KRT81 and HNF1A expression in pancreatic ductal adenocarcinoma: investigation of predictive and prognostic value of immunohistochemistry-based subtyping.

Even after decades of research, pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal disease and responses to conventional treatments remain mostly poor. Subclassification of PDAC into distinct biological subtypes has been proposed by various groups to further improve patient outcome and reduce unnecessary side effects. Recently, an immunohistochemistry (IHC)-based subtyping method using cytokeratin-81 (KRT81) and hepatocyte nuclear factor 1A (HNF1A) could recapitulate some of the previously established molecular subtyping methods, while providing significant prognostic and, to a limited degree, also predictive information. We refined the KRT81/HNF1A subtyping method to classify PDAC into three distinct biological subtypes. The prognostic value of the IHC-based method was investigated in two primary resected cohorts, which include 269 and 286 patients, respectively. In the second cohort, we also assessed the predictive effect for response to erlotinib + gemcitabine. In both PDAC cohorts, the new HNF1A-positive subtype was associated with the best survival, the KRT81-positive subtype with the worst, and the double-negative with an intermediate survival (p < 0.001 and p < 0.001, respectively) in univariate and multivariate analyses. In the second cohort (CONKO-005), the IHC-based subtype was additionally found to have a potential predictive value for the erlotinib-based treatment effect. The revised IHC-based subtyping using KRT81 and HNF1A has prognostic significance for PDAC patients and may be of value in predicting treatment response to specific therapeutic agents.

Alternating gemcitabine plus nab-paclitaxel and gemcitabine alone versus continuous gemcitabine plus nab-paclitaxel after induction treatment of metastatic pancreatic cancer (ALPACA): a multicentre, randomised, open-label, phase 2 trial.

BACKGROUND: A standardised dose-reduction strategy has not been established for the widely used gemcitabine plus nab-paclitaxel regimen in patients with metastatic pancreatic ductal adenocarcinoma. We aimed to investigate the efficacy and tolerability of alternating treatment cycles of nab-paclitaxel-gemcitabine combination therapy and gemcitabine alone versus continuous treatment with the nab-paclitaxel-gemcitabine combination. METHODS: ALPACA was a randomised, open-label, phase 2 trial conducted at 29 study centres across Germany. Patients aged 18 years or older with a histologically or cytologically confirmed diagnosis of metastatic pancreatic ductal adenocarcinoma who had not been previously treated for advanced disease were enrolled. After an induction phase with three cycles of nab-paclitaxel-gemcitabine combination therapy (nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2 administered intravenously on days 1, 8, and 15 of each 28-day cycle), patients were randomly assigned (1:1) by stratified permuted block randomisation either to continue treatment with standard nab-paclitaxel-gemcitabine or to receive alternating cycles of nab-paclitaxel-gemcitabine and gemcitabine alone. Patients and investigators were not masked to treatment allocation. Randomisation was done centrally by the study statistician using a computer-generated randomisation list, and was stratified by Karnofsky Performance Status and presence of liver metastases. The primary endpoint was the derivation of an unbiased point estimate and an associated confidence interval with a confidence coefficient of 80% for the hazard ratio (HR) for overall survival after randomisation, without testing a specific hypothesis, analysed by intention to treat in all patients who started randomised treatment. Safety was analysed according to treatment received. This trial is registered with ClinicalTrials.gov, NCT02564146, and is completed. FINDINGS: Between May 27, 2016, and May 27, 2021, 325 patients were enrolled. Following three cycles of induction treatment, 174 patients were randomly assigned: 85 to continue receiving standard nab-paclitaxel-gemcitabine, of whom 79 started treatment, and 89 to the alternating treatment schedule, of whom 88 started treatment. Of the 167 patients who started randomised treatment, 88 (53%) were female and 79 (47%) were male. Median overall survival after randomisation was 10·4 months (80% CI 9·2-12·0) in the group that received standard treatment and 10·5 months (10·2-11·1) in the group that received alternating treatment (HR 0·90, 80% CI 0·72-1·13; p=0·56). The most common adverse events of any grade were peripheral neuropathy (59 [74%] of 80 patients in the continuous treatment group vs 53 [62%] of 85 patients in the alternating treatment group) and fatigue (43 [54%] vs 44 [52%]). Treatment-emergent serious adverse events after randomisation occurred in 40 (50%) patients in the continuous treatment group and in 28 (33%) in the alternating treatment group. Fewer treatment-emergent adverse events of grade 3 or higher occurred in patients treated with alternating cycles compared with those receiving standard therapy, especially for peripheral neuropathy (17 [21%] patients in the continuous treatment group vs 12 [14%] in the alternating treatment group) and infections (16 [20%] vs nine [11%]). There were two treatment-related deaths after randomisation, both in the continuous treatment group (one multiple organ dysfunction syndrome, not treated after randomisation, and one interstitial lung disease). INTERPRETATION: Our findings suggest that a dose-reduced regimen with alternating cycles of nab-paclitaxel-gemcitabine and gemcitabine alone after three induction cycles is associated with similar overall survival to that for standard treatment with nab-paclitaxel-gemcitabine, but with improved tolerability. We therefore propose that a switch to the alternating schedule could be considered in a clinical setting for patients with metastatic pancreatic cancer who have at least stable disease after three cycles of nab-paclitaxel-gemcitabine treatment. FUNDING: Celgene/Bristol Myers Squibb.

Sequential therapy of refractory metastatic pancreatic cancer with 5-FU/LV/irinotecan (FOLFIRI) vs. 5-FU/LV/oxaliplatin (OFF). The PANTHEON trial (AIO PAK 0116).

PURPOSE: In patients with metastatic pancreatic cancer, after failure of gemcitabine/nab-paclitaxel, this trial compares the efficacy of second-line therapy with FOLFIRI vs. OFF (1:1 randomisation) with cross-over to the vice-versa regimen as third-line therapy. PATIENTS AND METHODS: The primary endpoint was PFS (progression-free survival: time from randomization until progression or death) of second-line therapy. The trial aimed to demonstrate non-inferiority of FOLFIRI vs OFF (non-inferiority margin of a hazard ratio (HR) of 1.5, power of 80% and a significance level of 5%, 196 events needed). Secondary endpoints included overall survival (OS), progression-free survival of third-line therapy and safety. The trial is registered with EudraCT Nr. 2016-004640-11. RESULTS: The trial was terminated with 60 evaluable (37 with FOLFIRI, 23 with OFF) patients due to insufficient recruitment. PFS of second-line therapy was 2.4 (95% CI 2.3-2.6) months with FOLFIRI vs 2.4 (95% CI 2.2-2.7) months with OFF (HR: 0.80, 95% CI 0.45-1.42, P = 0.43). OS was comparable between the arms (HR: 0.95, 95% CI 0.54-1.66), P = 0.84). Only 4 out of 28 (14%) patients receiving third-line therapy achieved a disease control (partial remission or stable disease). Both second-line regimens were well tolerated without new or unexpected safety signals being observed. CONCLUSION: The exploratory analysis of this early terminated trial suggests that FOLFIRI and OFF have similar efficacy ant toxicity as second-line therapy of PDAC after failure of gemcitabine/nab-paclitaxel. Third-line therapy regardless of regimen does not provide satisfactory efficacy in this sequential treatment algorithm.