Exploring external validity of chemotherapy for pancreatic ductal adenocarcinoma in real life.

INTRODUCTION: Cisplatin, nab-paclitaxel, capecitabine, and gemcitabine (PAXG) regimen activity was assessed in a single institution phase II trial (PACT-19) on pancreatic ductal adenocarcinoma (PDAC). The PACT-31 study explored the external validity of PACT-19 results. MATERIALS AND METHODS: Patients aged ≥18 and ≤75 years with KPS ≥70, and PDAC diagnosis receiving PAXG in the participating institutions were eligible and categorized as follows: A) PACT-19; B) PACT-31-HSR; C) PACT-31-non-HSR. With a sample of 175 patients, assuming a target 1-year overall survival of 60 % for metastatic and of 80 % for non-metastatic patients, the trial will be considered successful with the 1-year OS falling into the 95 % CI. RESULTS: Data from 68 PACT-19 and 168 PACT-31 patients were retrieved. After 124 events, 1yOS was 52.5 % (95 %CI: 44.6-60.4 %) for metastatic and 80.5 % (95 %CI: 71.9-89.1 %) for non-metastatic patients. Survival overlapped between PACT-19 and PACT-31-HSR (median 17.6 and 17.4 months, p = 0.21) and was significantly shorter in PACT-31-non-HSR (median 11.3 months; p = 0.03). Differences of dose-intensity, use of maintenance therapy, and treatment after progression between PACT-31-HSR and non-HSR were evidenced. DISCUSSION: PACT-19 results have external validity. The outcome difference between HSR and non-HSR centers endorses the need of creating a hub-and-spoke network aimed at sharing the expertise on rare-diseases.

Prognostic analysis and outcomes of metastatic pancreatic cancer patients receiving nab-paclitaxel plus gemcitabine as second or later-line treatment.

BACKGROUND: Pancreatic cancer (PC) first-line therapy often consists of polychemotherapy regimens, but choosing a second-line therapy after disease progression, especially following first-line FOLFIRINOX, remains a clinical challenge. This study presents results from a large, multicenter, retrospective analysis of Italian patients with metastatic PC (mPC) treated with Nab-paclitaxel/Gemcitabine (AG) as second or later line of treatment. Main objective of the study is to identify prognostic factors that could inform treatment decisions. METHODS: The study included 160 mPC patients treated with AG in 17 Italian institutions. AG was administered according to labelling dose, until disease progression, unacceptable toxicity or patient refusal. Variations in schedules, dose modifications, supportive measures, and response evaluation were determined by individual clinicians' practice. RESULTS: AG was well-tolerated and exhibited promising clinical activity. The overall response rate (ORR) and the disease control rate (DCR) were 22.5% and 45.6%, respectively. Median progression-free survival (PFS) and overall survival (OS) were 3.9 and 6.8 months, respectively. Among the patients who received AG as a second-line therapy (n = 111, 66.9%), median PFS and OS were 4.2 and 7.4 months, respectively. Notably, in the 76 patients (68%) receiving AG after first-line FOLFIRINOX, an ORR of 19.7% and a DCR of 46.0% were observed, resulting in a median PFS of 3.5 and median OS of 5.7 months. The study identified specific clinical or laboratory parameters (LDH, NLR, fasting serum glucose, liver metastases, ECOG PS, and first-line PFS) as independent prognostic factors at multivariate level. These factors were used to create a prognostic nomogram that divided patients into three risk classes, helping to predict second-line OS and PFS. CONCLUSIONS: This study represents the largest real-world population of mPC patients treated with AG as a second or later line of therapy. It supports the feasibility of this regimen following first-line FOLFIRINOX, particularly in patients with specific clinical and laboratory characteristics who derived prolonged benefit from first-line therapy.

Circulating microRNA Analysis in a Prospective Co-clinical Trial Identifies MIR652-3p as a Response Biomarker and Driver of Regorafenib Resistance Mechanisms in Colorectal Cancer.

PURPOSE: The multi-kinase inhibitor (mKi) regorafenib has demonstrated efficacy in chemorefractory patients with metastatic colorectal cancer (mCRC). However, lack of predictive biomarkers and concerns over significant toxicities hamper the use of regorafenib in clinical practice. EXPERIMENTAL DESIGN: Serial liquid biopsies were obtained at baseline and monthly until disease progression in chemorefractory patients with mCRC treated with regorafenib in a phase II clinical trial (PROSPECT-R n = 40; NCT03010722) and in a multicentric validation cohort (n = 241). Tissue biopsies collected at baseline, after 2 months and at progression in the PROSPECT-R trial were used to establish patient-derived organoids (PDO) and for molecular analyses. MicroRNA profiling was performed on baseline bloods using the NanoString nCounter platform and results were validated by digital-droplet PCR and/or ISH in paired liquid and tissue biopsies. PDOs co-cultures and PDO-xenotransplants were generated for functional analyses. RESULTS: Large-scale microRNA expression analysis in longitudinal matched liquid and tissue biopsies from the PROSPECT-R trial identified MIR652-3p as a biomarker of clinical benefit to regorafenib. These findings were confirmed in an independent validation cohort and in a "control" group of 100 patients treated with lonsurf. Using ex vivo co-culture assays paired with single-cell RNA-sequencing of PDO established pre- and post-treatment, we modeled regorafenib response observed in vivo and in patients, and showed that MIR652-3p controls resistance to regorafenib by impairing regorafenib-induced lethal autophagy and by orchestrating the switch from neo-angiogenesis to vessel co-option. CONCLUSIONS: Our results identify MIR652-3p as a potential biomarker and as a driver of cell and non-cell-autonomous mechanisms of resistance to regorafenib.