Unither | United Therapeutics Corporation

ch14.18 MAb for Neuroblastoma

In July 2010, we entered into a Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute (NCI) of the United States National Institutes of Health to collaborate on the late-stage development and regulatory agency submissions of Chimeric Monoclonal Antibody14.18 (Ch14.18) for children with high-risk neuroblastoma and patients with other forms of cancers. Ch14.18 is an antibody that has shown potential in the treatment of certain types of cancer by targeting GD2, a glycolipid on the surface of tumor cells. Neuroblastoma is a rare cancer of the sympathetic nervous system mainly affecting children. It is the most common extracranial, outside the skull, solid cancer in children and the most common cancer in infants. There are fewer than 1,000 new cases of neuroblastoma diagnosed each year. Ch14.18 is a chimera, composed of a combination of mouse and human DNA, monoclonal antibody that induces antibody dependent cell-mediated cytotoxicity, a mechanism of cell-mediated immunity whereby the immune system actively targets a cell that has been bound by specific antibodies.

Results from NCI’s phase III study were published in September 2010. In that study, immunotherapy with Ch14.18 significantly improved patient outcome compared with standard therapy in patients with high risk neuroblastoma. Specifically, the two-year estimate for event-free survival was 66%±5% in the Ch14.18 immunotherapy group and 46%±5% in the standard therapy group (p=0.01 without adjustment for interim analyses). The Ch14.18 immunotherapy group was also significantly better than the standard therapy group in the estimated rate of overall survival (86%±4% vs. 75%±5% at two years, p=0.02 without adjustment for interim analyses). This study was coordinated by the Children’s Oncology Group, a national consortium of researchers supported by the NCI.

Under the terms of the CRADA, NCI has completed a second phase III clinical trial in 105 patients to define more clearly the safety and toxicity profile of Ch14.18 immunotherapy in children, and we are developing the commercial production capability for the antibody. As part of developing our commercial production capability, we will need to demonstrate comparability of our Ch14.18 to the NCI-produced Ch14.18, which typically includes a series of analytical and bioanalytical assays and human pharmacokinetics. The human pharmacokinetics study is currently open to enrollment in the United States.

The NCI studies, including a previously-conducted phase III clinical trial and all other necessary studies supported by NCI, have been used as the basis for a marketing authorization application we filed with the European Medicines Agency in December 2013 seeking approval of Ch14.18 immunotherapy for the treatment of neuroblastoma. We also expect to file a biologics license application with the FDA during the first half of 2014.

We have received orphan drug designation for Ch14.18 from the FDA and the EMA.