RICHARD EPSTEIN: THE OTHER DRUG WAR:
Earlier this month, the Food and Drug Administration rejected the application of Biomarin Pharmaceutical to market its drug KyndrisaTM (drisapersen) for use in the treatment of Duchenne muscular dystrophy. The FDA, as is often the case when it rejects a drug application, listed all sorts of technical reasons why the data presented was not sufficient to establish by respectable scientific means that the drug in question was safe and effective in its intended use. Without question, much evidence from the clinical trials revealed serious complications from the drug’s use, including blood-platelet shortages that were potentially fatal, kidney damage, and severe injection-site reactions. But the no-treatment alternative could prove far worse.
Duchenne is a rare but fatal genetic disorder that attacks only young boys, roughly 1 in 3,500 to 5,000. Typically, it first manifests itself between two and five years of age. With time, it relentlessly weakens the skeletal muscles that control movement in the arms, legs, and trunk. Most of its victims are wheelchair-bound between the ages of seven and 13. By 20, many have died.
The source of the problem is the absence from the cell of the key chemical dystrophin, which is needed to control muscular movement. The proposed treatment is known as “exon-skipping,” which allows the body to produce the needed quantities of dystrophin. At present no drugs are on the market to fix the genetic defect. But other drugs are also under investigation. If the door is closed for drisapersen, it remains ajar for an unnamed drug produced by Sarepta Therapeutics, which will be reviewed by the FDA shortly. But, based on early rumblings from the FDA, it is likely that this drug too will be kept from the marketplace.
As might be expected, the decision by the FDA has left parent groups and their physicians tied up in knots. You can get a sense of their frustration by looking at the desperate petition of a mother whose son has the disease. Tonya Carlone wrote a public letter to the FDA pleading for the drug to be allowed on the market: “This medication has allowed my son, Gavin, to be able to ride a 2 wheel bike, to play on a soccer team, to run and play with his healthy 10 year old peers. Dr. Craig McDonald of UC Davis Medical Center and a Duchenne expert of over 30 years, has stated that he has never seen a boy with Duchenne at the age of 10 have as much function as Gavin.”
All irrelevant, says the FDA. But it’s critical to understand why parents like Ms. Carlone and physicians like Dr. McDonald are right and why the FDA is dead wrong. The FDA thinks the problem lies in the merits of a particular drug when it really lies in its deeply flawed approval process.
It’s not at all clear that the FDA has saved more lives than it has cost.