Not All Tests Can Be Companion Diagnostics

(This post is by Mia Burns, associate editor for Pharmalive.com.)

In another stumbling block for personalized medicine, MolecularMD has chosen to pull its premarketing approval application to the FDA for its BCR-ABL T315I Mutation Test. The company made this announcement yesterday with Ariad Pharmaceuticals. The test was meant to be a companion diagnostic to be used with Ariad's BCR-ABL inhibitor, ponatinib, which is under FDA review for the treatment of resistant or intolerant chronic myeloid leukemia and Philadelphia-chromosome positive acute lymphocytic leukemia. But the FDA's Center for Devices and Radiological Health told MolecularMD recently that the test is not considered a companion diagnostic for ponatinib. FDA guidance states that for a test to be considered as a companion diagnostic test, it must provide information that is essential for the safe and effective use of a therapeutic product. According to Joshua P. Cohen, Ph.D., Senior Research Fellow, Tufts Center for the Study of Drug Development says while the withdrawal is a minor blow, it will not have major repercussions to the development of personalized medicine.

“Personalized medicine will progress the same way a toddler learns to walk," he says. "The important thing is companies are collaborating at earlier stages in the drug development process to develop therapeutics and tests in tandem. In this respect, they are following FDA guidance on personalized medicine and co-development of test and therapeutic. Ultimately, the more co-developed product combinations companies launch the better off patients will be. Moreover, it is a win-win situation in that other stakeholders, such as payers, providers, and the pharmaceutical industry stand to benefit as well.” In July 2011, Dr. Cohen released a study titled "Lack of clinically useful diagnostics hinder growth in personalized medicines." Among the study findings was the fact that less than 1 percent of currently marketed drugs in U.S. have a companion diagnostic. Lack of clinical usefulness of many companion diagnostics has led payers to deny or restrict reimbursement of tests.

Just 10 percent of currently marketed drugs have pharmacogenomic info on labeling. Of eight drugs reviewed, AstraZeneca’s Iressa presents the highest barriers to developers and payers, followed by Tarceva, Erbitux, and Camptosar. Two widely cited reasons by payers and developers were a lack of evidence supporting efficacy of companion diagnostics and the cost of companion diagnostics. Patients also noted a lack of insurance coverage for companion tests. (Back story can be found here.)

“The input provided by the Agency to MolecularMD regarding its T315I mutation test indicates that the T315I mutation test is no longer required as a companion diagnostic test to identify patients with the BCR-ABL T315I mutation who may be treated with ponatinib,” said Harvey J. Berger, M.D. chairman and chief executive officer of Ariad. “We look forward to continuing our longstanding collaboration with MolecularMD, the world leader in BCR-ABL testing, in clinical trials of ponatinib in patients with CML.” “We are pleased to see ponatinib moving forward in its U.S. regulatory review and look forward to continuing our close involvement with its ongoing and future clinical development as a premier companion diagnostic partner ,” stated Dan Snyder, President, chief operation officer of MolecularMD.

(Image of ponatinib in its binding site courtesy of Hinemash6 on Wikimedia Commons.)

1 Comment

Sep 19, 2012 - 6:08pm
stumbling block for personalized medicine?

this is likely lobbied for by Ariad, as now ponatinib will be labeled more broadly for second-line CML, and not restricted to just the one mutation, as it would have been if approved with the companion diagnostic.