FDA Grants ‘Breakthrough Therapy’ Designation to Pirfenidone for Treatment of Pulmonary Fibrosis
Approval decision expected by November
The investigational anti-fibrotic agent pirfenidone (InterMune, Inc.) has been designated a “breakthrough therapy” by the FDA for the treatment of patients with idiopathic pulmonary fibrosis (IPF).
This designation is reserved for drugs that are intended to treat a serious or life-threatening disease or condition when preliminary clinical evidence has indicated that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints.
In May, a new drug application (NDA) for pirfenidone was submitted to the FDA, and the drug was scheduled for review within 6 months under the Prescription Drug User Fee Act.
Pirfenidone is an orally active, anti-fibrotic agent that inhibits the synthesis of transforming growth factor-beta (TGF-beta), a chemical mediator that controls many cell functions, including proliferation and differentiation, and that plays a key role in fibrosis. Pirfenidone also inhibits the synthesis of tumor necrosis factor-alpha (TNF-alpha), a cytokine that is known to have an active role in inflammation.
Pirfenidone is marketed as Esbriet in Canada and Europe. It is not approved for sale in the U.S.
IPF is an irreversible and ultimately fatal disease characterized by progressive loss of lung function due to fibrosis (scarring) in the lungs, which hinders the ability of the lungs to absorb oxygen. IPF inevitably causes shortness of breath, and a deterioration in lung function and exercise tolerance.
IPF patients follow different and unpredictable clinical courses, and it is not possible to predict whether a patient will progress slowly or rapidly, or when the rate of decline may change. Periods of transient clinical stability in IPF, when they occur, inevitably give way to continued disease progression.
The median survival time from diagnosis is 2 to 5 years, with a 5-year survival rate of approximately 20% to 40%, which makes IPF more rapidly lethal than many malignancies, including breast, ovarian, and colorectal cancers. IPF typically occurs in patients older than 45 years of age, and tends to affect slightly more men than women.
Source: InterMune, Inc.; June 17, 2014.