PAXG Chemotherapy Shows Superior Event-Free Survival Over mFOLFIRINOX in Pancreatic Cancer Trial
Key Insights
The PACT-21 CASSANDRA trial demonstrated that preoperative PAXG (search) chemotherapy achieved significantly better event-free survival compared to mFOLFIRINOX (search) in patients with resectable or borderline resectable pancreatic ductal adenocarcinoma (search).
After median follow-up of 28.5 months, PAXG (search) showed median event-free survival of 16.0 months versus 10.2 months with mFOLFIRINOX (search), with 3-year rates of 33% versus 13% respectively.
The study enrolled 260 patients who received 4 months of preoperative treatment, with PAXG (search) showing manageable toxicity profile similar to mFOLFIRINOX (search).
The Italian PACT-21 CASSANDRA trial has demonstrated superior outcomes with preoperative PAXG (search) chemotherapy compared to mFOLFIRINOX (search) in patients with resectable or borderline resectable pancreatic ductal adenocarcinoma (search) (PDAC (search)), potentially reshaping treatment standards for this challenging malignancy.
Trial Design and Patient Population
The open-label multicenter phase III trial enrolled 260 patients between November 2020 and April 2024, randomly assigning them to receive either preoperative PAXG (search) (n=132) or mFOLFIRINOX (search) (n=128) for 4 months. The PAXG regimen consisted of capecitabine at 625 mg/m² twice daily, cisplatin at 30 mg/m², nab-paclitaxel at 150 mg/m², and gemcitabine at 800 mg/m² administered every 14 days. The mFOLFIRINOX arm received fluorouracil at 2,400 mg/m², leucovorin at 400 mg/m², irinotecan at 150 mg/m², and oxaliplatin at 85 mg/m² every 14 days.
The study employed a 2×2 factorial design, with a second randomization allocating patients to receive 2 months of additional chemotherapy either before or after surgery. The primary endpoint was event-free survival in the intention-to-treat population.
Superior Efficacy Outcomes
After a median follow-up of 28.5 months (interquartile range 20.2-38.2 months), PAXG (search) demonstrated significantly superior event-free survival compared to mFOLFIRINOX (search). The median event-free survival was 16.0 months (95% CI: 12.4-19.8 months) in the PAXG group versus 10.2 months (95% CI: 8.6-13.5 months) in the mFOLFIRINOX group, representing a hazard ratio of 0.63 (95% CI: 0.47-0.84, P = 0.0018).
The survival advantage was sustained over time, with 1-year event-free survival rates of 61% versus 45% and 3-year rates of 33% versus 13% for PAXG (search) and mFOLFIRINOX (search), respectively. These findings represent a substantial improvement in outcomes for patients with this aggressive malignancy.
Safety and Tolerability Profile
Both treatment regimens demonstrated manageable toxicity profiles. Grade ≥3 adverse events occurred in 66% of patients receiving PAXG (search) compared to 61% in the mFOLFIRINOX (search) group. The most common severe adverse events in the PAXG arm included decreased neutrophils (43%), fatigue (9%), nausea (5%), and peripheral neuropathy (5%). In the mFOLFIRINOX group, the predominant grade ≥3 events were decreased neutrophils (29%), fatigue (8%), increased transaminases (8%), and nausea (6%).
The similar overall toxicity rates between the two regimens suggest that the superior efficacy of PAXG (search) was not achieved at the expense of increased treatment-related morbidity.
Clinical Implications and Future Directions
The trial results have significant implications for clinical practice in pancreatic cancer (search) treatment. According to the investigators, "PAXG (search) significantly improved [event-free survival] compared with mFOLFIRINOX (search) in resectable or borderline resectable PDAC (search). Preoperative PAXG could be considered a standard option for resectable or borderline resectable PDAC."
The researchers further emphasized that "preoperative PAXG (search) should be considered as the standard comparator group for future trials in this setting," indicating a potential paradigm shift in how clinical trials for pancreatic cancer (search) will be designed and conducted.
Context Within Current Treatment Landscape
This trial addresses an important gap in pancreatic cancer (search) treatment, where the optimal preoperative chemotherapy regimen has remained uncertain. While mFOLFIRINOX (search) has been established as a reference standard for fit patients in the adjuvant setting, the CASSANDRA trial suggests that PAXG (search) may offer superior outcomes in the preoperative context.
The study's findings are particularly relevant given the ongoing debate about optimal treatment sequencing in pancreatic cancer (search), where both neoadjuvant and adjuvant approaches have shown benefits in different clinical scenarios. The superior event-free survival demonstrated with PAXG (search) provides compelling evidence for its consideration as a new standard of care in this patient population.
The complete results of the second randomization, examining the timing of additional chemotherapy relative to surgery, are awaited and may provide further insights into optimal treatment sequencing strategies for patients with resectable and borderline resectable pancreatic ductal adenocarcinoma (search).