Eli Lilly and Company (NYSE: LLY) announced data from its Phase II study with cixutumumab in five subtypes of sarcoma, a cancer that develops from connective tissues in the body. Study results demonstrated that 57 percent of patients with a soft tissue sarcoma known as adipocytic sarcoma (a rare tumor that develops from fat cells) experienced stable disease. Results from the Phase II study will be presented on Monday, June 6 at 4:15 p.m. CDT during the Sarcoma Oral Abstract Session (Abstract #10004) at the 47th Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Ill.
Cixutumumab is a monoclonal antibody that targets the insulin-like growth factor-1 (IGF-1) receptor. The IGF pathway plays a major role in cancer cell proliferation, survival and resistance to therapy. Soft tissue sarcomas and the related Ewing family of tumors both have an overabundance of IGF-1 receptors on their surface. Preclinical and clinical studies have demonstrated that blocking the IGF-1 receptor may prevent IGF-1 signaling and therefore cancer growth.
This trial assessed progression-free survival as a primary endpoint in 113 patients with advanced or metastatic soft tissue sarcoma and Ewing family of tumors who were treated with cixutumumab. It used the Simon optimal two-stage design, a widely accepted method for determining the sample size in Phase II clinical trials, in which a pre-determined number of patients are treated in the trial's first stage; the trial is then halted and the response rate assessed. If a pre-specified minimal response rate has not been achieved, it is determined that the treatment is not worth pursuing and the trial is ended. Otherwise, the trial proceeds to a second stage, which continues until a pre-determined number of patients are enrolled.
The five tiers evaluated included: those with previously treated, advanced or metastatic rhabdomyosarcoma (tumors in muscles attached to bones); leiomyosarcoma (rare cancerous tumor of the smooth muscle cells); adipocytic sarcoma (rare tumor that develops from fat cells); synovial sarcoma (malignant tumor that develops in the synovial membrane of the joint); and Ewing sarcoma/peripheral primitive neuroectodermal tumor (tumor that forms in bone or soft tissue). Patients received cixutumumab 10 mg/kg intravenously over one hour every other week until disease progression or discontinuation for other reasons.
Patients were assessed at the completion of stage one (12 weeks). Stable disease was seen in 57 percent. Ewing sarcoma/peripheral primitive neuroectodermal tumor) was ended at the completion of stage one because the pre-specified response rate threshold was not met.
Among all enrolled patients in the trial, the most frequent treatment-related adverse events were hyperglycemia (high blood sugar) in 5 percent of patients.
"This study is just one example of Lilly Oncology's commitment to finding therapeutic options in difficult-to-treat cancers," said Richard Gaynor, M.D., vice president of product development and medical affairs at Lilly Oncology.