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Dexamethasone has antitumor activity in metastatic castration resistant prostate cancer (mCRPC). We aimed to investigate intravenous liposome‐encapsulated dexamethasone disodium phosphate (liposomal dexamethasone) administration in mCRPC patients. In this exploratory first‐in‐man study, patients in part A received a starting dose of 10 mg followed by five doses of 20 mg liposomal dexamethasone at 2‐week intervals. Upon review of part A safety, patients in part B received 10 weekly doses of 18.5 mg. Primary outcomes were safety and pharmacokinetic profile, secondary outcome was antitumor efficacy. Nine mCRPC patients (5 part A, 4 part B) were enrolled. All patients experienced grade 1–2 toxicity, one (part B) patient experienced grade 3 toxicity (permanent bladder catheter‐related urosepsis). No infusion‐related adverse events occurred. One patient had upsloping glucose levels ≤9.1 mmol/L. Trough plasma concentrations of liposomal‐ and free dexamethasone were below the lower limit of quantification (LLOQ) in part A, and above LLOQ in three patients in part B (t 1/2 ~50 h for liposomal dexamethasone), trough concentrations of liposomal‐ and free dexamethasone increased toward the end of the study. In seven of nine patients (78%) patients, stable disease was observed in bone and/or CT scans at follow‐up, and in one (part B) of these seven patients a >50% PSA biochemical response was observed. Bi‐ and once weekly administrations of IV liposomal dexamethasone were well‐tolerated. Weekly dosing enabled trough concentrations of liposomal‐ and free dexamethasone >LLOQ. The data presented support further clinical investigation in well‐powered studies. Clinical trial registration: ISRCTN 10011715., This trial is the first to report pharmacokinetic profile, safety and efficacy outcomes using weekly and bi‐weekly IV administered liposomal dexamethasone in mCRPC. Liposomal dexamethasone was well toleratedDutch Healthcare Institute. Systemic corticosteroids. Farmacotherapeutisch kompas. Consulted 2020. DD and considerably prolonged plasma half‐life of dexamethasone. Additional study is needed to determine targeting and patient outcomes with this regimen.

Fluorescence molecular endoscopy (FME) is an emerging technique that has the potential to improve the 22% colorectal polyp detection miss-rate. We determined the optimal dose-to-imaging interval and safety of FME using EMI-137, a c-Met-targeted fluorescent peptide, in a population at high risk for colorectal cancer. Methods: We performed in vivo FME and quantification of fluorescence by multidiameter single-fiber reflectance/single-fiber fluorescence spectroscopy in 15 patients with a dysplastic colorectal adenoma. EMI-137 was intravenously administered (0.13 mg/kg) at a 1-, 2- or 3-h dose-to-imaging interval (n = 3 patients per cohort). Two cohorts were expanded to 6 patients on the basis of target-to-background ratios. Fluorescence was correlated to histopathology and c-Met expression. EMI-137 binding specificity was assessed by fluorescence microscopy and in vitro experiments. Results: FME using EMI-137 appeared to be safe and well tolerated. All dose-to-imaging intervals showed significantly higher fluorescence in the colorectal lesions than in surrounding tissue, with a target-to-background ratio of 1.53, 1.66, and 1.74 for the 1-, 2-, and 3-h cohorts, respectively, and a mean intrinsic fluorescence of 0.035 vs. 0.023 mm-1 (P < 0.0003), 0.034 vs. 0.021 mm-1 (P < 0.0001), and 0.033 vs. 0.019 mm-1 (P < 0.0001), respectively. Fluorescence correlated with histopathology on a macroscopic and microscopic level, with significant c-Met overexpression in dysplastic mucosa. In vitro, a dose-dependent specific binding was confirmed. Conclusion: FME using EMI-137 appeared to be safe and feasible within a 1- to 3-h dose-to-imaging interval. No clinically significant differences were observed among the cohorts, although a 1-h dose-to-imaging interval was preferred from a clinical perspective. Future studies will investigate EMI-137 for improved colorectal polyp detection during screening colonoscopies.