Abstract 3913
Background
RX-3117 is an oral small-molecule hypomethylating agent, cyclopentyl pyrimidyl nucleoside that is activated by uridine cytidine kinase 2. RX-3117 shows efficacy in various xenograft models, including those of gemcitabine resistant bladder and colorectal cancers. Data from the stage 1 of a Phase 2a clinical study of RX-3117 as a single agent in subjects with advanced urothelial cancer are described below.
Methods
This Phase 2a study with a 2-stage design (NCT02030067) evaluates the efficacy of RX-3117 in eligible subjects (aged ≥ 18 years) with advanced urothelial cancer previously treated with an unlimited number of prior therapies. Primary objectives include safety and efficacy of the recommended Phase 2 dose (RP2D) and schedule identified in the Phase 1 portion of the study. Subjects received 700 mg of oral RX-3117 daily for 3 weeks with 1 week of rest in each 4-week cycle. The response criteria of complete response or partial response in 1 or more subjects or stable disease for 4 cycles in 2 or more subjects in Stage 1 in order to proceed to Stage 2.
Results
As of May 2017, 10 subjects with advanced urothelial cancer were treated with RX-3117 (4 females, 6 males). Of those 10 subjects, 70% received ≥ 3 prior therapies, had performance score of 0-1 and multiple disease sites (lung, liver, lymph nodes and pelvis). Two subjects met the protocol defined response criteria of stable disease for 4 cycles of RX-3117 treatment; one subject received treatment for 168 days and another subject continues receiving therapy (147 days at abstract submission). In addition, 1 subject showed tumor shrinkage as measured by RECIST (-15%); another subject still on treatment showed a 19% tumor reduction after 2 cycles of RX-3117. Related adverse events were G2 anemia, G1 anorexia, G1 epistaxis, G1 fatigue, G1 nausea, G1 diarrhea, G1/G2 vomiting, G2 mucositis, G3 leukopenia, G1/G3 neutropenia, and G3 thrombocytopenia. One subject had a treatment delay and dose reduction.
Conclusions
Single agent RX-3117 appears to be safe and well tolerated and shows evidence of preliminary tumor activity. The predefined efficacy criteria was met in Stage 1, and Stage 2 is ongoing. Results from Stage 1 of the phase 2a will be presented.
Clinical trial identification
NCT02030067
Legal entity responsible for the study
Rexahn Pharmaceuticals, Inc
Funding
Rexahn Pharmaceuticals, Inc
Disclosure
J. Poore, C. Peterson, E. Benaim: Employee of Rexahn Pharmaceuticals, Inc. All other authors have declared no conflicts of interest.