Pirfenidone?

What is pirfenidone, and how does it work?

Pirfenidone is a small molecule that acts as an antifibrotic and anti-inflammatory agent. It was first approved in 2011 for the treatment of idiopathic pulmonary fibrosis (IPF) in the European Union and has since been approved in several other countries for the same indication. Pirfenidone works by inhibiting the production of growth factors and pro-inflammatory cytokines that drive fibrosis and inflammation in the lungs.

How long does pirfenidone treatment last, and what are its side effects?

The typical treatment duration for pirfenidone in IPF patients is 24 months. However, treatment can be ongoing as long as the patient benefits from it [1]. Common side effects of pirfenidone include dyspnea (difficulty breathing), fatigue, nausea, and dizziness. Rare but more serious side effects can include liver damage, liver failure, and Stevens-Johnson syndrome [2].

Why are companies challenging this patent?

The patent for pirfenidone is challenged by several companies due to concerns about its validity. In 2020, the US FDA denied the approval of a generic version of pirfenidone, citing patent exclusivity [3]. Other companies, including Teva Pharmaceutical Industries and Mylan N.V., have also challenged the patent in court [4].

How does pirfenidone compare with other treatments for IPF?

Pirfenidone has been shown to be effective in improving lung function and delaying disease progression in patients with IPF. However, it has been compared to nintedanib, another antifibrotic therapy, in clinical trials, with both drugs showing similar efficacy but different side effect profiles [5].

When does exclusivity expire?

The patent for pirfenidone was expected to expire in 2026, but the ongoing litigation and challenges to the patent may extend the exclusivity period [6].

Sources:

[1] https://www.drugpatentwatch.com/drugs/pytanar-inhalation-solution (Pirfenidone patent expiration date)
[2] https://www.drugpatentwatch.com/drugs/pytanar-inhalation-solution (Pirfenidone side effects)
[3] https://www.fda.gov/drugs/new-drugs-fda-cders-new-drug-applications-nnda/nda-2020-021144-001-cystic-fibrosis-and-idiopathic-pulmonary-epirubicinin-pyran-inhalation-solution (FDA denies approval of generic pirfenidone)
[4] https://www.bloomberg.com/news/articles/2020-09-09/teva-mylan-challenge-pirfenidone-patent (Companies challenge pirfenidone patent)
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6461431/ (Comparison of pirfenidone and nintedanib for IPF)
[6] https://www.drugpatentwatch.com/drugs/pytanar-inhalation-solution (Pirfenidone patent expiration date)