to be approved with a companion test, back in 1998. Progress has been slow since, however. According to a study published in July 2011 by Joshua Cohen at the Tufts Center for the Study of Drug Development in Boston, less than one percent of drugs available in the U.S.—most of them cancer drugs—have a companion diagnostic.
Part of the problem, Cohen determined, is that insurers are reluctant to reimburse for the tests because there is not enough proof to justify the cost that using them improves the efficacy of the drugs. But most of the existing tests were developed after the drugs they’re paired with were already on the market. Stephen Little, Qiagen’s vice president of personalized healthcare, told me in an interview that co-developing a test with a drug is a different story. “Once the FDA approves the drug and the test in tandem, based on clinical evidence, reimbursement is pretty straightforward,” he said.
The FDA has made it clear in numerous forums that it is keen to issue such joint approvals. In the summer of 2011 the agency issued draft guidelines for the development and regulatory approval of companion diagnostics in order to set up a clear pathway and speed such co-developments along.
Cancer is particularly suited to test/drug pairing, thanks to the discovery of more and more genetic mutations associated with cancer. The shift in oncology to targeted therapies over the last decade has made the search for diagnostics that can identify patients with those targets an obvious scientific, and business, strategy. “A successful diagnostic will clearly enhance the benefit to risk ratio,” said Andrew Dorner, vice president of translational medicine for Millennium: The Takeda Oncology Company in Cambridge, MA. “I think the general strategy for pharmaceutical development now is to understand how we can select those patients most likely to respond to a drug.” That both speeds up clinical trial enrollment and makes it easier to prescribe the drug to the correct patients if and when it’s approved, he said.
In fact, a companion diagnostic developed by Qiagen for AstraZeneca’s (NYSE: [[ticker:AZN]]) lung cancer drug gefitinib (Iressa) basically saved the drug. Gefitinib won FDA approval in 2003 for non-small cell lung cancer but its use was soon severely restricted
