FDA Issues Complete Response to Inhaled Treprostinil For Pulmonary Arterial Hypertension

The US Food and Drug Administration (FDA) has issued a complete response letter declining to approve the new drug application (NDA) for inhaled treprostinil (Tyvaso DPI).

The agent is indicated for the treatment of pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD), to improve exercise ability.

The CRL was issued to United Therapeutics. The letter pointed to a single deficiency preventing approval, related to an open inspection issue at a third-party facility that performs analytical testing of the treprostinil drug substance.

Additionally, the FDA letter noted no deficiencies or issues of operations at the Mannkind Corporation facility for manufacturing, testing, and packaging of the finished agent and device were observed.

Further, the letter mentioned the FDA has not completed a review of a Citizen’s Petition submitted in July 2021, relating to the safety of an excipient in inhaled treprostinil, but did not cite it as a deficiency.

Reaction

In a statement, Martine Rothblatt, PhD, Chairperson and Chief Executive Officer of United Therapeutics, commented that the company is pleased with the feedback on the label.

“We are confident that the single deficiency identified in the complete response will be resolved quickly and that Tyvaso DPI can receive approval by the summer of 2022, if not earlier,” Rothblatt said.

Then, in an accompanying statement, Michael Benkowitz, President and Chief Operating Officer of United Therapeutics, supported the product launch goal of no later than the summer of 2022.

"We reaffirm the achievability of our near-term goal of doubling the number of patients on Tyvaso by the end of 2022, and our longer-term goal of having 25,000 patients on our products by the end of 2025,” Benkowitz said.