Second-line treatment in inoperable pancreatic adenocarcinoma: A systematic review and synthesis of all clinical trials

There remains uncertainty regarding the optimal second-line chemotherapy in advanced pancreatic ductal adenocarcinoma (PDAC). The current recommendation of 5-fluorouracil and oxaliplatin may not be relevant in current practice, as FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan and oxaliplatin) has become a more popular first line therapy in fit patients. The majority of studies in this setting are single-arm Phase II trials with significant heterogeneity of patient populations, treatments and outcomes. In this review, we sought to systematically review and synthesise all prospective data available for the second-line treatment of advanced PDAC.

Pharmacodynamic separation of gemcitabine and erlotinib in locally advanced or metastatic pancreatic cancer: therapeutic and biomarker results

PURPOSE

Erlotinib marginally improves survival when administered continuously with gemcitabine to patients with advanced pancreatic cancer; however, preclinical data suggest that there is antagonism between chemotherapy and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors when these are delivered concurrently. We tested a pharmacodynamic separation approach for erlotinib plus gemcitabine and interrogated EGFR signaling intermediates as potential surrogates for the efficacy of this strategy.

METHODS

Patients with measurable, previously untreated locally advanced unresectable or metastatic pancreatic cancer were treated with gemcitabine 1000 mg/m(2) as an intravenous infusion over 30-min on days 1, 8, 15 and erlotinib 150 mg/day on days 2-5, 9-12, 16-26 of each 28-day cycle. The primary endpoint was progression-free survival (PFS); secondary endpoints included RECIST objective response rate (ORR) and safety. The study was terminated after thirty patients due to funding considerations.

RESULTS

The median PFS was 2.07 months (95% CI; 1.87-5.50 months) and the ORR was 11%. No unexpected safety signals were seen: the most common grade 3 or higher adverse events were neutropenia (23%), lymphopenia (23%), and fatigue (13%). Patients with mutant plasma Kirsten rat sarcoma virus (KRAS) had significantly lower median PFS (1.8 vs. 4.6 months, p = 0.014) and overall survival (3.0 vs. 10.5 months, p = 0.003) than those without detected plasma KRAS mutations.

CONCLUSIONS

Although pharmacodynamically separated erlotinib and gemcitabine were feasible and tolerable in patients with advanced pancreatic cancer, no signal for increased efficacy was seen in this molecularly unselected cohort. Detection of a KRAS mutation in circulating cell-free DNA was a strong predictor of survival.

A phase II study of erlotinib in gemcitabine refractory advanced pancreatic cancer

BACKGROUND

Erlotinib induced skin toxicity has been associated with clinical benefit in several tumour types. This phase II study evaluated the efficacy of erlotinib, dose escalated to rash, in patients with advanced pancreatic cancer previously treated with gemcitabine.

METHODS

Erlotinib was given at an initial dose of 150 mg/day, and the dose was escalated by 50mg every 2 weeks (to a maximum of 300 mg/day) until >grade 1 rash or other dose limiting toxicities occurred. Erlotinib pharmacokinetics were performed, and baseline tumour tissue was collected for mutational analysis and epidermal growth factor receptor (EGFR) expression. The primary end-point was the disease control rate (objective response and stable disease >8 weeks).

RESULTS

Fifty-one patients were accrued, and 49 received treatment. Dose-escalation to 200-300 mg of erlotinib was possible in 9/49 (18%) patients. The most common ⩾ grade 3 adverse events included fatigue (6%), rash (4%) and diarrhoea (4%). Thirty-seven patients were evaluable for response, and the best response was stable disease in 12 patients (32% (95% confidence interval (CI) 17-47%)). Disease control was observed in nine patients (24% (95% CI: 10-38%)). Median survival was 3.8 months, and 6 month overall survival rate was 32% (95% CI 19-47%). Mutational analysis and EGFR expression were performed on 29 patients, with 93% having KRAS mutations, none having EGFR mutations, and 86% expressing EGFR. Neither KRAS mutational status nor EGFR expression was associated with survival.

CONCLUSIONS

Erlotinib dose escalated to rash was well tolerated but not associated with significant efficacy in non-selected patients with advanced pancreatic cancer.

Second-line treatment in advanced pancreatic cancer: a comprehensive analysis of published clinical trials

BACKGROUND

There is currently no standard of care for the second-line treatment of advanced pancreatic cancer. The aim of this analysis was to compare the different therapeutic approaches in this setting.

METHODS

We carried out a systematic analysis of second-line studies in advanced pancreatic cancer that have progressed on or following gemcitabine and published or presented from 2000 to 2012.

RESULTS

Forty-four clinical trials (t) were identified; of which 34 met the inclusion criteria treating an aggregate total of 1503 patients (n). Patients who received treatments (t: 33; n: 1269) had a median overall survival (OS) of 6 months compared with 2.8 months for patients who received best supportive care only (t: 2; n: 234) (P = 0.013). The gemcitabine and platinum-based combination (t: 5; n: 154) provided a median progression-free survival and OS of 4 and 6 months compared with 1.6 and 5.3 for the rest of the regimens (t: 29; n: 1349) (P = 0.059 and 0.10, respectively) and 2.9 and 5.7 for the combination of 5-fluorouracil and platinum agents (t: 12; n: 450) (P = 0.60 and 0.22, respectively).

CONCLUSION(S)

Although not conclusive, these data showed that the advantage of second-line chemotherapy in pancreatic cancer is very limited and there is a need for more studies.

Second-line therapy for advanced pancreatic cancer: a review of the literature and future directions

Whereas first-line chemotherapy (CT) with single-agent gemcitabine or gemcitabine-based combinations provides a proven benefit in patients with locally advanced or metastatic pancreatic cancer (PC), the role of salvage CT after gemcitabine-failure is not well-established and to date no regimen has emerged as preferred in this setting. Several clinical trials have investigated the efficacy and toxicity-profile of second-line CT and indicated that selected patients may obtain significant benefit from it, also with regard to survival. However, definitive results from large randomized phase III studies are still lacking, and the evidence for clinical benefit of salvage CT is based on small phase II trials that evaluated different treatment schedules in heterogeneous populations. The main goal of this paper is reviewing this topic.