Genentech’s Esbriet (pirfenidone), approved by the U.S. Food and Drug Administration (FDA) in 2014 to treat idiopathic pulmonary fibrosis (IPF), prolongs survival in patients and is generally safe, concludes a review, “Role of pirfenidone in the management of pulmonary fibrosis,” that recently appeared in the journal Therapeutics and Clinical Risk Management.

Pulmonary fibrosis (PF) is characterized by scarring of lung tissue and is a type of interstitial lung disease (ILD), while IPF has unknown causes. Doctors have difficulty distinguishing IPF from other interstitial lung diseases. Patients with IPF survive an average three to five years after diagnosis.

Esbriet has been shown to slow the decline in forced vital capacity (FVC), a measure of lung function, over time in IPF patients, and to lengthen progression-free survival. The ASCEND Phase 3 randomized controlled trial (NCT01366209), which studied 555 IPF patients, showed that Esbriet cut by 47.9 percent the number of patients whose FVC worsened by more than 10 percent.

Analysis of results from two trials pooled together — ASCEND and CAPACITY (NCT00287716) — showed fewer deaths from IPF progression among patients treated with Esbriet.

The RECAP trial (NCT00662038), with patients enrolled in the CAPACITY trial, showed similar effects for patients who had been untreated control subjects, but were then given Esbriet. The drug’s safety profile was similar to that for the Esbriet-treated subjects in the initial trial.

Esbriet can, however cause serious side effects, including liver dysfunction, interactions with other drugs and stomach upset. Patients on Esbriet must be closely monitored for these effects. Nonetheless, data from five randomized controlled trials, with a total of 1,299 patients followed for nearly 10 years, showed that most patients tolerate Esbriet well in the long term, and that the drug is generally safe. In fact, according to the authors,”treatment of IPF patients with pirfenidone is being perceived as a standard-of-care approach to disease management.”

Besides IPF, other forms of ILD can also lead to the loss of lung function due to progressive fibrosis, such as lung disease associated with connective tissue disease (CTD-ILD) or chronic fibrosing hypersensitivity pneumonitis (HP). Few studies have, however, been done on Esbriet and other antifibrotic agents in these diseases.

“Antifibrotic agents such as pirfenidone may also have a meaningful impact on other forms of pulmonary fibrosis,” said the researchers, emphasizing that “clinical trials are needed to determine if pirfenidone can benefit patients with other forms of fibrosing ILD such as chronic HP or CTD-associated ILD.”