ARRY-520 inhibits kinesin spindle protein, or KSP, which plays an essential role in mitotic spindle formation. KSP inhibitors induce proliferating cells to die by disrupting mitotic spindle formation during cell division.

ARRY-520 has shown promising clinical activity. In a Phase 1 dose-escalation study, we enrolled patients with relapsed or refractory MM—each of whom had received at least two prior lines of therapy (including both Velcade® (bortezomib)—and an IMiD-based regimen such as Revlimid® (lenalidomide)) with a median of five prior therapies. In December 2010, we presented Phase 1 interim results of 32 treated patients. Anti-tumor activity was observed in patients and there were responses in both relapsed and refractory patients. In addition, select patients demonstrated a long duration of response and durable stable disease.

Also during fiscal 2011, we completed patient enrollment in a Phase 2 single-agent trial of ARRY-520 in patients with relapsed or refractory MM. We expect to announce interim results of this Phase 2 trial by calendar year end. We are expanding this Phase 2 study with a combination of ARRY-520 and dexamethasone in patients with refractory MM. We continue to enroll a Phase 1b combination study of ARRY-520, Velcade and dexamethasone in patients with relapsed and refractory MM. We currently have a safety database with over 135 patients treated with ARRY-520, with multiple patients treated in excess of 1 year. In addition to our efforts, M.D. Anderson, in collaboration with Array and Onyx Therapeutics, Inc., initiated an investigator-sponsored Phase 1b study with ARRY-520 and carfilzomib in patients with refractory MM.

Scientific Posters

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