Ana, Sarah Sta

TPS4208 Background: Metastatic pancreatic ductal adenocarcinoma (mPDAC) carries a 5-year relative survival of 3%. Immune checkpoint inhibitors have thus far failed to improve outcomes due to an immunosuppressive tumor microenvironment (TME). Signaling through the C-X-C motif chemokine receptor 4 (CXCR4)/C-X-C motif chemokine ligand 12 (CXCL12) axis results in exclusion of anti-tumor immune cells in mouse PDAC models. Longitudinal survival studies testing combinations of CXCR4i, aPD-1, and gemcitabine in the KPC mouse model of PDAC demonstrated a survival benefit with the combination of all three agents. Results from a multicenter, investigator-initiated, single arm pilot study evaluating the preliminary safety and efficacy ofMotixafortide (CXCR4i), Cemiplimab (aPD1), Gemcitabine, and Nab-paclitaxel (MCGN) in 11 patients with treatment-naïve mPDAC were recently presented. Seven patients (64%) achieved a partial response, including 6 confirmed partial responses, and 10 patients (91%) had disease control, compared to historic partial response and disease control rates of 23% and 48%, respectively, with gemcitabine and nab-paclitaxel (GN). Preliminary median progression-free survival (PFS) was 9.6 months compared to historic median PFS of 5.5 months with GN. Analysis of paired pre- and on-treatment biopsy samples from demonstrated an increase in CD8+ T-cell density in tumors from all 11 patients treated with MCGN (p=0.007). Based on these promising results, the protocol was amended from a single arm expansion totaling 40 patients to a randomized phase 2 study. Methods: This is an open-label, multicenter, investigator-initiated phase 2 clinical trial. Patients are randomized 2:1 to receive MCGN or GNalone (N=108). The primary endpoint is progression free survival. The study has 80% power to detect an improvement in PFS from 6 to 9.2 months (HR 0.65) with a one-sided alpha of 0.20. One interim analysis for futility is planned when 50% of the PFS events are observed. Secondary objectives include response rate, disease control rate, duration of clinical benefit and overall survival. Patients will undergo optional paired biopsies which will be analyzed in conjunction with samples collected from the phase I pilot study. Exploratory studies include interrogation of the TME using quantitative multiplex immunofluorescence and single-cell RNA sequencing. The randomized phase 2 trial is open to enrollment and one patient has been randomized as of 1/29/2024. Clinical trial information: NCT04543071 .

TPS4200 Background: Metastatic pancreatic ductal adenocarcinoma (mPDAC) is a uniformly fatal disease for which treatments result in limited benefit. Failure of immune checkpoint blockade is attributed to multiple immunosuppressive pathways within the tumor microenvironment. The C-X-C motif chemokine receptor 4 (CXCR4)/C-X-C motif chemokine ligand 12 (CXCL12) axis results in exclusion of anti-tumor immune cells. Preclinical studies demonstrated that simultaneous CXCR4 inhibition (CXCR4i) and anti-programmed cell death 1 (aPD1) resulted in tumor stabilization. We extended these findings by testing multiple combinations of CXCR4i, aPD1, and gemcitabine in the KPC mouse model of PDAC. Mice treated with gemcitabine, CXCR4i, and aPD1 (triple therapy) experienced a survival benefit compared to mice treated with either gemcitabine alone, or with CXCR4i/aPD1. Tumors from mice treated with triple therapy demonstrated increased apoptosis and a favorable tumor immune microenvironment (TIME). Motixafortide with pembrolizumab, fluorouracil, and nanoliposomal irinotecan has shown encouraging results in the second-line setting in mPDAC with a confirmed ORR of 13.2% and progression free survival (PFS) of 3.8 months (m). The goal of this first-in-man trial is to test preliminary safety and efficacy of Motixafortide (CXCR4i), Cemiplimab (aPD1), Gemcitabine, and Nab-paclitaxel (MCGN) in treatment naïve mPDAC. Methods: This is an open label, multicenter, investigator-initiated simon-2-stage phase 2 clinical trial in mPDAC testing MCGN. The study includes a six-patient safety run-in cohort and an additional 4 patients comprising a pilot efficacy signal seeking study (N=10). If ≥3 of the 10 patients within the pilot stage were to experience a partial response (PR) by RECIST criteria within 16 weeks, the combination would be considered promising and an expansion cohort of an additional 30 patients was planned. On 09/21/22, we amended the study to forego the planned open-label expansion cohort (N=30) and transition directly to a randomized phase 2 trial testing MCGN compared toGemcitabine and Nab-paclitaxel (GN) alone (N=102), after completion of the pilot phase of the study. The primary endpoint is PFS. The study has 80% power to detect an improvement in PFS from 6 to 9.2 m (HR 0.65) with a one-sided alpha of 0.20. One interim analysis for futility is planned when 50% of the PFS events are observed. Secondary objectives include ORR, disease control rate, duration of clinical benefit and OS. Required (pilot portion) and optional (randomized portion) paired tumor biopsies will undergo exploratory analysis including interrogation of the TIME. This trial was started in September 2020 and has enrolled 10 patients to the pilot stage as of 02/2023. Clinical trial information: NCT04543071 .