SUNESIS REPORTS PROGRESS IN LUNG CANCER TRIALS

Sunesis Pharmaceuticals has reported initial results from the first stage of two Phase II clinical trials of SNS-595, a novel cell-cycle inhibitor, in first-line relapsed/refractory small-cell and non-small-cell lung cancer. Antitumor activity was observed, including evidence of stable disease, minor responses and partial responses reported in one arm of the small-cell lung cancer study, and minor and mixed responses and stable disease in the non-small-cell lung cancer trial.

Both clinical trials used a two-stage design, enabling an interim assessment of clinical activity in order to determine next steps for the compound's evaluation in each tumor indication. All patients received doses of 48 mg/m2 every three weeks, the maximum-tolerated dose identified in Phase I clinical trials.

The small-cell lung cancer clinical trial included two arms of relapsed or refractory patients -- treatment sensitive and treatment refractory. With nine of 11 evaluable patients in the treatment-sensitive arm of the trial having stable disease or objective responses by the end of two cycles of treatment, the clinical results have exceeded the prespecified requirement of at least two partial or complete responses in the first 20 evaluable patients for advancing to stage two. Based on the interim data analysis, Sunesis plans to continue Phase II clinical evaluation of SNS-595 in treatment-sensitive small-cell lung cancer patients who had previously responded to first-line therapy but subsequently relapsed after more than three months.

In the second arm of the small-cell lung cancer trial, 20 evaluable patients classified as treatment refractory were enrolled. Although there were reports of stable disease, and one minor response, none of the patients in this arm of the trial achieved an objective response. Based on these data, Sunesis will discontinue enrollment in this arm.

Sunesis' Phase II clinical trial of non-small-cell lung cancer patients enrolled a total of 25 evaluable patients who had previously failed first-line therapy. More than 50 percent of patients achieved stable disease or better, including some minor and mixed responses. However, objective responses have not been observed to date. Based on the strict requirements of the trial design, Sunesis does not expect to enroll additional patients in this trial.