Four months after seeking federal approval to start selling its latest product, United Therapeutics Corp. (NASDAQ: UTHR) has its response — and it's not exactly all the Silver Spring drugmaker had hoped.
The company said Monday that the Food and Drug Administration has declined to give its stamp of approval for Tyvaso DPI, an inhaler that dispenses a dry powder form of the pulmonary arterial hypertension (PAH) drug, treprostinil. The company had sought the agency’s green light in April to take the inhaler to market as a treatment for PAH and PAH associated with interstitial lung disease, after buying a voucher to speed up the regulatory process and earning priority review for it.
But the FDA issued Friday a complete response letter withholding its nod “at this time” and noting “a single deficiency preventing approval of Tyvaso DPI, related to an open inspection issue at a third-party facility that performs analytical testing of treprostinil drug substance,” the biotech said Monday.
It noted that the agency didn’t indicate any problems with the Danbury, Connecticut, manufacturing facility run by its development partner, MannKind Corp. (NASDAQ: MNKD) — important, because an approval also hinged on that facility clearing an inspection.
United Therapeutics said it’s still awaiting the FDA’s review of a Citizen Petition — a request made by someone else to change how a drug is marketed, among other things — that was submitted in July regarding the safety of an inactive substance in Tyvaso DPI.
Outside of those issues, United Therapeutics said it’s addressed all other requests from the FDA — and it’s still pursuing an approval, albeit a potentially delayed one. “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,” Chairperson and CEO Martine Rothblatt said in a statement Monday.
United Therapeutics’ stock price fell 2.5% as of Monday afternoon to $182.23 compared with Friday’s closing price of $187.07 per share.
Tyvaso DPI consists of a small inhaler that fits in a pocket and doesn’t require batteries or an external power source, making it a more convenient option than the company's existing nebulized Tyavso treatment. The company said it would serve a potential U.S. market of at least 75,000 patients: 45,000 PAH patients, plus roughly 30,000 additional patients with interstitial lung disease, which causes scarring of the lungs and hinders breathing.
United Therapeutics has said it hopes to double the number of patients using its Tyvaso therapies, at about 3,000 as of April, by the end of 2022 and to have 25,000 total patients using its products by the end of 2025.
Expanding its product line is critical to United Therapeutics' top line, and ability to fend off increasing generic competition. Its current lineup of PAH drugs that use treprostinil — Remodulin, Tyvaso and Orenitram — accounted for a majority of its revenue, at $695.4 million of its total $825.6 million for the first half of 2021, according to Securities and Exchange Commission filings. That reflected a roughly 15% jump from the first half of 2020, though the company has said in filings that its patient base using treprostinil treatments hit an all-time high in the fourth quarter last yer, a trend that continued into the first half of this year. United Therapeutics closed 2020 with $1.48 billion in total net revenue.
The company is now studying treprostinil's inhaled form for other uses, while also expanding beyond its core PAH business and into the pulmonary fibrosis space.
United Therapeutics, which changed its legal status in October to operate as a public benefit corporation, hopes its expanded pipeline helps its plans to double its nearly 1,000-person headcount and grow its real estate footprint.
Rothblatt, a Washington Business Journal Power 100 leader of 2021, is also leading the company's work in the field of xenotransplantation — transplanting organs between species — to help boost the supply for people in need of transplants.
