Purpose: KEYNOTE-158 (ClinicalTrials.gov identifier: NCT02628067) investigated the efficacy and safety of pembrolizumab across multiple cancers. We present results from patients with previously treated advanced well-differentiated neuroendocrine tumors (NET). Patients and Methods: Pembrolizumab 200 mg was administered every 3 weeks for 2 years or until progression, intolerable toxicity, or physician/patient decision. Tumor imaging was performed every 9 weeks for the first year and then every 12 weeks. Endpoints included objective response rate (ORR) per RECIST v1.1 by independent central radiologic review (primary) and duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety (secondary). Results: A total of 107 patients with NETs of the lung, appendix, small intestine, colon, rectum, or pancreas were treated. Median age was 59.0 years (range, 29–80), 44.9% had ECOG performance status 1, 40.2% had received ≥3 prior therapies for advanced disease, and 15.9% had PD-L1–positive tumors (combined positive score ≥1). Median follow-up was 24.2 months (range, 0.6–33.4). ORR was 3.7% (95% CI, 1.0–9.3), with zero complete responses and four partial responses (three pancreatic and one rectal) all in patients with PD-L1–negative tumors. Median DOR was not reached, with one of four responses ongoing after ≥21 months follow-up. Median PFS was 4.1 months (95% CI, 3.5–5.4); the 6-month PFS rate was 39.3%. Median OS was 24.2 months (95% CI, 15.8–32.5). Treatment-related adverse events (AE) occurred in 75.7% of patients, 21.5% of whom had grade 3–5 AEs. Conclusions: Pembrolizumab monotherapy showed limited antitumor activity and manageable safety in patients with previously treated advanced well-differentiated NETs.

PURPOSE: To evaluate the efficacy and safety of tucatinib and trastuzumab in patients with previously treated human epidermal growth factor receptor 2–positive (HER2+) metastatic biliary tract cancer (mBTC). METHODS: SGNTUC-019 (ClinicalTrials.gov identifier: NCT04579380 ) is an open-label phase II basket study evaluating the efficacy and safety of tucatinib and trastuzumab in patients with HER2-altered solid tumors. In the biliary tract cancer cohort, patients had previously treated HER2 overexpressing or amplified (HER2+) tumors (identified with local testing) with no prior HER2-directed therapy. The primary end point was confirmed objective response rate (cORR) per investigator assessment. Patients were treated on a 21-day cycle with tucatinib (300 mg orally twice daily) and trastuzumab (8 mg/kg intravenously followed by 6 mg/kg every 3 weeks). RESULTS: Thirty patients were enrolled. As of data cutoff (January 30, 2023), the median duration of follow-up was 10.8 months. The cORR was 46.7% (90% CI, 30.8 to 63.0), with a disease control rate of 76.7% (90% CI, 60.6 to 88.5). The median duration of response and progression-free survival were 6.0 months (90% CI, 5.5 to 6.9) and 5.5 months (90% CI, 3.9 to 8.1), respectively. At data cutoff, 15 patients (50.0%) had died, and the estimated 12-month overall survival rate was 53.6% (90% CI, 36.8 to 67.8). The two most common treatment-emergent adverse events (TEAEs) were pyrexia (43.3%) and diarrhea (40.0%). Grade ≥3 TEAEs were reported in 18 patients (60.0%), with the most common being cholangitis, decreased appetite, and nausea (all 10.0%), which were generally not treatment related. TEAEs led to treatment regimen discontinuation in one patient, and there were no deaths due to TEAEs. CONCLUSION: Tucatinib combined with trastuzumab had clinically significant antitumor activity and was well tolerated in patients with previously treated HER2+ mBTC.

We compared the efficacy of modified 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin (mFOLFIRINOX) with that of gemcitabine plus nab-paclitaxel (GnP) for locally advanced pancreatic cancer (LAPC). Patients with untreated LAPC were randomly assigned (1:1) to receive mFOLFIRINOX or GnP. One-year overall survival (OS) was the primary endpoint. The major secondary end-points included progression-free survival (PFS), response rate (RR), carbohydrate antigen 19-9 (CA19-9) response, and adverse events. The sample size was 124 patients to select a more effective regimen with a minimum probability of 0.85 and to examine the null hypothesis of the 1-year OS <53%. Of the 126 patients enrolled from 29 institutions, 125 were deemed eligible. The 1-year OS was 77.4% (95% CI, 64.9-86.0) and 82.5% (95% CI, 70.7-89.9) in the mFOLFIRINOX and GnP arms, respectively. The median PFS was 11.2 (95% CI, 9.9-15.9) and 9.4 months (95% CI, 7.4-12.8) in the mFOLFIRINOX and GnP arms, respectively. The RR and CA19-9 response rate were 30.9% (95% CI, 19.1-44.8) and 57.1% (95% CI, 41.0-72.3) and 42.1% (95% CI 29.1-55.9) and 85.0% (95% CI, 70.2-94.3) in the mFOLFIRINOX and GnP arms, respectively. Grade 3-4 diarrhoea and anorexia were predominant in the mFOLFIRINOX arm. GnP was considered the candidate for a subsequent phase III trial because of its better RR, CA19-9 response, and mild gastrointestinal toxicities. Both regimens displayed higher efficacy in the 1-year survival than in the historical data of gemcitabine monotherapy.

Background & Aims Corticosteroids are now widely accepted as a treatment for autoimmune pancreatitis (AIP). However, the molecular mechanism by which steroid treatment improves AIP remains largely unknown. The aim of this study was to elucidate cellular mechanisms by which corticosteroids improve both pancreatic exocrine function and histopathology in AIP. Methods Pancreatic exocrine function was evaluated by the secretin-stimulated function test and pancreatic biopsy specimens were processed for histologic analysis at the time of diagnosis and 3 months after initiation of steroid treatment. Expression and localization of proteins was assayed by immunohistochemistry. Analysis of immunoglobulin (Ig)G4-positive plasma cells was used to verify inflammation in AIP. Results The number of IgG4-positive plasma cells in pancreatic sections was decreased by steroid treatment, indicating reduced inflammation. Fluid, bicarbonate (HCO₃⁻), and digestive enzyme secretions all were impaired in most patients with AIP. Corticosteroids improved both HCO₃⁻ and digestive enzyme secretion. A large fraction of the cystic fibrosis transmembrane conductance regulator (CFTR), which plays a central role in pancreatic duct HCO₃⁻ secretion, was mislocalized to the cytoplasm of duct cells before treatment. Corticosteroids corrected the localization of CFTR to the apical membrane, accounting for the improved HCO₃⁻ secretion. Steroid treatment resulted in regeneration of acinar cells, accounting for restored digestive enzyme secretion. Conclusions Corticosteroids reduce inflammation and restore both digestive enzyme and HCO₃⁻ secretion in patients with AIP by regenerating acinar cells and correcting CFTR localization in pancreatic duct cells. Mislocalization of CFTR may explain aberrant HCO₃⁻ secretion in other forms of pancreatitis.

Background and study aim: Malignancy in pancreatic neuroendocrine tumors (PNETs) is graded by assessing the resected specimens according to the World Health Organization (WHO) 2010 criteria. The feasibility of such grading using endoscopic ultrasound-guided fine-needle aspiration (EUS–FNA) specimens remains unclear. The aim of this study was to ascertain the optimal method of measuring the Ki-67 index in EUS–FNA specimens, using resected specimens as the criterion standard. Patients and methods: A total of 58 consecutive patients diagnosed with PNETs between March 1998 and May 2011 were included. The study measured intratumoral Ki-67 index heterogeneity, concordance rates of PNET grading by EUS–FNA with grade of the resected tumor, optimal method of measuring the Ki-67 index in EUS–FNA specimens, and survival analysis based on EUS–FNA specimen grading. Results: Intratumoral dispersion of Ki-67 index in resected specimens was 0.033 for Grade 1 and 0.782 for Grade 2 tumors (P < 0.001). Concordance rates for WHO classification between EUS–FNA and resected specimens were 74.0 % using the mean Ki-67 index in EUS–FNA specimens and 77.8 % using the highest Ki-67 index. The concordance rate rose to 90 % when EUS–FNA samples with less than 2000 tumor cells were excluded (26 % of EUS–FNA cases). The Kaplan–Meier survival curves were significantly stratified by the EUS–FNA grading of PNETs with 5-year survival rates of 100 %, 58.3 %, and 0 %, for Grade 1, Grade 2, and neuroendocrine carcinoma (NEC) tumors, respectively. Conclusions: Grading of PNETs by the highest Ki-67 index in EUS–FNA specimens with adequate cellularity has a high concordance with grading of resected specimens, and can predict long term patient survival with high accuracy.