Most recent news items about mesothelioma focus on asbestos litigation and lawyer advertising for clients to file cases, bankruptcy trust claims, or both. A recent news story, however, focuses on a potential treatment option for patients with mesothelioma. The U.S. Food and Drug Administration (FDA) recently granted a drug in development to treat malignant pleural mesothelioma “orphan drug” designation. The FDA’s Office of Orphan Products Development grants “orphan drug” designation to some new drugs that may be effective at treating diseases that affect fewer than 200,000 Americans. Orphan drug status provides incentives to companies to develop drugs that might otherwise be unprofitable, and a company can use the exclusivity to develop drugs that anyone else might develop but do not have a large affected population. The FDA’s designation gives drug creators grant funding, tax credits for certain research, a waiver of the Biologics License Application user fee, and the potential for marketing exclusivity in the United States for seven years.
The drug, CRS-207, is being made by Aduro Biotech, Inc. (Aduro). While trials of CRS-207 are ongoing, interim results were presented at the International Mesothelioma Interest Group Conference in October 2014. When CRS-207 was combined with chemotherapy, 75% of patients showed partial positive response and another 19% showed no change in their mesothelioma. Additionally, patients taking CRS-207 were estimated to live 7.5 months without progression of their mesothelioma (compared to 5.7 months in patients not taking CRS-207). Moreover, one patient taking CRS-207 showed no disease progression for 19 months. There was no discussion that these results were unexpected, but at least Aduro is taking CRS-207 through the motions of the clinical trials.
CRS-207 is intended for patients who have not undergone prior therapy and who are not eligible for surgical resection. The drug reportedly works by weakening mesothelial tumors and making them more susceptible to other treatments such as chemotherapy. CRS-207 is a genetically engineered bacteria that causes the immune system to attack mesothelin, a naturally occurring protein in the human body. Since mesothelin can be over-expressed on the surface of a mesothelial tumor cells, the protein essentially “flags” the tumor in ways that were known to researchers. CRS-207 works by finding these flags, attacking and weakening the tumor, and making the them more susceptible to other treatments which may otherwise be ineffective.