Guggenheim Partners called Insmed’s Phase IIb readout “impressive across the board,” with an efficacy profile that positions TPIP to be best-in-class in pulmonary arterial hypertension.
Insmed’s investigational inhaled drug significantly improved blood flow and functional performance in patients with pulmonary arterial hypertension, according to topline Phase IIb data released on Tuesday.
The drug candidate, trepostinil palmitil inhalation powder (TPIP), demonstrated a 35% placebo-adjustment reduction in pulmonary vascular resistance, a key heart function marker in pulmonary arterial hypertension (PAH) and the study’s primary endpoint. TPIP also met all of its secondary endpoints, including improving six-minute walk distance by 35.5 meters, as compared with placebo.
In a note to investors Wednesday afternoon, analysts at Guggenheim Partners said Insmed’s readout “blows away expectations,” calling it “impressive across the board.” TPIP’s efficacy profile, if it remains consistent in late-stage studies, “firmly support TPIP as being the best-in-class prostacyclin,” they added.
Insmed’s stock rose about 29% Tuesday after the data were announced.
Guggenheim also called TPIP’s safety profile “very reassuring,” with side effects that were “consistent with other inhaled trespronstinils.” Insmed said treatment-emergent adverse events (TEAE) developed in 88.4% of patients on TPIP, versus 75.8% of placebo comparators. Serious TEAEs arose in 7.2% and 3% of participants in these respective groups.
Cough emerged as a common side effect in the TPIP group, with a frequency rate of 40.6% compared to 21.2% in those receiving placebo. “While there may be some questions raised on the rates of cough in the trial,” Guggenheim noted, “we believe this is within the range of what should be expected for an inhaled product like TPIP.” Cough concerns are also “far outweighed” by TPIP’s efficacy profile, the analysts contended.
With Tuesday’s data, Insmed will “immediately” approach the FDA to discuss the design for a Phase III study of TPIP in PAH, which the company expects to initiate in “early 2026,” according to Tuesday’s release. Insmed also plans to study TPIP in pulmonary hypertension associated with interstitial lung disease, for which a Phase III study is set to start before the end of the year.
Writing to investors on Tuesday, analysts at Truist Securities noted that TPIP further boosts Insmed’s overall business prospects. The biotech, which has one approved therapy in the inhaled antibiotic Arikayce, is currently awaiting the FDA’s decision for its DPP1 blocker brensocatib for bronchiectasis. A verdict is expected by Aug. 12, and Truist is optimistic, expecting an approval.
“We like [Insmed’s] competitive product profile and pipeline strategy,” the analysts wrote, with brensocatib as a “potential FTM [first-to-market] therapy” along with TPIP “as a potential best-in-class prostanoid treatment in PAH.”
Overall, the potential of Insmed’s pipeline could make the biotech “of interest to big pharma looking for synergistic ways to fill gaps in their respiratory/pulmonary portfolios,” Truist wrote.
