Nab-paclitaxel plus gemcitabine with or without capecitabine and cisplatin in metastatic pancreatic adenocarcinoma (PACT-19): a randomised phase 2 trial.

Background: Current treatment for metastatic pancreatic ductal adenocarcinoma includes combination chemotherapy, such as FOLFIRINOX or nab-paclitaxel plus gemcitabine. We investigated the activity of a novel four-drug regimen, consisting of cisplatin, nab-paclitaxel, capecitabine, and gemcitabine, compared with nab-paclitaxel plus gemcitabine, in the PACT-19 trial.

Methods: This single-centre, randomised, open-label, phase 2 trial was done in San Raffaele Hospital in Italy. We enrolled patients aged 18-75 years with pathologically confirmed stage IV pancreatic ductal adenocarcinoma who had received no previous chemotherapy and had Karnofsky performance status of at least 70. Patients were randomly assigned (1:1) by computer-generated permutated block randomisation (block size of four) stratified by baseline concentration of carbohydrate antigen 19-9 to PAXG (cisplatin 30 mg/m, nab-paclitaxel 150 mg/m, and gemcitabine 800 mg/m on days 1 and 15 and oral capecitabine 1250 mg/m on days 1-28 every 4 weeks), or nab-paclitaxel and gemcitabine alone (nab-paclitaxel 125 mg/m and gemcitabine 1000 mg/m on days 1, 8, and 15 every 4 weeks). The primary endpoint was the proportion of patients who were progression-free at 6 months, analysed in the intention-to-treat population. Data cutoff was on March 31, 2018. The safety population included all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT01730222, and is now closed.

Findings: Between April 22, 2014, and May 30, 2016, we randomly assigned 83 patients to treatment: 42 patients to PAXG and 41 patients to nab-paclitaxel plus gemcitabine. At 6 months, 31 (74%, 95% CI 58-86) of 42 patients in the PAXG group were alive and free from disease progression compared with 19 (46%, 31-63) of 41 patients in the nab-paclitaxel plus gemcitabine group. The most frequent grade 3 adverse events were neutropenia (12 [29%] of 42 in the PAXG group vs 14 [34%] of 41 in the nab-paclitaxel plus gemcitabine group), anaemia (nine [21%] vs nine [22%]), and fatigue (seven [17%] vs seven [17%]). The most common grade 4 adverse event was neutropenia (five [12%] in the PAXG group vs two [5%] in the nab-paclitaxel plus gemcitabine group). Two (5%) treatment-related deaths occurred in the nab-paclitaxel plus gemcitabine group compared with none in the PAXG group.

Interpretation: Despite the small sample size, our findings suggest that the PAXG regimen warrants further investigation in a phase 3 trial in patients with metastatic pancreatic ductal adenocarcinoma.

Funding: Celgene.