Administered as a single agent, SNS-595 demonstrated anti-tumor activity, with 88% (15 of 17) of evaluable patients having best responses of stable disease or better, including two partial responses (PRs). Based on these results, SNS-595 has achieved the pre-specified criterion (two or more responses) for proceeding to the second stage of this trial.
Patients received SNS-595 once every three weeks by IV infusion for up to eight cycles. SNS-595 was generally well tolerated at the current dosing level among 19 patients with sufficient follow-up to yield safety data. Incidence of febrile neutropenia was 11% (2 of 19) among these patients. In addition, 5% (1 of 19) of these patients experienced grade 3/4 nausea and 11% (2 of 19) of these patients experienced grade 3/4 fatigue.
Of the 15 evaluable patients who achieved stable disease or PRs, eight remain on study and are continuing to receive additional cycles of treatment. Of note, four of the patients with measurable tumor shrinkage, including the two patients with PRs, previously failed prior platinum-containing regimens and treatment with doxorubicin HCl liposome injection (Doxil). Of the two patients with PRs, one has received eight cycles of treatment and continues on study. The other patient progressed within 60 days of initial response.
Daniel Adelman, senior vice president, development and chief medical officer of Sunesis, said: “We are pleased to report SNS-595’s early, yet positive, demonstration of clinical activity. We have met the pre-specified criterion to advance this compound to the second stage of our Phase II clinical trial, by showing sufficient evidence of anti-tumor activity.”