The phase 1/2, open-label, multi-center clinical trial is designed to evaluate the safety and activity of 33A administered in combination with azacitidine in patients with previously untreated International Prognostic Scoring System (IPSS) Intermediate-2 or high risk MDS. Phase 1 of the study will identify the recommended dose of 33A when combined with azacitidine in this patient population. The phase 2 portion of the trial will be a randomized, double-blind, placebo-controlled study evaluating azacitidine with or without 33A.The primary endpoint in phase 1 is determination of the recommended 33A dose in combination with azacitidine. The primary endpoint in phase 2 is to compare the overall response rate between the two treatment arms. The secondary endpoints include evaluation of safety, best response, duration of response, progression-free survival and overall survival. The phase 1/2 trial will enroll approximately 130 patients at approximately 35 centers in North America.In addition to this MDS trial, Seattle Genetics is evaluating 33A broadly across multiple lines of therapy in patients with AML, including the following ongoing trials:
- A phase 1 trial of 33A monotherapy and in combination with HMAs in AML patients who have relapsed/declined intensive frontline therapy or are newly diagnosed;
- A phase 1b trial in combination with standard of care intensive chemotherapy, including cytarabine and daunorubicin, for younger fit patients with AML; and,
- A phase 1/2 trial in patients with relapsed or refractory AML evaluating 33A monotherapy as a pre-conditioning regimen prior to an allogeneic stem cell transplant and also for use as maintenance therapy following transplant.
