Two decades of research toward the treatment of locally advanced and metastatic pancreatic cancer: Remarkable effort and limited gain

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy that is diagnosed at the locally advanced or metastatic stage in approximately 80% of cases. Relative to other tumor types, progress in the treatment of this disease has been painfully slow. While agents targeting DNA repair have proven successful in a subset of patients, the majority of PDACs do not exhibit validated molecular targets. Hence, conventional chemotherapy remains at the forefront of therapy for this disease. In this review, we study two decades of efforts to improve upon the gemcitabine backbone - 67 phase II and III trials enrolling 16,446 patients - that culminated in the approvals of gemcitabine/nab-paclitaxel (Gem/NabP) and FOLFIRINOX. Today, these remain gold standards for the first-line treatment of locally advanced unresectable and metastatic PDAC, while ongoing efforts focus on improving upon the Gem/NabP backbone. Because real world data often do not reflect the data of randomized controlled trials (RCTs), we also summarize the retrospective evidence comparing the efficacy of Gem/NabP and FOLFIRINOX in the first-line setting - 29 studies reporting a median overall survival of 10.7 and 9.1 months for FOLFIRINOX and Gem/NabP, respectively. These values are surprisingly comparable to those reported by the pivotal RCTs at 11.1 and 8.5 months. Finally, there is a paucity of RCT data regarding the efficacy of second-line therapy. Hence, we conclude this review by summarizing the data that ultimately demonstrate a small but significant survival benefit of second-line therapy with Gem/NabP or FOLFIRINOX. Collectively, these studies describe the long journey, the steady effort, and the myriad lessons to be learned from 20 years of PDAC trials to inform strategies for success in clinical trials moving forward.

Real-world comparative effectiveness of nab-paclitaxel plus gemcitabine versus FOLFIRINOX in advanced pancreatic cancer: a systematic review

BACKGROUND

No clinical trial has directly compared nab-paclitaxel/gemcitabine (nab-P/G) with FOLFIRINOX (fluorouracil/leucovorin/oxaliplatin/irinotecan) in metastatic or advanced pancreatic cancer (mPC or aPC). We conducted a systematic review of real-world studies comparing these regimens in the first-line setting.

METHODS

Embase and MEDLINE databases through 22 January 2019, and Gastrointestinal Cancers Symposium 2019 abstracts were searched for real-world, retrospective studies comparing first-line nab-P/G versus FOLFIRINOX in mPC or aPC that met specific parameters. Studies with radiotherapy were excluded. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Of 818 records initially identified, 35 were duplicates and 749 did not meet the eligibility criteria, mostly because they were either not comparative (n = 356) or not first line (n = 245). The remaining 34 studies (21 mPC; 13 aPC) assessed >6915 patients who received nab-P/G or FOLFIRINOX. In the studies identified, the median overall survival (OS) reached 14.4 and 15.9 months with nab-P/G and FOLFIRINOX, respectively, and median progression-free survival reached 8.5 and 11.7 months, respectively. Safety data were reported in 14 studies (2205 patients), including 8 single-institutional studies. In most single-institutional studies that reported safety data, rates were higher with FOLFIRINOX versus nab-P/G for grade 3/4 neutropenia (five of six studies) and febrile neutropenia (all three studies), while rates of grade 3/4 peripheral neuropathy were higher with nab-P/G in four of seven studies.

CONCLUSIONS

Although FOLFIRINOX was associated with slightly longer median OS in more studies, the differences, when available, were not statistically significant. Therefore, a randomized, controlled trial is warranted. Toxicity profile differences represent key considerations for treatment decisions.