LAP-NET1: Results of a phase 1b evaluating NP137, an inhibitor of the epithelial-to-mesenchymal transition, in combination with mFOLFIRINOX for the first-line treatment of locally advanced pancreatic ductal adenocarcinoma.

4197 Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy characterized by aggressive tumor dissemination and resistance to therapy; processes significantly driven by the epithelial-to-mesenchymal transition (EMT). Netrin-1 is a key regulator for EMT. NP137, an anti-netrin-1 antibody, has shown to inhibit EMT in preclinical models and in a phase 1 monotherapy trial. Methods: LAPNET-01 (NCT06203821) is a single arm phase Ib clinical study to assess the combination of NP137 with mFOLFIRINOX in naive locally advanced unresectable PDAC. A safety lead-in (3–12 pts, 3+3 design, NP137 14 vs 9 mg/kg) was followed by a 40-patient expansion. Treatment consisted of NP137 + mFOLFIRINOX every 2 weeks, up to 12 cycles. The primary endpoint was safety at 6 months (all-grade and grade 3/4 adverse events [AEs], CTCAE v5.0). Secondary endpoints included objective response rate (ORR), progression-free survival (PFS) and overall survival (OS), surgical conversion rate and exploratory transcriptomic analyses. Laser capture microdissection was performed on 22 pre-treatment and 6 surgery samples to allow microbulk RNA sequencing. Immunohistochemistry was also performed on pre-treatment samples. Results: A total of 43 patients were enrolled in this trial. NP137 was well tolerated. AE occurred in 100% of patients (58% grade ≥ 3). ORR and disease control rate were 29% and 95%. Median PFS was 10.9 months (95% CI, 10.0 – 15.6) and median OS was 16.4 months (95% CI, 12.8 – NR) with 21 patients still alive at time of the data cut-off. Surgery was made possible in 23% of patients. Microbulk RNA sequencing revealed that the main pathway downregulated with the combination mFOLFIRINOX+NP137 is EMT, bringing a clinical validation of the main mechanism of action of NP137. Moreover, patients with tumors expressing high levels of the netrin-1 receptor neogenin (high-NEO1) at baseline (both at the RNA and proteic level (IHC)) demonstrated an improved outcomes compared to the low-NEO1 subgroup including longer median PFS (15.7 vs 10.2 months, p = 0.01) and longer median OS (not reached vs 16.5, p = 0.024). These results are consistent with experimental data demonstrating the implication of NEO1 in PDAC EMT and its progression. Conclusions: NP137 in combination with mFOLFIRINOX demonstrates a favorable safety profile, promising clinical activity and a mechanistically distinct mode of action supported by translational analyses. These results warrant further investigation of netrin-1 blockade in randomized trials and provide a rationale for biomarker-driven development of NP137 in PDAC. Further work is ongoing to better characterize the distribution of NEO1 in first-line unresectable PDAC. Clinical trial information: NCT06203821 .