Sun BioPharma, Inc. announced that it has summarized initial Phase 1 clinical data for SBP-101, which was presented in a poster session at the American Society for Clinical Oncology (ASCO) 2020 Gastrointestinal Cancers Symposium. SBP-101 is a proprietary polyamine analogue designed to induce polyamine metabolic inhibition, a metabolic pathway of critical importance in cell function in multiple tumor types. Based upon the study data presented, the adverse event profile of SBP-101 at the optimal dose level was manageable and an expansion study in patients with pancreatic ductal adenocarcinoma is planned to begin during the second quarter of 2020. Preliminary Results Demonstrate Tolerability and Clinical Activity in Metastatic Treatment-Naïve Patients: As of the data cut off date of January 4, 2020, the addition of SBP-101 to the combination of gemcitabine plus nab-paclitaxel did not increase the frequency of grade 3/4 hematologic adverse events, peripheral neuropathy, nausea or diarrhea when compared to historical control data for patients who were treated with gemcitabine plus nab-paclitaxel. The most common adverse events (all grades) attributed to treatment with SBP-101 were fatigue, elevated LFTs, and injection site pain. The most common grade 3/4 adverse event was elevation in liver function tests, which in most cases was asymptomatic, and in all cases reversed when SBP-101 was interrupted and decreased or discontinued. Study results in evaluable subjects enrolled in the two highest dose cohorts (N=13) demonstrated an overall response rate (ORR) of 62%, including 8 partial responses (PRs). The disease control rate was 85% by RECIST criteria. Eleven subjects in those cohorts (69%, N=16) saw a maximum decrease in CA 19-9 of more than 60%. As of January 4, 2020, 8 of 16 subjects remained on study. Median duration of response, progression free survival and overall survival had not been reached. Phase 1a/1b Trial Design: This ongoing multicenter, open label, Phase 1 trial enrolled 20 patients with pancreatic ductal adenocarcinoma across three dose cohorts. Study participants received a subcutaneous dose of SBP-101 at 0.2, 0.4 or 0.6 mg/kg on days 1-5 of each 28-day cycle, in addition to intravenous doses of 1000 mg/m2 of gemcitabine and 125 mg/m2 of nab-paclitaxel on days 1, 8 and 15. The goal of this study was to determine a recommended dose of SBP-101 for further development. Endpoints include safety, tolerability, and pharmacokinetics, in addition to early measures of efficacy including ORR as measured by RECIST, and CA19-9 levels. Based upon preliminary safety and efficacy signals, the protocol was amended to follow subjects for progression-free survival and overall survival.