The CD33 antigen is expressed on a number of hematologic malignancies, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), myelodysplastic syndrome and several myeloproliferative disorders. Due to its limited expression on normal cells, both unconjugated antibodies with effector function and antibody-drug conjugates (ADCs) have therapeutic potential in these diseases.
Under the license agreement, Seattle Genetics receives exclusive rights to PDL’s anti-CD33 program and associated US patents and patent applications, as well as supplies of clinical grade material and a non-exclusive CD33 license under PDL’s antibody humanization patents.
PDL will receive an upfront fee, progress-dependent milestone payments and royalties on net sales of any resulting commercial products. In addition, Seattle Genetics has agreed to reduce the royalties payable by PDL, with respect to a limited number of products that PDL may develop under the existing ADC collaboration between the two companies.