RX-5902: A phosphorylated p68 targeting agent to treat subjects with advanced solid tumors.

Abstract

TPS778 Background: Phosphorylated p68 may play a vital role in cell proliferation and tumor/cancer progression. RX-5902 is a novel compound that targets phosphorylated p68 RNA helicase (also known as DDX5), a member of the DEAD box family of RNA helicases. As a single agent, RX-5902 inhibits tumor growth and enhances survival in a variety of xenograft tumor models (e.g., pancreatic, renal, ovarian, melanoma). Methods: This Phase 1, open-label, multicenter study evaluates the efficacy and safety of RX-5902 in subjects with solid tumors. RX-5902 is administered orally 1, 3 or 5 times per week for 3 weeks with 1 week of rest in each 4 week cycle. Dose escalation starts with an accelerated design treating 1 subject per dose followed by a standard 3 + 3 design using a modified Fibonacci sequence after the occurrence of a single Grade 2 or greater adverse event that is considered at related to RX-5902. The primary endpoint is the overall safety profile characterized by the type, frequency, severity, timing of onset, duration and relationship to study therapy of any adverse events, or abnormalities of laboratory tests or electrocardiograms as well as the description of any dose limiting toxicities that occur during Cycle 1, serious adverse events, or adverse events leading to discontinuation of study treatment. Secondary endpoints include pharmacokinetic parameters (e.g., time to maximum observed concentration [Tmax], maximum observed plasma concentration [Cmax], trough concentration [Ctrough], area under the concentration-time curve [AUC]) and Indices of anti-tumor activity (e.g., overall response rate, time to response, duration of response, and progression-free survival during treatment. Exploratory endpoints are biochemical levels of drug targets in blood and tumor samples. Eligible subjects must have confirmed histologic or cytologic evidence of metastatic or locally advanced solid neoplasm that has failed to respond to standard therapy, progressed despite standard therapy or for which standard therapy does not exist. There is no limit on the number of prior treatment regimens. Clinical trial information: NCT02003092.