Wainberg, Zev A.

LBA5 Background: Available 2L therapies offer limited clinical benefit in mPDAC with reported mPFS of 3–4 mo and mOS of 6–7 mo. Aberrant RAS pathway activation is the key driver of PDAC, with oncogenic RAS mutations (mut) identified in >90% of cases, most commonly at codon G12. Daraxonrasib is an oral, RAS(ON) multi-selective, tri-complex inhibitor of the active, GTP-bound state of mutant and wild type RAS. Methods: RASolute 302 (NCT06625320) is a global, randomized, open-label, Ph 3 study in pts with 2L mPDAC and ECOG PS 0-1. Pts were randomized 1:1 to receive daraxonrasib 300 mg PO QD or investigator’s choice of SOC cytotoxic chemo. Dual primary endpoints were OS and PFS by BICR in the RAS G12 mutant (RAS G12) population. Key secondary endpoints included OS and PFS by BICR in the overall population, ORR by BICR in RAS G12 and overall populations. Results: 248 pts were randomized to daraxonrasib and 252 to chemo. Baseline characteristics were balanced between arms. At data cutoff (Feb 10, 2026; mFU: 8.5 mo), all primary and key secondary endpoints were met. Statistically significant, clinically meaningful improvements in OS and PFS were observed with daraxonrasib vs chemo in the RAS G12 and overall populations (Table). Gr ≥3 TRAEs occurred in 43.6% of pts receiving daraxonrasib vs 57.5% receiving chemo. The most common (≥10%) Gr ≥3 TRAEs were rash (13.7%) and stomatitis (12.0%) for daraxonrasib; neutrophil decrease (18.2%) and anemia (16.4%) for chemo. TRSAEs occurred in 10.8% of pts receiving daraxonrasib vs 18.7% receiving chemo. Discontinuation due to TRAEs occurred in 1.2% of pts for daraxonrasib vs 11.2% for chemo. Median/mean daraxonrasib dose intensity was 93.1%/84.7%. Conclusions: Daraxonrasib demonstrated unprecedented improvements in OS and PFS vs chemo in pts with 2L mPDAC with or without an identified tumor RAS mut. Daraxonrasib was generally well tolerated, with a manageable safety profile and with no new safety signals. Results support daraxonrasib as the new SOC for 2L mPDAC. Clinical trial information: NCT06625320 . RAS G12 Overall b Daraxonrasibn=228 Chemo n=231 Daraxonrasib n=248 Chemo n=252 OS Median; mos(95% CI) 13.2(10.0–NE) 6.6(5.4–8.2) 13.2(10.0–NE) 6.7(5.8–8.0) HR(95% CI)P-value 0.40(0.30-0.54)<0.0001 0.40(0.30-0.53)<0.0001 PFS a Median; mos(95% CI) 7.3(6.3–8.1) 3.5(2.9–3.8) 7.2(5.7–7.5) 3.6(2.9–4.2) HR(95% CI)P-value 0.45(0.34-0.59)<0.0001 0.49(0.38-0.64)<0.0001 ORR a %(95% CI) 33.2(27.0–39.9) 11.8(7.8–16.8) 31.6(25.8–38.0) 11.2(7.5–15.9) a By BICR. b RAS G12, G13 or Q61 mut or no RAS mut identified.

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide. Over 95% of gastric cancers are adenocarcinomas, which are typically classified based on anatomic location and histologic type. Gastric cancer generally carries a poor prognosis because it is often diagnosed at an advanced stage. Systemic therapy can provide palliation, improve survival, and enhance the quality of life in patients with locally advanced or metastatic disease. The implementation of biomarker testing has had a significant impact on clinical practice and patient care. Targeted therapies have demonstrated encouraging results in clinical trials for the treatment of patients with locally advanced or metastatic disease. This selection from the NCCN Clinical Practice Guidelines in Oncology for Gastric Cancer highlights recommendations for biomarker testing and discusses updates for the treatment of advanced disease, including peritoneal carcinoma as only disease and unresectable locally advanced, recurrent, or metastatic disease.

PURPOSE The outcomes of anti–PD-1 agents plus fluoropyrimidine/platinum in frontline advanced gastroesophageal adenocarcinomas (aGEAs) remain poor. We investigated the safety, tolerability, and activity of fluoropyrimidine/oxaliplatin and tislelizumab with the DKK1-neutralizing antibody DKN-01 in aGEAs in a phase IIa open-label study. PATIENTS AND METHODS Patients had untreated human epidermal growth factor receptor 2–negative aGEAs, RECIST v1.1 measurable disease, Eastern Cooperative Oncology Group (ECOG) performance status 0-1, and adequate organ function. Patients received intravenous DKN-01 300 mg once every 2 weeks, tislelizumab 200 mg once every 3 weeks, oxaliplatin 130 mg/m 2 once every 3 weeks, and capecitabine 1,000 mg/m 2 twice daily on days 1-15 of each 21-day cycle. The primary end point was safety and tolerability. Key secondary end points included objective response rate (ORR) by RECISTv1.1, progression-free survival (PFS), and overall survival (OS). RESULTS Between September 18, 2020, and April 8, 2021, 25 patients were enrolled. All patients who received at least one dose of DKN-01 were included in the safety analysis. Most patients had gastroesophageal junction tumors, median age was 61 years, 76% were male, and 55% were ECOG of 0. All patients reported at least one treatment-emergent adverse event. The ORR was 73% (95% CI, 49.8 to 89.3), with a disease control rate of 95%. The ORR was 90% (95% CI, 55.5 to 99.7) in the DKK1-high tumor patients and 67% (95% CI, 29.9 to 92.5) in the DKK1-low tumor patients. The median PFS was 11.3 months (95% CI, 5.8 to 12.0) and the 12-month PFS rate was 33%. The median OS was 19.5 months (95% CI, 15.2 to 24.4) with a 12-month OS rate of 76% and an 18-month OS rate of 55%. CONCLUSION DKN-01 can be safely combined with frontline fluoropyrimidine/oxaliplatin and tislelizumab and demonstrates encouraging activity independent of PD-L1 expression levels. A randomized phase II trial is ongoing (ClinicalTrials.gov identifier: NCT04363801 ).

4136 Background: NAPOLI 3 (NCT04083235, N = 770), a global, randomized, open-label phase 3 study, demonstrated that NALIRIFOX significantly improved overall survival (OS, primary endpoint) and progression-free survival compared with nab-paclitaxel and gemcitabine in patients with untreated mPDAC. Here, we report an updated analysis of OS. Methods: Eligible patients with histopathologically/cytologically confirmed untreated mPDAC were randomized (1:1) to receive liposomal irinotecan 50 mg/m2 + oxaliplatin 60 mg/m2 + leucovorin 400 mg/m2 + 5-fluorouracil 2400 mg/m2 (NALIRIFOX, n = 383) on days 1 and 15 of a 28-day cycle or nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2 (Gem+NabP, n = 387) on days 1, 8 and 15 of a 28-day cycle. Randomization was stratified by ECOG performance status, geographic region and presence/absence of liver metastases. An updated OS analysis (data cutoff: 3 October 2023) was conducted. Kaplan–Meier methods were used to estimate median (95% confidence interval [CI]) OS and hazard ratios (HRs [95% CI]) were estimated using stratified Cox proportional hazard models. The difference between groups was tested using a stratified log-rank test. Results: The median follow-up for OS was 28.7 months in the NALIRIFOX arm and 29.7 months in the Gem+NabP arm. At data cutoff, 11 patients were still receiving study treatment, all of whom were in the NALIRIFOX arm. With a total of 673 OS events (NALIRIFOX, n = 328; Gem+NabP, n = 345), median OS was 11.1 months (95% CI 10.0–12.1) in the NALIRIFOX arm compared with 9.2 months (8.3–10.6) in the Gem+NabP arm (HR 0.84 [95% CI 0.72–0.98]; nominal p = 0.026). At 12 months and 18 months, survival rates were 45.6% (95% CI 40.5–50.5) and 26.6% (22.2–31.1), respectively, in the NALIRIFOX arm and 39.6% (34.7–44.5) and 20.0% (16.1–24.1), respectively, in the Gem+NabP arm. Conclusions: In this 29-month follow-up of NAPOLI 3, NALIRIFOX continued to demonstrate improved OS compared with Gem+NabP, with 11 patients still receiving the NALIRIFOX regimen. These data confirm NALIRIFOX as a new possible standard of care and reference regimen for the first-line treatment of patients with mPDAC. Clinical trial information: NCT04083235 .

687 Background: The NAPOLI 3 study (NCT04083235, N = 770) reported that NALIRIFOX improved overall survival (OS) vs Gem+NabP with manageable toxicity in 1L treatment of metastatic pancreatic adenocarcinoma. We explored changes in CA19-9 levels and their potential associations with efficacy as an important tumor marker in pancreatic adenocarcinoma. Methods: In NAPOLI 3, CA19-9 was evaluated at baseline and every 8 weeks until patients discontinued study treatment. The detection limit of CA19-9 was 8000 kU/L in this study. The Cox proportional hazards regression and logistic regression were employed to investigate the relationship between CA19-9 decrease and OS, progression-free survival (PFS), and overall response rate (ORR). Results: Patients with evaluable CA19-9 (levels =< 8000) at baseline and additional measurements at weeks 8 and 16 were included in the analysis (NALIRIFOX, n = 179; Gem+NabP, n = 194). The median baseline CA19-9 level was 378.0 and 409.7 kU/L for the NALIRIFOX and Gem+NabP arms, respectively. Overall, patients with (vs without) any CA 19-9 decrease by week 16 had a higher ORR (59.9% vs 35.2%; p = 0.002), a longer median PFS (9.2 vs 6.2 months; p < 0.001) and a longer median OS (14.2 vs 8.7 months; p = 0.005), respectively in a pooled analysis of the treatments. In the NALIRIFOX arm, patients with any CA19-9 decrease by week 16 had a higher confirmed ORR of 65.1% compared with those without at 42.4% ( p < 0.001), a median PFS of 9.5 vs 7.1 months ( p < 0.001) and a median OS of 15.4 versus 8.4 months ( p = 0.004), respectively. In the Gem+NabP arm, patients with CA19-9 decrease by week 16 had a higher ORR of 55.5% compared with those without at 23.8% ( p = 0.012), a median PFS of 7.6 versus 5.8 months ( p < 0.001) and a median OS of 13.7 versus 11.9 months ( p = 0.235), respectively. Conclusions: CA19-9 decrease by week 16 has the potential to be an early prognostic factor for OS, PFS and ORR. The results should be interpreted with caution as a considerable percentage of patients were excluded due to non-evaluable CA19-9 that exceeded the lab detection limit of 8000 kU/L. Clinical trial information: NCT04083235 .

4027 Background: DKN-01 is an anti-DKK1 mAb which has demonstrated anti-tumor activity in patients with advanced GEA with low tumor PD-L1 expression, a subset with very limited therapeutic options. DKN-01 has immunomodulatory activity, stimulates a pro-inflammatory tumor microenvironment, and upregulates PD-L1 levels. Here we present 2-year survival data for 1L advanced GEA patients who received combination treatment with DKN-01, the Fc-optimized anti-PD-1 tislelizumab, and CAPOX chemotherapy. The ORR was previously reported (68% in ITT and 79% in PD-L1-low populations). Methods: This Phase 2, multi-center, single arm Part A of the DisTinGuish (NCT04363801) study investigated DKN-01 + tislelizumab + CAPOX as 1L therapy in advanced HER2(-) GEA, regardless of DKK1 and PD-L1 expression levels. Tumor DKK1 and PD-L1 were assessed by central laboratories. The primary endpoint was ORR in a modified intent to treat population (>1 dose DKN-01); secondary endpoints included PFS and OS in the ITT population. Results: Twenty-five patients were enrolled from September 2020 to April 2021. As of 23 January 2023: Median age was 61 years (22, 80); 17 patients had GEJ adenocarcinoma; 8 had gastric cancer. Twenty-one patients had tumors with evaluable DKK1 expression. Twenty-two patients had tumors with evaluable PD-L1 expression; the majority (73%) were low expressors (vCPS <5%). Median (m) duration on treatment is 11.3 months (mo). Seven patients remain on study, with 4 on-treatment beyond 2 years. The mPFS is 11.3 mo in the overall ITT population and 10.7 mo in patients with low tumor PD-L1 expression. The mOS is 19.5 mo in the overall ITT population and 18.7 mo in the patients with low tumor PD-L1 expression. Treatment related adverse events (TRAEs) were mild with most G1/2. The most common AEs related to the study drug regimen were nausea (72%), diarrhea (64%) and fatigue (60%). Five patients experienced G3 DKN-01-TRAEs including decreased neutrophil count (1), diarrhea (1), vomiting (1), hypophosphatemia (2), and pulmonary embolism (1). Conclusions: At 2-years of follow-up, 1L treatment of advanced GEA patients with DKN-01 in combination with tislelizumab and CAPOX resulted in a prolongation of PFS and OS compared with the modern SOC regimen of nivolumab plus chemotherapy, both in the overall population (mPFS 11.3 vs 7.7 mo; mOS 19.5 vs 13.8 mo) and in the PD-L1 low subgroup (mPFS 10.7 vs 7.5 mo; mOS 18.7 vs 12.4 mo), alongside a manageable safety profile. The prolonged PFS and OS observed in the current study are notable, especially in our trial population dominated by patients with tumors of low PD-L1 expression, where the known benefit of anti-PD-1 therapy is limited. The ongoing Part C of this study is evaluating mFOLFOX6/CAPOX plus tislelizumab with or without DKN-01 in the same 1L GEA patient population. Further evaluation of biomarkers is also ongoing. Clinical trial information: NCT04363801 .

4006 Background: Liposomal irinotecan + 5-fluorouracil/leucovorin (5-FU/LV) is approved in the USA and Europe for mPDAC following progression with gemcitabine-based therapy. A phase 1/2 study (NCT02551991) demonstrated promising anti-tumor activity in patients with mPDAC who received first-line liposomal irinotecan 50 mg/m2 + 5-FU 2400 mg/m2 + LV 400 mg/m2 + oxaliplatin 60 mg/m2 (NALIRIFOX). Here, we present results from NAPOLI 3 (NCT04083235), a randomized, open-label, phase 3 study investigating the efficacy and safety of NALIRIFOX compared with nab-paclitaxel 125 mg/m2 + gemcitabine 1000 mg/m2 (Gem+NabP) as first-line therapy in patients with mPDAC. Methods: Eligible patients with histopathologically/cytologically confirmed untreated mPDAC were randomized (1:1; stratified by Eastern Cooperative Oncology Group [ECOG] performance status, geographic region and presence/absence of liver metastases) to receive NALIRIFOX on days 1 and 15 of a 28-day cycle or Gem+NabP on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), overall response rate (ORR) and safety. OS was evaluated when at least 543 events were observed using a stratified log-rank test with an overall one-sided significance level of 0.025. Results: Overall, 770 patients (NALIRIFOX, n = 383; Gem+NabP, n = 387) were included. Baseline characteristics were balanced between arms. At a median follow-up of 16.1 months, 544 events had occurred. Median OS was 11.1 months in the NALIRIFOX group versus 9.2 months in the Gem+NabP group; median PFS was 7.4 months versus 5.6 months. Median (95% CI) duration of response was 7.3 (5.8–7.6) and 5.0 (3.8–5.6) months in patients who received NALIRIFOX and Gem+NabP, respectively. Grade 3/4 treatment-emergent adverse events occurring in at least 10% of patients receiving NALIRIFOX versus Gem+NabP included diarrhea (20.3% vs 4.5%), nausea (11.9% vs 2.6%), hypokalemia (15.1% vs 4.0%), anemia (10.5% vs 17.4%) and neutropenia (14.1% vs 24.5%). Conclusions: First-line NALIRIFOX demonstrated clinically meaningful and statistically significant improvement in OS and PFS compared with Gem+NabP in patients with mPDAC. The NALIRIFOX safety profile was consistent with the profiles of the regimen components and generally manageable. Clinical trial information: NCT04083235 . [Table: see text]