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Poster display

4004 - Phase 1/2a study of RX-5902 in advanced solid tumors (ST): An orally bioavailable inhibitor of phosphorylated P68 and modulator of &bgr;-catenin nuclear translocation


10 Oct 2016


Poster display


S. Gail Eckhardt


Annals of Oncology (2016) 27 (6): 114-135. 10.1093/annonc/mdw368


S..G. Eckhardt1, W.L. Gluck2, M. Gutierrez3, C. Peterson4, R. Mazhari5, E. Benaim6

Author affiliations

  • 1 Medical Oncology, University of Colorado Denver, 80247 - Denver/US
  • 2 Clinical Research, Translational Oncology Research, 29605 - Greenville/US
  • 3 Clinical Research, The John Theurer Cancer Center, 07601 - Hackensack/US
  • 4 Clinical Operations, Rexahn Pharmaceuticals, Inc, 20850 - Rockville/US
  • 5 R&d, Rexahn Pharmaceuticals, Inc, 20850 - Rockville/US
  • 6 Chief Medical Officer, Rexahn Pharmaceuticals, 20850 - Rockville/US


Abstract 4004


RX–5902 is a novel compound targeting phosphorylated p68 (p-p68) RNA helicase (ie, DDX5), a member of the DEAD box family of RNA helicases. P-p68 may play a role in cell proliferation and cancer progression by blocking the nuclear translocation of ß-catenin. Final data from the first clinical study of single agent RX-5902 to treat solid tumors and the ongoing Phase 2a in advanced triple-negative breast cancer (TNBC) and ovarian cancer (OC) are described.


This is a Phase 1/2a study (NCT02003092) designed to evaluate safety, tolerability and pharmacokinetics (PK) following increasing doses of RX-5902 at varying schedules. Primary objectives include safety, tolerability and dose limiting toxicities to identify the maximum tolerated dose and a recommended phase 2 dose and schedule (RP2D). Secondary objectives were PK and antitumor activity. Eligible subjects (aged ≥ 18 years) with relapsed/refractory ST received oral RX-5902 at 1, 3, 5 or 7 times per week for 3 weeks followed by 1 week of rest or for 4 weeks. Based on the RP2D of the Phase 1, a Phase 2a is ongoing in patients with advanced TNBC and OC in a 2-stage design.


As of May 2016, 24 subjects were enrolled (11 Females, 13 males). No dose limiting toxicities or treatment related SAEs were reported. Seven subjects experienced stable disease (breast, neuroendocrine, paraganglioma, head/neck and colorectal cancers); 3 subjects received treatment for > 1 year. The most common side effects were grade 1 related adverse events: nausea, vomiting and fatigue; no grade 2 related events were reported. RX–5902 was orally bioavailable with median Tmax of 2 hours and half-life of 12 hours. Doses were successfully escalated to 300 mgs daily for 5 days, with a 3 weeks on, 1 week off schedule. Daily doses of 300-400 mgs daily for 28 days are being tested.


RX-5902 is safe and well tolerated at the doses and schedules tested. Early anti-tumor activity was observed in patients with breast, neuroendocrine, paraganglioma, squamous cell cervical and colorectal cancers. Final results from the phase 1 and data on the first stage of the Phase 2a in patients with TNBC and advanced OC will be presented.

Clinical trial identification


Legal entity responsible for the study

Rexahn Pharmaceuticals, Inc


Rexahn Pharmaceuticals, Inc


C. Peterson, R. Mazhari, E. Benaim: Employee of Rexahn Pharmaceuticals, Inc. All other authors have declared no conflicts of interest.

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