The study is designed to evaluate the safety, pharmacokinetic profile and antitumor activity of escalating doses of SGN-33, and is expected to enroll up to 60 patients at multiple centers in the United States.
The patient population in the trial will include those individuals with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) who are not eligible for intensive chemotherapy or stem cell transplantation as well as those who have failed previous therapy.
SGN-33 targets the CD33 antigen, which is expressed on a number of hematologic malignancies, such as AML, MDS and several myeloproliferative disorders.
Seattle Genetics exclusively licensed the program, including associated patents and clinical grade material, from Protein Design Labs in April 2005. This antibody was previously tested in more than 350 patients, primarily with relapsed and refractory AML. The safety profile and activity, especially in patients with low tumor burden, suggest that this may be an important therapeutic tool for AML and MDS patients, who currently have few treatment options.
“While this antibody has shown activity in previous clinical studies, we believe that by optimizing the dose and administration schedule we have an opportunity to exploit the therapeutic potential of SGN-33,” stated Dr Clay Siegall, president and CEO of Seattle Genetics.