March 25th, 2013
Once Again FDA Rejects Oral Treprostinil for Pulmonary Arterial Hypertension
Larry Husten, PHD
For the second time the FDA has issued a complete response letter rejecting the new drug application (NDA) of oral treprostinil for the treatment of pulmonary arterial hypertension (PAH). The manufacturer of the drug, United Therapeutics, said in a press release that it planned to discuss the decision with the FDA.
“We remain confident that oral treprostinil will play an important role in treating PAH and we are committed to working collaboratively with the FDA to accomplish this goal in the most timely and appropriate manner,” said the company’s chairman and CEO.
Trepostinil is a prostacyclin vasodilator that is already approved for the treatment of PAH in an injectable form (Remodulin) and in an inhalable form (Tyvaso). The FDA initially rejected the NDA for the drug last October.
My limited experience with Tyvaso (n=1) has been an unmitigated success. It would be nice if this agent was available and could work as an oral agent.
PAH is a significant disease which can now be treated. Hopefully, as more therapies become available and as sildenafil is now generic, the price of the treatments may come down.
That is a fair observation. In monotherapy as studied in the FREEDOM-M trial, oral treprostinil improved 6 minute walk test by an average of 23 meters after 12 weeks of treatment. And when added to patients already taking PDE-5 inhibitor and/or ERA as studied in the FREEDOM-C trial, oral treprostinil did not further improve 6 minute walk distance.