Mikhail, Sameh

Background: Treatment with nab-paclitaxel with gemcitabine demonstrates a survival advantage when compared with single-agent gemcitabine. However, the combination is associated with significant toxicities, leading to a high rate of drug discontinuation. We implemented a modified regimen of gemcitabine and nab-paclitaxel (mGNabP) in an attempt to minimize toxicities while maintaining efficacy. Methods: A total of 79 evaluable patients with metastatic pancreatic adenocarcinoma (mPC) treated with a modified regimen of gemcitabine (1000 mg/m 2 ) and nab-paclitaxel (125 mg/m 2 ) on days 1, 15 of every 28-day cycle were identified from our prospective database. A total of 57 patients received this regimen as first-line treatment and were evaluated for toxicities, progression-free survival (PFS), and overall survival (OS). Overall, 22 patients with advanced or metastatic PC treated with the modified regimen outside the first-line setting were only evaluated for toxicities. Results: The median OS and PFS were 10 months [95% confidence interval (CI) 5.9–13 months] and 5.4 months (95% CI 4.1–7.4 months) for patients that received the modified regimen as first-line therapy. Neurotoxicity occurred in 27% with only 1.6% of patients experiencing grade ⩾3 toxicity. The incidence of grade ⩾3 neutropenia was 19%, resulting in growth factor support in 12% of patients. This rate was similar in patients who received the modified regimen for first-line treatment of mPC versus the overall group. Conclusions: A modified regimen of biweekly nab-paclitaxel with gemcitabine is associated with a lower cost, acceptable toxicity profile and appears to be relatively effective in pancreatic cancer. Prospective randomized studies confirming its potential benefits compared with standard weekly mGNabP are warranted.

BACKGROUNDBiliary tract cancers (BTCs) are uncommon and are associated with a dismal prognosis. Combinations of gemcitabine and platinum chemotherapy (gemcitabine and platinum–based therapy [GP]) form the standard approach for treating advanced BTC. To characterize the spectrum of mutations and to identify potential biomarkers for a GP response in BTC, this study evaluated the genomic landscape and assessed whether mutations affecting DNA repair were associated with GP resistance.METHODSPretreatment, formalin‐fixed, paraffin‐embedded samples from 183 BTC patients treated with GP were analyzed. Cox regression models were used to determine the association between mutations, progression‐free survival (PFS), and overall survival (OS).RESULTSWhen genes with an incidence > 10% were considered, no individual gene was independently predictive of a GP response. In patients with unresectable BTC who received GP as their first‐line therapy, the joint status of cyclin‐dependent kinase inhibitor 2A (CDKN2A), tumor protein 53 (TP53), and AT‐rich interaction domain 1A (ARID1A) was associated with PFS (P = .0004) and OS (P ≤ .0001). Patients with mutations in CDKN2A and TP53 were identified as a poor‐prognosis cohort with a median PFS of 2.63 months and a median OS of 5.22 months. Patients with mutant ARID1A, regardless of the single‐mutation status of TP53 or CDKN2A, had similar outcomes. A patient who exhibited mutations in all 3 genes had a median PFS of 20.37 months, and OS was not reached.CONCLUSIONSIn the largest exploratory analysis of this kind for BTC, 3 prevalent, mutually exclusive mutations represent distinct patient cohorts. These mutations are prognostic and may represent a predictive biomarker for a GP response. Prospective studies to validate these findings are needed, and they should include the incorporation of therapies that exploit the genomic instability observed with these mutations in BTC. Cancer 2016;122:3657‐66. © 2016 American Cancer Society.