1086P Intratumoral (IT) administration of autologous CD1c(BDCA-1)+/CD141(BDCA-3)+myeloid dendritic cells (myDC) with the immunologic adjuvant AS01B plus ipilimumab (IPI) and IV nivolumab (NIVO) in patients with refractory advanced melanoma: A phase Ib clinical trial

965MO Nivolumab (NIVO) plus ipilimumab (IPI) vs lenvatinib (LEN) or sorafenib (SOR) as first-line (1L) treatment for unresectable hepatocellular carcinoma (uHCC): Expanded analyses from CheckMate 9DW

1317P Real-world immunotherapy (IO) rechallenge outcomes with nivolumab (NIV) in advanced non-small cell lung cancer (aNSCLC) in France: LIST study interim results

441O A phase I clinical trial on the intracranial administration of autologous CD1c(BDCA-1)+ /CD141(BDCA-3)+ myeloid dendritic cells (myDC) in combination with ipilimumab (IPI) and nivolumab (NIVO) in patients with recurrent high-grade glioma (rHGG)

LBA30 ATHENA-COMBO, a phase III, randomized trial comparing rucaparib (RUCA) + nivolumab (NIVO) combination therapy vs RUCA monotherapy as maintenance treatment in patients (pts) with newly diagnosed ovarian cancer (OC)

1646P A multicohort phase II trial of androgen deprivation therapy (ADT), docetaxel (DOCE) and nivolumab (NIVO) in patients (pts) with newly diagnosed metastatic hormone sensitive prostate cancer (mHSPC) enriched for inflamed tumours and DNA damage repair (DDR) alterations: Cohort 3 results

Abstract Background Adverse events (AEs) can limit treatment immune checkpoint inhibitors (ICI) efficacy and worsen patient outcomes. Our group recently identified a germline IL7 SNP as a potential biomarker for prediction of irAEs (Groha, Nat Med 2022). In the current study, we sought to replicate the association between this IL7 SNP (rs16906115) and AEs in two clinical trials of patients with cancer treated with ICI regimens. Methods In the CheckMate-025 (CM025) trial (NCT01668784), involving patients with metastatic renal cell carcinoma (mRCC) randomized to either nivolumab (NIVO) or everolimus (EVE), whole-exome sequencing (WES) data from tumor and peripheral blood samples were analyzed. The Cancer Genome Analysis pipeline was utilized to identify somatic alterations, and the STITCH pipeline was employed to determine SNP carrier status. In the BinTA-0037 (BTA-0037) trial (NCT03631706), focusing on patients with metastatic non-small cell lung cancer (mNSCLC), the carrier status of a surrogate SNP rs16906062 (R2=0.66) was determined from tumor WES in the pembrolizumab (PEMBRO) arm. Within each treatment arm, time to incident AEs were compared between carriers (SNP+) and non-carriers (SNP-) via multivariable Cox regression, controlling for age, sex, race, ECOG and sample purity. A SNP´treatment interaction term was also included in the entire CM025 cohort. Censoring for AEs occurred at death or last follow-up. A recurrent event analysis for AEs was conducted using the Andersen-Gill model, controlling for the same variables. Additionally, overall survival (OS) and progression-free survival (PFS) were also assessed. Results In total, 534 pts were included (NIVO: n=189, PEMBRO: n=152, EVE: n=193), among which 82 (15.4%) 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% in females, P=0.046). Similarly, no differences in somatic alterations, including single nucleotide and copy number variants were seen between SNP+ and SNP- in CM025. SNP carrier status had no effect on OS nor PFS in all treatment arms (all P≥0.22). The rate of grade 2+ AEs was significantly higher in SNP+ vs. SNP- in the NIVO arm (Figure A, HR=2.91[1.48-5.72]), but not in the EVE (Figure B, control, non-ICI) arm (HR=0.63[0.3-1.29], SNP´treatment Pinteraction=0.002). Similarly, the rate of all grade AEs in the PEMBRO arm of BTA-0037 was higher in SNP+ vs. SNP- (Figure C, HR=2.30[1.60-4.60]). 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). Figure: Kaplan-Meier curves showing the cumulative rate of adverse events in the NIVO (A) and EVE (B) arms of CM025, as well as the PEMBRO arm of BTA0037 (C), in SNP- and SNP+. Conclusions The IL7 SNP (rs16906115) is associated with significantly higher rates of grade 2+ AEs, including recurrent events, in pts with mRCC or mNSCLC treated with single agent PD-1 inhibitors but not with non-ICI regimens, with no effect on survival and efficacy outcomes. These results confirm the SNP’s predictive potential as a biomarker for irAEs to guide therapeutic decisions in pts treated with ICIs.

In PIVOT IO 001 (NCT03635983), the combination of the investigational interleukin-2 agonist bempegaldesleukin (BEMPEG) with nivolumab (NIVO) had no added clinical benefit over NIVO monotherapy in unresectable/metastatic melanoma. Pre-defined baseline and on-treatment changes in selected biomarkers were analyzed to explore the potential mechanisms underlying the clinical observations. In each treatment arm, higher baseline tumor mutational burden or immune infiltration/inflammation was associated with improved efficacy compared with lower levels. On-treatment peripheral biomarker changes showed that BEMPEG + NIVO increased all immune cell subset counts interrogated, including regulatory T cells. This was followed by attenuation of the increase in CD8 + T cells, conventional CD4 + T cells, and systemic interferon gamma levels at later treatment cycles in the combination arm. Changes in tumor biomarkers were comparable between arms. These biomarker results help provide a better understanding of the mechanism of action of BEMPEG + NIVO and may help contextualize the clinical observations from PIVOT IO 001.

LBA8007 Background: In CheckMate 77T, perioperative NIVO showed statistically significant EFS improvement vs neoadjuvant (neoadj) chemo followed by adjuvant (adj) placebo (PBO) in pts with stage (stg) II or III resectable NSCLC. We report clinical outcomes by baseline (BL) stg III N2 status, a subgroup with poor historical 5 y survival (26%–36%; Goldstraw J Thorac Oncol 2016). Methods: Adults with resectable stg IIA–IIIB (N2; AJCC v8) NSCLC were randomized to neoadj NIVO 360 mg Q3W + chemo (4 cycles [cyc]) followed by adj NIVO 480 mg Q4W (13 cyc) or neoadj PBO Q3W + chemo (4 cyc) followed by adj PBO Q4W (13 cyc). Primary endpoint: EFS per BICR. Exploratory analysis: efficacy and safety in pts with BL clinical stg III N2 or non N2 disease (dz). Results: BL characteristics were generally similar between pts with stg III N2 (NIVO, 91; PBO, 90) and non N2 dz (55; 57), and between treatment (tx) arms, except a higher percent of pts with N2 dz had NSQ histology and ECOG PS 0 (both arms). Pts with N2 dz had improved EFS with NIVO vs PBO (HR 0.46; 1 y EFS 70% vs 45%) and higher pCR (22.0% vs 5.6%; median f/u 25.4 mo; Table). Pts with non N2 also had EFS benefit with NIVO vs PBO (HR 0.60; 1 y EFS 74% vs 62%) and higher pCR (25.5% vs 5.3%; Table). Surgical feasibility was similar between pts with N2 and non N2 dz and numerically higher with NIVO vs PBO. Of pts with N2 dz, 77% (NIVO) vs 73% (PBO) had definitive surgery (pneumonectomy 1% vs 14%; R0 resection 86% vs 86%); of pts with non N2 dz, 82% vs 79% had definitive surgery (pneumonectomy 13% vs 9%; R0 resection 84% vs 87%). Tumor downstaging postsurgery was seen in most pts with stg III dz and was deeper with NIVO vs PBO: 61% vs 50% (N2; 33% vs 14% to ypT0), 87% vs 76% (non N2; 27% vs 11% to ypT0). Of all pts with stg III dz, nodal downstaging postsurgery was 52% (NIVO) vs 45% (PBO); 46% vs 36% to ypN0. Grade 3–4 TRAEs occurred in 34% (NIVO) and 26% (PBO) of pts with N2; 29% and 21% of pts with non N2 dz. Conclusions: In this exploratory analysis, perioperative NIVO showed clinical benefit vs PBO in pts with stg III NSCLC, regardless of N2 status. Over half of pts with stg III dz had nodal downstaging with NIVO; majority downstaged to ypN0. This first comprehensive analysis by nodal status among pts with stg III dz from a global phase 3 study of perioperative immunotherapy further supports perioperative NIVO as a tx option for pts with resectable NSCLC. Clinical trial information: NCT04025879 . [Table: see text]

LBA4008 Background: First-line therapies based on programmed death ligand 1 (PD-L1) inhibitors are standard of care (SOC) in uHCC and demonstrate improved outcomes over SOR; however, prognosis remains poor and there is an unmet need for alternative therapies with long-term benefits. Second-line NIVO + IPI demonstrated clinically meaningful efficacy and manageable safety in SOR-treated patients (pts) with HCC in CheckMate 040, leading to its accelerated approval in the United States. We report first results from the preplanned interim analysis of the phase 3, open-label, randomized CheckMate 9DW trial evaluating the efficacy and safety of NIVO + IPI vs LEN or SOR as first-line therapy for pts with uHCC (NCT04039607). Methods: Adult pts with previously untreated HCC not eligible for curative surgical or locoregional therapies, Child-Pugh score 5–6, and ECOG performance status 0–1 were included. Pts were randomly assigned 1:1 to receive NIVO 1 mg/kg + IPI 3 mg/kg Q3W (up to 4 cycles) followed by NIVO 480 mg Q4W or investigator’s choice of LEN 8 mg or 12 mg QD or SOR 400 mg BID until disease progression or unacceptable toxicity. NIVO was given for a maximum of 2 years. The primary endpoint was overall survival (OS). Secondary endpoints included objective response rate (ORR) and duration of response (DOR) per blinded independent central review (BICR) using RECIST v1.1. Results: In total, 668 pts were randomized to NIVO + IPI (n = 335) or LEN/SOR (n = 333); among 325 pts treated in the LEN/SOR arm, 275 (85%) received LEN. After a median (range) follow-up of 35.2 (26.8–48.9) months (mo), median OS was 23.7 mo with NIVO + IPI vs 20.6 mo with LEN/SOR (HR, 0.79; 95% CI, 0.65–0.96; P = 0.0180) (Table), with respective 24-mo OS rates (95% CI) of 49% (44–55) vs 39% (34–45). ORR was higher with NIVO + IPI (36%) vs LEN/SOR (13%; P < 0.0001); complete response was observed in 7% of pts with NIVO + IPI vs 2% with LEN/SOR. Median DOR was 30.4 mo with NIVO + IPI vs 12.9 mo with LEN/SOR (Table). A summary of treatment-related adverse events (TRAEs) is shown in the Table. Conclusions: NIVO + IPI demonstrated statistically significant OS benefit vs LEN/SOR in pts with previously untreated uHCC, as well as higher ORR and durable responses with a manageable safety profile. These results support this combination as a potential new first-line SOC for uHCC. Clinical trial information: NCT04039607 . [Table: see text]

LBA9584 Background: Neoadjuvant (neoadj) ipilimumab (IPI) + nivolumab (NIVO) showed improved event-free survival compared to adjuvant (adj) NIVO, but at the cost of increased immune related toxicity (irAEs). In the PRADO trial, impairment of health-related quality of life (HRQoL) was predominantly driven by the extent of the surgery and not by irAEs. To evaluate the effect of neoadj IPI+NIVO on HRQoL, we report the 36w HRQoL outcomes from the phase 3 NADINA trial. Methods: Eligible patients (pts) with resectable, macroscopic stage III melanoma were randomly assigned to receive 2 cycles of neoadj IPI+NIVO followed by a therapeutic lymph node dissection (TLND; w6) and only in partial- or non-responders, 1y of adj systemic treatment; or TLND (w0) followed by 12 cycles adj NIVO. EORTC QLQ-C30 questionnaires (qtn) were digitally collected at baseline, w6, w12 and thereafter q12w. The unadjusted HRQoL scores (scale 0-100) were assessed for pts who completed 39w of follow-up (FU) on January 12, 2024. Results: 261/423 randomized pts had 39w FU at data cutoff. 81% completed the qtn at BL, with thereafter an average compliance of 80%. QLQ-C30 data were available for 107 pts in the neoadj arm and 103 in the adj arm. Physical-, role-, emotional functioning, and pain were comparable between the neoadj and adj arm across all timepoints (Table), as were fatigue and the summary score. A numerical trend towards worsening of physical-, role functioning, and pain was seen at w6 for the adj arm and at w12 for the neoadj arm, representing the post-surgery QoL timepoints. Conclusion: Using fully digitalized data collection, this first HRQoL analysis of neoadj vs adj immunotherapy in stage III melanoma showed comparable results between the neoadj and adj arms. Physical-, role functioning, and pain were impaired in both groups at the first post-surgery timepoint. Clinical trial information: NCT04949113 . [Table: see text]

LBA9519 Background: The combination of ipilimumab (IPI) and nivolumab (NIVO) remains a standard of care for patients with advanced melanoma, especially those with poor prognostic factors, albeit with a significant risk of toxicity. Therapeutic cancer vaccines are ideally positioned to improve outcomes without significantly increasing toxicity. UV1 is a therapeutic cancer vaccine generating T-cell responses against the universal cancer antigen telomerase. In a Phase I trial in melanoma (N = 30), UV1 plus pembrolizumab demonstrated a tolerable safety profile, a complete response rate of 33%, median PFS of 18.9 months, and 2-year OS rate of 73.3%. Recently, results from a randomized Phase II trial indicated a longer overall survival and a higher response rate for previously treated patients with advanced mesothelioma receiving UV1 in combination with IPI-NIVO (1). Methods: In this Phase II, open-label, multicenter study, we randomly assigned treatment-naïve patients with unresectable or metastatic melanoma (stage IIIb-IIId or IV) to IPI 3mg/kg + NIVO 1mg/kg for 4 cycles, followed by NIVO 480 mg as maintenance, with or without 8 intradermal injections of 300 µg UV1 (+GM-CSF). The primary endpoint was progression-free survival (PFS) assessed by blinded independent central review (BICR) according to RECIST 1.1. Secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response, and safety. Results: A total of 156 patients underwent randomization; 78 patients were assigned to the IPI-NIVO-UV1 arm and 78 patients to the IPI-NIVO arm. The median age was 60, 48% had M1C or D disease, 38% had LDH >upper limit of normal, and 42% had a positive BRAF mutation status. With a minimum follow-up of 18 months, the 12-month PFS rate was 57% in both arms (HR 0.95, 95% CI 0.59-1.55, p value 0.845). The ORR was similar with IPI-NIVO-UV1 compared to IPI-NIVO, at 60% vs 59%, respectively (Odds ratio 1.12, 95% CI 0.58-2.16, p value 0.867). The 12-month OS rate was 87% and 88%, respectively (HR 1.15, 95% CI 0.60-2.20, p value 0.674). The occurrence of grade >3 adverse events was similar in both treatment arms. Conclusion: UV1 did not improve on outcomes of IPI-NIVO, in terms of PFS. Longer follow-up is required for the accurate assessment of OS. No significant toxicity increases were observed with the addition of UV1. Data from a biomarker driven cohort are awaited. 1. Helland et al, Eur J Cancer 2024. Clinical trial information: NCT04382664 .

Bempegaldesleukin (BEMPEG) is a pegylated interleukin (IL)-2 cytokine prodrug engineered to provide controlled and sustained activation of the clinically validated IL-2 pathway, with the goal of preferentially activating and expanding effector CD8+ T cells and natural killer cells over immunosuppressive regulator T cells in the tumor microenvironment. The open-label, phase III randomized controlled PIVOT-09 trial investigated the efficacy and safety of BEMPEG plus nivolumab (NIVO) as first-line treatment for advanced/metastatic clear cell renal cell carcinoma (ccRCC) with intermediate-/poor-risk disease. Patients with previously untreated advanced/metastatic ccRCC were randomly assigned (1:1) to BEMPEG plus NIVO, or investigator's choice of tyrosine kinase inhibitor (TKI; sunitinib or cabozantinib). Coprimary end points were objective response rate (ORR) by blinded independent central review and overall survival (OS) in patients with International Metastatic RCC Database Consortium (IMDC) intermediate-/poor-risk disease. Overall, 623 patients were randomly assigned to BEMPEG plus NIVO (n = 311) or TKI (n = 312; sunitinib n = 225, cabozantinib n = 87), of whom 514 (82.5%) had IMDC intermediate-/poor-risk disease. In patients with IMDC intermediate-/poor-risk disease, ORR with BEMPEG plus NIVO versus TKI was 23.0% (95% CI, 18.0 to 28.7) versus 30.6% (95% CI, 25.1 to 36.6; difference, -7.7 [95% CI, -15.2 to -0.2]; P = .0489), and median OS was 29.0 months versus not estimable (hazard ratio, 0.82 [95% CI, 0.61 to 1.10]; P = .192), respectively. More frequent all-grade treatment-related adverse events (TRAEs) with BEMPEG plus NIVO versus TKI included pyrexia (32.6% v 2.0%) and pruritus (31.3% v 8.8%). Grade 3/4 TRAEs were less frequent with BEMPEG plus NIVO (25.8%) versus TKI (56.5%). First-line BEMPEG plus NIVO for advanced/metastatic ccRCC did not improve efficacy in patients with intermediate-/poor-risk disease but led to fewer grade 3/4 TRAEs versus TKI.

3503 Background: NIVO + IPI demonstrated superior progression-free survival (PFS) vs chemo in patients (pts) with previously untreated MSI-H/dMMR mCRC in the randomized phase 3 CheckMate 8HW study (NCT04008030). We report expanded efficacy analysis from the prespecified interim analysis of NIVO + IPI vs chemo in the 1L setting. Methods: Pts with unresectable or mCRC and MSI-H/dMMR status by local testing were enrolled across different lines of therapy and randomized 2:2:1 to NIVO (240 mg) + IPI (1 mg/kg) Q3W (4 doses, then NIVO 480 mg Q4W), NIVO (240 mg) Q2W (6 doses, then NIVO 480 mg Q4W), or chemo ± targeted therapies; treatments continued until disease progression or unacceptable toxicity (all arms) or for up to 2 years (NIVO ± IPI arms). In pts with blinded independent central review (BICR)–documented progression with chemo, crossover to NIVO + IPI was permitted. Dual primary endpoints were PFS by BICR per RECIST v1.1 for NIVO + IPI vs chemo (1L) and NIVO + IPI vs NIVO (all lines) in pts with centrally confirmed MSI-H/dMMR mCRC. PFS2 (time from randomization to progression after subsequent systemic therapy, initiation of second subsequent systemic therapy, or death) was a key exploratory endpoint. Results: Among 303 pts randomized to NIVO + IPI (n = 202) or chemo (n = 101), 171 pts in the NIVO + IPI arm and 84 pts in the chemo arm had centrally confirmed MSI-H/dMMR. At 31.5-months (mo) median follow-up (range 6.1–48.4), NIVO + IPI demonstrated superior PFS vs chemo (HR 0.21; 97.91% CI 0.13–0.35; P < 0.0001). Subsequent systemic therapy was received by 20 (12%) and 57 (68%) pts in the NIVO + IPI and chemo arms, respectively. In the chemo arm, 56 (67%) pts received subsequent immunotherapy (39 [46%] crossed over to NIVO + IPI on study; 17 [20%] received non-study immunotherapy). Median PFS2 was not reached (NR) with NIVO + IPI and 29.9 mo with chemo (HR 0.27; 95% CI 0.17–0.44; Table). Any grade and grade 3/4 treatment-related adverse events (TRAEs) are presented (Table). Treatment-related deaths were reported for 2 pts in the NIVO + IPI arm. Conclusions: Clinical benefit with 1L NIVO + IPI vs chemo was maintained after subsequent therapy, as shown by improved PFS2 in pts with centrally confirmed MSI-H/dMMR mCRC. No new safety concerns were identified with NIVO + IPI. These results further support NIVO + IPI as a standard-of-care 1L treatment option for pts with MSI-H/dMMR mCRC. Clinical trial information: NCT04008030 . [Table: see text]

9524 Background: NIVO + RELA as a fixed-dose combination (FDC) demonstrated a statistically significant progression-free survival (PFS) benefit vs NIVO in RELATIVITY-047 (NCT03470922), with a clinically meaningful, but not statistically significant, improvement in OS and a numerically higher objective response rate (ORR), resulting in regulatory approval of the FDC. Here we report updated descriptive analyses with 3 years of follow-up. Methods: Patients (pts) were randomized 1:1 to receive NIVO 480 mg + RELA 160 mg FDC or NIVO 480 mg Q4W. PFS per RECIST v1.1 was assessed by blinded independent central review (BICR); secondary endpoints included OS and ORR per BICR. Exploratory analyses included MSS (death due to melanoma, with censoring of deaths due to other causes), CNS metastasis-free survival in specified populations, and efficacy on subsequent systemic therapy. Results: At database lock (19 Oct 2023), median follow-up was 33.8 months (mo; range, 0.3–64.2). NIVO + RELA continued to show a benefit vs NIVO for PFS, OS, ORR, and MSS (Table). NIVO + RELA was also favored over NIVO across the majority of key subgroups. Subsequent systemic therapy was received by 135 pts (38%) on NIVO + RELA and 141 pts (39%) on NIVO. Grade 3–4 treatment-related adverse events (TRAEs) occurred in 78 pts (22%) on NIVO + RELA and 43 pts (12%) on NIVO; TRAEs (any grade) led to treatment discontinuation in 63 pts (18%) and 35 pts (10%), respectively. No new treatment-related deaths were reported since the last analysis. Conclusions: At 3 years of follow-up, NIVO + RELA continued to show a benefit vs NIVO for PFS, OS, ORR, and MSS. OS and MSS demonstrated sustained improvement, with the OS HR 95% CI upper bound < 1. Efficacy results also continued to favor NIVO + RELA vs NIVO across the majority of prespecified subgroups. Safety of NIVO + RELA remained consistent with previous reports, with no new or unexpected safety signals. CNS metastasis-free survival and efficacy outcomes on subsequent systemic therapy will be presented. Clinical trial information: NCT03470922 . [Table: see text]

2037 Background: Intracerebral (iCer) administration (admin) of ipilimumab (IPI) and nivolumab (NIVO) plus IV NIVO following resection of recurrent high-grade glioma (rHGG) was well tolerated and showed encouraging overall survival (OS) (J. Duerinck et al. JITC 2021). The safety of additional postoperative (postop) bi-weekly intracavitary (iCav) admin of NIVO or NIVO + IPI (: first in human intracranial CTLA-4 blockade) was investigated in a phase I trial (3+3 design with cohort expansion). Methods: Within 24h prior to surgery, 10 mg NIVO IV was admin, followed by a maximal safe resection and injection of the brain tissue lining the resection cavity with 5 mg IPI + 10 mg NIVO, and positioning of a catheter in the resection cavity connected to an Ommaya reservoir. Only in patients (pts) receiving postop iCav IPI, 10 mg NIVO and 5 mg IPI were admin via the Ommaya at the end of surgery. Postop 1, 5, or 10 mg NIVO was admin iCav as a single agent. In subsequent pts, postop 10 mg iCav NIVO was combined with 1, 5 or 10 mg iCav IPI. All postop iCav admin were combined with NIVO 10 mg IV, and repeated Q2w (< 24w). On-treatment CSF samples were used for cytology, chemical analysis, and measurements of NIVO/IPI concentrations. Results: 43 pts (32 male) initiated treatment, all receiving the predefined pre- and intraop doses of IV and iCer IPI/NIVO. No unexpected AE related to the intraop treatment occurred. Postop treatment was initiated in 39 pts, all receiving 10 mg NIVO IV Q2w. Postop NIVO IV was combined with iCav NIVO 1, 5 or 10 mg in 3, 4, and 9 pts. The median number of postop IV/iCav NIVO admin was 7 (3-7), 4.5 (0-11), and 2 (1-11), resp. Next, postop iCav NIVO 10 mg was combined with iCav IPI 1, 5 or 10 mg in 10, 6, and 11 pts. The median number of postop IV/iCav NIVO + IPI admin was 3 (0-12), 4 (1-11), and 4 (0-12), resp. Dose limiting toxicity consisted of transient grade 3 aseptic neutrophilic pleocytosis with pyrexia and neurological deterioration in 1 and 3 pts treated with 5 and 10 mg IPI iCav, resp. Most frequent TRAEs were fatigue (n=24), headache (n=19), fever (n=17), and bacterial Ommaya colonization (n=11). No grade 5 AE occurred. At database lock, all pts were off study treatment, 1 pt stayed progression-free, and 5 were alive (mFU 80w (31-140)). OS compared favorably against a Belgian historical control cohort (469 pts; log rank p: 0.010) with an improved 1 and 2y OS rate (33 vs. 18.6% and 11.7 vs. 5.7%, resp.). Adding iCav IPI postop did not significantly alter PFS or OS. There was an elevated protein level and lymphocytic pleocytosis in >90% of CSF samples and no evidence for NIVO accumulation in the CSF (IPI under evaluation). Conclusions: In this first in human phase I trial on intracranial CTLA-4/PD-1 blockade in pts with rHGG amenable for resection, intraop iCer and postop iCav admin of NIVO+/- IPI was found to be feasible and safe up to a bi-weekly postop iCav dose of 1 mg IPI + 10 mg NIVO; with encouraging OS results. Clinical trial information: NCT03233152 .

4034 Background: NIVO + chemo and NIVO + IPI are approved for the treatment of advanced ESCC in the US, EU, Japan, and many other countries based on the results from CheckMate 648 (NCT03143153). Here, we report 45-mo follow-up results. Methods: Adults with previously untreated, unresectable advanced, recurrent, or metastatic ESCC were randomized to NIVO (240 mg Q2W) + chemo (fluorouracil + cisplatin Q4W), NIVO (3 mg/kg Q2W) + IPI (1 mg/kg Q6W) or chemo. The primary endpoints were overall survival (OS) and progression-free survival (PFS) per blinded independent central review (BICR) in patients (pts) with tumor cell programmed death ligand 1 (PD-L1) ≥ 1%. Results: In total, 970 pts were randomized to NIVO + chemo, NIVO + IPI, or chemo. With 45-mo minimum follow-up, NIVO + chemo and NIVO + IPI demonstrated continued OS benefit and higher 45-mo OS rates vs chemo in pts with tumor cell PD-L1 ≥ 1% and all randomized pts (Table). Duration of response (DOR) was longer (Table) and the proportion of responders with DOR ≥ 45 mo was greater with NIVO + chemo and NIVO + IPI vs chemo in pts with tumor cell PD-L1 ≥ 1% (7% and 23% vs 0%, respectively) and all randomized pts (14% and 18% vs 6%). Any-grade treatment-related adverse events (TRAEs) occurred in 96% of pts with NIVO + chemo, 80% with NIVO + IPI, and 90% with chemo; grade 3/4 TRAEs occurred in 49%, 33%, and 37% of pts, respectively. No additional TRAEs leading to discontinuation and no new treatment-related deaths were reported with longer follow-up. Conclusions: After 45 mo of follow-up, NIVO + chemo and NIVO + IPI continued to demonstrate clinically meaningful survival benefit and more durable responses vs chemo, with no new safety signals. These results further support NIVO + chemo and NIVO + IPI as 1L treatment options for advanced ESCC. Clinical trial information: NCT03143153 . [Table: see text]

4040 Background: NIVO + chemo demonstrated superior overall survival (OS) and clinically meaningful progression-free survival (PFS) benefit vs chemo and an acceptable safety profile in previously untreated, advanced non-HER2+ GC/GEJC/EAC, leading to approvals in many countries. NIVO + chemo continued to demonstrate clinically meaningful improvement in efficacy at 2 and 3-yr follow-ups. We present 4-yr follow-up results for NIVO + chemo vs chemo from CheckMate 649. Methods: Adults with previously untreated, unresectable advanced, or metastatic GC/GEJC/EAC were enrolled, regardless of programmed death ligand 1 (PD-L1) expression. HER2+ patients (pts) were excluded. Randomized pts received NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded independent central review (BICR) in pts with PD-L1 combined positive score (CPS) ≥ 5. Results: 1581 pts were randomized to NIVO + chemo or chemo. At the 48-month (mo) minimum follow-up, NIVO + chemo continued to demonstrate OS and PFS benefit vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts (Table). OS benefit with NIVO + chemo was observed in most prespecified subgroups. Objective response rates (ORR) were higher and responses were more durable with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts (Table). In the exploratory analysis of OS by response at the 18-week landmark timepoint, there were numerically more pts achieving response with NIVO + chemo vs chemo, and median OS (95% CI) with NIVO + chemo was numerically longer in responders vs non-responders both in pts with PD-L1 CPS ≥ 5 (20.5 [17.5–25.0] vs 14.0 [11.6–15.7]) and all randomized pts (19.4 [17.5–21.7] vs 13.1 [11.6–14.4]). No new safety signals were identified, consistent with the 3-yr follow-up. Conclusions: NIVO + chemo is the first PD-1 inhibitor/chemo combination to demonstrate long-term efficacy and acceptable safety after 4 yrs of follow up in previously untreated advanced GC/GEJC/EAC. These results are consistent with earlier follow-ups, further supporting NIVO + chemo as a standard 1L treatment in these pts. Clinical trial information: NCT02872116 . [Table: see text]

4535 Background: NIVO IV has improved outcomes in multiple tumor types. Evolving treatment paradigms have created a need for administration options that address treatment burden and improve efficiencies of healthcare systems. In a phase 1/2 study (CheckMate 8KX), pts were highly satisfied with NIVO SC and preferred it over NIVO IV [Lonardi et al, ESMO 2022; Lonardi et al, SITC 2023]. CheckMate 67T (NCT04810078) is a multicenter, randomized, open-label, phase 3 study that demonstrated pharmacokinetic and objective response rate noninferiority of NIVO SC vs IV in pts with locally advanced or metastatic ccRCC [George et al, ASCO-GU 2024]. This exploratory analysis assessed non-inferiority of HRQoL between pts randomized to NIVO SC (n=248) vs NIVO IV (n=247) in CheckMate 67T. Methods: HRQoL was measured using patient-reported outcomes (PROs), FKSI-19 (kidney cancer-related HRQoL) and the EQ-5D-5L (pt’s health status). FKSI-19 total score (range 0-76, higher score better HRQoL)and EQ-5D-5L visual analogue scale (VAS) (range 0-100, higher score better health HRQoL) scores were evaluated longitudinally on-treatment visits with ≥10 pts per arm included in model [week 57]) using linear mixed models (constrained longitudinal data analysis), with least squares (LS) mean changes from baseline and differences in the LS mean between NIVO SC and NIVO IV assessed; non-inferiority of NIVO SC vs NIVO IV was evaluated by examining overall treatment differences for on-treatment visits relative to prespecified thresholds. Results: PRO data were available for 247 pts (99.6%) for NIVO SC and 245 pts (99.2%) for NIVO IV, with completion rates >87% across instruments up to week 57 for both treatment arms. HRQoL was maintained over time for both NIVO arms for FKSI-19 total score and subscales and EQ-5D-5L VAS. NIVO SC was non-inferior to NIVO IV across FKSI-19 total score and subscales and EQ-5D-5L VAS (Table). Conclusions: These results demonstrate maintenance of HRQoL for pts with advanced or metastatic ccRCC while on treatment with NIVO, regardless of the mode of administration (SC or IV), supporting the use of NIVO SC as a new option to align with patient preferences. Clinical trial information: NCT04810078 . [Table: see text]

e21521 Background: Immune checkpoint inhibitors (ICI) are the standard treatment for patients (pts) with MM. However, only a subset of pts respond to ICIs. Temozolomide (TEM) is used in refractory settings but with low objective response rates and no clear overall survival benefit. The efficacy of combined ICI + TEM is not well described. Methods: This was a single center, retrospective study of pts with MM who received treatment with nivolumab (NIVO) and TEM or TEM alone between 11/6/2013 and 11/6/2023. Demographic information, disease characteristics, LDH, treatment, toxicity, objective response, and outcomes were collected. Results: 34 patients were included. 16 were treated with NIVO + TEM and 18 were treated with TEM alone. In the NIVO + TEM group, 81% were male (n = 13) with median age of 59.5 years (range 20-79), and in the TEM group, 56% were male with median age 61 (range 35-81). For NIVO + TEM, 31% had partial response (PR; n = 5), 6% had stable disease (SD, n = 1), and 63% had progressive disease (PD; n = 10). For TEM, 11% had PR (n = 2), 22% had SD (n = 4), and 67% had PD (n = 12) (p = 0.37). For NIVO + TEM, 2 PRs were durable, ongoing at 442 and 741 days; 3 PRs were transient (85-179 days); 1 pt had durable SD ongoing at 201 days. For TEM, PR durations were 173 and 504 days, and SD durations between 213-435 days. Five pts with PD treated with NIVO + TEM had mixed responses (31%) compared with 1 pt treated with TEM (6%). Median progression free survival (PFS) was 80 days (range 11-748) for NIVO + TEM and 55.5 days (7-415) for TEM (p = 0.31). Median overall survival (OS) was 160 days (43-363) for NIVO + TEM and 118 days (7-1938) for TEM (p = 0.15). There were 26 adverse events (AEs) for NIVO + TEM (27% grade 1, 42% grade 2, 19% grade 3, and 12% grade 4; thrombocytopenia and pneumonitis), and 25 AEs for TEM (40% grade 1, 40% grade 2, 12% grade 3, and 8% grade 4; thrombocytopenia) [p = 0.64]. Conclusions: NIVO + TEM occasionally produced durable responses, although outcome metrics were not clearly superior to TEM alone in this small study. Further studies should quantify the benefit of ICI + chemotherapy regimens in refractory MM. [Table: see text]