ABSTRACT
Recent efforts to personalize treatment with platinum-based chemotherapy and PARP inhibitors have produced promising results in homologous recombinant deficient (HRD) metastatic pancreatic cancer (MPC). However, new strategies are necessary to overcome resistance. The below case series documents patients treated at the HonorHealth Research Institute with a diagnosis of HRD MPC who received Mitomycin C (MMC) treatment from January 2013 until July 2018. Five HRD MPC patients treated with MMC were evaluated. All patients received at least one course of treatment. Mean age at MMC treatment initiation was 58 years. There were 3 females and 2 males. All patients had tumors that progressed on platinum-based chemotherapy, four patients had previous exposure to Olaparib. The median PFS was 10.1 months, and the median OS was 12.3 months. Responses were observed only in patients harboring BRCA2 mutations, no response was observed in the PALB2 mutation carrier. MMC in this heavily previously treated PC was safe, with overall manageable grade 2 gastrointestinal toxicities including nausea and vomiting, and G3 hematological toxicities including anemia and thrombocytopenia. Pancreatic cancer patients with HRD may benefit from MMC treatment. Further clinical investigation of MMC in pancreatic cancer is warranted.
ABSTRACT
LESSONS LEARNED: This trial evaluating a novel plant extract, PBI-05204, did not meet its primary endpoint of overall survival but did show signals of efficacy in heavily pretreated mPDA. PBI-05204 was generally well tolerated, with the most common side effects related to treatment being vomiting (23.7%), nausea (18.4%), decreased appetite (18.4%), and diarrhea (15.8%). Additional trials are needed to explore the role of PBI-05204 in cancer treatment. BACKGROUND: Survival for metastatic pancreatic ductal adenocarcinoma (mPDA) is dismal, and novel agents are needed. PBI-05204 is a modified supercritical carbon dioxide extract of Nerium oleander leaves. Oleandrin, the extract's major cytotoxic component, is a cardiac glycoside that has demonstrated antitumor activity in various tumor cell lines with a mechanism involving inhibition of Akt phosphorylation and through downregulation of mTOR. METHODS: A phase II, single-arm, open-label study to determine the efficacy of PBI-05204 in patients with refractory mPDA therapy was conducted. The primary endpoint was overall survival (OS), with the hypothesis that 50% of patients would be alive at 4.5 months. Secondary objectives included safety, progression-free survival (PFS), and overall response rate. Patients received oral PBI-05204 daily until progressive disease (PD), unacceptable toxicity, or patient withdrawal. Radiographic response was assessed every two cycles. RESULTS: Forty-two patients were enrolled, and 38 were analyzed. Ten patients were alive at 4.5 months (26.3%) with a median PFS of 56 days. One objective response (2.6%) was observed for 162 days. Grade ≥ 3 treatment-emergent adverse events occurred in 63.2% of patients with the most common being fatigue, vomiting, nausea, decreased appetite, and diarrhea. CONCLUSION: PBI-05204 did not meet its primary endpoint for OS in this study. Recent preclinical data indicate a role for PBI-05204 against glioblastoma multiforme when combined with chemotherapy and radiotherapy. A randomized phase II trial is currently being designed.
