Seattle Genetics starts phase 1 trial of SGN-CD352A in relapsed or refractory multiple myeloma

SGN-CD352A is an investigational CD352-targeted antibody-drug conjugate (ADC) utilizing Seattle Genetics’ proprietary ADC technology, an engineered cysteine antibody (EC-mAb) stably linked to a highly potent cytotoxic agent called a pyrrolobenzodiazepine (PBD) dimer.

CD352 is broadly expressed on B-cell cancers including multiple myeloma, chronic lymphocytic leukemia and non-Hodgkin lymphoma, while exhibiting low expression on normal white blood cells.

The trial is designed to assess the safety and antitumor activity of SGN-CD352A. This study represents Seattle Genetics’ first clinical-stage ADC program in development for MM, demonstrating the breadth of potential therapeutic applications for its industry-leading ADC technology platform.

Robert Lechleider, M.D., Senior Vice President, Clinical Development at Seattle Genetics, said: “More than 124,000 people worldwide are diagnosed annually with multiple myeloma, most relapsing or becoming resistant to current therapies.

“SGN-CD352A is a novel targeted investigational compound for multiple myeloma, and it is our latest antibody-drug conjugate, or ADC, in an expanding and robust pipeline of clinical stage empowered antibody therapies to address blood cancers and solid tumors. As we begin clinical development of our first compound for multiple myeloma, we continue to explore the broad potential of our ADC technology platform for people with cancer.”

The phase 1, open-label multicenter clinical study is designed to evaluate the safety and preliminary antitumor activity of SGN-CD352A as a single agent in adults with relapsed or refractory MM.

The trial will be conducted in two parts, with a dose escalation part to identify the maximum tolerated dose of SGN-CD352A followed by an expansion part to further define safety and antitumor activity. SGN-CD352A will be administered every four weeks, and the study will enroll approximately 75 relapsed or refractory patients at multiple centers in the United States.

Preclinical SGN-CD352A data presented at the 2016 American Association of Cancer Research (AACR) Annual Meeting demonstrated that SGN-CD352A specifically binds to target cells and induces potent antitumor activity in both MM and non-Hodgkin lymphoma disease models.

In addition to being a potential new monotherapy for MM, the tolerability profile from preclinical results suggests that SGN-CD352A may be combined with current standard of care treatments for MM.

ADCs are designed to selectively deliver cell-killing agents to tumor cells, and thus may reduce many of the toxic effects of traditional chemotherapy while enhancing antitumor activity. With more than 15 years of experience and innovation, Seattle Genetics is the leader in ADC development.