The future of cancer therapy and molecular diagnostics lies with personalized medicine, with each new drug coming to market with a companion diagnostic. The FDA and its physician panels are getting much more serious about the need for the latter as evidenced by some recent news (see: A Push to Tie New Drugs to Testing). Below is an excerpt from the story:
The Food and Drug Administration last year rejected the company’s drug to treat a subset of leukemia patients whose tumors had a particular genetic mutation. The main problem was not the drug itself, the agency said. Rather, ChemGenex had not specified a companion test that could reliably detect the mutation so that the drug could be given to the patients it is intended to help. These days, it is often not enough for pharmaceutical companies simply to bring a drug to market. Regulators and insurers are also prodding the companies to develop tests to pinpoint which patients are most likely to benefit from a drug, thereby sparing other patients from needless side effects and expense. The pressure has thrust drug and diagnostics companies into sometimes awkward partnerships aimed at developing such tests, which are called companion diagnostics. There were at least 25 such deals in 2010 and 15 in the first half of 2011, up from only seven in 2008....But the simultaneous approval of new drugs and tests is still rare....There are numerous economic, scientific and regulatory obstacles to developing companion diagnostics, executives and analysts say. Often, scientists simply do not know what to test for to predict a drug’s effectiveness, or they don’t find out until near the end of the drug’s clinical trials. And coordinating development and approval of a drug and a test — by two separate companies reviewed by two F.D.A. divisions — can raise the cost of drug development if not done well....Moreover, it is often a dance between a giant and a pixie, locked in an embrace but with a tendency to move in opposite directions. Pharmaceutical companies can spend hundreds of millions of dollars to develop a drug, then can reap billions of dollars a year in sales with high profit margins. Diagnostic companies typically spend several million dollars to develop a test, with annual revenues also around that level, and low profit margins. For pharmaceutical companies, the risk is that a test can lower sales of their drugs by restricting use to a fraction of potential patients.
I am having some trouble believing the claim that pharmaceutical companies "scientists simply do not know what to test for to predict a drug’s effectiveness, or they don’t find out until near the end of the drug’s clinical trials." It's highly unlikely that a pharmaceutical company would invest millions, or even billions, of dollars in the development of a new drug and not have a deep understanding of its mode of action or gene target. If this is the case, then they surely would have some idea about how to develop a companion diagnostic. This latter knowledge is also increasingly important in the research subject selection during drug trials. The companion diagnostic can be used to choose the ideal research subjects for inclusion in the trials and, in so doing, increase the therapeutic effect of the drug.
No, I think that the root of the problem is embedded in the following two points: (1) drug companies want to try to avoid the availability of a companion diagnostic because its presence would reduce the number of potential drug recipients; and (2) they are uncomfortable partnering with diagnostic companies which would hold key scientific knowledge and whose performance could put the success of the new drug at risk.
What we now see with the ChemGenex case cited above is an FDA physician panel stressing the need for companion diagnostics for new anti-cancer agents that can cost thousands of dollars per month. Here's a relevant quote about this topic from another article emphasizing the criticality of a "single clean, validated [companion] diagnostic test "(see: ChemGenex shares battered after FDA panel setback):
Members of the [FDA oncology] panel [that reviewed the ChemGenex drug application] raised questions about the company's trial data and its testing strategy. The therapy is designed to treat leukemia in patients with a specific genetic mutation, and researchers used various tests to identify patients for the clinical trials. The experts want a single clean, validated diagnostic test to make sure the right patients are being given the drug. "...."I doubt it will be years, but I suspect it will be months" before a test can be validated, said ChemGenex CMO Adam Craig. ...."This is something that just represents fairly sloppy drug development," said Gail Eckhardt, the panel chairwoman.
This article is quite intriguing. Isn't the goal of pharmaceutical companies is to develop a much better and effective drug to combat ailments. hmmmmm
Posted by: lixus rip blend | January 07, 2012 at 03:26 AM