First-in-human phase I study of PRS-050 (Angiocal), an Anticalin targeting and antagonizing VEGF-A, in patients with advanced solid tumors.

BACKGROUND: To report the nonrandomized first-in-human phase I trial of PRS-050, a novel, rationally engineered Anticalin based on human tear lipocalin that targets and antagonizes vascular endothelial growth factor A (VEGF-A). METHODS: Patients with advanced solid tumors received PRS-050 at 0.1 mg/kg to 10 mg/kg by IV in successive dosing cohorts according to the 3+3 escalation scheme. The primary end point was safety. RESULTS: Twenty-six patients were enrolled; 25 were evaluable. Two patients experienced dose-limiting toxicity, comprising grade (G) 3 hypertension and G3 pyrexia, respectively. The maximum tolerated dose was not reached. Most commonly reported treatment-emergent adverse events (AEs) included chills (52%; G3, 4%), fatigue (52%; G3, 4%), hypertension (44%; G3, 16%), and nausea (40%, all G1/2). No anti-PRS-050 antibodies following multiple administration of the drug were detected. PRS-050 showed dose-proportional pharmacokinetics (PK), with a terminal half-life of approximately 6 days. Free VEGF-A was detectable at baseline in 9/25 patients, becoming rapidly undetectable after PRS-050 infusion for up to 3 weeks. VEGF-A/PRS-050 complex was detectable for up to 3 weeks at all dose levels, including in patients without detectable baseline-free VEGF-A. We also detected a significant reduction in circulating matrix metalloproteinase 2, suggesting this end point could be a pharmacodynamic (PD) marker of the drug's activity. CONCLUSIONS: PRS-050, a novel Anticalin with high affinity for VEGF-A, was well-tolerated when administered at the highest dose tested, 10 mg/kg. Based on target engagement and PK/PD data, the recommended phase II dose is 5 mg/kg every 2 weeks administered as a 120-minute infusion. TRIAL REGISTRATION: ClinicalTrials.gov NCT01141257 http://clinicaltrials.gov/ct2/show/NCT01141257.

Phase I clinical and pharmacokinetic study of BBR 3576, a novel aza-anthrapyrazole, administered i.v. every 4 weeks in patients with advanced solid tumors: a phase I study group trial of the Central European Society of Anticancer-Drug Research (CESAR).

BBR 3576 is a novel aza-anthrapyrazole with limited potential for cardiotoxicity in preclinical models. This phase I clinical and pharmacokinetic study was performed to determine the maximum tolerated dose, the dose-limiting toxicity (DLT) and the pharmacokinetic profile of BBR 3576 administered i.v. as a 1-h infusion repeated every 4 weeks. In total, 27 patients were treated at doses starting from 1 to 150 mg/m2. The dose levels 1, 2, 4, 8, 16, 32, 64, 90, 125 and 150 mg/m2 were investigated in one, three, one, three, two, one, three, four, three and six patients, respectively. The DLT was a grade 3 stomatitis at 150 mg/m2. At this dose level as well as at 125 mg/m2, neutropenia grade 3 and 4 were frequently seen, but not reaching the criteria for DLT. Time to neutrophil nadir was about 2 weeks and recovery took place within 1 week. Other bone marrow toxicities were mild; lymphopenia was also observed. No significant drug-induced cardiotoxicity was observed. The plasma concentration versus time curves of BBR 3576 showed a biexponential profile with a linear kinetic behavior. A very large volume of distribution, a high plasma clearance and long elimination half-lives were calculated. Renal unchanged drug excretion was less than 10% and therefore a minor excretion route. No objective antitumor responses were found. On the basis of this study, the recommended dose for phase II studies is 150 mg/m2, although the maximum tolerated dose as per protocol definition was not reached. This trial showed that BBR 3576 has a manageable toxicity profile on a 4-week schedule. Phase II studies have started in patients with solid tumors, as suggested by preclinical data in different in vivo model systems.