CHICAGO and SAN FRANCISCO, June 4, 2011 /PRNewswire/ -- Nektar Therapeutics (Nasdaq: NKTR ) today announced positive results from a Phase 2 clinical study evaluating single-agent NKTR-102 as a second- and third-line treatment in patients with metastatic breast cancer during the 2011 American Society of Clinical Oncology Meeting (ASCO). NKTR-102, a next-generation topoisomerase I inhibitor, is Nektar's lead oncology drug candidate and is being evaluated in multiple cancer indications. The randomized Simon two-stage study presented at ASCO evaluated two 145 mg/m2 dose schedules of single-agent NKTR-102, every two weeks (q14d) and every three weeks (q21d), in 70 metastatic breast cancer patients who failed a prior taxane therapy. Eighty-nine percent (62/70) of patients in the study received a prior anthracycline/taxane with or without capecitabine.
More than one million women worldwide are diagnosed with breast cancer every year and the disease is the leading cause of cancer-related death among women.(1)
A total of 66 of the 70 patients treated with single-agent NKTR-102 in the Phase 2 study were assessable for the primary endpoint of objective tumor response rate (ORR), including confirmed complete responses (CRs) and partial responses (PRs) per RECIST 1.0. As of May 9, 2011, for the q14d day schedule, the confirmed and unconfirmed ORR was 35 percent (11/31) and the confirmed ORR was 32 percent (10/31), including two confirmed CRs. Clinical benefit rate for the 31 evaluable patients in the q14d schedule was 42% (13/31) (defined as confirmed CR+ PR+ Stable Disease (SD) >6 mos). For the q21d schedule, the confirmed and unconfirmed ORR was 31 percent (11/35) and the confirmed ORR was 26 percent (9/35). Clinical benefit rate for the 35 evaluable patients in the q21d schedule was 49% (17/35). Clinical benefit rate for t