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.
Treprostinil 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.
A combination tablet containing the cholesterol-lowering drugs ezetimibe and atorvastatin is back on the path to possible FDA approval, according to Merck, which already markets Zetia (ezetimibe) and Vytorin, the combination of ezetimibe and simvastatin. Merck has repeatedly stumbled in its efforts to gain FDA approval of the proposed new drug, which has been dubbed “Son of Vytorin.” The new drug application (NDA) submission was first rejected by the FDA in 2009 and, again, last year.
Merck said yesterday that the FDA had accepted Merck’s resubmission of its NDA, which included additional data provided by Merck in response to the FDA’s rejection of the application last year. Merck said it also planned to pursue approval of the drug in other countries.
Despite its potent cholesterol-lowering effects, the clinical benefits of ezetimibe have never been demonstrated, prompting furious debates about the proper role of surrogate endpoints. Last year the FDA rejected a new indication for Vytorin and Zetia (ezetimibe alone) in chronic kidney disease patients, as the independent effect of ezetimibe had not been assessed in SHARP, the pivotal study for the indication. Results of the IMPROVE-IT trial, expected this year, may finally resolve the question of whether ezetimibe is beneficial.
Click here to read the Merck press release…