pf-3084014 and Neoplasms

Notch is a key player in various developmental processes during the embryonic stage as well as in regulating tissue homeostasis, cell differentiation, and stem cell maintenance in adult life. Activation of Notch signaling occurs following Notch receptor-ligand interaction and subsequent enzymatic proteolysis by the gamma-secretase complex, resulting in the cytoplasmic release of a Notch intracellular domain, which translocates to the nucleus to initiate the downstream transcriptional machinery. Notch activation and its aberrant signaling have been broadly linked to the pathogenesis of cancer and some chronic inflammatory diseases resulting in pathologic fibrotic processes. This review focuses on the molecular basis of Notch-induced signaling and its interaction with other pathways to identify therapeutic targets. We also highlight current efforts to pharmacologically intervene in Notch signaling and discuss promising ongoing experimental and clinical studies.

Topics: Amyloid Precursor Protein Secretases; Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Carcinogenesis; Clinical Trials as Topic; Fibrosis; Genes, Tumor Suppressor; Humans; Inflammation; Ligands; Neoplasms; Receptors, Notch; Signal Transduction

To estimate the maximum tolerated dose (MTD) for continuous oral administration of the γ-secretase inhibitor PF-03084014, determine the recommended phase II dose (RP2D), and evaluate safety and preliminary activity in patients with advanced solid tumors.. This open-label, phase I study consisted of a dose-finding portion based on a 3+3 design, followed by an expansion cohort. PF-03084014 was administered orally, twice daily (BID) for 21 continuous days. Tested doses ranged from 20 to 330 mg BID. In the expansion cohort, patients were to receive the estimated MTD or a lower dose of PF-03084014.. A total of 64 patients received treatment. The MTD was estimated to be 220 mg BID. The RP2D was determined to be 150 mg BID, based on the better safety profile versus the 220-mg BID dose, given comparable NOTCH-related target inhibition. The most common treatment-related adverse events were diarrhea, nausea, fatigue, hypophosphatemia, vomiting, rash, and decreased appetite, which were generally mild to moderate in severity. One patient with advanced thyroid cancer had a complete response, and five of seven response-evaluable patients with desmoid tumor achieved a partial response (71.4% objective response rate). Tumor responses were mostly durable, ranging from 1.74+ to 24+ months. PF-03084014 demonstrated a generally dose-dependent pharmacokinetic profile at doses ranging from 20 to 330 mg BID. Consistent downmodulation of NOTCH-related HES4 gene expression was observed in peripheral blood from all evaluable patients.. Further development of PF-03084014 for the treatment of patients with advanced solid tumors is warranted and currently under evaluation.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Amyloid Precursor Protein Secretases; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Humans; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Tetrahydronaphthalenes; Treatment Outcome; Valine