LIQ861, Inhaled Form of Treprostinil, Fares Well in Phase 3 Trial for PAH

LIQ861, Liquidia Technology‘s investigational inhaled formulation of treprostinil, is safe and well-tolerated in patients with pulmonary arterial hypertension (PAH), according to final results from a Phase 3 clinical trial.

The trial results supported the new drug application for LIQ861 that was accepted for review by the U.S. Food and Drug Administration (FDA) in early April. The agency is set to make a decision on the therapy’s approval by Nov. 24.

“We are encouraged by PRINT technology and our pipeline, including the recent acceptance of the LIQ861 NDA [new drug application] for review by the FDA.” Neal Fowler, CEO of Liquidia, said in a press release. “We look forward to working closely with the FDA as it continues to review our drug application.”

Designed to be delivered via a palm-size inhaler, LIQ861 is a dry powder formulation of treprostinil, which is a vasodilator — a medication that widens blood vessels and lowers blood pressure. Treprostinil already is approved for PAH in other forms, including an oral formulation sold under the brand name Orenitram, an injection under the brand name Remodulin, and an inhaled solution under the brand name Tyvaso, all by United Therapeutics.

LIQ861 is based on Liquidia’s PRINT technology, which is an engineering platform that enables the production of uniform drug particles with tightly controlled size, shape, and chemical properties. PRINT was used to enhance deep-lung delivery of LIQ861 for people with PAH.

“LIQ861 is a great example of how our PRINT technology allows us to take good science and make it better,” Fowler said.

The open-label Phase 3 INSPIRE trial (NCT03399604) was intended primarily to assess the safety and tolerability of LIQ861. It enrolled 121 people with PAH (81.8% female, average age 55), all of whom were treated with LIQ861 at doses ranging from 26.5 to 159 micrograms. Of the participants, 55 transitioned to LIQ861 from Tyvaso, and the remaining 66 were on stable treatment with two or fewer unrelated oral PAH medications, to which LIQ861 was added.

Results from the trial originally were planned to be shared at the International Society for Heart & Lung Transplantation annual meeting, scheduled for late April. However, because the meeting was canceled due to the COVID-19 pandemic, the results were released as an online presentation,   “INSPIRE: Final Results from a Phase 3, Open-Label, Pivotal Study to Evaluate the Safety and Tolerability of LIQ861 in Pulmonary Arterial Hypertension.”

Of the 121 total participants, 113 (93%) completed two months of treatment; the remaining 11 stopped taking the therapy for reasons including adverse side effects, their choice, or being lost to follow-up.

There were five serious adverse events during the two months of treatment, including a possible seizure, an instance of intestinal bleeding, and a fractured leg bone. None of the serious adverse events were deemed related to LIQ861.

Other treatment-emergent adverse side effects were generally mild to moderate in severity. The most common included cough (42.1%), headache (26.4%), throat irritation (15.7%), dizziness (10.7%), diarrhea (9.1%), chest discomfort (8.3%), nausea (7.4%), shortness of breath (5%), flushing (5%), and throat pain (4.1%).

These were “consistent … with known side-effects of prostacyclins [the medication class to which treprostinil belongs],” Nicholas Hill, MD, a professor at Tufts University and principal investigator of the INSPIRE trial, said in the presentation.

“This final two-month analysis of LIQ861 from the INSPIRE study is consistent with earlier findings and particularly encouraging for physicians as the data show that LIQ861 can be successfully titrated [measured and adjusted] to therapeutic levels across a wide range of inhaled doses and was very well tolerated,” Hill said in the press release.

“If approved, LIQ861 may provide an effective and more convenient treatment option for patients when compared with those that are currently available,” he said.