BACKGROUND:There is an unmet need for additional and more efficacious therapies for patients with unresectable metastatic oesophageal cancer. We aimed to evaluate the efficacy and safety of adding tiragolumab and atezolizumab to chemotherapy as first-line treatment for unresectable or metastatic oesophageal squamous cell carcinoma. METHODS:The SKYSCRAPER-08 randomised, double-blind, placebo-controlled, phase 3 trial was done at 67 centres in mainland China, South Korea, Thailand, Taiwan, and Hong Kong and enrolled adult patients (aged ≥18 years) with treatment-naive, unresectable locally advanced, unresectable recurrent, or metastatic oesophageal squamous cell carcinoma, with an Eastern Cooperative Oncology Group performance status of 0-1. Patients were randomly assigned (1:1) to receive tiragolumab (600 mg) plus atezolizumab (1200 mg) and chemotherapy (paclitaxel [175 mg/m2] and cisplatin [60-80 mg/m2]) or placebo and chemotherapy through intravenous infusion for six 21-day cycles. The primary outcomes were independent review facility-assessed progression-free survival and overall survival in the intention-to-treat population (defined as all randomly assigned patients, regardless of whether they received any study treatment). This study was registered with ClinicalTrials.gov, NCT04540211, and is ongoing. FINDINGS:Between Oct 30, 2020, and Nov 30, 2021, 461 patients were assigned to receive tiragolumab plus atezolizumab and chemotherapy (n=229) or placebo and chemotherapy (n=232); 406 (88%) were male and 55 (12%) female, and all patients were Asian. Median survival follow-up was 12·6 months (IQR 6·8-18·0). Median independent review facility-assessed progression-free survival (cutoff June 15, 2022) in the tiragolumab plus atezolizumab and chemotherapy group was 6·2 months (95% CI 5·7-7·2) versus 5·4 months (95% CI 4·4-5·5) in the placebo and chemotherapy group (HR 0·56, 95% CI 0·45-0·70; p<0·0001). Median overall survival (cutoff Feb 13, 2023) was 15·7 months (95% CI 13·3-20·4) and 11·1 months (95% CI 9·6-13·6; HR 0·70, 95% CI 0·55-0·88; p=0·0024). The most common grade 3-4 adverse events in the tiragolumab plus atezolizumab and chemotherapy group versus the placebo and chemotherapy group were white blood cell count decrease (46 [20%] of 228 vs 35 [15%] of 227), neutrophil count decrease (78 [34%] vs 78 [34%]), and anaemia (19 [8%] vs 24 [11%]). Serious adverse events occurred in 94 (41%) of 228 patients in the tiragolumab plus atezolizumab and chemotherapy group and 89 (39%) of 227 in the placebo and chemotherapy group; the most common serious adverse event was pneumonia (17 [7%] of 228 and 13 [6%] of 227). Treatment-related deaths occurred in six patients (3%) in the tiragolumab plus atezolizumab and chemotherapy group (immune-mediated lung disease, pneumonitis, cardiac arrest, gastrointestinal haemorrhage, hepatic failure, and bacterial pneumonia) and two (1%) in the placebo and chemotherapy group (gastrointestinal infection and death of unknown cause). No new safety signals were identified. INTERPRETATION:Independent review facility-assessed progression-free survival and overall survival were significantly better in the tiragolumab plus atezolizumab and chemotherapy group compared with chemotherapy alone for unresectable locally advanced, unresectable recurrent, or metastatic oesophageal squamous cell carcinoma. These data support the rationale for exploring dual checkpoint inhibition added to chemotherapy for this group of patients with a high unmet need. FUNDING:F Hoffmann-La Roche-Genentech.

Background Therapeutic options for advanced esophageal squamous cell carcinoma (ESCC) after first-line failure remain limited, particularly in patients previously exposed to immune checkpoint inhibitors (ICIs). We evaluated the efficacy, safety, and exploratory biomarker correlates of camrelizumab, an ICI, combined with nimotuzumab, an anti-epidermal growth factor receptor (EGFR) monoclonal antibody, as second-line therapy for ESCC. Methods In this multicenter, single-arm, phase II study, patients with advanced ESCC who progressed after first-line therapy received camrelizumab (200 mg every 2 weeks) plus nimotuzumab (400 mg weekly). The primary endpoint was the objective response rate (ORR). Results Between November 2021 and December 2024, 46 patients were enrolled. The confirmed ORR was 32.6% (15/46; 95% CI 19.5 to 48.0) and the disease control rate was 82.6% (38/46; 95% CI 68.6 to 92.2). Median progression-free survival (PFS) was 9.13 months (95% CI 5.95 to 9.76), and median overall survival (OS) was 12.62 months (95% CI 9.40 to 15.01). Clinical activity was observed across subgroups, including immunotherapy-naïve and previously treated patients (ORR 32.0% vs 33.3%). Patients with EGFR amplification demonstrated a higher ORR (47.1% vs 24.0%) and longer median OS (13.17 vs 9.99 months). Among patients with M1 disease (n=39), the ORR was 30.8% (95% CI 17.0 to 47.6), the median PFS was 8.48 months (95% CI 5.95 to 9.59), and the median OS was 12.55 months (95% CI 7.95 to 14.88). Treatment-related adverse events occurred in 80.4% of patients, with grade ≥3 events in 8.7%. Exploratory analyses suggested that MUC16 mutations were associated with lower ORR (8.3% vs 46.4%, p=0.030), NOTCH3 mutations with prolonged survival (median PFS not reached vs 8.21 months, HR 0.20, p=0.015; median OS not reached vs 10.58 months, HR 0.22, p=0.026), and MTAP deletions with shorter PFS (3.71 vs 9.49 months, HR 3.18, p=0.005). Conclusions Camrelizumab combined with nimotuzumab demonstrated encouraging antitumor activity and a manageable safety profile as second-line therapy for advanced ESCC. Trial registration number NCT03766178 .

369 Background: There is an unmet need to improve the efficacy of first-line treatment in advanced GC/GEJC pts with negative or low PD-L1 expression. This Ib/II, open-label study (NCT05024812) aimed to identify the efficacy and safety of fruquintinib (VEGFR-1, -2, -3 inhibitor) plus toripalimab (anti-PD-1), and SOX as first-line therapy in GC/GEJC. Here we update the survival results and a specific focus on PD-L1 CPS features. Methods: The study of phase Ib employed a 3+3 dose escalation design, pts were treated with fruquintinib 3mg/d (dose level; DL1), 4mg/d (DL2), or 5mg/d (DL3) po, d1-14 , in combination with fixed dose of toripalimab (240mg, iv, d1), oxaliplatin (130 mg/m2, iv, d1) and S-1 (40-60mg based on BSA, po, d1-14) every 3 weeks. It had been reported in phase Ib that fruquintinib 5mg/d was defined as the RP2D. In phase II, a further 64 pts would be treated with the same regimen. Primary endpoint of phase II was PFS per RECIST 1.1. Secondary endpoints included ORR, DCR, OS, DOR and safety. Results: The data cut-off date was April 2025, 44 pts (9 in phase Ib; 35 in phase II) were enrolled. 43 pts had PD-L1 CPS available. 40.9% were CPS＜1 and 72.7% were CPS＜5. Of the 43 pts evaluable for tumor response, the ORR was 58.1% with 3 pts achieving complete responses and DCR was 95.3%. After a median follow-up of 12.09 months, the mPFS was 10.25 (95% CI: 5.91–NA) months and the mOS was still immature. The estimated 12-month and 18-month OS rate were 64% and 42%, respectively. Pts with CPS ＜1 were more likely to achieve higher response rate (76.5 vs 44.0%) and higher 9-month PFS rate than CPS ≥1 (81 vs 46%). Most TRAEs were grade 1-2 and grade ≥3 TRAEs occurred in 38.6% of pts. The most frequent grade 3 to 4 TRAEs were neutrophil count decreased (6.8%) and impaired liver function (6.8%). Conclusions: Fruquintinib combined with SOX and toripalimab provided promising efficacy and manageable toxicity profile as first-line therapy for pts with advanced metastatic GC/GEJC, especially in pts with negative PD-L1 expression. More data including the potential predictive response biomarkers would be further analyzed and reported. Clinical trial information: NCT05024812 .

Importance:Patients with extensive-stage small cell lung cancer (ES-SCLC) have poor prognoses and unmet medical needs. Objective:To evaluate the efficacy and safety of toripalimab plus etoposide and platinum-based chemotherapy (EP) vs placebo plus EP as a first-line treatment for patients with ES-SCLC. Design, Setting, and Participants:This multicenter, double-blind, placebo-controlled phase 3 randomized clinical trial (EXTENTORCH study) enrolled patients from September 26, 2019, to May 20, 2021, and was conducted at 49 sites in China. Eligible patients had histologically or cytologically confirmed ES-SCLC without previous systemic antitumor therapy for ES-SCLC. Data were analyzed between May 6, 2023, and June 1, 2024. Interventions:Patients were randomized (1:1) to receive toripalimab, 240 mg, or placebo plus EP every 3 weeks for up to 4 to 6 cycles, followed by maintenance with toripalimab or placebo until disease progression, intolerable toxic effects, or up to 2 years of treatment. Main Outcomes and Measures:The primary end points were investigator-assessed progression-free survival (PFS) and overall survival (OS). Whole-exome sequencing results identified correlative biomarkers for clinical efficacy. Results:Among 595 screened patients, 442 eligible patients were randomized (median [range] age, 63 [30-77] years; 366 [82.8%] male); 223 patients were randomized to toripalimab plus EP, and 219 to placebo plus EP. By April 20, 2023, the median (range) survival follow-up was 13.7 (0.0-42.7) months. Compared with placebo, toripalimab improved investigator-assessed PFS (hazard ratio [HR], 0.67 [95% CI, 0.54-0.82]; P < .001), and significantly reduced the risk of death (HR, 0.80 [95% CI, 0.65-0.98]; P = .03). The median OS was 14.6 (95% CI, 12.9-16.6) months in the toripalimab group vs 13.3 (95% CI, 11.8-14.4) months in the placebo group. Whole-exome sequencing results from 300 patients identified low intratumor heterogeneity, HLA-A11+ HLA-B62- haplotype, wild-type KMT2D and COL4A4, or sequence variations in CTNNA2 or SCN4A correlated with favorable PFS and OS in the toripalimab group. No new safety signals were observed. Grade 3 or higher treatment-emergent adverse event incidence was similar between the toripalimab and placebo safety set groups (199 of 222 patients [89.6%] vs 193 of 216 patients [89.4%], respectively). Conclusions and Relevance:In this phase 3 randomized clinical trial, adding toripalimab to first-line chemotherapy demonstrated significant improvements in PFS and OS for patients with ES-SCLC. The treatment exhibited an acceptable safety profile, supporting this combination regimen as a new treatment option for patients with ES-SCLC. Trial Registration:ClinicalTrials.gov Identifier: NCT04012606.

Background:Trastuzumab deruxtecan (T-DXd; 6·4 mg/kg) is approved for metastatic human epidermal growth factor receptor 2 (HER2)-positive (HER2+) gastric or gastroesophageal junction (GEJ) adenocarcinoma after a trastuzumab-based regimen. We report the final analysis of DESTINY-Gastric06, evaluating T-DXd in pretreated patients from China with advanced HER2+ gastric cancers (GC). Methods:The single-arm, multicenter, phase 2 DESTINY-Gastric06 trial (NCT04989816) enrolled patients from China with HER2+ (immunohistochemistry [IHC] 3+ or IHC 2+; locally documented) advanced gastric or GEJ adenocarcinoma with two or more prior treatments. Patients received T-DXd 6·4 mg/kg intravenous infusion every 3 weeks. The primary endpoint was confirmed objective response rate in HER2+ (IHC 3+ or IHC 2+/in situ hybridization-positive) tumors (full analysis set) by independent central review. Secondary endpoints included investigator-assessed confirmed objective response rate, progression-free survival by independent central review, overall survival, and safety. Findings:Of 126 patients screened between August 20, 2021, and December 7, 2022, 95 were enrolled (intent-to-treat; 73 patients had centrally confirmed HER2+ tumors). Median follow up was 10·2 months. Among the 73 patients, confirmed objective response rate (95% confidence interval) by independent central review was 28·8% (18·8-40·6%) and by investigator assessment was 37·0% (26·0-49·1%). Median progression-free survival by independent central review was 5·7 months. Median overall survival was 11·1 months. The most common Grade 1-2 adverse event was white blood cell count decreased (53·7%; 51/95). Interpretation:Consistent with other GC trials, T-DXd showed durable benefit, with no new safety signals, in pretreated patients from China with HER2+ advanced GC; data support T-DXd as a third- or later-line therapeutic option in this population. Funding:AstraZeneca.

ImportanceGastric cancer, including gastroesophageal junction cancer, is one of the most commonly diagnosed cancers worldwide, with high mortality. Sugemalimab is a fully human anti–programmed death-ligand 1 (PD-L1) antibody. The combination of sugemalimab and chemotherapy showed promising antitumor activity and safety in a phase 1b study among patients with treatment-naive, unresectable, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. This combination was further evaluated in the GEMSTONE-303 phase 3 trial.ObjectiveTo evaluate the efficacy of sugemalimab in combination with capecitabine and oxaliplatin (CAPOX) compared with placebo plus CAPOX as first-line treatment for patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 combined positive score (CPS) of 5 or greater.Design, Setting, and ParticipantsGEMSTONE 303 is a phase 3, randomized, double-blind, placebo-controlled study conducted at 54 sites in China that enrolled patients from April 9, 2019, through December 29, 2021, with follow-up to July 9, 2023. A total of 479 eligible patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 CPS of 5 or greater who did not receive any prior systemic therapy were randomized.InterventionPatients received sugemalimab (1200 mg intravenously) (n = 241) or placebo (n = 238) every 3 weeks for up to 24 months, plus CAPOX every 3 weeks for up to 6 cycles.Main outcomes and MeasuresPrimary outcomes were overall survival and investigator-assessed progression-free survival.ResultsBaseline characteristics were well balanced between the 2 groups. Most patients were male (71.4% in sugemalimab group, 74.8% in placebo group). Median follow-up was 25.1 months in the sugemalimab group and 26.3 months in the placebo group. The sugemalimab group demonstrated significant improvements in overall survival (median, 15.6 months [95% CI, 13.3-17.8] vs 12.6 months [95% CI, 10.6-14.1]; hazard ratio, 0.75 [95% CI, 0.61-0.92]; P = .006) and progression-free survival (median, 7.6 months [95% CI, 6.4-7.9] vs 6.1 months [95% CI, 5.1-6.4]; hazard ratio, 0.66 [95% CI, 0.54-0.81]; P < .001). Grade 3 or higher treatment-related adverse events occurred in 53.9% of patients in the sugemalimab group and 50.6% in the placebo group.Conclusions and RelevanceSugemalimab plus chemotherapy significantly prolonged overall survival and progression-free survival with a manageable safety profile in previously untreated patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma.Trial RegistrationClinicalTrials.gov Identifier: NCT03802591

Donafenib, a deuterium-modified sorafenib derivative, has improved survival outcomes in patients with advanced hepatocellular carcinoma (HCC). This study aimed to investigate the treatment-related adverse events and their associations with overall survival (OS) and time to progression (TTP) in patients with advanced HCC treated with donafenib. In this retrospective analysis, data from 334 patients with unresectable or metastatic HCC who had a Child–Pugh liver function score ≤ 7 and had not received prior systemic treatment were collected from the ZGDH3 study. Donafenib (0.2 g) was administered orally twice daily until either intolerable toxicity or disease progression occurred. The associations between adverse events (AEs) and OS/TTP were analyzed using the Kaplan–Meier method, and statistical significance was tested using the log-rank test. A stratified Cox proportional hazards model was used to estimate hazard ratios (HR) and 95

423 Background: The efficacy of first-line treatment in advanced GC/GEJC patients (pts) with negative or low PD-L1 expression still needs to be improved. This phase Ib/II, open-label study (NCT05024812) evaluating fruquintinib (a highly selective VEGFR-1, -2, -3 inhibitor) plus toripalimab (anti-PD-1), and SOX has shown preliminary antitumor activity as first-line therapy in GC/GEJC. Here we update the results with longer follow-up duration and a specific focus on PD-L1 CPS features. Methods: The study of phase Ib employed a 3+3 dose escalation design, pts were treated with fruquintinib 3mg/d (dose level; DL1), 4mg/d (DL2), or 5mg/d (DL3) po, d1-14, in combination with fixed dose of toripalimab (240mg, iv, d1), oxaliplatin (130 mg/m 2 , iv, d1) and S-1 (40-60mg based on BSA, po, d1-14) every 3 weeks. It had been reported in phase Ib that fruquintinib 5mg/d was defined as the RP2D. In phase II, a further 64 pts would be treated with the same regimen. Primary endpoint of phase II was PFS per RECIST 1.1. Secondary endpoints included ORR, DCR, OS, DOR and safety. Results: As of August 15, 2024, 32 pts (9 in phase Ib; 23 in phase II) had been enrolled. Pts characteristics included: median age 62 (range 38–73); 66% male; 88% with ECOG PS 1, and 31% with liver metastasis. 31 pts had PD-L1 CPS available. 40.6% were CPS < 1 and 68.8% were CPS < 5. Of the 30 pts evaluable for tumor response, the ORR was 63.5% (95% CI 43.9–80.1) with 4 pts achieving complete responses and DCR was 96.7% (95% CI 82.8–99.9). After a median follow-up of 10.94 months, the median PFS was 9.33 (95% CI: 5.68–NA) months and OS result was not reached. Pts with CPS < 5 were more likely to achieve higher response rate (65.0 vs 55.6%) and longer PFS than CPS ≥5 (12.68 vs 8.11 months). Similar trends were observed in pts with CPS < 1 and CPS ≥1 (ORR: 75.0 vs 52.9%; PFS: 12.68 vs 8.11 months). Treatment-related adverse events (TRAEs) were mainly grade 1-2 and the most common ones were hypoalbuminemia (50%), neutrophil count decreased (34%), anemia (41%), platelet count decreased (34%) and white blood cell decreased (34%). Grade 4 TRAEs occurred in 2 pts (impaired liver function, hypertriglyceridemia). There were no treatment related deaths in the trial. Conclusions: Fruquintinib combined with SOX and toripalimab provided favorable efficacy and manageable toxicity profile as first-line therapy for pts with advanced metastatic GC/GEJC, especially in pts with negative or low PD-L1 expression. More data including the potential predictive response biomarkers would be further analyzed and reported. Clinical trial information: NCT05024812 .

Immune checkpoint inhibitors (ICIs) combined with anti-vascular endothelial growth factor (VEGF) have been the standard first-line treatment of hepatocellular carcinoma (HCC). However, the efficacy of this combination in post-line treatment is still unknown. This study aimed to evaluate the efficacy and safety of the combination of anti-PD-L1 envafolimab and novel humanized anti-VEGF suvemcitug as second-line treatment for patients with HCC. This open-label, prospective phase II clinical study (NCT05148195) comprised safety run-in stage and dose expansion stage of HCC cohort. Eligible patients were aged ≥ 18 years and had undergone at least a prior line of treatment. Patients received fixed-dose envafolimab and suvemcitug until termination of disease progression, unacceptable toxicities, or withdrawal. The primary endpoint of safety run-in stage was recommended dose (RD), and dose expansion stage was objective response rate (ORR). As of August 10, 2023, no dose-limiting toxicity was observed in six patients in the safety-run-in stage, and 2 mg/kg dose every 3 weeks was declared the RD of suvemcitug. Among 20 patients with HCC, the median age was 54.5 (range, 42–70) years. Of these patients, 20 (100.0

e14589 Background: Pucotenlimab, an anti-PD-1 antibody, demonstrated robust antitumor activity in patients (pts) with MSI-H/dMMR, based on findings from the phase II study 1 . Here, we present the long-term survival results and updated safety profile. Methods: Eligible pts were aged ≥18 years with histologically/cytologically confirmed advanced MSI-H/dMMR solid tumors, who had failed at least 1 line of standard systemic therapy. MSI-H/ dMMR status was assessed in a central lab. Pts received pucotenlimab 200 mg Q3W until disease progression, unacceptable toxicity, or patient withdrawal. The primary endpoint was the Independent Review Committee (IRC) evaluated ORR per RECIST1.1, the secondary endpoints included DoR, PFS, OS, and safety. The tumor response data was collected until 36 months for each subject. Results: 100 pts were enrolled from Oct 2018 to Dec 2020, the most common cancer types were colorectal cancer (CRC, N=71GC, N=10; EC, N=7; Other, N=12). By the cut-off date (Sep 19, 2024), median follow-up period was 43.8m (range: 0.3, 61.7). The updated ORR by IRC was 50.0% (95%CI: 39.8, 60.2, CR=12%). The mPFS was 33.8m (95%CI: 7.1, NR), while the 36-m rates were 49.7% (95%CI: 39.2, 59.3). The mDoR was not reached, 36-m DoR rate was 81.1% (95%CI: 66.7, 89.7). The mOS was 55.9 m (95%CI: 55.9, NR), with the 60-m OS rate 46.3% (95%CI: 19.1, 69.9). Pts in the CRC cohort had optimizing clinical benefits, with an ORR by IRC of 57.7% (95%CI: 46.8, 70.7), a 36-m PFS rate of 52.5% (95%CI: 39.9, 63.7), and a longer mOS was 55.9 m (95%CI: 55.9, NR). The 60-m OS rate was 44.3% (95%CI: 10.7, 74.3). The common treatment-related adverse events (TRAEs) of any grade included AST increased (28.0%), ALT increased (26.0%), and anemia (24.0%). TRAEs ≥ Grade 3 were reported in 24 pts (24.0%). No new safety signals were identified in this analysis, and patients had good tolerance to long-term treatment. Conclusions: Pucotenlimab as ≥2L therapy for advanced MSI-H/dMMR solid tumors demonstrates durable OS and PFS benefit. The updated, long-term follow-up data confirmed durable clinical benefit of pucotenlimab in this patient population, especially for CRC pts. References:1. Zhang B, et al. Cell Rep Med. 2023;4(12):101301. Clinical trial information: NCT03704246 .

This phase II study is designed to evaluate the combination therapy involving suvemcitug and envafolimab with FOLFIRI in microsatellite-stable or mismatch repair–proficient (MSS/pMMR) colorectal cancer (CRC) in the second-line treatment setting. This study is a non-randomized, open-label prospective study comprising multiple cohorts (NCT05148195). Here, we only report the data from the CRC cohort. Participants received envafolimab, suvemcitug, and FOLFIRI until disease progression, unacceptable toxicity, or voluntary withdrawal. The recommended dose (RD) and objective response rate (ORR) by investigator assessment were primary endpoints. Secondary endpoints comprised progression-free survival (PFS) and duration of response (DoR). Disease control rate (DCR), overall survival (OS), and safety were also analyzed. At the data cutoff, no dose-limiting toxicity event was observed in the safety run-in stage, and 2 mg/kg Q2W was declared as RD for suvemcitug combined with envafolimab and FORFIRI. Among 20 patients, 50.0

Importance Gastric cancer, including gastroesophageal junction cancer, is one of the most commonly diagnosed cancers worldwide, with high mortality. Sugemalimab is a fully human anti-programmed death-ligand 1 (PD-L1) antibody. The combination of sugemalimab and chemotherapy showed promising antitumor activity and safety in a phase 1b study among patients with treatment-naive, unresectable, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. This combination was further evaluated in the GEMSTONE-303 phase 3 trial. Objective To evaluate the efficacy of sugemalimab in combination with capecitabine and oxaliplatin (CAPOX) compared with placebo plus CAPOX as first-line treatment for patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 combined positive score (CPS) of 5 or greater. Design, Setting, and Participants GEMSTONE 303 is a phase 3, randomized, double-blind, placebo-controlled study conducted at 54 sites in China that enrolled patients from April 9, 2019, through December 29, 2021, with follow-up to July 9, 2023. A total of 479 eligible patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 CPS of 5 or greater who did not receive any prior systemic therapy were randomized. Intervention Patients received sugemalimab (1200 mg intravenously) (n = 241) or placebo (n = 238) every 3 weeks for up to 24 months, plus CAPOX every 3 weeks for up to 6 cycles. Main outcomes and Measures Primary outcomes were overall survival and investigator-assessed progression-free survival. Results Baseline characteristics were well balanced between the 2 groups. Most patients were male (71.4% in sugemalimab group, 74.8% in placebo group). Median follow-up was 25.1 months in the sugemalimab group and 26.3 months in the placebo group. The sugemalimab group demonstrated significant improvements in overall survival (median, 15.6 months [95% CI, 13.3-17.8] vs 12.6 months [95% CI, 10.6-14.1]; hazard ratio, 0.75 [95% CI, 0.61-0.92]; P = .006) and progression-free survival (median, 7.6 months [95% CI, 6.4-7.9] vs 6.1 months [95% CI, 5.1-6.4]; hazard ratio, 0.66 [95% CI, 0.54-0.81]; P < .001). Grade 3 or higher treatment-related adverse events occurred in 53.9% of patients in the sugemalimab group and 50.6% in the placebo group. Conclusions and Relevance Sugemalimab plus chemotherapy significantly prolonged overall survival and progression-free survival with a manageable safety profile in previously untreated patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. Trial Registration ClinicalTrials.gov Identifier: NCT03802591

Background Intratumoral oncolytic herpes simplex virus 2-GM CSF (OH2) injection has shown safety and antitumor efficacy in patients with solid tumors. Here, we examined the safety and efficacy of OH2 as a single agent or in combination with HX008, an NMPA-approved PD-1 inhibitor, in locally advanced or metastatic sarcoma patients.Methods This multicenter, phase 1/2 trial enrolled patients with injectable sarcoma lesions, who had failed at least 1 or more lines of standard treatment. Patients were treated with OH2 at three dose levels (106, 107 and 108 CCID50/mL) as single agent or in combination with a fixed dose of HX008. The primary endpoints were safety and tolerability in phase 1 and objective response rate determined by RECIST (V.1.1) criteria and immune-RECIST in phase 2.Results Between October 20, 2020 and December 30, 2023, 26 patients were enrolled. Seven patients were treated with single-agent OH2 and 19 with HX008 and OH2 combination. No dose-limiting toxicities were observed during the dose escalation. We documented four partial or complete responses in injected lesions, and one partial response in non-injected lesions, which were all from the combination group. Hence, the overall response rate was 0% and 16.7% in the single agent and combination groups, respectively. The duration of response was 3.9–6.5 months. The most frequent treatment-related adverse events (TRAEs) were fever (n=9). Grade 3 or 4 TRAEs were reported in four patients (15.4%). A clear increase in CD8+cell density in the tumor microenvironment was observed in the patients’ post-treatment specimens compared with baseline.Conclusions Intratumoral injection of oncolytic virus OH2 is well tolerable in patients with sarcoma. Further investigation of OH2 with HX008 in select sarcoma subtypes is warranted.

335 Background: Immune checkpoint inhibitors (ICIs) plus chemotherapy has become the standard first-line regimen for advanced GC/GEJC, but the efficacy still needs to be improved. Fruquintinib is an oral, highly selective VEGFR 1/2/3 inhibitor that has synergistic antitumor effects when combined with ICIs/chemotherapy. Additionally, the phase III study (NCT03223376) of fruquintinib combined with paclitaxel in second-line GC/GEJC has achieved positive topline result. Therefore, this study was aimed to evaluate the efficacy and safety of fruquintinib combined with SOX and toripalimab as a first-line therapy in GC/GEJC. Methods: In this phase Ib/II, open-label trial (NCT05024812), patients (pts) aged 18-75 years who were HER2-negative with no previous anti-tumor therapy were enrolled. The Ib phase employed a 3+3 dose escalation design, pts were treated with fruquintinib 3mg/d, po, d1-14 (dose level; DL1), 4mg/d (DL2), or 5mg/d (DL3) in combination with fixed dose of toripalimab (240mg, iv, d1), oxaliplatin (130 mg/m2, iv, d1) and S-1 (40-60mg based on BSA, po, d1-14) every 3 weeks. The primary objective of phase Ib was to determine the DLT in first treatment cycle defining the PR2D. Additional 64 pts were enrolled in the phase II dose expansion stage using RP2D. Primary endpoint of phase II was PFS per RECIST 1.1. Secondary endpoints included ORR, DCR, OS, DOR and safety. Results: At data cut-off (August 31, 2023), 17 pts (9 in phase Ib; 8 in phase II) with median age 65 years old had been enrolled. 59% were male, 100% had ECOG PS 1 and 35% had liver metastasis. 10/17 (59%) pts were PD-L1 CPS ≥1. No DLTs were observed at all three dose levels. Fruquintinib 5mg/d was defined as the RP2D. Of the 16 pts evaluable for tumor response, 9 pts achieved PR, 7 pts achieved SD. The ORR was 56.3% (9/16), the DCR was 100% (16/16). Pts with PD-L1 CPS ＜1 were more likely to achieve better responses (4PR in 6 pts, ORR-66.7%). After a median follow-up of 5.4 months, the median PFS was 9.3 (95% CI: 4.76–NA) months and OS result was not mature. Median DOR was not reached and two responders were estimated to have a response duration ≥8.0 months. Majority of TRAEs were grade 1-2, including neutrophil count decreased (64.3%), white blood cell decreased, hypoproteinemia and platelet count decreased (all were 42.9%). Grade 3 TRAEs included neutrophil count decreased (11.8%), platelet count decreased, impaired liver function, rash, pruritus and mucositis (5.9%, one patient for each). There were no treatment related deaths in the trial. Conclusions: Fruquintinib combined with SOX and toripalimab was well tolerated, with encouraging antitumor activity as first-line treatment for advanced metastatic GC/GEJC, especially in pts with CPS ＜1. The trial is still recruiting, more data including the potential predictive response biomarkers would be further analyzed and reported. Clinical trial information: NCT05024812 .

e16055 Background: Treatment regimens for many advanced solid tumors are limited and alternative options are needed.Utidelone is approved for the treatment of advanced breast cancer in China. NCT04911907 is a single-arm, multicenter, phase II study to assess the efficacy and safety of utidelone in advanced cancer. Stage I of the trial, completed in October 2023, included patients (pts) with pretreated advanced solid tumors. Based on the stage I data, a stage II expansion cohort (USO-G) investigated utidelone plus sintilimab and oxaliplatin as first-line therapy for advanced gastric cancer (GC). Here, we report efficacy and safety data from stage I and stage II for interim analysis. Methods: Eligible pts aged 18–70 years with pretreated advanced solid tumors were enrolled in stage I and received utidelone monotherapy (35 mg/m 2 /day iv on days 1–5 every 21 days). In stage II, eligible pts with metastatic and/or unresectable HER2 negative GC received utidelone (30mg/m 2 /day iv on days 1–5 every 21 days) plus sintilimab (200 mg iv Q3W) and oxaliplatin (130 mg/m 2 /day Q3W for up to 6 cycles), until disease progression or unacceptable toxicity. Results: From March 18 th 2021 to October 13 th 2022, 79 pts were enrolled into 7 tumor cohorts and 54 pts were evaluable for efficacy. The best overall responses were 1 CR, 3 PRs and 3 SDs in 10 esophageal cancer pts, 3 PRs and 5 SDs in 15 GC pts, 1 PR and 3 SDs in 10 ovarian cancer pts, SD for all 4 cholangiocarcinoma pts, 3 SDs in 4 cervical cancer pts, 2 SDs in 3 pancreatic cancer pts and a PR in 1 neuroectodermal tumor patient. Grade 3/4 TRAEs occurred in 27.8% of pts in stage I, and included anemia (13.9%), peripheral neuropathy (11.4%) and neutropenia (7.6%). No treatment-related deaths occurred. Gastric cancer was chosen as the expansion cohort indication. As of February 1 st 2024, 14 eligible pts with GC with a median age of 57 years (range, 41–69) were enrolled. The median follow-up was 5.5 months (range, 1.0–9.7) and the longest duration of response was 8.0 months. A total of 8 PRs and 3 SDs were achieved in the 11 pts evaluable for efficacy, and 6 pts including the 3 with SD were still receiving treatment. Grade 3/4 TRAEs occurred in 28.6% of pts including diarrhea (14.3%), fatigue (14.3%), neutropenia (14.3%), and vomiting (7.1%). Other AEs were all Grade 1 or 2, with no treatment-related deaths. Conclusions: Utidelone monotherapy showed antitumor activity and manageable toxicity in pts with advanced solid tumors. Utidelone plus sintilimab and oxaliplatin demonstrated promising efficacy and an acceptable safety profile as first-line treatment for pts with GC. Stage II of the USO-G study is still actively enrolling; further data will be provided at the time of presentation. Clinical trial information: NCT04911907 .

e16087 Background: Increasing evidences prove the encouraging efficacy of neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma (ESCC). However, the safety of chemotherapy is still unsatisfactory. Previous studies have confirmed the good efficacy and tolerance of PD-1 inhibitors combined with angiogenesis inhibitors in advanced ESCC. This trial is to assess the effectiveness and safety of camrelizumab (PD-1 inhibitor) plus chemotherapy or apatinib (angiogenesis inhibitor) as neoadjuvant therapy for locally advanced ESCC. Methods: This was an open-label, non-randomized phase 2 trial of patients with stage cT2-4aN0-3M0 ESCC. Eligible patients were 18-75 years old, had ECOG PS score of 0-1. Patients received 2 cycles (1 cycle per 4 weeks) of camrelizumab (200 mg Q2W) and apatinib (250 mg QD). Surgery was performed within 4-6 weeks after neoadjuvant therapy. The primary endpoint was major pathological response (MPR) rate. Secondary endpoints included pathological complete response (pCR) rate, R0 resection rate, disease-free survival (DFS), overall survival (OS), and safety. Results: Between Feb 2022 and Dec 2023, 24 patients (19 males and 5 females) with a median age of 67 years were enrolled in the study. Twenty-one patients completed neoadjuvant therapy, the ORR was 50% and the DCR was 95%. Nineteen patients completed surgery and all patients (100%) reached R0 resection, 3 patients (3/19, 10.5%) reached pCR, 8 patients (8/19, 42.1%) reached MPR, and 13 patients (13/19, 68.4%) had TNM downstaging. The median follow-up was 11.9 months, and the median DFS had not yet reached. Any grade and grade ≥3 adverse events occurred in 87.5% and 8.3% of 24 patients, respectively. The most common AEs were increased alanine aminotransferase (8/24, 33.3%), increased alanine aminotransferase (7/24, 29.2%) and thrombocytopenia(7/24, 29.2%). No new safety signals or treatment-related deaths were observed. Conclusions: Neoadjuvant camrelizumab in combination with apatinib in patients with locally advanced ESCC showed promising pathological response and downstaging effect with acceptable security. The study enrollment is ongoing, and further survival and safety data will be reported in the future. Clinical trial information: NCT03917966 .

Importance Patients with extensive-stage small cell lung cancer (ES-SCLC) have poor prognoses and unmet medical needs. Objective To evaluate the efficacy and safety of toripalimab plus etoposide and platinum-based chemotherapy (EP) vs placebo plus EP as a first-line treatment for patients with ES-SCLC. Design, Setting, and Participants This multicenter, double-blind, placebo-controlled phase 3 randomized clinical trial (EXTENTORCH study) enrolled patients from September 26, 2019, to May 20, 2021, and was conducted at 49 sites in China. Eligible patients had histologically or cytologically confirmed ES-SCLC without previous systemic antitumor therapy for ES-SCLC. Data were analyzed between May 6, 2023, and June 1, 2024. Interventions Patients were randomized (1:1) to receive toripalimab, 240 mg, or placebo plus EP every 3 weeks for up to 4 to 6 cycles, followed by maintenance with toripalimab or placebo until disease progression, intolerable toxic effects, or up to 2 years of treatment. Main Outcomes and Measures The primary end points were investigator-assessed progression-free survival (PFS) and overall survival (OS). Whole-exome sequencing results identified correlative biomarkers for clinical efficacy. Results Among 595 screened patients, 442 eligible patients were randomized (median [range] age, 63 [30-77] years; 366 [82.8%] male); 223 patients were randomized to toripalimab plus EP, and 219 to placebo plus EP. By April 20, 2023, the median (range) survival follow-up was 13.7 (0.0-42.7) months. Compared with placebo, toripalimab improved investigator-assessed PFS (hazard ratio [HR], 0.67 [95% CI, 0.54-0.82]; P < .001), and significantly reduced the risk of death (HR, 0.80 [95% CI, 0.65-0.98]; P = .03). The median OS was 14.6 (95% CI, 12.9-16.6) months in the toripalimab group vs 13.3 (95% CI, 11.8-14.4) months in the placebo group. Whole-exome sequencing results from 300 patients identified low intratumor heterogeneity, HLA-A11+ HLA-B62- haplotype, wild-type KMT2D and COL4A4, or sequence variations in CTNNA2 or SCN4A correlated with favorable PFS and OS in the toripalimab group. No new safety signals were observed. Grade 3 or higher treatment-emergent adverse event incidence was similar between the toripalimab and placebo safety set groups (199 of 222 patients [89.6%] vs 193 of 216 patients [89.4%], respectively). Conclusions and Relevance In this phase 3 randomized clinical trial, adding toripalimab to first-line chemotherapy demonstrated significant improvements in PFS and OS for patients with ES-SCLC. The treatment exhibited an acceptable safety profile, supporting this combination regimen as a new treatment option for patients with ES-SCLC. Trial Registration ClinicalTrials.gov Identifier: NCT04012606

BACKGROUND:The interim analysis of the randomized phase 3 ESCORT-1st study demonstrated significantly longer overall survival (OS) and progression-free survival (PFS) for camrelizumab-chemotherapy than placebo-chemotherapy in untreated advanced/metastatic esophageal squamous cell carcinoma (ESCC). Here, we present the final analysis of this study and investigate potential indicators associated with OS. METHODS:Patients were randomized 1:1 to receive camrelizumab (200 mg) or placebo, both in combination with up to six cycles of paclitaxel (175 mg/m2) and cisplatin (75 mg/m2). All treatments were administered intravenously every 3 weeks. The co-primary endpoints were OS and PFS assessed by the independent review committee. FINDINGS:As of April 30, 2022, the median OS was significantly longer in the camrelizumab-chemotherapy group compared to the placebo-chemotherapy group (15.6 [95% confidence interval (CI): 14.0-18.4] vs. 12.6 months [95% CI 11.2-13.8]; hazard ratio [HR]: 0.70 [95% CI 0.58-0.84]; one-sided p < 0.0001), with 3-year OS rates of 25.6% and 12.8% in the two groups, respectively. The 2-year PFS rates were 20.4% in the camrelizumab-chemotherapy group and 3.4% in the placebo-chemotherapy group. Adverse events were consistent with those reported in the interim analysis. Higher PD-L1 expression correlated with extended OS, and multivariate analysis identified sex and prior history of radiotherapy as independent indicators of OS. CONCLUSIONS:The sustained and significant improvement in efficacy with camrelizumab-chemotherapy compared to placebo-chemotherapy, along with the absence of accumulating or delayed toxicities, supports the long-term use of camrelizumab-chemotherapy as a standard therapy in untreated advanced/metastatic ESCC. FUNDING:This study was funded by Jiangsu Hengrui Pharmaceuticals Co., Ltd.