Abstract 1079: Pharmacokinetics and biodistribution of LNA-i-miR-221 in NOD.SCID mice and Cynomolgus monkeys
Authors: Di Martino Maria Teresa , Gallo Cantafio Maria Eugenia , Nielsen Boye S. , Arbitrio Mariamena , Gullà Annamaria , Mignogna Chiara , Breda Massimo , Frandsen Niels M. , Tagliaferri Pierosandro , Tassone Pierfrancesco 
Published: July 2016

miRNAs therapeutics is based on the use of oligonucleotide engineered to efficiently replace or sequester endogenous miRNAs. miR-221 is upregulated in several tumors, including multiple myeloma (MM), where it promotes cancer cell proliferation mainly via targeting the negative regulators of G1/S cell cycle progression p27 and/or p57. We previously demonstrated that direct miR-221 inhibition by the use of an original LNA inhibitor, LNA-i-miR-221, induces significant anti-MM activity and upregulates canonical targets in vitro and in vivo.To assess pharmacokinetics (PK)/pharmacodynamics of LNA-i-miR-221, we set-up, and report here, novel assays for oligo quantification in plasma, urine and tissues of NOD.SCID mice and Cynomolgus monkeys. We investigated the LNA-i-miR-221 PKs by UHPLC-MS/MS, following solid-phase extraction, in plasma and urine, and tissue uptake by in-situ hybridization (ISH). In particular, PK profile was calculated by UHPLC-MS/MS after single dose i.p injection of LNA-i-miR-221 (25 mg/kg) in mouse and the Tmax was identified at 1.5 hours with Cmax of 1110 ng/mL. Three hours after bolus injection, the plasma concentration was about 60% reduced and the molecule was not detectable at later time-points. The plasma exposure of the oligo showed an AUClast of 2330 h*ng/mL. Similarly, in monkeys the LNA-i-miR-221 plasma concentration following a single i.v. bolus injection (8.75 mg/kg) peaked at a Tmax of ½ hour, with a Cmax of 23600 ng/mL. The plasma exposure of the oligo showed an AUClast of 49300h*ng/mL, C0 of 61400 ng/mL and the t1/2 was 12.8 hours. Urine PK evaluation was performed in monkey on samples collected from 2 up to 48 hours. The excreted LNA-i-miR-221 was quantified equal to 0.68 mg with a total urinary recovery of approximately 2.68% of the amount injected (25,375 mg). Specifically, the urinary concentration/time-points plot shows the excretion of 9394,5 ng/mL (1.63% of recovery) in the interval of 2-6 hours. In addition, murine tissues analyzed by ISH revealed strong signals and long-lasting accumulation of the oligo in mice vital organs together with upregulation of the main canonical miR-221 target p27, as assessed by IHC. In addition, ISH analysis excluded that the LNA-i-miR-221 crosses the blood-brain barrier. All together PK results demonstrated that LNA-i-miR-221 has a short serum half-life with a rapid tissue uptake and minimum urinary excretion of the intact molecule, with a very long tissue half-life and biological activity. Moreover, we report preliminary toxicity analysis in non-human primates. No changes in the monkeys’ behavior, body weight or food consumption were observed in treated animals.In conclusion our results suggest that LNA-i-miR-221 is a promising anti-MM agent associated with a favorable PK, long-lasting tissue bioavailability and good safety profile in mice and in monkeys, providing the rationale for translation of this novel miR-221 inhibitor in early clinical investigation

Citation Format: Maria Teresa Di Martino, Maria Eugenia Gallo Cantafio, Boye S. Nielsen, Mariamena Arbitrio, Annamaria Gullà, Chiara Mignogna, Massimo Breda, Niels M. Frandsen, Pierosandro Tagliaferri, Pierfrancesco Tassone. Pharmacokinetics and biodistribution of LNA-i-miR-221 in NOD.SCID mice and Cynomolgus monkeys. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1079.