Responses to immune checkpoint inhibition among MSI-H pancreatic ductal adenocarcinoma: A multi-institutional case series

4145

Background: Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer death. Outcomes remain poor, due to irresectability at diagnosis for many and sub-optimal responses to systemic therapy. Cytotoxic chemotherapy remains the standard of care. High microsatellite instability (MSI-H) predicts response to immune checkpoint inhibition (ICI) in many cancers. Detecting high MSI is rare in PDAC (incidence <2%), but case reports demonstrate potential therapeutic benefit with ICI. Here, we present multi-institutional data to characterize the clinical behavior of MSI-H PDAC, with special attention to response to ICI. Methods: Cases of MSI-H PDAC were obtained by reviewing data of all PDAC patients from our tertiary cancer center who had undergone genomic sequencing by one commercially available platform. The resulting cohort was supplemented with MSI-H PDAC cases identified by GI oncology specialists at multiple institutions. De-identified patient data were compiled and analyzed. Results: 15 MSI-H PDAC patients were identified. 20% had stage II disease at diagnosis, 27% stage III, and 53% stage IV. 73% of patients received ICI (n=11); 40% as 1st line and 33% as 2nd line. These patients demonstrated 100% overall response rate; 45% complete response (1 pathologic CR, 4 radiographic CR) and 55% partial response. No patient that received ICI had lost response or died after a median follow-up of 18 months (range 6-89 mos). 1 patient had oligoprogression of a single hepatic lesion after 7 mos that was then irradiated; this patient retained radiographic CR for 17 subsequent mos (ongoing). In this cohort, we observe poor responses to cytotoxic chemotherapy. In total, 12 regimens were trialed among 9 patients. Overall response rate was 0%. 42% achieved disease stability, with median duration of response of 2 mos; only 2 cases maintained disease stability for >5 mos. 4 patients did not receive ICI; all patients died, with a median survival of 7.5 mos. Conclusions: MSI-H PDAC represents a rare but important subtype of PDAC with unique clinical behavior. Given its rarity, large-scale analyses and trials are unlikely to be performed, making case series such as ours crucial. In our cohort, we observe impressive, durable responses to ICI, along with very poor responses to cytotoxic chemotherapy. Our data argues for consideration of ICI in any patient presenting with MSI-H PDAC, including in the first-line and neoadjuvant settings.

KRAS wild-type pancreatic ductal adenocarcinoma: Molecular and therapeutic opportunities

4130

Background: KRAS is mutationally activated in over 90% of pancreatic ductal adenocarcinoma (PDAC). Compared to pts with KRAS mutation, KRAS wild-type (wt) PDAC seem to have better response to therapy and may harbor potentially actionable molecular alterations. Here, we analyze the molecular profile and clinical outcome of a cohort of pts with KRAS wt PDAC. Methods: A retrospective review was conducted on pts with PDAC who underwent CLIA-certified Next Generation Sequencing (NGS) testing at Mayo Clinic between December 1, 2018 and December 1, 2021. Pts with KRAS wt PDAC with available reports were included. Their genomic drivers, RNA expression, demographics, disease characteristics, therapies offered, and clinical outcome data were collected. The study was approved by the institutional IRB. Results: Of the 241 eligible pts, 8% (19) has KRAS wt PDAC. Among those, 2 pts had no mutation identified by the gene/molecular panel used. Of the 17 pts (89%) with identified alterations, mutations found in ³ 2 pts were TP53 (53%), CDKN2A (16%) and CDKN2B/ERBB2/PTEN/MSH3/RNF43/FBXW7/KMT2D/GNAS (11% each). Chromosomal rearrangements were identified in 5 (26%): CADPS2-BRAF, GP2-ERBB2, PTPRK-RSPO3, EML4-NTRK3 and TFG-MET. RNA expression results were available in 12 pts: common overexpression were ERBB2 (27%) and MET/NRAS/MYC/CCDN1/CCNE1/AR (18% each); and the under-expression MGMT (18%). Among the 13 pts with available MSI status via NGS, 2 (11%) were MSI-high (both had high TMB [28.4 and 23.7 m/MB]) while all others were TMB < 10 m/MB. The median age at diagnosis was 61 years (68% males). 8/19 (42%) were Stage IV at diagnosis with 15/19 (79%) pts ultimately diagnosed with metastatic disease. Among metastatic pts, median lines of treatment received was 2.5 (range:0-4). 4 pts received FOLFIRINOX (FFX), 2 gemcitabine/ nab-paclitaxel (GP) and tumor response were comparable to previously reported results. 1 received 1st-line pembrolizumab and remained on therapy at the time of analysis. The median length of follow up from diagnosis was 29 months. A patient with TFG-MET re-arrangement previously progressed on FFX and GP was treated using a MET inhibitor, and achieved significant CA19-9 drop and pancreas tumor shrinkage at 1st restaging, with ongoing response. Conclusions: The molecular profile of KRAS wt PDAC is highly heterogeneous and difficult to generalize. Novel approaches (e.g., basket trials) are needed to develop therapy for this rare PDAC subgroup.

ACCRU-GI-2008: A phase II randomized study of atezolizumab (Atezo) plus a multi-kinase inhibitor (MKI) versus MKI alone in patients with unresectable advanced hepatocellular carcinoma (aHCC) who previously received atezolizumab plus bevacizumab (Bev)

TPS4170

Background: IMbrave150 is the first study demonstrating the benefit of anti-PDL1 in the frontline treatment of aHCC, and established Atezo/Bev as a new 1st line standard for aHCC. There is currently limited evidence to guide subsequent therapy for aHCC patients progressing on Atezo/Bev. ACCRU-GI-2008 is designed to determine the benefit of continuing Atezo into 2nd line and the safety of Atezo plus a MKI in patients with aHCC who previously received Atezo/Bev. The study is being conducted across 12 centers in the United States (ClincalTrials.gov#: NCT05168163). Methods: This study utilizes a 2:1 randomized phase II design where eligible patients will receive either Atezo/MKI (experimental arm) or MKI alone (control). Patients will be stratified according to the MKI choice (cabozantinib or lenvatinib, per physician’s decision), etiology of HCC (viral vs. non-viral) and alpha-fetoprotein level ( < 400 vs. > = 400 ng/mL). The major eligibility criteria are histological/cytological diagnosis or clinical diagnosis of HCC per the AASLD or WASL 2018 guidelines, has advanced disease not amendable to curative treatment, previously received and progressed on Atezo/Bev, has received only 1 previous line of systemic therapy (2nd line only), ECOG PS 0-1, Child Pugh Class A, adequate organ reserves and RECIST v1.1 measurable disease; previous MKI for advanced disease is excluded. The primary endpoints are overall survival (OS) and progression free survival (PFS). A total sample size of 122, with 89 PFS events, we will have 80% power to detect an improvement in median PFS from 4 to 7 months, assuming a one-sided significance level of 0.05. With approximately 84 deaths, we will have 80% power to detect an improvement in median OS from 10 to 18 months, assuming a one-sided significance level of 0.05. The overall one-sided significance level, for the study, is 0.1. An OS interim analysis will be conducted at 89 PFS events. Secondary endpoints include objective response, duration of response, and adverse events. Archival tumor and serial blood samples will be collected to evaluate for potential prediction biomarkers and mechanisms of sensitivity/resistance. Baseline and on-treatment tumor biopsy specimens will also be collected from the initial 10 patients of each arm. The study is approved by the ethics committee and enrollment to the study will be underway by Q2/3 2022. Clinical trial information: NCT05168163.

ELU-FRα-1: A study to evaluate ELU001 in patients with solid tumors that overexpress folate receptor alpha (FRα)

TPS3158

Background: ELU001 is a novel, first-in-class, new molecular entity described as a C’Dot Drug Conjugate (CDC). ELU001 consists of ̃12 folic acid targeting moieties and ̃22 exatecan topoisomerase-1 inhibitor payloads on Cathepsin-B cleavable linkers covalently bound to the surface of each silicon core/polyethylene glycol C’Dot nanoparticle. CDCs are small in size (̃6 nm), have a greater ability to penetrate into and through tumors as compared to ADCs, and are rapidly eliminated by the kidneys. The rapid systemic elimination is expected to lead to less toxicity than is observed with targeting platforms like ADCs that have a longer half-life in circulation. ELU001’s high avidity is believed to promote internalization into FRα overexpressing cancer cells, selectively delivering it’s ̃22 molecules of payload. The first-in-human clinical trial, ELU-FRα-1, is currently recruiting patients that have advanced, recurrent or refractory FRα overexpressing tumors considered to be topoisomerase 1 inhibitor-sensitive based on the literature, and, in the opinion of the Investigator, have no satisfactory therapeutic options available. Methods: This is a Phase 1 / 2 multicenter, open label clinical trial with two parts: Part 1 Dose Escalation and Part 2 Tumor Group Expansion Cohort(s). In Part 1, patients with cancer types with a high likelihood of having FRα overexpressing tumors based on historical data, (specifically, ovarian, endometrial, colorectal, gastric, gastroesophageal junction, triple negative breast, or non-small cell lung cancers, or cholangiocarcinoma), will be enrolled to the study. Patients will receive ELU001 on a weekly dose regimen (QW) (once a week for 3 weeks, 1 week rest) or every other week dose regimen (Q2W, with no rest between cycles). Retrospective analysis of FRα expression will be determined. Part 2 uses a Simon’s Two-Stage design to evaluate 4-6 tumor group expansion cohorts, each consisting of patients with specific tumor types (to be identified based on emerging data) that overexpress FRα (prospectively determined prior to enrollment). The primary objective for Part 1 is to identify the MTD/RP2D and for Part 2 is ORR. Dose Escalation will recruit about 25 patients per dose regimen (QW or Q2W). Dose Expansion will recruit about 15 patients per tumor group expansion cohort. Secondary objectives are anti-tumor activity (DOR, PFS, TFST, PFS2, OS), frequency, severity and tolerability of adverse events, PK, ADA, and FRα expression assessments. The study is actively enrolling in the US – Cohorts 1-2 have been completed without DLT. Enrollment to Cohort 3 began in December 2021. Clinical trial information: NCT05001282 .

A two-part, phase II, multi-center study of the ERK inhibitor ulixertinib (BVD-523) for patients with advanced malignancies harboring MEK or atypical BRAF alterations (BVD-523-ABC)

TPS3172

Background: Ulixertinib (BVD-523) is a small molecule inhibitor of extracellular signal-regulated kinases 1/2 (ERK1/2) in development as a novel anti-cancer drug. Early clinical data demonstrated anti-tumor activity, especially for patients with tumors harboring atypical BRAF or MEK1/2 alterations (Sullivan et al., Cancer Discov. 2018;8(2):184-195). Atypical BRAF (non-V600) alterations can be categorized according to characteristics of molecular signaling (Class II or III), are seen in approximately 3% of all human cancers, and there are currently no approved therapies for this indication. Similar to atypical BRAF alterations, the incidence of MEK1/2 alterations are rare in human tumors (< 1 %). Preclinical data have demonstrated activity of ulixertinib in MEK mutant models. Ulixertinib has FDA fast-track designation for patients with solid tumors, other than CRC, with specific BRAF mutations (G469A, L485W, or L597Q). Designed with intent to register, the BVD-523-ABC clinical trial will continue evaluation of ulixertinib in patients with tumors harboring any atypical BRAF or MEK1/2 alteration (NCT04488003). Methods: This multi-center, phase II study, will be conducted in two parts and assess the clinical benefit, safety, pharmacokinetics, and pharmacodynamics of ulixertinib in patients with advanced malignancies. Ulixertinib will be administered at the RP2D of 600 mg BID for 28-day treatment cycles. Eligible patients will have locally advanced or metastatic cancer which progressed following standard systemic therapies, or for which the patient is not a candidate or refused systemic therapy. Planned correlative analyses include reverse phase protein array and transcriptomics of tumor tissue. Part A is open-label and tumor agnostic, except for group 4 and 6 (CRC patients only). Patients will enroll into one of six groups based on BRAF (groups 1-4) or MEK1/2 (groups 5-6) tumor alteration (38 patients per group). Overall response rate (ORR) is the primary endpoint for Part A, with secondary endpoints including duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Part B is tumor histology specific. Patients will be randomized to receive either ulixertinib or physician's choice of treatment in a 2:1 ratio. Up to three specified tumor histologies will be defined, guided by available Part A data (n = 80-100 per histology). The primary endpoint of Part B is PFS, and secondary endpoints include OS, ORR, and DOR. This study has enrolled 43 patients of the planned 228 in Part A at the time of abstract submission. Clinical trial information: NCT04488003.

Understanding Suboptimal Response to Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs), as a novel class of anticancer therapy, can be more efficacious and less toxic than chemotherapy, but their clinical success is confined to certain tumor types. Elucidating their targets, mechanisms and scope of action, and potential synergism with chemotherapy and/or targeted therapies are critical to widen their clinical indications. Treatment response to an ICI targeting programmed death-1 (anti-PD-1) is sought to be understood here by conducting a preplanned correlative analysis of a phase II clinical trial in patients with small bowel adenocarcinoma (SBA). The cytolytic capacity of circulating immune cells in cancer patients using a novel ex vivo cytotoxicity assay is evaluated, and the utility of circulating biomarkers is investigated to predict and monitor the treatment effect of anti-PD-1. Baseline expression of Bim and NKG7 and upregulation of CX3CR1 in circulating T cells are associated with the clinical benefit of anti-PD-1 in patients with SBA. Overall, these findings suggest that the frequency and cytolytic capacity of circulating, effector immune cells may differentiate clinical response to ICIs, providing a strong rationale to support immune monitoring using patient peripheral blood.

Malignant glioma subset from actuate 1801: Phase I/II study of 9-ING-41, GSK-3β inhibitor, monotherapy or combined with chemotherapy for refractory malignancies

Background

GSK3β serine/threonine kinase regulates metabolism and glycogen biosynthesis. GSK3β overexpression promotes progression and resistance through NF-κB and p53 apoptotic pathways. GSK3β inhibits immunomodulation by downregulating PD-L1 and LAG-3 checkpoints and increasing NK and T-cell tumor killing. 9-ING-41, a small-molecule, selective GSK3β inhibitor, showed preclinical activity in chemo-resistant PDX glioblastoma models, including enhanced lomustine antitumor effect.

Methods

Refractory malignancies (n = 162) were treated with 9-ING-41 monotherapy (n = 65) or combined with 8 cytotoxic regimens after prior exposure (NCT03678883). Recurrent gliomas (n = 18) were treated with 9-ING-41 IV TIW q21day cycles at 3.3, 5, 9.3, 15 mg/kg, as monotherapy or combined with lomustine 30 mg/m² PO weekly q84day cycles. Primary objective was safety.

Results

RP2D of 15 mg/kg IV TIW was confirmed across all 9 regimens, no accentuated chemotherapy toxicity noted. Glioma subtypes included: 13 glioblastoma, 2 anaplastic astrocytomas, 1 anaplastic oligodendroglioma, 1 astrocytoma. Median age 52 (30-69) years; 6 female, 12 male; median ECOG 1 (0-2); median recurrences 3 (1-6). All received upfront radiation/temozolomide (18/18), plus salvage nitrosoureas (15/18), bevacizumab (8/18), TTFields (6/18), or immunotherapy (4/18). IDH/mutation(3/18); 1p19q/codeletion(1/18); MGMT/methylated(1/18). Four received 9-ING-41 monotherapy, 14 concurrent with lomustine. No severe toxicities were attributed to 9-ING-41, only mild vision changes (9/18, 50%), or infusion reactions (4/18, 22%). Lomustine-related toxicities: G3/4 thrombocytopenia (3/14, 21%), G1/2 fatigue (4/14, 28%). Median days on therapy was 55 (4-305); 1 partial response (>50%) was noted. Median OS was 5.5 (95% CI: 2.8-11.4) months and PFS-6 was 16.7%.

Conclusion

9-ING-41 plus/minus lomustine is safe and warrants further study in glioma patients.

A phase I study of pharmacokinetic (PK)-driven sequential dosing of rucaparib (RUB) with irinotecan liposome (nal-IRI) and fluorouracil (5FU) in metastatic gastrointestinal (mGI) and pancreas (PANC) cancers

563

Background: RUB is an oral PARP1,2,3 inhibitor that demonstrated efficacy in patients (pts) with ovarian and prostate cancers harboring deleterious BRCA mutations. RUB exerts synergistic anti-tumor effect with IRI preclinically though the combination has overlapping toxicities. We previously published on the population PK of nal-IRI (Adiwijaya, Ma et al, Clin Pharm Ther 2017). We conducted a phase I study to evaluate a novel sequential dosing of RUB with nal-IRI/5FU in mGI cancer pts. Methods: Eligible pts had incurable mGI cancer previously received > 1 line of therapy (rx), ECOG PS 0-1, had RECIST measurable disease, adequate organ reserves and not received IRI for metastatic disease. Previous PARPi rx was excluded. The endpoints included dose limiting toxicity (DLT), maximum tolerated dose (MTD) and toxicity profile. The dose escalation utilized the 3+3 design. RUB was given oral bid on Day 4 to 13 and 18 to 27 with nal-IRI i.v. and 5FU i.v. 2400 mg/m2 over 46 hr on Day 1 and 15, every 28 day. Planned dose levels were RUB 400 mg/nal-IRI 50 mg/m2 (DL1), 400 mg/70 mg/m2 (DL2) and 600 mg/70 mg/m2 (DL3). Adverse events (AEs) were scored per CTCAE v4.03. Molecular profile was evaluated by CLIA-certified NGS testing. Results: Eighteen pts including 11 colorectal (CRC), 6 PANC, 1 gastroesophageal (GE) were enrolled and 12 were evaluable for DLTs. DL2 was not tolerable (DLT: G3 diarrhea, nausea and vomiting) and DL2A was added (RUB 600 mg/nal-IRI 50 mg/m2). DL2A enrolled 6 pts with no DLT and was determined as the MTD. Of DLT-evaluable pts, G3 and worse treatment-related AEs from all cycles were diarrhea (33%), fatigue (25%), leukopenia (25%), neutropenia (25%), anemia (8%) and nausea (8%). Four of 12 response evaluable pts had partial response: 2 CRC (1 had ATM mut), 1 PANC ( ATM mut), 1 GE ( BRCA2 mut) whilst 3 responders previously had platinum (PLA). Five pts had stable disease beyond 16 weeks (range 18.9 to 100.7 weeks), and all had prior PLA. Conclusions: The study successfully determined the MTD of RUB in combination with nal-IRI and 5FU. Encouraging efficacy was observed in PLA-treated mGI cancers including responses in those harboring ATM and BRCA alterations. The study is proceeding to evaluate the efficacy of the combination in metastatic pancreas cancer pts with and without BRCA1/2 or PALB2 alterations. Clinical trial information: NCT03337087.

CTNI-13. MALIGNANT GLIOMA SUBSET FROM ACTUATE 1801 PHASE 1/2 STUDY OF 9-ING-41, A GLYCOGEN SYNTHASE KINASE 3 BETA (GSK-3β) INHIBITOR, AS A SINGLE AGENT AND COMBINED WITH CHEMOTHERAPY REFRACTORY

BACKGROUND

GSK3β serine/threonine kinase regulates metabolism and glycogen biosynthesis. GSK3β overexpression promotes tumor progression and resistance through NF-κB and p53 apoptotic pathways. GSK3β inhibits immunomodulation by downregulating checkpoints, e.g. PD-L1 and LAG-3, and increasing NK and T-cell mediated tumor killing. 9-ING-41 is a small-molecule, potent, selective GSK3β inhibitor with preclinical activity. In chemoresistant PDX glioblastoma models, 9-ING-41 enhanced lomustine antitumor effect.

METHODS

Patients with refractory malignancies were treated with 9-ING-41 monotherapy (n=65) or combined with 8 cytotoxic regimens after prior exposure (n=162) in the first-in-human study (NCT03678883). The recurrent gliomas subset was treated with 9-ING-41 monotherapy IV TIW q21day cycles at 3.3, 5, 9.3, 15mg/kg, or combined with lomustine 30 mg/m² PO weekly q84day cycles. Primary objective was safety and tolerability.

RESULTS

An RP2D of 15mg/kg IV TIW was confirmed across all 9 regimens, no accentuation of chemotherapy toxicity noted. Of 18 glioma patients enrolled, 13 were glioblastoma, 2 anaplastic astrocytomas, 1 anaplastic oligodendroglioma, and 1 diffuse astrocytoma; 6 female, 12 male; median age 52 (30-69) years; median ECOG was 1 (0-2). All received initial radiation and temozolomide (18/18), prior salvage therapies included nitrosoureas (15/18), bevacizumab (8/18), TTFields (6/18), checkpoint inhibitor (4/18). Median recurrences 3 (1-6). NGS alterations included: IDH/wildtype (11), IDH/mutation(3); 1p19q/codeletion(10); MGMT/unmethylated(11), MGMT/methylated(1); EGFR/amplification(6), EGFR/v3mutation(3), TERT/mutation(6), PTEN/loss(3), NF1/rearrangement(2), ATRX/loss (2), TP53/mutation(4), CDKN2A/deletion(2), RB1/loss(1), PALB2/mutation(10). Four patients received 9-ING-41 monotherapy, 14 concurrently treated with lomustine. No SAEs or grade 3/4 AEs attributed to 9-ING-41 noted, only G1/2 vision changes (9/18, 50%), infusion reactions (4/18, 22%). Lomustine-related toxicities included G3/4 thrombocytopenia (3/14, 21%), and G1/2 fatigue (4/14, 28%). Median therapy duration was 55 (4-305); 1 partial response ( &gt;50%) noted with 9-ING-41/lomustine. Median PFS and OS were 1.9 (0.3-11.1) and 6.0 (1.6-16.6) months, respectively.

CONCLUSIONS

9-ING-41 plus/minus lomustine is safe and warrants further study in glioma patients.

Neoadjuvant Chemotherapy Switch in Borderline Resectable/Locally Advanced Pancreatic Cancer

Background

Neoadjuvant chemotherapy (NAC) is an integral part of preoperative treatment for patients with borderline resectable/locally advanced (BR/LA) pancreatic ductal adenocarcinoma (PDAC). The identification of a chemotherapeutic regimen that is both effective and tolerable is critical for NAC to be of oncologic benefit. After initial first-line (FL) NAC, some patients have lack of response or therapeutic toxicities precluding further treatment with the same regimen; optimal decision making regarding this patient population is unclear. Chemotherapy switch (CS) may allow for a larger proportion of patients to undergo curative-intent resection after NAC.

Methods

We reviewed our surgical database for patients undergoing combinatorial NAC for BR/LA PDAC. Variant histologic exocrine carcinomas, intraductal papillary mucinous neoplasm-associated PDAC, and patients without research consent were excluded.

Results

Overall, 468 patients with BR/LA PDAC receiving FL chemotherapy were reviewed, of whom 70% (329/468) continued with FL chemotherapy followed by surgical resection. The remaining 30% (139/468) underwent CS, with 72% (100/139) of CS patients going on to curative-intent surgical resection. Recurrence-free survival (RFS) and overall survival (OS) were not significantly different between the resected FL and CS cohorts (30.0 vs. 19.1 months, p = 0.13, and 41.4 vs. 36.4 months, p = 0.94, respectively) and OS was significantly worse in those undergoing CS without subsequent resection (19 months, p < 0.0001). On multivariable analysis, carbohydrate antigen (CA) 19-9 and pathologic treatment responses were predictors of RFS and OS.

Conclusion

CS in patients undergoing NAC for BR/LA pancreatic cancer does not incur oncologic detriment. The incorporation of CS into NAC treatment sequencing may allow a greater proportion of patients to proceed to curative-intent surgery.

Intact SMAD-4 is a predictor of increased locoregional recurrence in upfront resected pancreas cancer receiving adjuvant therapy

BACKGROUND

Previous reports suggest that intact SMAD4 expression is associated with a locally aggressive pancreas cancer phenotype. The objectives of this work were to determine the frequency of intact SMAD4 and its association with patterns of recurrence in patients with upfront resected pancreas cancer receiving adjuvant therapy.

METHODS

A tissue microarray was constructed using resected specimens from patients who underwent upfront surgery and adjuvant gemcitabine with no neoadjuvant treatment for pancreas cancer. SMAD4 expression was determined by immunohistochemical staining. Associations of SMAD4 expression and clinicopathologic parameters with clinical outcomes were evaluated using Cox proportional hazard models.

RESULTS

One hundred twenty-seven patients were included with a median follow up of 5.7 years. Most patients had stage ≥ pT3 tumors (75%) and pN1 (68%). All patients received adjuvant gemcitabine, and 79% of patients received adjuvant chemoradiotherapy. Ten (8%) patients had intact SMAD4 expression. Grade was the only clinicopathologic parameter statistically associated with SMAD4 expression (P=0.05). Median overall survival was 2.1 years. On univariate analysis, SMAD4 expression was associated with increased locoregional recurrence (hazard ratio 7.0, P<0.01, 95% confidence interval: 2.8-18.0) but not distant recurrence (P=0.06) or overall survival (P=0.73). On multivariable analysis, SMAD4 expression (hazard ratio 9.6, P<0.01, 95% confidence interval: 3.7-24.8) and adjuvant chemoradiotherapy (hazard ratio 0.3, P=0.01, 95% confidence interval: 0.1-0.8) were associated with higher and lower locoregional recurrence, respectively.

CONCLUSIONS

In patients with upfront resected pancreas cancer, SMAD4 expression was associated with an increased risk of locoregional recurrence. Prospective evaluation of the frequency of SMAD4 expression and validation of its predictive utility is warranted.

The role of microbiome in pancreatic cancer

Recent studies of the human microbiome have offered new insights into how the microbiome can impact cancer development and treatment. Specifically, in pancreatic ductal adenocarcinoma (PDAC), the microbiota has been shown to modulate PDAC risk, contribute to tumorigenesis, impact the tumor microenvironment, and alter treatment response. These findings provide rationale for further investigations into leveraging the microbiome to develop new strategies to diagnose and treat PDAC patients. There is growing evidence that microbiome analyses have the potential to become easily performed, non-invasive diagnostic, prognostic, and predictive biomarkers in pancreatic cancer. More excitingly, there is now emerging interest in developing interventions based on the modulation of microbiota. Fecal microbiota transplantation, probiotics, dietary changes, and antibiotics are all potential strategies to augment the efficacy of current therapeutics and reduce toxicities. While there are still challenges to overcome, this is a rapidly growing field that holds promise for translation into clinical practice and provides a new approach to improving patient outcomes.

FGFR Inhibitor Toxicity and Efficacy in Cholangiocarcinoma: Multicenter Single-Institution Cohort Experience

Cholangiocarcinomas (CCA) are a group of heterogeneous tumors arising from the biliary epithelia. Significant sequencing efforts have provided further insights into the molecular mechanisms of this disease including fibroblast growth factor receptor (FGFR) alterations, which occurs in approximately 15%-20% of intrahepatic CCAs. Herein, we describe the FGFR inhibitor (FGFRi)-associated treatment toxicity and cancer-specific outcomes from a multicenter single-institution cohort.

METHODS

This is a retrospective study of patients with CCA and known FGFR alterations treated with FGFRi. We describe the toxicity and efficacy in patients treated at Mayo Clinic between January 2010 and December 2020.

RESULTS

Our group identified 61 patients with advanced or metastatic CCA, 19 males (31%) and 42 females (69%), harboring FGFR alterations who received FGFRi. The most common grade 1 or higher adverse events for all patients included fatigue (92%), AST elevations (78%), anemia (80%), decreased platelet count (63%), and hyperphosphatemia (74%). Median progression-free survival on FGFRi was 5.8 months for all patients (95% CI, 4.9 to 9.0). Females had significantly longer progression-free survival at 6.9 months (95% CI, 5.2 to 11.8) on FGFRi compared with males at 4.9 months (95% CI, 2.8 to not estimable; P = .038).

CONCLUSION

FGFRi are well tolerated with clinical efficacy. With the recent approval of FGFRi by the US Food and Drug Administration and ongoing clinical trials for new FGFRi, understanding outcomes and toxicity associated with these medications is important for precision oncology.

A phase I study of the anaplastic lymphoma kinase inhibitor ceritinib in combination with gemcitabine-based chemotherapy in patients with advanced solid tumors

In this phase I, dose-escalation study, we sought to determine the maximum tolerated dose (MTD) of the anaplastic lymphoma kinase/c-ROS oncogene 1 receptor (ALK/ROS1) inhibitor ceritinib in combination with gemcitabine-based chemotherapy in patients with advanced solid tumors. Secondary objectives were characterization of the safety profile, pharmacokinetics and preliminary efficacy of these combinations, and identification of potential biomarkers of efficacy. Ceritinib was combined with gemcitabine (Arm 1), gemcitabine/nab-paclitaxel (Arm 2) or gemcitabine/cisplatin (Arm 3). Drug concentrations in plasma were measured by tandem mass spectrometric detection (LC-MS/MS). We analyzed archival tumor tissue for ALK, ROS1, hepatocyte growth factor receptor (c-MET) and c-Jun N-terminal kinase (JNK) expression by immunohistochemistry. Arm 2 closed early secondary to toxicity. Twenty-one patients were evaluable for dose-limiting toxicity (DLT). There was one DLT in Arm 1 (grade 3 ALT increase) and three DLTs in Arm 3 (grade 3 acute renal failure, grade 3 thrombocytopenia, grade 3 dyspnea). The MTD of ceritinib was determined to be 600 mg (Arm 1) and 450 mg orally daily (Arm 3). Main toxicities were hematologic, constitutional and gastrointestinal as expected by the chemotherapy backbone. The apparent clearance for ceritinib decreased substantially after repeated dosing; cisplatin did not significantly affect the pharmacokinetics of ceritinib. The overall response rate was 20%; the median progression-free survival was 4.8 months. Three out of five response-evaluable cholangiocarcinoma patients had clinical benefit. Increased expression of c-MET was associated with a lack of clinical benefit. Ceritinib in combination with gemcitabine and gemcitabine/cisplatin has a manageable toxicity profile. Further development of this strategy in tumors with ALK or ROS1 fusions is warranted.

Synergistic Pharmacodynamic Effects of Gemcitabine and Fibroblast Growth Factor Receptor Inhibitors on Pancreatic Cancer Cell Cycle Kinetics and Proliferation

Median survival of pancreatic ductal adenocarcinoma cancer (PDAC) is 6 months, with 9% 5-year survival. Standard-of-care gemcitabine (Gem) provides only modest survival benefits, and combination therapies integrating novel targeted agents could improve outcomes. Fibroblast growth factor (FGF) receptors (FGFRs) play important roles in PDAC growth and invasion. Therefore, FGFR inhibitors (FGFRi) merit further investigation. Efficacy of Gem combined with NVP-BGJ398, a pan-FGFRi, was investigated in multiple PDAC cell lines exposed to the drugs alone and combined. Cell cycle distribution and cell numbers were quantified over time. Two pharmacodynamic models were developed to investigate Gem/BGJ398 interactions quantitatively: a drug-mediated cell proliferation/death model, and a drug-perturbed cell cycle progression model. The models captured temporal changes in cell numbers, cell cycle progression, and cell death during drug exposure. Simultaneous fitting of all data provided reasonable parameter estimates. Therapeutic efficacy was then evaluated in a PDAC mouse model. Compared with Gem alone, combined Gem + FGFRi significantly downregulated ribonucleotide-diphosphate reductase large subunit 1 (RRM1), a gemcitabine resistance (GemR) biomarker, suggesting the FGFRi inhibited GemR emergence. The cell proliferation/death pharmacodynamic model estimated the drug interaction coefficient ψ _death = 0.798, suggesting synergistic effects. The mechanism-based cell cycle progression model estimated drug interaction coefficient ψ _cycle = 0.647, also suggesting synergy. Thus, FGFR inhibition appears to synergize with Gem in PDAC cells and tumors by sensitizing cells to Gem-mediated inhibition of proliferation and cell cycle progression. SIGNIFICANCE STATEMENT: An integrated approach of quantitative modeling and experimentation was employed to investigate the nature of fibroblast growth factor receptor inhibitor (FGFRi)/gemcitabine (Gem) interaction, and to identify mechanisms by which FGFRi exposure reverses Gem resistance in pancreatic cancer cells. The results show that FGFRi interacts synergistically with Gem to sensitize pancreatic cancer cells and tumors to Gem-mediated inhibition of proliferation and cell cycle progression. Thus, addition of FGFRi to standard-of-care Gem treatment could be a clinically deployable approach to enhance therapeutic benefit to pancreatic cancer patients.

Malignant glioma subset from Actuate 1801: A phase 1/2 study of 9-ING-41, a glycogen synthase kinase 3 beta (GSK-3β) inhibitor, as a single agent and combined with chemotherapy, in patients with refractory hematologic malignancies or solid tumors

2051

Background: GSK-3β, a serine/threonine kinase, is a key regulator of metabolism and glycogen biosynthesis. GSK-3β aberrant overexpression promotes tumor progression and chemotherapy resistance through NF-κB and p53-mediated apoptotic pathways. GSK-3β inhibition impacts immunomodulation through downregulation of checkpoints, such as PD-L1 and LAG-3, and increasing NK and T-cell mediated killing of tumor cells. 9-ING-41 is a small-molecule potent selective GSK-3β inhibitor with preclinical antitumor activity against several tumor types. In chemoresistant PDX models of glioblastoma (GBM), 9-ING-41 enhanced the antitumor effect of CCNU and CPT-11. Methods: In the first-in-human study (NCT03678883), patients (pts) with refractory malignancies received 9-ING-41 monotherapy (n = 65) or in combination with one of 8 cytotoxic regimens after prior treatment with the same chemotherapy (n = 162). We report the subset of pts with recurrent gliomas treated with 9-ING-41 monotherapy IV twice a week in 21-day cycles at different dose levels (3.3, 5, 9.3, 15mg/kg), or in combination with lomustine 30 mg/m² orally once weekly in 84-day cycles. Primary objective was safety and tolerability. Results: An RP2D of 15mg/kg IV was confirmed across all 9 regimens, no accentuation of chemotherapy-related toxicity noted. Of 18 glioma patients enrolled, 13 were GBM, 2 anaplastic astrocytomas, 1 diffuse astrocytoma, and 1 anaplastic oligodendroglioma. Four patients received single agent 9-ING-41, 14 treated concurrently with lomustine. Demographics: 6 female, 12 male; median age 52 (30-69) years; median ECOG was 1 (0-2). All received first-line radiation and temozolomide (18/18), prior therapies for recurrences included nitrosoureas (15/18), bevacizumab (8/18), TTFields (6/18), immune checkpoint inhibitor (4/18). Median recurrences 3 (1-6). Genomic alterations from available NGS reports included: IDH WT (11), IDH mutation (3), MGMT promoter unmethylated (11), MGMT promoter methylated (1), 1p19q co-deletion (10), EGFR amplification (6), EGFR v3 mutation (3), TERT promoter mutation (6), PTEN loss (3), NF1 rearrangement (2), ATRX loss (2), TP53 mutated (4), CDKN2A deletion (2), RB1 loss (1), PALB-2 mutation (10). No SAEs or grade 3/4 AEs attributed to 9-ING-41 were noted; AEs included G1/2 transient vision changes (9/18, 50%), infusion reactions (4/18, 22%). Side effects from lomustine included: G3/4 thrombocytopenia (3/14, 21%), and G1/2 fatigue (4/14, 28%). Best overall response: 1 minimal response (-43%) after 2 cycles of 9-ING-41 and lomustine. Median days on therapy was 55 (4-305), 4/18 (22%) were stable for 20 weeks or longer. Conclusions: These results show 9-ING-41 alone or in combination is safe and warrants further study in glioma patients. Clinical trial information: NCT03678883.

Predicting Adverse Pathologic Features and Clinical Outcomes of Resectable Pancreas Cancer With Preoperative CA 19-9

Background

We evaluated preoperative CA 19-9 levels in patients with resected pancreatic cancer to analyze whether they were predictive of clinical outcomes and could help select patients for additional therapy. We hypothesized that elevated CA 19-9 would be associated with worse pathologic findings and oncologic outcomes.

Methods

This study assessed 509 patients with non-metastatic pancreatic adenocarcinoma who underwent resection at our institution from 1995-2011 and had preoperative CA 19-9 recorded. No patients received neoadjuvant therapy. CA 19-9 level was analyzed as a continuous and a dichotomized (> vs. ≤ 55 U/mL) variable using logistic and Cox models.

Results

Median follow-up was 7.8 years, and the median age was 66 years (33-90). 64% of patients had elevated preoperative CA 19-9 (median: 141 U/mL), that did not correlate with bilirubin level or tumor size. Most patients had ≥ T3 tumors (72%) and positive lymph nodes (62%). The rate of incomplete (R1 or R2) resection was 19%. Increasing preoperative CA 19-9 was associated with extra-pancreatic extension (p=0.0005), lymphovascular space invasion (p=0.0072), incomplete resection [HR (95% CI) 2.0 (1.2-3.5)], and lower OS [HR = 1.6 (1.3-2.0)]. Each doubling in preoperative CA 19-9 value was associated with an 8.3% increased risk of death [HR = 1.08 (1.02-1.15)] and a 10.0% increased risk of distant recurrence [HR = 1.10 (1.02-1.19)]. Patients classified as non-secretors had comparable outcomes to patients with normal CA 19-9.

Conclusions

Elevated preoperative CA 19-9 level was associated with adverse pathologic features, incomplete resection, and inferior clinical outcomes. Neither tumor size nor bilirubin confound an elevated CA 19-9 level. Preoperative CA 19-9 level may help select patients for additional therapy.

Nanoliposomal irinotecan (Nal-IRI)-based chemotherapy after irinotecan -based chemotherapy in patients with pancreas cancer

BACKGROUND

Nanoliposomal irinotecan (Nal-IRI) is a preferred second-line treatment for metastatic pancreas cancer. It is unclear, however, whether patients who had received irinotecan derive benefit.

METHODS

Medical records of metastatic pancreas cancer patients who had received irinotecan and then Nal-IRI were reviewed. The primary endpoint was overall survival after the initiation of Nal-IRI (an a priori threshold of >4 months defined success); adverse events and quotes from the medical record on decision-making were also recorded.

RESULTS

Sixty four patients met eligibility criteria with a median age of 65 years (range: 36, 80 years). The median overall survival from initiation of Nal-IRI was 5.1 months (95% confidence interval (CI): 4.3, 5.6 months). An exploratory comparison, based on no cancer progression with irinotecan versus progression, showed improved survival with Nal-IRI in the former group: 6.1 months (95% CI: 5.1, 9.3 months) versus 4.3 months (95% CI: 2.3, 4.8 months); p = 0.0006. Nal-IRI adverse events occurred as expected. Qualitative data illustrate several themes, including "limited treatment options," which appeared to drive the decision to prescribe Nal-IRI.

CONCLUSION

Nal-IRI might be considered in pancreas cancer patients who had received irinotecan, particularly in the absence of disease progression with the latter.

A phase I pharmacokinetic and safety study of Paclitaxel Injection Concentrate for Nano-dispersion (PICN) alone and in combination with carboplatin in patients with advanced solid malignancies and biliary tract cancers

PURPOSE

Paclitaxel injection concentrate for nano-dispersion (PICN) is a Cremophor-free, nanotechnology-driven paclitaxel formulation. This phase I study examined the safety, tolerability, pharmacokinetics and maximum tolerated dose (MTD) of PICN alone and in combination with carboplatin. Its early efficacy in unresectable biliary tract cancers (BTCs) was also evaluated.

METHODS

This multi-center study comprised two parts. Part A contained a dose-escalation cohort following "3 + 3" design using PICN monotherapy in advanced solid tumors (Part A1); Part A2 dose-expansion cohort was then conducted in advanced BTCs due to observed efficacy in Part A1. Part B1 and B2 evaluated escalating dose of PICN with carboplatin in advanced solid tumors. PICN was administered as a 30 min-infusion every 3 weeks without pre-medications for hypersensitivity reactions.

RESULTS

Thirty-six patients received PICN monotherapy in Part A and 21 received PICN plus carboplatin in Part B. The MTD of PICN was determined to be 295 mg/m² both as a monotherapy and in combination with carboplatin at AUC 5. Dose-proportional exposure in paclitaxel C_max and AUC was observed overdose range from 175 to 325 mg/m² for PICN monotherapy and its combination with carboplatin. Carboplatin did not alter PICN exposure. Clinically significant toxicities mainly include neutropenia and peripheral neuropathy. PICN monotherapy yielded a response rate of 20% in unresectable BTCs.

CONCLUSION

This study demonstrated the safety and stable pharmacokinetics of PICN as a monotherapy and in combination with carboplatin. Single-agent PICN showed promising antitumor activity in advanced BTCs, warranting further studies to investigate its role in gastrointestinal cancers.

Nanoliposomal irinotecan-based chemotherapy after regular irinotecan-based chemotherapy in patients with pancreas cancer

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Background: Pancreas cancer is an aggressive malignancy with limited therapeutic options. Nanoliposomal irinotecan (Nal-IRI) is a preferred second-line treatment, and current guidelines recommend its use in the absence of prior irinotecan. This study aimed to assess whether patients who had received regular irinotecan derive benefit from Nal-IRI. Methods: Medical records of metastatic pancreas cancer patients who had received regular irinotecan and then Nal-IRI were reviewed. The following information was extracted from each medical record: patient demographics, confirmation of a diagnosis of exocrine pancreas cancer, initial cancer stage, dates of administration of the drugs of interest, adverse events that occurred with Nal-IRI treatment, reasons for stopping regular irinotecan, and reasons for starting and stopping Nal-IRI. The primary endpoint was overall survival after the initiation of Nal-IRI (an a priori threshold of > 4 months defined success). Survival data were censored based on date of last follow up. Direct quotes from the medical record were documented to provide insight on prescribing Nal-IRI when guidelines advised the contrary. Results: Sixty four patients met eligibility criteria with a median age of 65 years (range: 36, 80 years). Prior to Nal-IRI, 61 patients had received FOLFIRINOX, and 3 FOLFIRI. Of these, 32 patients manifested progressive disease on regular irinotecan-based therapy. Nal-IRI was prescribed with a fluoropyrimidine; only one patient received monotherapy. At time of analysis, 54 patients had died. Median overall survival from initiation of Nal-IRI was 5.1 months (95% confidence interval (CI): 5.6, 4.3, months). An exploratory comparison, based on no cancer progression with regular irinotecan versus progression, showed improved survival with Nal-IRI in the former group: 6.1 months (95% CI: 9.3, 5.1 months) versus 4.3 months (95% CI: 4.8, 2.3 months); p=0.0006. Nal-IRI adverse events occurred as expected. Qualitative data illustrated several themes, including “limited treatment options,” which appeared to drive the decision to prescribe Nal-IRI. Conclusions: Nal-IRI might be considered in pancreas cancer patients who had received regular irinotecan, particularly in the absence of disease progression with the latter.

[The study of the protection function of the sphingosine kinase 1 in the nerve cell damage caused by acrylamide]

Objective: To study the protective effect and effect of SphK1 overexpression on the injury of nerve cells induced by acrylamide. Methods: ACR with 99% purity was prepared into 1.25 mmol/L and 2.5 mmol/L solutions. SH-SY5Y cells were divided into control group (NC group) , experimental group and SphK1 activator group. The experimental group was given ACR solution with final concentration of 1.25 mmol/L and 2.5 mmol/L respectively for 24 h. In the SphK1 activator group, on the basis of the exposure concentration of the experimental group, the SphK1 specific activator (12-) phorbol tetradecanoate (-13-) acetate (PMA) solution[prepared by dimethyl sulfoxide (DMSO) , the final concentration was 100 nmol/l], and other treatments were the same as the experimental group. Control group (NC group) added PMA solution into normal cells. Western blot was used to detect the expression of SphK1 protein; CCK-8 was used to detect the proliferation of SH-SY5Y cells; hoechst33342 method was used to observe the morphological changes of nerve cells; flow cytometry was used to analyze the apoptosis of cells. Results: Compared with NC group, the expression of SphK1 protein in the experimental group and the SphK1 activator group was significantly lower (P<0.05) . Compared with the experimental group, the expression of SphK1 protein in each concentration of SphK1 activator group was increased, and the difference was statistically significant (P<0.05) . In addition to 1.25 mmol/L SphK1 activator group, compared with NC group, the relative growth survival rate of experimental group and 2.5 mmol/L SphK1 activator group were lower, the difference was statistically significant (P<0.05) . Compared with the experimental group, the relative survival rate of cells in the SphK1 activator group was higher, and the difference was statistically significant (P<0.05) . With the increase of exposure concentration, the cells in the experimental group showed the morphological characteristics of early apoptosis at ACR 1.25 mmol/L and late apoptosis at ACR 2.5 mmol/L. Compared with NC group, the apoptosis rate of experimental group and SphK1 activator group at ACR 2.5 mmol/L was significantly different (P<0.05) ; compared with experimental group, the apoptosis rate of SphK1 activator group at ACR 2.5 mmol/L was lower, the difference was statistically significant (P<0.05) . Conclusion: The SphK1 excessive expression plays the protective function to the nerve cell damage caused by acrylamide.

Role of Surgery and Perioperative Therapy in Older Patients with Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

It is unclear whether results from recent trials of resectable pancreatic ductal adenocarcinoma (PDAC) are generalizable to older patients, who are underrepresented. We aimed to evaluate outcomes of surgery and of neoadjuvant and adjuvant therapy in older patients with resectable PDAC.

PATIENTS AND METHODS

We included patients aged ≥65 years with upfront resectable PDAC from a prospectively maintained pancreatic cancer registry from 2007 to 2016. Patients were stratified into ages 65-75 and 75+ years. Overall survival (OS) was assessed in treatment comparisons: (A) surgery (n = 636) versus nonsurgical (n = 178), (B) neoadjuvant therapy (n = 139) versus upfront surgery (n = 497), and (C) adjuvant therapy (n = 379) versus surgery alone (n = 118). We compared neoadjuvant (n = 139) versus adjuvant therapy (n = 379) in an exploratory analysis.

RESULTS

Nine hundred and three patients had a median age of 73.7 (range, 65-96.6) years. Median OS was 26.6 versus 11.9 months (adjusted hazard ratio [HRadj ], 0.4; 95% confidence interval [CI], 0.31-0.52; p < .001) in Comparison A groups, 30.7 versus 25.8 months (HRadj , 0.69; 95% CI, 0.49-0.96; p = .03) in Comparison B groups, and 26.9 versus 17.4 months (HRadj , 0.62; 95% CI, 0.44-0.88; p = .008) in Comparison C groups, respectively. OS benefit in these treatment comparisons was present in age group 75+ with HRadj 0.24 (95% CI, 0.16-0.36; p < .001) in Comparison A and HRadj 0.52 (95% CI, 0.27-1; p = .049) in Comparison B, but not in Comparison C with HRadj 0.68 (95% CI, 0.43-1.08; p = .1). Statistically comparable median OS of patients who received neoadjuvant or adjuvant therapy stratified by age groups was observed.

CONCLUSION

Older patients with resectable PDAC who received surgery, neoadjuvant therapy, or adjuvant therapy appeared to have improved survival outcomes compared with those who did not receive such treatment.

IMPLICATIONS FOR PRACTICE

Older patients with resectable pancreatic ductal adenocarcinoma (PDAC) in general are underrepresented in large clinical trials and less well studied in terms of the role of surgery, neoadjuvant therapy, and adjuvant therapy. This study collected data on older patients with resectable PDAC from a prospectively maintained single-institutional pancreatic cancer registry of a tertiary referral center from 2007 to 2016. It was found that, with multidisciplinary evaluation, older patients with resectable PDAC who received surgery, neoadjuvant therapy, or adjuvant therapy appeared to have improved survival outcomes compared with those who did not receive such treatment. These results are of substantial importance to practitioners who treat older patients, who are traditionally underrepresented in most clinical trials.