Phase III APACT trial of adjuvant nab-paclitaxel plus gemcitabine (nab-P + Gem) versus gemcitabine (Gem) alone for patients with resected pancreatic cancer (PC): Outcomes by geographic region

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Background: The APACT trial was one of the largest and most geographically diverse trials of adjuvant chemotherapy for resected PC, allowing for comparison of outcomes by geographic region. In this analysis, we report updated overall survival (OS) results for the intent-to-treat (ITT) population and examine outcomes by geographic region. Methods: Treatment-naive patients with histologically confirmed PC, macroscopic complete resection, Eastern Cooperative Oncology Group performance status 0 or 1, and carbohydrate antigen 19-9 < 100 U/mL were eligible. Stratification factors were resection status (R0/R1) and lymph node status (positive/negative). Treatment was initiated ≤ 12 weeks postsurgery. Patients received nab-P 125 mg/m2 + Gem 1000 mg/m2 or Gem 1000 mg/m2 on days 1, 8, and 15 of six 28-day cycles. The primary endpoint was disease-free survival by independent review. Secondary endpoints were OS and safety. Results: The updated OS analysis (data cutoff date, January 2020) revealed a median OS of 41.8 months with nab-P + Gem compared with 37.7 months with Gem alone (hazard ratio [HR] 0.81; 95% CI, 0.68 - 0.97; nominal P = 0.047; Table). In each geographic region, the median OS with nab-P + Gem was numerically longer than with Gem alone. Conclusions: The updated OS analysis of the ITT population supports the previously reported trend favoring nab-P + Gem. The geographic regional analyses reveal numerically longer OS with nab-P + Gem vs Gem alone and variable outcomes by region; however, the differences do not support the trend observed in the ITT population, potentially due to limited sample sizes. Registration: EudraCT (2013-003398-91). Clinical trial information: NCT01964430 . [Table: see text]

Metronomic chemotherapy following the maximum tolerated dose as a multitarget antitumor therapy affecting angiogenesis, tumor dissemination, and cancer stem cells

e22057

Background: Metronomic chemotherapy has been suggested as a maintenance administration strategy after the Maximum Tolerated Dose (MTD) treatment in a multi-targeted chemo-switch schedule (C-S). We report the effectiveness of this chemo-switch schedule in mice models of human pancreatic and ovarian cancer. Methods: In pancreas cancer models, Gemcitabine (G) was administered on four different schedules: metronomic (METG), Maximum Tolerated Dose (MTDG), chemo-switch schedule (C-SG, MTDG dosing followed by the METG) and anti-angiogenic (MTDG followed by the administration of monoclonal anti-VEGF receptor antibody DC101). In ovarian cancer model, animals were treated following a Cyclophosphamide chemo-switch schedule (C-S CTX). Results: In all these models C-S schedule had the most favorable effect, reaching at least 80% of tumor growth inhibition in absence of increased toxicity. Moreover, in the pancreas cancer model while peritoneal metastases were observed in control and MTD groups, no dissemination was observed in the MET and C-S groups. C-S treatment caused a decrease in angiogenesis and its effect on tumor growth was similar to obtained by the MTD followed by anti-angiogenic DC101 treatment. At the molecular level, C-S treatment combined an increase in thrombospondin-1 expression with a decrease in number of CD133+ cancer cells and triple positive CD133+/CD44+/CD24+ cancer stem cells. Conclusions: These findings provide confirmation that the chemo-switch schedule is a challenging clinical strategy with demonstrated inhibitory effects on tumor dissemination, angiogenesis and cancer stem cells.

Pimasertib plus gemcitabine in metastatic pancreatic adenocarcinoma: Results of a safety run-in part of a phase II trial

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Background: Activating MAPK pathway mutations (predominantly RAS) occur with a high incidence in metastatic pancreatic adenocarcinoma (mPaCa). Pimasertib is a MEK1/2 inhibitor with potent activity in cell lines and xenografts with an activated MAPK pathway. This two-part trial in patients (pts) with mPaCa comprises a dose-escalation safety run-in and a randomized phase II part (EudraCT 2009-011992-61). We defined the maximum tolerated dose (MTD), safety, pharmacokinetics (PK) and antitumor activity of two pimasertib dosing schedules (S), and the recommended phase II dose (RP2D). Methods: Dose-escalation (3+3 design) in two dosing S of oral pimasertib: once-daily (qd) - 5 days on, 2 days off (S1); and twice-daily (bid) - continuous (S2) combined with the standard dose of gemcitabine (gem). Results: 53 pts (median age 61 years and ECOG performance status 0-1) have been treated at six dose levels in S1 (15 to 120 mg qd) and at 60 and 75 mg bid in S2. MTDs were defined as 120 mg qd and 75 mg bid. Two pts had a dose-limiting toxicity (DLT) in the DLT observation period: a grade (G) 3 confusion with ataxia and disorientation at 60 mg bid and a G4 suicidal ideation at 75 mg bid. G3-4 adverse events (AEs) in >5% of pts were: neutropenia (32%), thrombocytopenia (25%), asthenia (19%), dyspnea (9%), transaminitis (9%), anemia (8%), and diarrhea, pulmonary embolism, pulmonary sepsis (6% each). Most common AEs were asthenia (70%), ocular AEs (68%), skin rash (62%), nausea (58%), diarrhea (58%), peripheral edema (51%), thrombocytopenia (49%), vomiting (45%), mucositis (43%), neutropenia (38%), decreased appetite (36%) and anemia (34%). The main ocular AE was serous retinal detachment (58%); manageable retinal vein occlusion occurred in five pts. PK data were comparable to pimasertib monotherapy and published gem data. Partial responses were noted in 10 pts and stabilisation ≥3 months in 13 pts. Hot spot mutations in genes activating the MAPK and PI3K/AKT pathway and correlation with clinical outcome are being investigated. Conclusions: Pimasertib MTDs were reached. The RP2D was defined as 60 mg bid. PK was dose proportional and associated with target inhibition. Sustained responses were seen in both dosing schedules. Clinical trial information: 2009-011992-61.