Inhaled treprostinil slowed lung function decline in idiopathic pulmonary fibrosis across two pooled trials

Design

Pooled analysis of two replicate phase 3, randomised, double-blind, placebo-controlled trials

Population

1,191 people with idiopathic pulmonary fibrosis (597 treprostinil, 594 placebo)

Primary outcome

Change in absolute FVC at week 52

Effect

-45.4 mL vs -161.7 mL; difference 111.8 mL (95% CI 79.7 to 144.0)

TETON-1 and TETON-2 were replicate phase 3, double-blind trials that randomised people with idiopathic pulmonary fibrosis (IPF) to inhaled treprostinil or placebo. This pooled analysis covers 1,191 participants (597 on treprostinil, 594 on placebo). The primary end point was change in absolute forced vital capacity (FVC) at week 52.

Median FVC change was -45.4 mL with treprostinil and -161.7 mL with placebo, a between-group difference of 111.8 mL (95% CI 79.7 to 144.0; P < 0.0001). Treprostinil was superior in five of six secondary end points, including time to first clinical worsening, time to first IPF exacerbation, quality of life (K-BILD), percent predicted FVC and DLCO. Deaths were 41 (6.9%) with treprostinil and 56 (9.4%) with placebo. Cough was the commonest adverse event. The manufacturer funded the trials.

A difference of about 112 mL over a year is a modest absolute gain in a progressive disease, and the abstract does not report a formal survival test. The pooled analysis combines two trials that were already published separately. It does not tell you how treprostinil compares with, or adds to, antifibrotic therapy.

• Inhaled treprostinil reduced the 52-week fall in FVC by about 112 mL compared with placebo.
• Time to clinical worsening and to IPF exacerbation also favoured treprostinil.
• Cough was the commonest adverse event; ask about it at follow-up.
• Check regulatory status and access locally; the pooled analysis does not address them.

Why it matters

It adds a different mechanism to a disease where slowing decline is the main goal.

Don't overread it

The gain is modest in absolute terms, the trials were manufacturer-funded, and comparison with antifibrotic therapy was not reported.

The statistics, in plain English

The 111.8 mL figure is the difference in how much lung function was lost over a year. Both groups lost lung function, but the treatment group lost less than a third as much as the placebo group, going by median change.

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