Clinical Trial to Test Safety of Drug Targeting Leukemia Cells

Editor’s note: Researchers have launched a new clinical trial—a research study with volunteer patients—to test a new drug to treat chronic lymphocytic leukemia (CLL). The drug is called cirmtuzumab (also known as UC-961). It targets a protein called ROR1, which is only found in tumors and helps them grow and metastasize. The researchers will enroll 33 to 78 patients with relapsed or refractory (does not respond to treatment) CLL, who will be treated with cirmtuzumab in San Diego.

“Researchers at the University of California, San Diego School of Medicine, in partnership with the California Institute for Regenerative Medicine (CIRM) and Celgene Corporation, a New Jersey-based biopharmaceutical company, have launched a phase 1 human clinical trial to assess the safety and efficacy of a novel monoclonal antibody for patients with chronic lymphocytic leukemia (CLL).

“CLL is the most common form of blood cancer in adults, with more than 15,000 new cases diagnosed each year in the United States. The new antibody targets ROR1, a protein used by embryonic cells during early development that is also exploited by cancer cells to promote tumor growth and metastasis – the spreading of cancer throughout the body that is responsible for 90 percent of all cancer-related deaths.

“ROR1 is not expressed by normal adult cells, making it a specific marker of cancer cells in general and cancer stem cells in particular. Because ROR1 is a primary driver of tumor growth and metastasis, researchers believe it presents an excellent target for anti-cancer therapy.

“Developed at UC San Diego Moores Cancer Center by Thomas Kipps, MD, PhD, who holds the Evelyn and Edwin Tasch Chair in Cancer Research, and colleagues, the antibody is called cirmtuzumab (also known as UC-961). In previous animal studies, Kipps’ team reported that ROR1 is singularly expressed on CLL and also on a variety of different cancers, including cancers of the breast, pancreas, colon, lung and ovary. In mouse models of CLL, ROR1 acts as an accelerant when combined with another oncogene to produce a faster-growing, more aggressive cancer.”