Abstract 1319: A novel formulation of CX-5461, a small-molecule inhibitor of rRNA synthesis, and its use for treatment of acute myeloid leukemia models
Notice bibliographique
Résumé
Abstract CX-5461 is a RNA polymerase I inhibitor currently in Phase I clinical trial in Australia for patients with advanced hematologic malignancies. In the pre-clinical setting, CX-5461 is efficacious in a wide range of hematologic and solid tumor models when given orally or intraperitoneally. Currently, the compound is given intravenously (iv) in the first-in-human clinical trial. CX-5461 is solubilized in low pH (3.5) 50 mM sodium phosphate as it is sparingly soluble in water (<1 mg/mL) and at physiological pH. The use of such low pH phosphate buffers affects infusion tolerance. While CX-5461 has nanomolar range activity in vitro, in vivo studies are conducted with either high dosages or frequent dosing. The chemical structure of CX-5461 also suggests potential drug instability under physiological conditions. We have addressed these solubility and stability issues by developing a lipid-based nanoparticulate (LNP) formulation which relies on a previously unrecognized interaction between CX-5461 and copper. Copper (Cu) coordination with CX-5461 was demonstrated using 1H NMR and UV-Vis. Cu-LNPs were prepared with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and cholesterol (CHOL) (55:45 molar ratio) using extrusion methods. CX-5461 was loaded into Cu-LNPs at 60°C for 30 minutes and the external buffer was exchanged to Hepes Buffered Saline (pH 7.4). Pharmacokinetic (PK) studies were performed in CD-1 mice given a dose of 30 mg/kg (iv) and plasma concentrations of CX-5461 were determined by HPLC. Efficacy studies were performed in RAG2M mice with established subcutaneous (sc) MV-4-11 tumors and in a MV-4-11 bone marrow engraftment model (30 mg/kg given iv, Q4Dx3). Our 1H NMR data suggests that CX-5461 binds to copper at a 1:1 molar ratio. Copper complexation does not affect the anticancer activity of CX-5461 as determined in several cancer cell lines in vitro. Using copper-complexation as a driving force, CX-5461 was efficiently loaded into LNPs (∼100 nm) prepared to contain copper (300 mM CuSO4). Resulting LNPs have a drug-to-lipid-ratio of 0.2. The LNP formulation has significantly improved the PK profile of CX-5461 and increased the total exposure to drug by an order of magnitude (AUC = 4156 μg-hr/mL for LNP and 319 μg-hr/mL for free CX-5461). The LNP formulation of CX-5461 is more active than the current low-pH formulation of CX-5461 when given iv in leukemia xenograft models. Specifically 37 days after sc tumor cell inoculation the tumor sizes were 720 mm3 and 240 mm3 in control and LNP-CX5461-treated animals respectively. The clinical formulation administered at the same dose exhibited tumor volumes that were comparable to the untreated controls. We have generated the first LNP formulation of CX-5461 using the copper complexation technology developed in our laboratory. LNP-CX-5461 is suitable for iv administration and is more efficacious than the current formulation in our pre-clinical studies. Citation Format: Ada W.Y. Leung, Malathi Anantha, Kathleen E. Prosser, Mohamed Wehbe, Charles J. Walsby, Marcel B. Bally. A novel formulation of CX-5461, a small-molecule inhibitor of rRNA synthesis, and its use for treatment of acute myeloid leukemia models. [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 1319.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».