related quality of life (HRQoL) with first-line (1L) nivolumab (NIVO) plus ipilimumab (IPI) vs chemotherapy (chemo) in patients (pts) with microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) metastatic colorectal cancer (mCRC): CheckMate 8HW

419P Nivolumab (NIVO) + chemotherapy (chemo) vs chemo as first-line (1L) treatment for advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): Additional analyses from 4-year (y) follow-up (FU) of CheckMate 649

398P Nivolumab (NIVO) plus chemotherapy (chemo) or ipilimumab (IPI) vs chemo as first-line (1L) treatment for advanced esophageal squamous cell carcinoma (ESCC): Additional analysies from 45-month (mo) follow-up of CheckMate 648

Abstract Introduction: The phase 3 randomized CheckMate 274 trial in patients (pts) with high-risk muscle-invasive urothelial carcinoma (MIUC) demonstrated improved disease-free survival (DFS) with nivolumab (NIVO) vs placebo (PBO) in intent-to-treat (ITT) and tumor programmed death ligand 1 expression ≥1% pts (primary endpoints). With extended follow-up, continued efficacy was observed, and immature overall survival favored NIVO in both populations. Extending from previous exploratory tumor biomarker analyses (Necchi et al. ESMO 2022), we conducted a post hoc analysis of tertiary lymphoid structures (TLS), which are ectopic lymphoid structures often found within the solid tumor microenvironment. A subset of TLS has been associated with improved outcomes to neoadjuvant immunotherapy in UC. Using artificial intelligence (AI)–based algorithms, we explored the biomarker utility of TLS from CheckMate 274. Methods: We used a reproducible AI-based algorithm to identify and classify TLS in situ using hematoxylin and eosin (H&E) images from pretreatment tumor tissue specimens (n=272/699 treated pts). Images were scored for the presence or absence of lymphoid aggregate (LA), immature TLS (iTLS), and mature TLS (mTLS) and scored as either positive (+) or negative (−) for the respective TLS category. Relationships between TLS categories and DFS were explored (minimum follow-up, 5.9 months). Results: Most tumors exhibited some form of LA/TLS (245/272; 90.1%), with a higher incidence of LA (237/272; 87.1%) compared with mTLS (89/272; 32.7%). There was heterogeneity of TLS within the tumors, with most tumors demonstrating more than 1 form of TLS (198/272; 72.8%). In the PBO arm, median DFS was modest for most TLS categories (5.7–8.3 months) but was substantially improved for mTLS+ tumors (22.1 months; 95% CI, 5.4–not estimable [NE]); n=41), representing a 2.7- to 3.9-fold increase relative to any other category. In contrast, treatment with NIVO resulted in 2.1- to 4.0-fold improvements in median DFS relative to PBO across all but the mTLS+ category (22.9 months; 95% CI,11.9–NE; n=48), which was similar to the PBO arm. The largest increases in median DFS (95% CI) for NIVO vs PBO were observed for LA+ (27.6 [16.1–NE; n=114] vs 8.3 [5.6–11.9; n=123] months; HR, 0.56; 95% CI, 0.39–0.80; P=0.0015), iTLS+ (27.0 [16.1–NE; n=91] vs 8.2 [5.4–21.2; n=105] months; HR, 0.61; 95% CI, 0.41–0.91; P=0.0143), and mTLS− tumors (24.6 [11.4–NE; n=81] vs 6.1 [5.2–8.5; n=102] months; HR, 0.53; 95% CI, 0.36–0.78; P=0.0012]). Conclusion: These results suggest that a novel AI-based TLS maturity classification using H&E images is feasible to investigate the tumor microenvironment in MIUC, with potential broad application in other studies. Citation Format: Johannes Alfred Witjes, Matthew D. Galsky, Jürgen E. Gschwend, Dean F. Bajorin, Matthew I. Milowsky, Gautam Jha, Roger Li, Jun Li, Vanessa Matos-Cruz, Scott Ely, George Lee, Vipul Baxi, Joshua Zhang, Saurabh Gupta, Justin M. David. Exploratory analysis of tumor tertiary lymphoid structures using a novel artificial intelligence–based approach in patients with muscle-invasive urothelial carcinoma from the CheckMate 274 trial [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr PR010.

Abstract Background: CheckMate 7FL (CM 7FL; NCT04109066) is a prospective, phase 3, randomized, multicenter, double-blind trial investigating nivolumab (NIVO) in combination with neoadjuvant chemotherapy (NACT) and adjuvant endocrine therapy (ET) in patients (pts) with high-risk, estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2−) primary breast cancer (BC). The primary endpoint (pathological complete response, pCR) was met, resulting in a statistically significant improvement with added NIVO to NACT; residual cancer burden (RCB) 0–1 rate was meaningfully improved. NIVO benefit was larger in pts with PD-L1+ tumors (SP142 assay, % immune cells ≥ 1%). This analysis focuses on additional biomarkers to explore associations with NIVO treatment effect. Methods: The study enrolled newly diagnosed pts, stages T1c–2 N1–2 or T3–4 N0–2, grade 2 (ER 1–‍10%) or 3 (ER ≥ 1%). Pts were randomized 1:1 to NACT + NIVO 360 mg Q3W/NIVO 240 mg Q2W (arm A) or NACT + placebo (PBO; arm B). Clinical efficacy data included pCR (ypT0/is ypN0) and RCB 0–1 rates in the modified ITT (mITT) population and the SP142 PD-L1+ subgroup. Baseline PD-L1 expression from core biopsies was evaluated with the Dako 28-8 assay using the combined positive score (CPS) algorithm. Various cutoffs (CPS ≥ 1, 10, and 20) were used for this exploration. Concordance between PD-L1 SP142 and 28-8 CPS was evaluated, with assays performed on different slides from the same tumor biopsy blocks. Results of efficacy by ER and/or progesterone receptor (PR) expression, as well as Ki67 index and stromal tumor-infiltrating lymphocytes, will be presented at the meeting. Results: Overall, 830 pts were screened, 521 randomized, and 517 treated, with the primary efficacy population (mITT; n = 510) including all randomized pts but excluding 11 pts from Russian sites with insufficient follow-up. A total of 510 and 349 pts (68.4% of mITT population) were evaluated by PD-L1 SP142 and 28-8 CPS assays, respectively. The prevalence of PD-L1+ by CPS was balanced in arms A and B (52% vs 50% had CPS ≥ 1; 19% vs 16% had CPS ≥ 10, and 11% vs 9% had CPS ≥ 20, respectively). NIVO effect was larger in pts with tumors with increasing PD-L1 expression, with a ∆pCR rate (unweighted rate difference between arms A and B) of 16.6% in CPS ≥ 1 (40.4% vs 23.8% in arms A/B; 95% CI, 2.8 to 29.4), 32.4% in CPS ≥ 10 (65.7% vs 33.3% in arms A/B; 95% CI, 7.3 to 52.3), and 52.3% in CPS ≥ 20 (78.9% vs 26.7% in arms A/B; 95% CI, 18.6 to 72.4). In comparison, the ∆pCR rate was 10.7% in the mITT population (24.5% vs 13.8% in arms A/B; 95% CI, 3.9 to 17.4) and 5.7% in pts with CPS < 1 (14.0% vs 8.2% in arms A/B; 95% CI, -4.0 to 15.5; refer to the Table for additional details). Unweighted rate differences between arms A and B for RCB 0–1 (∆RCB 0–1 rate) followed a similar trend and were observed to be 17.0% in CPS ≥ 1, 34.4% in CPS ≥ 10, and 52.3% in CPS ≥ 20. In comparison, the ∆RCB 0–1 rate was 9.4% in the mITT population and 3.3% in pts with CPS < 1 (refer to the Table for additional details). Further biomarker data and cutoffs will be presented at the meeting. Conclusions: Greater PD-L1 expression was associated with higher pCR and RCB 0–1 rates, suggesting that pts with PD-L1+, high-risk, ER+/HER2− primary BC can achieve substantial pCR rates with the addition of NIVO to NACT. Table. Summary pCR and RCB 0–1 rates by PD-L1 SP142 and 28-8 CPS at various cutoffs. Note: CPS data with the cutoff at 5 will be presented at the meeting. Citation Format: Sherene Loi, Giuseppe Curigliano, Roberto Salgado, Roberto Iván Romero Díaz, Suzette Delaloge, Carlos Ignacio Rojas García, Marleen Kok, Cristina Saura, Nadia Harbeck, Elizabeth Mittendorf, Denise Yardley, Lajos Pusztai, Alberto Suárez Zaizar, Andrei Ungureanu, Felipe Ades, Rajalakshmi Chandra, Raheel Nathani, Misena Pacius, Thomas Spires, Jenny Wu, Heather McArthur. Biomarker Results in High-risk Estrogen Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative Primary Breast Cancer Following Neoadjuvant Chemotherapy ± Nivolumab: an Exploratory Analysis of CheckMate 7FL [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS01-01.

Abstract Background: Genomic determinants of benefit to immune checkpoint inhibitors (ICI) among pts with MBC and high tumor mutational burden (TMB-H) are largely unknown. NIMBUS was an open-label, single-arm, multicenter, phase 2 study assessing the efficacy of NIVO 3 mg/kg intravenously every 14 days plus IPI 1 mg/kg IV every 6 weeks in pts with TMB-H HER2-negative MBC. The objective of this current study was to evaluate genomic profiling of pts included in NIMBUS and its association with benefit to ICI. Methods: In NIMBUS, eligible pts were required to have measurable HER2-negative MBC, TMB ≥9 Mut/Mb assessed by a cancer-gene panel evaluating > 300 genes and performed in a CLIA-certified laboratory, and 0-3 prior lines of chemotherapy in the advanced setting. The primary objective was overall response rate (ORR) according to RECIST 1.1. Secondary objectives include progression-free survival (PFS), and overall survival (OS). We performed genomic analyses on the pre-treatment tissue, and on baseline and on treatment plasma from pts run on the Foundation Medicine Inc (Boston, MA) FoundationOne®CDx (F1CDx®) and FoundationOne®Liquid CDx (F1LCDx®) panel, respectively. Results: A total of 30 pts (21 with estrogen receptor (ER)-positive and 9 with triple-negative breast cancer) were included in this study. After a median follow-up of 30.6 months, 6 pts (20%) achieved partial response (PR) for a confirmed ORR of 20% (95% CI: 7.7-38.6%). Exploratory analyses did not reveal differences in ORR based on ER status, PD-L1 status, or stromal TIL. The median PFS was 1.4 months (95% CI: 1.3 – 4.6), and the median OS was 16.9 months (95% CI: 7.1-not reached). Pts who achieved PR had a 3-year OS of 75% versus 25% in non-responders. A total of 29 pts (6 responders and 23 non-responders) had at least one pre-treatment genomic panel performed: 16 had both, 5 had pretreatment F1CDx only and 8 had F1LCDx panel only. Blood TMB (bTMB) was highly correlated with tissue TMB by F1CDx (r = 0.95). Using data from the most recent genomic panel available, (24 for baseline blood, and 5 for pretreatment tissue), the most frequently mutated genes ( > 30%) in this population were: TP53 (66%); PIK3CA (45%), ESR1 (35%), CDH1 (35%), ROS1 (31%). ESR1 and PTEN mutations were associated with absence of PR while PALB2 was associated with objective response. We observed a significant correlation between ESR1 mutations and a decrease in OS among pts with ER+ disease. Among the entire 29 pts, a negative correlation between PTEN with PFS and OS, and positive correlation between PALB2 with PFS was observed (Table). Among the 24 pts with baseline F1LCDx panel evaluable, the median TMB was 7.6 Mut/Mb ([interquartile range 0.0–113.8). Median TMB was 8.9 Mut/Mb and 41.7 Mut/mB among pts without and with PR, respectively. Baseline TMB > 20 mut/Mb was found in all pts with PR and in one of those without response. Paired serial blood samples demonstrated that among responding pts, TMB was significantly reduced from baseline to end of treatment (EOT) compared to those with no clinical benefit [n=16, p=0.0015]. Lastly, the tumor fraction (TF) estimates from 7 paired baseline to EOT samples demonstrated that all responders had a decrease or no change in TF compared to an increase in non-responders [n=7, p=0.017]. Conclusion: In the NIMBUS trial, all pts with PR to NIVO plus low dose IPI had a TMB > 20 Mut/Mb and had a decrease in TMB during treatment. ESR1 and PTEN mutations were associated with lack of benefit, while PALB2 mutation was associated with increased benefit. If validated, these results could help tailor the use of ICI among pts with TMB-H MBC. Association between genomic alterations in ESR1, PTEN and PALB2 and benefit to nivolumab and low dose ipilimumab among patients with HER2-negative MBC and TMB-H HR: hazard ratio; MBC: metastatic breast cancer; mOS: median overall survival (months); mPFS: median progression-free survival (months); TMB-H: tumor mutational burden above > 9 mutations/megabase. Citation Format: Romualdo Barroso-Sousa, Tyler Chinsky, Tianyu Li, Sangeetha Reddy, Leisha Emens, Beth Overmoyer, Saud AlDubayan, Hoyin Chu, Paulina Lange, Julie Kasparian, Ameer Basta, Molly DiLullo, Victoria Attaya, Melissa Hughes, Nancy Lin, Nabihah Tayob, Rinath Jeselsohn, Elizabeth Mittendorf, Sara Tolaney. Genomic determinants of benefit to nivolumab (NIVO) plus low dose ipilimumab (IPI) among patients (pts) with hypermutated HER2-negative metastatic breast cancer (MBC): results of NIMBUS trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-27-12.

Abstract Background: Tamnorzatinib (ONO-7475) is an orally active small molecule Axl/Mer dual inhibitor that not only directly acts on cancer cells to suppress their proliferation, but also on immune cells and exerts characteristics of cancer immunotherapy. Methods: We performed a phase 1 study to assess the tolerability, safety, and pharmacokinetics of ONO-7475 alone (Part A) and in combination with nivolumab (NIVO) (Part B) in Japanese patients (pts) with advanced or metastatic solid tumors (NCT03730337). Patients received once-daily ONO-7475 (3-10 mg, orally) as a monotherapy or in combination with NIVO (240 mg, i.v., every 2 weeks). Results: Twelve pts in both Part A and Part B (three each at 3 and 6 mg, and six at 10 mg ONO-7475) received the study treatment. Baseline characteristics, safety, and efficacy outcomes are summarized in the Table. While one of six pts in the Part B 10-mg cohort developed dose-limiting toxicities of grade 4 nephritis, grade 3 colitis, and grade 3 hepatic function abnormal, no others did. In biomarker analyses, activation of T cell function and an increase in T cell number, an increase in inflammatory (M1) macrophages/immunosuppressive (M2) macrophages ratio, and suppression of epithelial-to-mesenchymal transition were observed after treatment. Conclusion: ONO-7475 was tolerated at repeated once-daily oral doses up to 10 mg as a monotherapy and in combination with NIVO in pts with advanced or metastatic solid tumors. TABLE 1. NAND Table. Baseline Characteristics, Safety Outcomes, and Efficacy Outcomes Part A (ONO-7475 alone) N = 12 Part B (ONO-7475 + NIVO) N = 12 Baseline Characteristics Median age, years (range) 63.5 (31–76) 56.0 (39–72) Female, n (%) 8 (66.7) 9 (75.0) ECOG PS, n (%) 0 8 (66.7) 10 (83.3) 1 4 (33.3) 2 (16.7) Safety Outcomes Number of patients with AEs (%) Any grade 11 (91.7) 11 (91.7) Glade ≥3 0 2 (16.7) *2 Number of patients with SAEs (%) 2 (16.7) *1 1 (8.3) *3 *1 Pyrexia and diverticulitis (1 patient each) *2 Grade 4 neutrophil count decreased (1 patient), grade 4 lymphocyte count decreased and nephritis (1 patient each), and grade 3 colitis, enterocolitis infectious, device related infection, anemia, hyperglycemia, and hepatic function abnormal (1 patient) *3 Colitis, hepatic function abnormal, and nephritis Efficacy Outcomes Objective Response Rate, n (%) [95% CI] 0 [0.0, 26.5] 1 (8.3) [0.2, 38.5] Disease Control Rate, n (%) [95% CI] 3 (25.0) [5.5, 57.2] 4 (33.3) [9.9, 65.1] Best Overall Response, n (%) [95% CI] Complete Response 0 [0.0, 26.5] 0 [0.0, 26.5] Partial Response 0 [0.0, 26.5] 1 (8.3) [0.2, 38.5] Stable Disease 3 (25.0) [5.5, 57.2] 3 (25.0) [5.5, 57.2] Progressive Disease 9 (75.0) 5 (41.7) Not Evaluable 0 3 (25.0) Median OS, months [95% CI] 12.21 [4.93, not reached] 16.99 [5.98, not reached] Median PFS, months [95% CI] 1.86 [0.92, 3.84] 2.17 [0.95, 3.78] Citation Format: Yuki Katsuya, Kan Yonemori, Toshio Shimizu, Takafumi Koyama, Sigehisa Kitano, Kazuki Sudo, Shunsuke Kondo, Jun Sato, Hiroaki Hozumi, Noboru Yamamoto. A phase 1 study of tamnorzatinib (ONO-7475), an Axl/Mer dual inhibitor, alone and in combination with nivolumab in patients with advanced or metastatic solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT062.

Abstract CheckMate 548 (NCT02667587, CM548) is a phase III, randomized trial evaluating first line nivolumab (NIVO) in combination with standard of care (SOC) [surgical resection followed by radiotherapy and temozolomide (TMZ)] versus placebo plus SOC in patients with newly diagnosed glioblastoma (GBM) positive for promoter methylation of O6-methylguanine DNA methyltransferase (MGMT). MGMT promoter methylation status and PD-L1 expression predict better outcomes in GBM patients treated with TMZ and in patients treated with NIVO in other indications, respectively. However, the impact of varying levels of MGMT promoter methylation and PD-L1 expression on patient outcome in GBM remains unclear. In CM548, MGMT promoter methylation levels were quantified through a central lab assay (LapCorp) and PD-L1 expression was determined by percentage of detectable membrane staining of tumor cells. MGMT methylation and PD-L1 data were prospectively generated at the time of enrolment. Our analyses showed that increasing levels of MGMT promoter methylation level were associated with longer overall survival in patients treated with SOC alone (n = 349). However, no survival benefit was observed with increasing levels of MGMT methylation in patients treated with NIVO in combination with SOC (n = 353). In addition, our data showed a non-linear relationship between PD-L1 expression and overall survival across both arms. In patients with intermediate PD-L1 expression (≥5%, <20%), longer survival was observed in the nivolumab + SOC arm compared to SOC alone. This benefit was not observed in patients with low (≥1%, <5%) and high (>20%) PD-L1 expression. Potential mechanisms driving these observed associations are currently explored using genomic data generated from patient samples. MGMT promoter methylation and PD-L1 expression are potential clinically relevant predictive biomarkers of response to treatments administered in the CM-548; however, the binary classification of positive/negative status of these markers does not fully capture their relationship with efficacy in CM548. Data generated from our exploratory analyses suggests that new, refined criteria are needed for better patient outcomes prediction. Citation Format: Yu-Han Hung, Aparna Chhibber, Michael Lim, Michael Weller, David A. Reardon, Antonio Omuro, Keith L. Ligon, Ana Lako, Ann Forslund. Exploratory analyses of MGMT promoter methylation and PD-L1 expression from newly diagnosed glioblastoma patients in CheckMate 548 study suggest refinement in thresholds for predicting response to standard of care and nivolumab treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT230.

Abstract Background: Recent advances in immunotherapy have introduced new treatment modalities for aRCC. In absence of guideline recommendations, it is unclear what factors drive providers in selecting 1L treatments for aRCC. To address this gap, we described the baseline demographic and clinical characteristics of patients with aRCC who received 1L NIVO+CABO, PEM+LEN, or NIVO monotherapy in the RW setting. Methods: In this retrospective cohort study, treating oncologists from a US nationally representative network abstracted electronic health record data from patients with aRCC who initiated 1L NIVO+CABO or NIVO monotherapy (off-label in the US) between 2/1/2021 and 6/12/2023, or PEM+LEN between 9/1/2021 and 6/12/2023. Patient demographic and clinical characteristics were summarized descriptively. Results: Compared with patients who received NIVO+CABO (n = 200) or PEM+LEN (n = 100), patients who received NIVO (n = 147) were relatively older at 1L initiation (Table). Sex, race, and region of residence were comparable across cohorts. Patients who received NIVO were more likely to have an ECOG PS score of ≥ 2 (59.2%) compared with NIVO+CABO (14.5%) or PEM+LEN (20%) cohorts. The distribution of MSKCC or IMDC risk scores at 1L initiation was comparable across cohorts . Grade 3 or 4 tumors were reported among 56.5%, 41.0%, and 43.5% of those who received NIVO+CABO, PEM+LEN, and NIVO, respectively. Conclusions: This study suggests that 1L treatment for aRCC using IO monotherapy may be more likely to be considered than IO-TKI therapy for older patients and those with poorer ECOG PS, possibly reflecting perceived tolerability of TKI combinations in these patient populations. Further research is needed to understand the impact of these 1L treatment selection patterns on outcomes. Table: Key patient characteristics at 1L initiation. PEM+LEN NIVO+CABO NIVO n = 100 n = 200 n = 147 Mean age, year (standard deviation) 64.4 (7.9) 66.3 (7.4) 74.1 (9.6) Male, n (%) 93 (63.3) 122 (61.0) 93 (63.3) Race, n (%) White 61 (61.0) 127 (63.5) 91 (61.9) Non-white/unknown 39 (39.0) 73 (36.5) 56 (38.1) Region of residence, n (%) Northeast 23 (23.0) 44 (22.0) 37 (25.2) Midwest 22 (22.0) 53 (26.5) 27 (18.4) South 20 (20.0) 34 (17.0) 33 (22.4) West 35 (35.0) 69 (34.5) 50 (34.0) MSKCC or IMDC risk score, n (%) Favorable 13 (13.0) 28 (14.0) 22 (15.0) Intermediate 57 (57.0) 100 (50.0) 74 (50.3) Poor 28 (28.0) 68 (34.0) 41 (27.9) ECOG-PS, n (%) 0 or 1 80 (80.0) 171 (85.5) 60 (40.8) ≥2 20 (20.0) 29 (14.5) 87 (59.2) Grade of tumor differentiation, n (%) Grade 1 3 (3.0) 10 (5.0) 16 (10.9) Grade 2 56 (56.0) 77 (38.5) 67 (45.6) Grade 3 36 (36.0) 98 (49.0) 55 (37.4) Grade 4 5 (5.0) 15 (7.5) 9 (6.1) Citation Format: Kevin K. Zarrabi, Benjamin Miron, Xin Yin, Lisa Rosenblatt, Sarah B. Guttenplan, William John, Taavy A. Miller, Parisa Asgarisabet, Prathamesh Pathak, Monica Ahlquist, Yul Brian Gash, Daniel M. Geynisman. Characteristics of patients with advanced renal cell carcinoma (aRCC) who received first-line (1L) nivolumab plus cabozantinib (NIVO+CABO), pembrolizumab plus lenvatinib (PEM+LEN), or nivolumab (NIVO) monotherapy in the real-world (RW) setting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5095.

Abstract Introduction: IT TAVO-EP (tavokinogene telseplasmid delivered by electroporation) results in localized expression of IL12 in the tumor microenvironment (TME). This study (NCT04526730) evaluated NeoAd TAVO-EP and NIVO. All patients provided a written informed consent (Advarra IRB Pro00041794). Biomarkers of tumoral and systemic immune responses were conducted and correlated with clinical outcomes. Methods: NeoAd phase comprised up to 3 × 4-week cycles of IT TAVO-EP and iv NIVO followed by surgery. Endpoints included pathologic complete response (pCR), near pCR, major response (pMR; pCR + near pCR) and nonresponse (pNR). Biospecimens were collected at screening, C1D8, C2D1 (~30 days from treatment start), pre-surgery (~90 days). Slides cut from FFPE tissue were analyzed by chromogenic immunohistochemistry (IHC) for CD8+ tumor infiltrating lymphocytes (TIL) and PD-L1 (22C3 CDx assay). RNA extracted from FFPE tissue was subjected to NanoString’s IO360 transcriptomic analysis, including Tumor Inflammation Signature (TIS). PBMCs were stained and analyzed via flow cytometry on an LSR Fortessa X-20. Serum samples were analyzed for cytokine levels using Luminex® MAGPIX® platform (15-plex). Results: 16 pts were treated; 1 with PR declined surgery, 1 with early distant PD did not have surgery, 14 had surgery: 2 pNR, 3 near pCR, 9 pCR; pMR rate 12/15 (80%). In tumor, at baseline, 9/11 pts tested had <20% CD8+ TIL, 7/11 <10% PD-L1 tumor proportion score (TPS) and 6/10 TIS of ≤0, predicting non-response to anti-PD-1. In 5 pts with evaluable matched tissue at baseline and C2D1: 5/5 had increased peritumoral CD8+ T cells, 4/5 increased CD8+ TIL, 2/5 increased PD-L1, 4/5 increased TIS at C2D1 compared to baseline. Tumoral transcriptome profile revealed significant upregulation of genes involved in innate and adaptive immune responses (IFN-gamma, APM, granzymes, CD8, PD-L1, JAK1, chemokines, others) at C2D1. In blood, proliferating Ki-67+/PD-1+/CD8+ T cells expanded at C2D1 while total PD1+/CD8+ cells decreased. Decrease of PD1+CD8+ cells and other subtypes in blood at C2D1 coincided with TME infiltration by CD8+ cells. Serum effector cytokines including IL12, IFN-gamma and IL2, showed no biologically meaningful changes following treatment or differences between responders and non-responders. Conclusions: At baseline, most patients exhibited low CD8+ TIL, PD-L1 and TIS, with enhanced immune activation following treatment in the TME and blood including increased immune-related gene expression, CD8+ TIL, peritumoral CD8+ T cells and TIS. Four of 5 pts with negative predictive baseline biomarkers [CD8+TIL/PD-L1/TIS]low experienced pCRs supporting activity of IL12/anti-PD1 based regimens in this setting. Citation Format: Ahmad A. Tarhini, Zeynep Eroglu, Jonathan S. Zager, Ricardo J. Gonzalez, Amod A. Sarnaik, C Wayne Cruse, Deanryan B. De Aquino, Edith Abraham, Diana M. Acevedo, Allison Richards, Michael J. Schell, Denise Kalos, Pei-Ling Chen, Jane L. Messina, David A. Canton, Vernon K. Sondak. Tumoral and systemic immune modulation with neoadjuvant (NeoAd) intratumoral (IT) TAVO-EP (plasmid IL-12 electro gene transfer) and nivolumab (NIVO) in patients (pts) with operable locoregionally advanced melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3734.

Abstract Introduction: Sarcopenia, progressive and generalized loss of skeletal muscle mass, is difficult and labor intensive to directly measure as it requires manual segmentations by radiologists from computed tomography (CT) scans. Sarcopenia has been shown to be a prognostic factor in some metastatic cancers. We evaluated the impact of sarcopenia derived via an automated segmentation algorithm on outcomes in the Phase 3 NSCLC clinical trial, CheckMate 227 (NCT02477826) Methods: The sarcopenia score assessment involves automated selection of the L3 vertebra level slice from abdominal or chest, abdomen, and pelvis (CAP) CT scans, followed by automated segmentation of the muscle area from that slice. Sarcopenia scores were derived from previously established definitions of sarcopenia, with values below 41 cm2/m2 for female patients (regardless of BMI) and below 43 cm2/m2 or 53 cm2/m2 for male (based on BMI < 25 kg/m2 or ≥ 25 kg/m2). Among the 967 patients with evaluable scans, sarcopenia at baseline was identified in 68.39% (n=329/481) patients receiving nivolumab (NIVO) with ipilimumab (IPI) and 70.2% (n=341/486) receiving chemotherapy (Chemo). Results: There was a trend of worse overall survival (OS) in patients with baseline sarcopenia across both treatment arms (minimum follow up 49.4 months). In patients with baseline sarcopenia vs ITT, median OS was 16.5 mo vs. 21.8 mo (p= 0.219) within the NIVO + IPI arm and 12.9 mo vs.15.0 mo (p= 0.273) within the Chemo arm respectively. Any increase in muscle mass from baseline to week 12 was associated with better OS for patients treated with NIVO+IPI (n=98) with sarcopenia at baseline compared to those without an increase in muscle mass (median OS 45.3 mo vs.19.5 mo, p= 0.012). This was not seen in those who received Chemo (n=87). Weight and muscle mass were moderately correlated at baseline (r=0.60). Conclusions: We found that in CheckMate 227, baseline sarcopenia is associated with numerically worse OS, regardless of treatment, leading to potential use as a negative prognostic biomarker. Patients with NSCLC receiving immunotherapy might benefit from changes in muscle mass being monitored during treatment. Validation of these findings in other studies and other tumor types is warranted. Citation Format: Wiem Safta, Rafael Santana-Davila, David Paulucci, William J. Geese, Diederik J. Grootendorst. An analysis of the prognostic role of sarcopenia derived with fully automated deep learning slice-based muscle estimation in patients with metastatic non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7650.