Hospitals

Shire agrees to more clinical trials for blood pressure drug, but threat of FDA action lingers

One year after Shire (NASDAQ:SHPGY) pulled its drug for low blood pressure, ProAmatine, from the market after reaching an impasse with the U.S. Food and Drug Administration, it has agreed to do the additional clinical tests the regulator wanted. The agreement was made with the Center for Drug Evaluation and Research, a division of the […]

One year after Shire (NASDAQ:SHPGY) pulled its drug for low blood pressure, ProAmatine, from the market after reaching an impasse with the U.S. Food and Drug Administration, it has agreed to do the additional clinical tests the regulator wanted.

The agreement was made with the Center for Drug Evaluation and Research, a division of the FDA. The FDA commissioner still has to make a decision on the matter. If the commissioner rejects the proposed agreement, the agency could move ahead with a hearing for the company with U.S. headquarters in Philadelphia, Pennsylvania. Although Shire must wait for a decision before it can proceed with the clinical trials, the FDA said the generic version of the drug, midodrine HCl, will remain available to patients while the trials are conducted.

The FDA’s proposal to withdraw marketing approval last year marked the second time the agency has issued such a notice for a drug approved under its accelerated approval regulations.

Shire had resisted repeated requests for additional testing, arguing it had satisfied the testing requirements in 2005, but the FDA said it has not verified the clinical  benefits of the drug.  A letter sent to Shire in May 2001 said the company overstated the efficacy of ProAmatine.

Dr. Jeffrey Jonas, senior vice president of research and development for Shire, said: “The time frame outlined in the proposal for additional clinical trials is consistent with Shire’s original request and we are appreciative that we have come to agreement with CDER on this path forward. We’ve been committed to completing these additional clinical trials to confirm the efficacy of midodrine as a treatment for SOH and keep this important medication available for patients.”

Although Shire no longer manufactures the drug, a spokesman said it agreed to do the additional tests because it holds the New Drug Application for ProAmatine and did not want to risk the generic versions of the drug being pulled from the market.

The five generic versions currently on the market manufactured by Apotex, Impax (NASDAQ:IPXL), Mylan (NASDAQ:MYL), Sandoz and Upsher-Smith.

About 100,000 patients in the United States filled prescriptions for brand or generic forms of midodrine in 2009, according to a database used by the FDA.

Chelsea Therapeutics (NASDSAQ:CHTP) has been developing a drug that would address the dizziness and fainting that some Parkinson’s disease patients experience. Charlotte, North Carolina-based Chelsea is trying to commercialize its drug candidate Northera as an alternative to ProAmatine, which carries a black-box warning that it may raise  patients’ blood pressures when they are in a reclined position.

Northera already has orphan drug designation from the FDA. Last month, the FDA accepted Chelsea’s application for priority review of Northera, setting an action date of March 28 to issue an approval decision.

Northera is already available in Japan as the drug Droxidopa. Japanese pharmaceutical company Dainippon Sumitomo Pharma commercialized Droxidopa in Japan for treating frozen gait and dizziness upon standing associated with Parkinson’s disease, as well as orthostatic hypotension. Chelsea licensed Droxidopa from Dainippoin Sumitomo in 2006. The drug could bring Chelsea sales beyond the U.S. market. The licensing deal gives Chelsea global commercialization rights to the drug outside of Japan, Korea, China and Taiwan.

Here’s a time line to give some context.

  • 1996: ProAmatine was approved under Subpart H (an accelerated approval process) for the treatment of symptomatic orthostatic hypotension, or low blood pressure.
  • 2000: Shire becomes the New Drug Application holder as part of an acquisition.
  • 2003: Midodrine is sold as a generic drug and Shire’s exclusive patent on midodrine ends.
  • 2005: Shire re-tests ProAmatine but not to the FDA’s satisfaction. The FDA wants the drug tested for efficacy. A possible hearing is in the offing
  • 2010: Shire withdraws ProAmatine from market as generic rivals push down value of drug, side effects that include high blood pressure and FDA raising the issue of a hearing.

Frank Vinluan contributed to this story.