Untreated Metastatic Pancreatic Ductal Adenocarcinoma Research Articles

Abstract CT214: Paricalcitol addition to chemotherapy in patients with previously untreated metastatic pancreatic ductal adenocarcinoma (PINBALL)

Abstract Background Vitamin D agonism has been shown in preclinical studies to decrease the production of collagen, decrease myeloid derived suppressor cells, and decrease regulatory T cells in pancreatic ductal adenocarcinoma (PDAC). Paricalcitol is a vitamin D analog used for vitamin D replacement for those with secondary hyperparathyroidism. Two individuals with PDAC who had been developed resistance gemcitabine based combination therapy had shown clinical benefit with the addition of paricalcitol. This clinical study was done to study the effect of adding paricalcitol to individuals with metastatic PDAC receiving gemcitabine based combination therapy (NCT04054362, NCT03415854) . Methods Adults with a histologically- or cytologically-confirmed diagnosis of metastatic PDAC and who were previously untreated were eligible. Individuals received gemcitabine based combination- either gemcitabine plus nab-paclitaxel or gemcitabine plus nab-paclitaxel and cisplatin and had to either demonstrate progressive or stable disease. Paricalcitol was given at a fixed dose of 25 mcg IV three days a week. The combination continued until either disease progression or poor tolerance. The primary objective was to determine the clinical benefit of adding paricalcitol to gemcitabine based combination therapy for metastatic PDAC. Secondary objectives included assessing safety and pharmacodynamic through patient biopsies. Results A total of 34 patients were enrolled across two sites. 16 patients received paricalcitol. The overall response rate was 0% ( CR, PR). Disease control rate at 9 weeks was 21.4% (CR+PR+ SD). PFS upon addition of paricalcitol was 1.6 months. OS upon addition of paricalcitol was 4.8 months. Grade 3/4 AE's attributed to paricalcitol include 13% thrombocytopenia; 19% anemia; 6% transaminitis; 6% pleural effusion; 6% ascites- all grade 3. Conclusions The addition of paricalcitol demonstrated evidence of limited clinical benefit in individuals with metastatic PDAC receiving front-line gemcitabine based therapy. Paricalcitol was generally well tolerated. Tumor analysis is ongoing. Addition studies utilizing prospective treatment of paricalcitol for front line treatment of mPDAC are ongoing (NCT03520790). Trial funding provided by SU2C, CRUK, Lustgarten Foundation, and AACR. Citation Format: David Propper, Gayle Jameson, Denise Roe, Betsy Wertheim, Dan Von Hoff, Erkut H. Borazanci. Paricalcitol addition to chemotherapy in patients with previously untreated metastatic pancreatic ductal adenocarcinoma (PINBALL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT214.

Abstract C003: RAMP 205: A phase 1b/2a study of gemcitabine, nab-paclitaxel, avutometinib, and defactinib in untreated metastatic pancreatic ductal adenocarcinoma

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) accounts for ~90% of pancreatic cancer. Surgery is the only curative treatment. Unfortunately, most patients are diagnosed with advanced disease and are not candidates for resection. Combination chemotherapy approaches have provided incremental improvements to PDAC outcomes. However, impact on survival for patients with inoperable disease remains modest, with a 2-year survival rate of less than 7%. Activating mutations in the KRAS oncogene are a key initiating event in ~80-90% of PDAC. Permanent activation of KRAS drives tumor cell proliferation and survival, tumor microenvironment modulation, and metabolic alterations in PDAC. Patients with KRAS mutant PDAC have worse outcomes compared to those with KRAS wild-type PDAC. In addition, hyperactivation of focal adhesion kinase (FAK) has been correlated with high stromal density, resulting in therapeutic resistance and poor survival. Avutometinib is a first-in-class oral RAF/MEK clamp that potently inhibits MEK kinase activity while also blocking the compensatory reactivation of MEK by upstream RAF. Defactinib is a selective inhibitor of focal adhesion kinase (FAK), which has been shown to mediate resistance to multiple anticancer agents. Preclinical data have shown that the combination of avutometinib + FAK inhibition (FAKi) + chemotherapy (gemcitabine + paclitaxel as a surrogate for nab-paclitaxel) induced tumor regression in a autochthonous KRAS/TP53 mutant PDAC mouse model. Prior clinical experience of defactinib + pembrolizumab + chemotherapy was safe, showed responses, decreased stromal density, and increased CD8+ T cell infiltration in patients with PDAC (NCT02546531). Methods: RAMP 205 is a multi-center, open-label, single arm Phase 1b/2a study of gemcitabine and nab-paclitaxel in combination with avutometinib and defactinib in patients with previously untreated metastatic PDAC (NCT05669482). The study is being conducted in 2 parts: Parts A (dose evaluation) and Part B (dose expansion). The starting dose is 2.4 mg avutometinib orally (PO) twice weekly + 200 mg defactinib PO twice per day, in combination with standard once weekly gemcitabine/nab-paclitaxel (QW IV). All study drugs are dosed 3 weeks on, 1 week off. Following determination of the Recommended Phase 2 Dose (RP2D) in Part A, Part B will evaluate efficacy of the RP2D via objective response rate (primary endpoint). Mandatory tumor biopsies and blood samples will be collected for correlative studies, including circulating tumor DNA, molecular profiling and pharmacodynamic markers. Eligible patients must have histologic or cytologic evidence of metastatic PDAC and measurable disease according to RECIST v1.1. Patients with prior or concomitant treatment for metastatic PDAC or prior treatment with RAS/MAPK or FAK inhibitors are not eligible. The study will enroll ~35 patients with 6-12 patients in Part A, and 23 patients in Part B. Citation Format: Kian-Haut Lim, Manuel Hidalgo, Mark H. O'Hara, Kristen R. Spencer, Ignacio Garrido-Laguna, David G. DeNardo, Vijeta Bhambhani, Gloria Patrick, Yaofeng Cheng, Silvia Coma, Jonathan A. Pachter, Louis J. Denis. RAMP 205: A phase 1b/2a study of gemcitabine, nab-paclitaxel, avutometinib, and defactinib in untreated metastatic pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C003.

CEND-1: a game changer for pancreatic cancer chemotherapy?

The clinical development of systemic therapies for patients with metastatic pancreatic ductal adenocarcinoma has been a series of disappointments. Immunotherapy has been largely ineffective, targeted therapy only works in a few patients, and chemotherapy is less effective than in other cancer types. 1 Springfeld C Jäger D Büchler MW et al. Chemotherapy for pancreatic cancer. Presse Med. 2019; 48: e159-e174 Crossref PubMed Scopus (83) Google Scholar There are more than 530 000 deaths worldwide each year, ranking pancreatic ductal adenocarcinoma as the fifth most common cause of cancer death. In the USA there has been a small improvement in 5-year survival for all stages, increasing from approximately 5% to 11% in the past three decades, but this increase is insignificant when compared with other tumour types. Pancreatic ductal adenocarcinoma is characterised by a dense desmoplastic stroma that might contribute to chemotherapy resistance. 2 Hosein AN Brekken RA Maitra A Pancreatic cancer stroma: an update on therapeutic targeting strategies. Nat Rev Gastroenterol Hepatol. 2020; 17: 487-505 Crossref PubMed Scopus (228) Google Scholar Cancer-associated fibroblasts secrete TGF-β which promotes the stromal matrix and αvβ5 integrin expression involved in cancer cell adhesion, migration, and proliferation. In The Lancet Gastroenterology & Hepatology, Andrew Dean and colleagues 3 Dean A Gill S McGregor M Broadbridge V Järveläinen HA Price T Dual αV-integrin and neuropilin-1 targeting peptide CEND-1 plus nab-paclitaxel and gemcitabine for the treatment of metastatic pancreatic ductal adenocarcinoma: a first-in-human, open-label, multicentre, phase 1 study. Lancet Gastroenterol Hepatol. 2022; (published online July 5.)https://doi.org/10.1016/S2468-1253(22)00167-4 Summary Full Text Full Text PDF PubMed Google Scholar report the results from a phase 1 study in patients with untreated metastatic pancreatic ductal adenocarcinoma that might be a game changer at enhancing tumour delivery of standard chemotherapy by coadministration with the CEND-1 cyclic peptide. Dual αV-integrin and neuropilin-1 targeting peptide CEND-1 plus nab-paclitaxel and gemcitabine for the treatment of metastatic pancreatic ductal adenocarcinoma: a first-in-human, open-label, multicentre, phase 1 studyCEND-1 with nab-paclitaxel and gemcitabine has an acceptable safety profile, with no dose-limiting toxicities and encouraging activity. Adverse events were generally consistent with those seen with nab-paclitaxel and gemcitabine. Further randomised trials to determine the efficacy of CEND-1 are warranted. Full-Text PDF

Abstract CT549: Randomized Phase II trial of two different nutritional approaches for patients receiving treatment for their advanced pancreatic cancer

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by stromal fibrosis, hypoxia, and nutritional deprivation. PDAC tumors grow aggressively, diagnosis is typically made after metastasis and the disease remains associated with poor outcomes. The triplet chemotherapy regimen of gemcitabine, nab-paclitaxel with cisplatin was associated with a median overall survival of 16.4 months in patients with metastatic pancreatic cancer in the first-line setting (Jameson et al., 2020). Nutritional, metabolic interventions offer an opportunity to fundamentally change the tumor microenvironment and improve outcomes for patients. A medically supervised ketogenic diet (MSKD) defined as lower carbohydrate, lower protein, and higher fat can significantly reduce glucose and insulin and increase metabolically active ketone bodies. A ketogenic diet combined with triplet chemotherapy (gemcitabine, nab-paclitaxel, cisplatin) was shown to inhibit murine pancreatic KPC tumor growth and to triple the survival benefit of chemotherapy alone. The ketogenic diet combined with triple chemotherapy was associated with glucose depletion, altered TCA substrate usage, and NADH elevation. Methods: In this Phase II randomized clinical trial (NCT04631445), we are evaluating a medically supervised ketogenic diet (MSKD) versus a standard diet when combined with the triplet therapy in patients with treatment-naive advanced pancreatic cancer. The primary endpoint is progression free survival for triplet therapy while on MSKD or non-MSKD. Secondary endpoints include disease control rate (PR+ CR+ SD for at least 9 weeks), change in CA 19-9 (or CA125, or CEA if not expressers of CA 19-9), average insulin levels, HbA1c, body weight, a comparison of gut microbial diversity, changes in serum metabolites and quality of life via the EORTC QLQ-C30 assessment. Unlike prior ketogenic intervention studies, the MSKD is being supported by a continuous care nutrition intervention through Virta Health Corp, that offers tracking of daily ketone and glucose levels, a web-based software application, education, and communication with a remote care team to ensure sustained nutritional ketosis. A total of 40 patients with untreated metastatic PDAC are planned for enrollment, 20 randomized to each arm. The trial opened for accrual November 2020. Citation Format: Diana Hanna, Gayle S. Jameson, Drew W. Rasco, Angela Alistar, Richard C. Frank, Anthony B. El-Khoueiry, Julia E. Wiedmeier, Caroline Roberts, Brandon Fell, Sarah Hallberg, Denise Roe, Derek Cridebring, Joshua Rabinowitz, Stephen Thomas Gately, Daniel D. Von Hoff. Randomized Phase II trial of two different nutritional approaches for patients receiving treatment for their advanced pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT549.

Initial efficacy and biomarker analysis of a phase 1b study targeting IL-1β and PD-1 with chemotherapy in metastatic pancreatic cancer (PanCAN-SR1).

e16287 Background: Pancreatic ductal adenocarcinoma (PDA) has been refractory to therapeutic targeting of the immune microenvironment. In preclinical work, IL-1β was upregulated in PDA tumors, and in mouse models, IL-1β expression led to activation of pancreatic stellate cells and immunosuppression. We hypothesize that blockade of IL-1β and PD-1 will result in significant alterations in immune and fibroblast subsets within the PDA microenvironment. Methods: We conducted an open-label multicenter Phase Ib study evaluating gemcitabine and nab-paclitaxel with canakinumab (ACZ885), a high-affinity human anti-interleukin-1β (IL-1β) mAb, and spartalizumab (PDR001), a mAb directed against human PD-1. 10 subjects with untreated metastatic PDA and RECIST measurable disease were enrolled. The primary objective was to identify a recommended phase II/III dose by evaluating the incidence of DLTs in the first 56 days. All subjects underwent baseline and on-study tissue and blood collection for extensive exploratory correlative studies. Secondary objectives including safety and tolerability and preliminary assessment of clinical activity. Results: 10 subjects were enrolled between November 2020 and March 2021. 6 out of 10 were evaluable for the dose confirmation. In the dose confirmation analysis there were no dose limiting toxicities (DLTs) and the recommended Phase II/III dose was established as; gemcitabine (1000 mg/m2 IV) and nab-paclitaxel (125 mg/m2 IV) on day 1,8,15; canakinumab (250 mg via subcutaneous injection) and spartalizumab (400 mg IV) on day 1; of each 28 day cycle. Adverse events were consistent with those seen with chemotherapy and were predominately hematologic. A preliminary efficacy analysis confirms 1 PR and 7 pts with SD. Two of the 7 pts have been treated for 11 and 12 cycles, respectively, without progression. Activation of CD8 T cells in peripheral blood and increased serum levels of IFN-induced chemokines CXCL9/10 were observed in patient samples. Using an in vitro suppression assay, we showed that baseline serum, from patients deriving clinical benefit, could induce myeloid derived suppressor cells, but that this effect was abrogated with treatment. Single cell transcriptional profiling also revealed treatment-dependent shifts in T cell activation state and myeloid cells in the tumors of patients experiencing clinical benefit. Conclusions: In this Phase Ib study, we established the Phase II/III dose of canakinumab and spartalizumab with chemotherapy in first line metastatic PDA. Translational studies suggest putative biomarkers that may help identify responding pts. This novel combination is being evaluated in a randomized Phase II/III study through the Precision Promise clinical trial network. Clinical trial information: NCT04581343.

Mitazalimab in combination with mFOLFIRINOX in patients with metastatic pancreatic ductal adenocarcinoma (PDAC): Safety data from part of the OPTIMIZE-1 study.

e16237 Background: Mitazalimab is a human CD40 agonistic IgG1antibody being developed for cancer immunotherapy. Targeting CD40 kickstarts the cancer immunity cycle by licensing DCs leading to tumor-specific T cell priming and activation. Furthermore, in PDAC CD40 agonists on myeloid cells promote degradation of the desmoplastic tumor stroma, improving influx of T cells and chemotherapeutic agents into the tumor. Mitazalimab has shown to be safe and well tolerated (at doses up to 1200 μg/kg), with signs of clinical activity in solid tumors in a Phase I study (NCT02829099). Most drug related adverse events (AE) were grade 1 or 2. Methods: OPTIMIZE-1 (NCT04888312) is a Phase 1b/2, open-label, multicenter study designed to evaluate safety, tolerability, and efficacy of mitazalimab in combination with mFOLFIRINOX in adults diagnosed with previously untreated metastatic PDAC. In the first 21-day treatment cycle (Dose Limiting Toxicity (DLT) assessment period), mitazalimab is administered intravenously on day 1 and 10 and mFOLFIRINOX infusion starts on day 8. In the second and subsequent cycles, treatment follows a 14-day cycle schedule where mitazalimab is administered 2 days after mFOLFIRINOX. The primary objective of the first part of the study (Phase 1b) is to determine the recommended Phase 2 Dose (RP2D) of mitazalimab in combination with mFOLFIRINOX. Mitazalimab will be escalated from 450 µg/kg to 900 µg/kg following a Bayesian optimal interval design with at least 3 patients enrolled per dose level. A minimum of 6 patients will be evaluated at the RP2D. In Part 2 of the study, mitazalimab at the RP2D will be administered in combination with mFOLFIRINOX. The primary endpoint is RECIST-defined overall response rate. Progression-free survival and overall survival will be assessed as secondary endpoints. Here we report data from the Phase 1b (dose escalation) part of this study. Results: Five patients with histologically confirmed, previously untreated metastatic PDAC were treated at the 450 µg/kg dose level. Key baseline characteristics included: 2 female, 3 male; median age 65 (range 60-68); ECOG score of 0 or 1; median time since primary diagnosis 13 days (range 7-82). Treatment related AEs were only grade 1 or 2 (reported in 4 of 5 patients). Treatment related AEs occurring in > 1 patient were fever, muscle pain and nausea. No DLTs were reported. No patients required dose interruption/reduction with mitazalimab or mFOLFIRINOX. Two patients discontinued treatment due to disease progression and three remain on study. The study continues and patients are currently being enrolled at the 900 µg/kg mitazalimab dose in combination with mFOLFIRINOX. Conclusions: Mitazalimab at 450 µg/kg dose combined with mFOLFIRINOX is safe and well tolerated. Enrollment at the 900 µg/kg dose is ongoing for this Phase 1b/2 study. Updated data from part 1 of the study will be presented. Clinical trial information: NCT04888312.

Randomized phase II trial of two different nutritional approaches for patients receiving treatment for their advanced pancreatic cancer.

TPS637 Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by stromal fibrosis, hypoxia, and nutritional deprivation. PDAC tumors grow aggressively, diagnosis is typically made after metastasis and the disease remains associated with poor outcomes. The triplet chemotherapy regimen of gemcitabine, nab-paclitaxel with cisplatin was associated with a median overall survival of 16.4 months in patients with metastatic pancreatic cancer in the first-line setting (Jameson et al., 2020). Nutritional, metabolic interventions offer an opportunity to fundamentally change the tumor microenvironment and improve outcomes for patients. A ketogenic diet defined as lower carbohydrate, lower protein, and higher fat can significantly reduce glucose and insulin and increase metabolically active ketone bodies and has been evaluated in patients with a variety of solid tumors (Weber et al, 2020). Recently, a ketogenic diet combined with triplet chemotherapy was shown to inhibit murine pancreatic KPC tumor growth and significantly prolong animal survival over chemotherapy alone. Tumor growth inhibition was associated with glucose depletion, altered TCA substrate usage, and NADH elevation. Methods: In this Phase II randomized clinical trial (NCT04631445), we are evaluating a medically supervised ketogenic diet (MSKD) versus a standard diet when combined with the triplet therapy in patients with treatment-naive advanced pancreatic cancer. The primary endpoint is progression free survival for triplet therapy while on MSKD or non-MSKD. Secondary endpoints include disease control rate (PR+ CR+ SD for at least 9 weeks), change in CA 19-9 (or CA125, or CEA if not expressers of CA 19-9), average insulin levels, HbA1c, body weight, a comparison of gut microbial diversity, changes in serum metabolites and quality of life via the EORTC QLQ-C30 assessment. Unlike prior ketogenic intervention studies, the MSKD is being supported by a continuous care nutrition intervention through Virta Health Corp, that offers tracking of daily ketone and glucose levels, a web-based software application, education, and communication with a remote care team to ensure sustained nutritional ketosis. A total of 40 patients with untreated metastatic PDAC are planned for enrollment, 20 randomized to each arm. The trial opened for accrual November 2020. Clinical trial information: NCT04631445.

Preliminary results of a phase 1 study of sea-CD40, gemcitabine, nab-paclitaxel, and pembrolizumab in patients with metastatic pancreatic ductal adenocarcinoma (PDAC).

559 Background: SEA-CD40 is an investigational nonfucosylated IgG1 monoclonal agonistic antibody targeted to CD40, expressed on antigen-presenting cells. SEA-CD40 binds with increased affinity to FcγRIIIa resulting in enhanced effector function and CD40 agonism, allowing amplification of immune stimulation and antitumor activity. PDAC can be treated with gemcitabine + nab-paclitaxel (GnP), often with poor survival. Combining chemotherapeutic agents with SEA-CD40 could facilitate robust antigen release and amplified presentation to CD8+ T cells. In preclinical models, the combination of SEA-CD40 and chemotherapy resulted in significant antitumor activity which is further enhanced with anti-PD1 treatment. We present data from an ongoing Phase 1 study (SGNS40-001) in a PDAC cohort evaluating the combination of SEA-CD40, GnP, and pembrolizumab (pembro). Methods: Patients (pts) ≥18 years old with untreated metastatic PDAC and Eastern Cooperative Oncology Group performance scores of 0 or 1 were enrolled. GnP were administered on Days 1, 8, and 15 of each 28-day cycle with 10 or 30 μg/kg SEA-CD40 IV on Day 3. Pembro was administered every 42 days starting on Day 8. Results: As of July 9, 2021, 61 pts were treated: 40 and 21 pts at 10 and 30 μg/kg SEA-CD40, respectively. Minimum follow-up was 5 months. The most frequent treatment-emergent adverse events (TEAEs) are shown in Table. 5 (8%) pts experienced an AE leading to treatment (tx) discontinuation (3 and 2 in 10 and 30 μg/kg SEA-CD40 dose, respectively), 35 (57%) pts experienced a serious TEAE (22 and 13 pts in 10 and 30 μg/kg, respectively). Two tx-related deaths occurred: colitis attributed to pembro, and septic shock attributed to GnP. Pts had transient increases in circulating cytokines and chemokines associated with immune activation and trafficking as well as increases in markers of activation on peripheral NK cells and T cells. Conclusions: The combination of SEA-CD40 + GnP + pembro demonstrated a tolerable safety profile. Evidence of immune activation was observed, consistent with the proposed mechanism of action. Follow-up for response and survival are ongoing. Clinical trial information: NCT02376699. [Table: see text]

Efficacy of SBP-101, a polyamine metabolic inhibitor, administered in combination with gemcitabine and nab-paclitaxel, as a first-line treatment for patients with metastatic pancreatic ductal adenocarcinoma.

575 Background: SBP-101, a polyamine metabolic inhibitor, inhibited growth in 6 human pancreatic ductal adenocarcinoma (PDA) cell lines and 3 murine xenograft tumor models of human PDA. SBP-101 monotherapy in heavily pre-treated PDA patients (> 2 prior regimens) showed a median survival of 5.9 months at the optimal dose level. Purpose: To assess the PK, safety and efficacy of SBP-101 in combination with gemcitabine (G) and nab-paclitaxel (A) in patients with previously untreated metastatic PDA. Methods: In a modified 3+3 dose escalation scheme, subcutaneous injections of SBP-101 were dosed at 0.2, 0.4 or 0.6 mg/kg days 1-5 of each 28-day cycle. G (1000 mg/m2) and A (125 mg/m2) were administered intravenously on Days 1, 8, and 15 of each cycle. PK was evaluated on day 1 of cycle 1 in cohorts 1-3. Safety was evaluated by clinical and laboratory assessments. Efficacy was assessed by CA19-9 levels, objective response using RECIST criteria, progression-free survival (PFS) and overall survival (OS). A 4th cohort using a modified dosing schedule of 0.4 mg/kg SBP-101 days 1-5 for cycles 1-2 and days 1, 8, and 15 every cycle thereafter was added to mitigate hepatic toxicity, and that dose and schedule were recommended for Phase 1b expansion. Results: Fifty patients were enrolled (N=25, Phase 1a and N=25, Phase 1b) and received up to 13 treatment cycles. SBP-101 plasma Cmax and AUC0-t increased in a slightly more than dose proportional manner and were unchanged by the addition of G and A. PK parameters of G and A were unaltered by increasing doses of SBP-101. The most common nonserious adverse events related to SBP-101 (>10%) are fatigue (N=14), LFT/transaminase abnormalities (N=15), vision abnormalities (N=10), injection site pain (N=13), dehydration (N=7), nausea (N=7). Serious adverse events related to SBP-101 observed in some subjects include hepatic toxicity (N=6) and retinal toxicity (N=8) both occurring after prolonged treatment and requiring dose reduction or discontinuation. At the recommended dose and schedule (N=30), CA19-9 levels decreased 60-99% in 19 of 29 evaluable patients, with 1/29 (3%) achieving a complete remission 13/29 achieving partial responses (45%) and 10/29 achieving stable disease at 8 weeks (35%). PFS was confounded by SBP-101 dosing holds implemented to investigate potential toxicity. Sixteen subjects are in survival follow-up. Median OS is 10.1 months and is not final. Conclusions: Interim results suggest SBP-101 may enhance first-line treatment with G and A in patients with metastatic PDA. Hepatic toxicity can be mitigated with dose reduction or discontinuation. A vision screening program will be used in future studies to mitigate retinal toxicity. Clinical trial information: NCT03412799.

Abstract PR-002: A phase II pilot trial of nivolumab (N) + albumin bound paclitaxel (AP) + paricalcitol (P) + cisplatin (C) + gemcitabine (G) (NAPPCG) in patients with previously untreated metastatic pancreatic ductal adenocarcinoma (PDAC)

Abstract Background: Effective therapy for the treatment of PDAC remains one of the greatest unmet oncology clinical needs. The addition of C to G and AP has shown 71% ORR in a previously reported study [JAMA Oncol. 2019 Oct 3;6(1):125-32]. In preclinical work, vitamin D (Vit D) analog therapy decreases myeloid derived suppressor cells and regulatory T cells, turning PDAC into a more immune favorable microenvironment. This trial combines AP/C/G with Vit D analog P and the anti-PD-1 antibody N as a combination therapy for patients with previously untreated metastatic PDAC. This trial evaluates the efficacy and safety of NAPPCG in that patient population (NCT02754726). Methods: Eligibility criteria include Stage IV PDAC, no prior chemotherapy for systemic disease, KPS ≥ 70, and RECIST 1.1 measurable disease. Doses are AP 125 mg/m2, G 1000 mg/m2, each infused over 30 minutes with C 25 mg/m2 infused over 60 minutes on days 1, 8, 22, and 29 of a 42-day cycle. N is given at a fixed dose of 240 mg as a 60 minute infusion on days 1, 15, and 29. P is given at a fixed dose of 25 µg IV twice weekly. Primary objective was to determine the efficacy of the combination for patients with previously untreated metastatic PDAC through determining CR, ORR, PFS, and OS. The secondary objective was to evaluate safety in patients with previously untreated metastatic PDAC. Exploratory endpoints include evaluating tissue molecular profile as it relates to treatment outcomes. Results: Trial was conducted May 2016 with enrollment completed August 2020. 35 patients have been enrolled in the study and 32 are evaluable (baseline and ≥1 follow up CT scan). Most common drug-related grade (Gr) 3-4 adverse events (AE’s), are thrombocytopenia 76% (gr 3 = 34%, gr 4 = 28%) with no serious bleeding events, anemia 37% (gr 3 = 37%, gr 4 = 0%), and CIPN 11% (gr 3 = 11%, gr 4 = 0%). Immune Related Adverse Events >5% were colitis (gr 3=8.6%, gr 4= 0%) and dermatitis (gr 3=8.6%, gr 4= 0%). By RECIST 1.1 criteria, the best response is 1 CR, 26 PR, 4 SD, 1 PD, yielding an 84% ORR (95% CI = (67%, 95%). Median PFS is 6 months (95% CI = (5, 8)). Median OS is 18 months (95% CI = (13, 22)). Conclusions: Although a small study, the high response rate is encouraging. Evaluation of exploratory endpoints is ongoing. Pursuing this regimen in localized PDAC is warranted due to its high ORR. Supported by grants from the Seena Magowitz Foundation, Mattress Firm, Bristol Myers Squibb, and SU2C. Citation Format: Erkut Borazanci, Gayle S. Jameson, Sunil Sharma, Frank Tsai, Ronald L. Korn, Lana Caldwell, Karen Ansaldo, David T. Ting, Denise Roe, Anna Bermudez, Daniel D. Von Hoff. A phase II pilot trial of nivolumab (N) + albumin bound paclitaxel (AP) + paricalcitol (P) + cisplatin (C) + gemcitabine (G) (NAPPCG) in patients with previously untreated metastatic pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PR-002.

537 OPTIMIZE-1, an open-label phase 1b/2 study assessing the safety and efficacy of mitazalimab in combination with chemotherapy in patients with metastatic pancreatic ductal adenocarcinoma

BackgroundMitazalimab is a human CD40 agonistic antibody (IgG1) developed for cancer immunotherapy. Targeting CD40 provides an opportunity to kickstart the cancer-immunity cycle by priming and activating tumor-specific T cells.1 2 Furthermore, the effects of CD40 agonists on myeloid cells promote degradation of the tumor stroma, improving the influx of T cells and chemotherapeutic agents into the tumor.1 Targeting CD40 with mitazalimab in pancreatic ductal adenocarcinoma (PDAC), which is defined by a desmoplastic tumor stroma that hosts immune-suppressive macrophages, has the potential to augment responses to chemotherapy, initiating an effective anti-tumor immune response. Data from a phase 1 study (NCT02829099) demonstrated early signs of clinical activity in solid tumors with one partial response and SD in 37% of the patients.3 Mitazalimab was safe and tolerable at intravenous doses up to 1200 μg/kg and most drug-related adverse events were grade 1 or 2.3 Biomarker data from this study demonstrated proof of mechanism, validating mitazalimab’s ability to activate CD40 in cancer patients. In preclinical hCD40tg mouse models, repeated administration of mitazalimab in combination with FOLFIRINOX induced a long-term survival when compared to chemotherapy alone.4MethodsOPTIMIZE-1 is a phase 1b/2, open-label, multicenter study designed to evaluate safety, tolerability, and efficacy of mitazalimab in combination with chemotherapy (mFOLFIRINOX) in adults diagnosed with previously untreated metastatic PDAC. Mitazalimab and mFOLFIRINOX will be administered by intravenous infusions following a 14-day cycle schedule where mitazalimab will be administered 2 days after mFOLFIRINOX, except for the first cycle of 21 days where mitazalimab will be administered on Day 1 and 10 and infusion of mFOLFIRINOX will start Day 8. In Part 1 (Phase 1b) of the study, the dose of mitazalimab will be escalated from 450 µg/kg to 900 µg/kg (2 dose levels to be evaluated) to obtain the recommended phase 2 dose (RP2D). Part 1 follows a Bayesian optimal interval design (BOIN) with at least 3 patients enrolled at each dose level. A minimum of 6 patients will be evaluated at the RP2D. In Part 2 of the study, the RP2D of mitazalimab will be administered in combination with mFOLFIRINOX to all patients. The study expansion will evaluate the clinical efficacy of mitazalimab in combination with mFOLFIRINOX assessing objective response rate (ORR) (primary endpoint), Progression-free survival (PFS) and Overall survival (OS) (secondary endpoints). The study expansion includes a Simon’s two-stage design with an interim analysis to allow stopping for futility or efficacy based on ORR.Trial RegistrationNCT04888312ReferencesEnell Smith K, Deronic A, Hägerbrand K, Norlén P & Ellmark P. Rationale and clinical development of CD40 agonistic antibodies for cancer immunotherapy. Expert Opinion on Biological Therapy 2021 Jun 17, 1–12.Ellmark P, Mangsbo SM, Furebring C, Totterman TH & Norlen P. Kick-starting the cancer-immunity cycle by targeting CD40. Oncoimmunology 2015;4:e1011484.Calvo E, et al. A phase I study to assess safety, pharmacokinetics (PK), and pharmacodynamics (PD) of JNJ-64457107, a CD40 agonistic monoclonal antibody, in patients (pts) with advanced solid tumors. Journal of Clinical Oncology 2019;37:2527–2527.Adnan Deronic MT, Anneli Nilsson, Peter Ellmark, Anette Fält, Karin Enell Smith. Mitazalimab, a potent CD40 agonist with potential for combination with chemotherapy. AACR Annual meeting Abstract 2021;1593.Ethics ApprovalThe study was approved 19 July 2021 by CHU UCL Namur, site Godinne Comité d’éthique Avenue Docteur G. Thérasse 1 5530 YVOIR, Belgium, approval number 32/2021and2 July 2021 by Comite de Protection des Personnes EST I, ‘France, approval number SI2G 21.00648.677157

Organoid Personalized Therapeutics and the Pancreatic Adenocarcinoma Signature Stratification for treatment (PASS) – 01 trial

Keywords: pancreatic cancer, patient-derived organoids, transcriptomic signatures, PASS-01 Background: Patients with advanced pancreatic ductal adenocarcinoma (PDAC) continue to have a dire prognosis and only a minority of patients is fit enough to receive second-line treatment. Using patient-derived organoids (PDOs), we have identified transcriptomic signatures of chemotherapy sensitivity that may be able to stratify patients such that they receive maximal benefit from the currently approved, first-line chemotherapy regimens [1-3]. We will now test this hypothesis in the Pancreatic Adenocarcinoma Signature Stratification for treatment (PASS) – 01 trial, which is a multi-institutional randomized phase II trial between FOLFIRINOX (mFFX) and gemcitabine/nab-paclitaxel (GA). Methods: The overall aim of PASS-01 is to evaluate biomarkers and gene signatures that may predict response to mFFX and GA. The primary objective is to determine the progression free survival (PFS) benefit of mFFX compared to GA. Using 1:1 randomization, 131 evaluable patients with untreated metastatic PDAC will be recruited to provide 80% power to detect a 2-month improvement in PFS with mFFX (one-sided alpha 0.2). Secondary and exploratory objectives include determine the objective response rate, duration of response and overall survival associated with mFFX or GA, whether the chemotherapy sensitivity signature predictions correlate with responders, if PDO transcriptomic profiles parallel those obtained from patient samples, whether GATA6 expression can serve as a biomarker of response [4], the use of serial cell free circulating tumor DNA and circulating tumour cell analysis to identify emerging or de novo resistance and evaluate biomarkers of immune-oncologic sensitivity. The main inclusion and exclusion criteria are similar to major efficacy trials, with the mandatory requirement that a minimum of 4 x 18G good quality tumour core biopsies can be safely obtainable under CT or US guidance. At progression, as per RECIST 1.1 criteria, chemotherapy sensitivity signatures (RNA) and/or PDO pharmacotyping and WGS data will be used where possible to guide second-line therapy in an effort to continually provide the most active therapeutic regimens to each patient. The trial is anticipated to open Q4 2020. Conclusions: PASS-01 will provide candidate biomarkers and gene signatures that predict response to mFFX and GA, which will be further investigated in a subsequent adaptive, stratified trial.

Scheduling nab-paclitaxel combined with gemcitabine as first-line treatment for metastatic pancreatic adenocarcinoma

BackgroundNab-paclitaxel plus gemcitabine (nabP+gemcitabine) offers modest survival gains for patients with metastatic pancreatic ductal adenocarcinoma (PDAC). Sequential scheduling of nabP+gemcitabine in a PDAC mouse model improved efficacy; this hypothesis was tested in a clinical trial.MethodsPatients with previously untreated metastatic PDAC were randomised to receive nabP+gemcitabine administered either concomitantly on the same day, or sequentially, with gemcitabine administered 24 h after nabP. The primary outcome measure was progression-free survival (PFS). Secondary outcome measures were objective response rate (ORR), overall survival (OS), safety, quality of life (QoL) and predictive biomarkers.ResultsIn total, 71 patients received sequential (SEQ) and 75 concomitant (CON) treatment. Six-month PFS was 46% with SEQ and 32% with CON scheduling. Median PFS (5.6 versus 4.0 months, hazard ratio [HR] 0.67, 95% confidence interval [95% CI] 0.47–0.95, p = 0.022) and ORR (52% versus 31%, p = 0.023) favoured the SEQ arm; median OS was 10.2 versus 8.2 months (HR 0.93, 95% CI 0.65–1.33, p = 0.70). CTCAE Grade ≥3 neutropaenia incidence doubled with SEQ therapy but was not detrimental to QoL. Strongly positive tumour epithelial cytidine deaminase (CDA) expression favoured benefit from SEQ therapy (PFS HR 0.31, 95% CI 0.13–0.70).ConclusionsSEQ delivery of nabP+gemcitabine improved PFS and ORR, with manageable toxicity, but did not significantly improve OS.Clinical trial registrationISRCTN71070888; ClinialTrials.gov (NCT03529175).

Randomised phase II trial of gemcitabine and nab-paclitaxel with necuparanib or placebo in untreated metastatic pancreas ductal adenocarcinoma

BackgroundNecuparanib, a rationally engineered low-molecular-weight heparin, combined with gemcitabine/nab-paclitaxel showed an encouraging safety and oncologic signal in a phase Ib trial. This randomised multicentre phase II trial evaluates the addition of necuparanib or placebo to gemcitabine/nab-paclitaxel in untreated metastatic pancreatic ductal adenocarcinoma (PDAC). Patients and methodsEligibility included 18 years, histologically or cytologically confirmed metastatic PDAC, measurable disease and Eastern Co-Operative Oncology Group performance status of 0–1. Patients were randomly assigned to necuparanib (5 mg/kg subcutaneous injection once daily) or placebo (subcutaneous injection once daily) and gemcitabine/nab-paclitaxel on days 1, 8 and 15 of 28-day cycles. The primary end-point was median overall survival (OS), and secondary end-points included median progression-free survival, response rates and safety. ResultsOne-hundred ten patients were randomised, 62 to necuparanib arm and 58 to placebo arm. The futility boundary was crossed at a planned interim analysis, and the study was terminated by the Data Safety Monitoring Board. The median OS was 10.71 months (95% confidence interval [CI]: 7.95–11.96) for necuparanib arm and 9.99 months (95% CI: 7.85–12.85) for placebo arm (hazard ratio: 1.12, 95% CI: 0.66–1.89, P-value: 0.671). The necuparanib arm had a higher incidence of haematologic toxicity relative to placebo patients (83% and 70%). ConclusionThe addition of necuparanib to standard of care treatment for advanced PDAC did not improve OS. Safety was acceptable. No further development of necuparanib is planned although targeting the coagulation cascade pathway remains relevant in PDAC. NCT01621243

Efficacy of SBP-101, in combination with gemcitabine and nab-paclitaxel, in first-line treatment of metastatic pancreatic ductal adenocarcinoma.

710 Background: SBP-101, a polyamine metabolic inhibitor, inhibited growth in 6 human pancreatic ductal adenocarcinoma (PDA) cell lines and 3 murine xenograft tumor models of human PDA. SBP-101 monotherapy in heavily pre-treated PDA patients (> 2 prior regimens, N=4) showed a median survival of 5.9 months at the optimal dose level. Purpose: To assess the safety, tolerability, PK, and efficacy of SBP-101 in combination with gemcitabine (G) and nab-paclitaxel (A) in patients with previously untreated metastatic PDA. Methods: In a modified 3+3 dose escalation scheme, subcutaneous injections of SBP-101 were dosed at 0.2, 0.4 or 0.6 mg/kg days 1-5 of each 28-day cycle. G (1000 mg/m2) and A (125 mg/m2) were administered intravenously on Days 1, 8, and 15 of each cycle. Safety and tolerability were evaluated by clinical and laboratory assessments. PK was evaluated on day 1 of cycle 1. Efficacy was assessed by CA19-9 levels, objective response as assessed by RECIST criteria, progression-free survival (PFS) and overall survival (OS). Results: Fifteen patients have been enrolled in 3 cohorts (1: N=4, 2: N=7, 3: N=4) and received up to 6 cycles of treatment (7 subjects are ongoing in cohorts 2 and 3). The most common adverse events related to SBP-101 are fatigue (N=4), nausea (N=2) and injection site pain (N=2). There is no evidence of SBP-101-related bone marrow suppression or peripheral neuropathy. One patient in cohort 2 developed grade 3-4 reversible liver enzyme elevation. PK parameters in cohort 1 were below the limits of detection at most time points, but plasma Cmax and AUC0-t were measurable in cohorts 2 and 3. In those cohorts, CA19-9 levels decreased 76-95% in 7 of 8 evaluable subjects (1 additional subject TBD), with 5 patients achieving partial responses (4 ongoing) and 1 achieving stable disease. Median PFS and OS have not yet been reached. Conclusions: Preliminary results suggest SBP-101 is well tolerated when administered with G and A. Signals of efficacy support continued development of SBP-101 in combination first-line treatment for PDA. Clinical trial information: NCT03412799.

Randomized, double-blind, placebo-controlled phase II study of istiratumab (MM-141) plus nab-paclitaxel and gemcitabine versus nab-paclitaxel and gemcitabine in front-line metastatic pancreatic cancer (CARRIE)

Preclinical data suggest that dual blockade of the insulin-like growth factor-1 receptor (IGF-1R) and HER3 pathways has superior activity to IGF-1R blockade alone in pancreatic ductal adenocarcinoma (PDAC). We tested whether istiratumab, an IGF-1R- and ErbB3-bispecific antibody, can enhance the efficacy of standard of care (SOC) chemotherapy in patients with metastatic PDAC selected for high IGF-1 serum levels. CARRIE was an international, randomized, double-blind, placebo-controlled phase II study for patients with previously untreated metastatic PDAC. In part 1, 10 patients were evaluated for pharmacokinetics and safety. In part 2, patients with high free serum IGF-1 levels were randomized 1 : 1 to receive either istiratumab [2.8g intravenously (i.v.) every 2 weeks] or placebo combined with gemcitabine/nab-paclitaxel at approved dose schedule. The co-primary endpoints were progression-free survival (PFS) in patients with high IGF-1 levels and PFS in patients with both high serum IGF-1 levels and heregulin (HRG)+ tumors. Key secondary endpoints were overall survival (OS), objective response rate (ORR) by RECIST v.1.1, and adverse events (AEs) rate. A total of 317 patients were screened, with 88 patients randomized in part 2 (experimental arm n= 43; control n= 45). In the high IGF-1 cohort, median PFS was 3.6 and 7.3 months in the experimental versus control arms, respectively [hazard ratio (HR)= 1.88, P= 0.027]. In the high IGF-1/HRG+ subgroup (n= 44), median PFS was 4.1 and 7.3 months, respectively (HR= 1.39, P= 0.42). Median OS and ORR for the overall population were similar between two arms. No significant difference in serious or grade ≥3 AEs was observed, although low-grade AEs leading to early discontinuation were higher in the experimental (39.5%) versus control arm (24.4%). Istiratumab failed to improve the efficacy of SOC chemotherapy in this patient setting. High serum IGF-1 levels did not appear to be an adverse prognostic factor when compared with non-biomarker-selected historic controls. ClinicalTrials.gov: NCT02399137; EUDRA CT: 2014-004572-34.

Paricalcitol Addition to Chemotherapy in Patients With Previously Untreated Metastatic Pancreatic Ductal Adenocarcinoma

Paricalcitol Addition to Chemotherapy in Patients With Previously Untreated Metastatic Pancreatic Ductal Adenocarcinoma

Phase 1b study of a small molecule antagonist of human chemokine (C-C motif) receptor 2 (PF-04136309) in combination with nab-paclitaxel/gemcitabine in first-line treatment of metastatic pancreatic ductal adenocarcinoma

SummaryBackground In pancreatic ductal adenocarcinoma (PDAC), the chemokine (C-C motif) ligand 2 (CCL2)/chemokine (C-C motif) receptor 2 (CCR2) axis plays a key role in immunosuppressive properties of the tumor microenvironment, patient prognosis, and chemoresistance. This phase Ib study assessed the effects of the orally administered CCR2 inhibitor PF-04136309 in combination with nab-paclitaxel and gemcitabine in patients with previously untreated metastatic PDAC. Methods Patients received PF-04136309 twice daily (BID) continuously plus nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2) administered on days 1, 8, and 15 of each 28-day cycle. The primary objectives were to evaluate safety and tolerability, characterize dose-limiting toxicities (DLTs), and determine the recommended phase II dose (RP2D) of PF-04136309. Results In all, 21 patients received PF-04136309 at a starting dose of 500 mg or 750 mg BID. The RP2D was identified to be 500 mg BID. Of 17 patients treated at the 500 mg BID starting dose, three (17.6%) experienced a total of four DLTs, including grade 3 dysesthesia, diarrhea, and hypokalemia and one event of grade 4 hypoxia. Relative to the small number of patients (n = 21), a high incidence (24%) of pulmonary toxicity was observed in this study. The objective response rate for 21 patients was 23.8% (95% confidence interval: 8.2–47.2%). Levels of CD14 + CCR2+ inflammatory monocytes (IM) decreased in the peripheral blood, but did not accumulate in the bone marrow. Conclusions PF-04136309 in combination with nab-paclitaxel plus gemcitabine had a safety profile that raises concern for synergistic pulmonary toxicity and did not show an efficacy signal above nab-paclitaxel and gemcitabine. ClinicalTrials.gov identifier: NCT02732938.

Abstract CT152: A Phase II pilot trial of nivolumab (N) + albumin bound paclitaxel (AP) + paricalcitol (P) + cisplatin (C) + gemcitabine (G) (NAPPCG) in patients with previously untreated metastatic pancreatic ductal adenocarcinoma (PDAC)

Abstract Background: Effective therapy for the treatment of PDAC remains one of the greatest unmet oncology clinical needs. The addition of C to G and AP has shown promising clinical data in a previously reported study [J Clin Oncol 35, 2017 (suppl 4S; abstract 341)]. In preclinical work, vitamin D (Vit D) analog therapy decreases myeloid derived suppressor cells and regulatory T cells, favorably influencing the immune environment. This trial combines AP/C/G with Vit D analog P and the anti-PD-1 antibody N as a combination therapy for patients with previously untreated metastatic PDAC. This trial evaluates the efficacy and safety of NAPPCG in that patient population (NCT02754726). Methods: Eligibility criteria include Stage IV PDAC, no prior chemotherapy for systemic disease, KPS ≥ 70, and measurable disease. Doses are AP 125 mg/m2 undiluted, G 1000 mg/m2 in 250 ml of normal saline (NS), each infused over 30 minutes with C 25 mg/ m2 in 500 ml of NS infused over 60 minutes on days 1, 8, 22, and 29 of a 42-day cycle. N is given at a fixed dose of 240 mg as a 60 minute infusion on days 1, 15, and 29. P is given at a fixed dose of 25 µg IV twice weekly. Primary objective is to determine the efficacy of the combination for patients with previously untreated metastatic PDAC through determining CR, ORR, PFS, and OS. The secondary objective is to evaluate safety in patients with previously untreated metastatic PDAC. Results: Trial was initiated May 2016 and 25 patients have been enrolled in the study and 24 are evaluable (baseline and ≥1 follow up CT scan). Most common drug-related grade (Gr) 3-4 adverse events (AE’s), are thrombocytopenia 76% (gr 3 = 44%, gr 4 = 32%) with no serious bleeding events, anemia 44% (gr 3 = 44%, gr 4 = 0%), and colitis 12% (gr 3 = 12%, gr 4 = 0%). By RECIST 1.1 criteria, response is 19 PR, 2 SD, 2 PD, yielding an 83% ORR. Median PFS is 8.17 months. Median OS is 15.3 months. Conclusions: Although a small study, the high response rate is encouraging. The clinical trial is now being expanded. Supported by grants from the Seena Magowitz Foundation, Mattress Firm, Bristol Myers Squibb, and SU2C. Citation Format: Erkut H. Borazanci, Gayle Jameson, Ronald Lee Korn, Lana Caldwell, Karen Ansaldo, Kristin Hendrickson, Katie Marceau, Kevin Gosselin, Daniel D. Von Hoff. A Phase II pilot trial of nivolumab (N) + albumin bound paclitaxel (AP) + paricalcitol (P) + cisplatin (C) + gemcitabine (G) (NAPPCG) in patients with previously untreated metastatic pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT152.

Phase 1 dose-escalation study of momelotinib, a Janus kinase 1/2 inhibitor, combined with gemcitabine and nab-paclitaxel in patients with previously untreated metastatic pancreatic ductal adenocarcinoma

SummaryPurpose Preclinical evidence suggests the importance of Janus activating kinase (JAK) and TANK-binding kinase 1 (TBK1) in pancreatic ductal adenocarcinoma (PDAC). We evaluated the safety and efficacy of momelotinib (MMB), a JAK1/2 inhibitor with additional activity against TBK1, plus albumin-bound paclitaxel + gemcitabine (nab-P + G), in patients with previously untreated metastatic PDAC. Experimental Design Patients were enrolled into five cohorts of increasing doses of MMB between 100 and 200 mg administered once or twice daily in combination with nab-P + G in 28-day cycles to determine maximum tolerated dose (MTD). Safety, efficacy, pharmacokinetics, and pharmacodynamics were assessed for all patients. Results Twenty-five patients were enrolled. Dose-limiting toxicities of Grade 3 diarrhea occurred in 1 patient each in the 100 and 200 mg MMB once-daily dose groups. MTD was not reached. The 200 mg MMB twice-daily was the maximum administered dose. Objective response rate was 28% (all partial responses), and 13 (52%) patients had a best response of stable disease. The most common adverse events (AEs) were fatigue (80%), nausea (76%), and anemia (68%). Grade 3 or 4 AEs, most commonly neutropenia (32%), were reported by 88% of patients, of which 44% were considered related to MMB. Pharmacokinetic analyses showed MMB concentrations were too low for TBK1 inhibition. Conclusions MMB was safe and well tolerated in combination with nab-P + G. As no OS or PFS benefit vs nab-P + G was apparent in context of suboptimal engagement of the target TBK1, this study does not support further development of MMB as a first-line therapy in pancreatic cancer.