To date, pirfenidone has only been used for the treatment of Idiopathic Pulmonary Fibrosis (IPF). DZL researchers have now investigated whether this drug may also help in the treatment of other progressive fibrotic interstitial lung diseases – successfully. The clinical trial on the efficacy with regard to the treatment of several such fibrotic diseases, which was co-financed by DZL together with Roche Pharma and started in 2016, has now been successfully completed with a publication in the renowned scientific journal The Lancet.
Fibrotic interstitial lung diseases (ILD), in many cases leading to lung failure, can arise in children and adults as a result of acute or chronic lung damage – caused by the inhalation of toxic gases or dust, in the context of systemic diseases (e.g. connective tissue diseases) or as a result of therapeutic measures (e.g. mechanical ventilation, chemotherapy). In a non-neglectable number of cases, however, the cause remains unknown and is then described as idiopathic interstitial pneumonia (IIP), also including idiopathic pulmonary fibrosis (IPF).
Albeit from different origins, many ILDs take a similar course with progression of disease severity and are associated with poor prognosis. For a few years, pirfenidone has been available as an anti-fibrotic treatment option for IPF. Even though it cannot completely stop the disease, it can slow down the scarring process significantly. However, other than for IPF, there are only few treatment options for ILD. In view of the pathomechanical and clinical similarities of IPF and other progressive fibrotic ILDs, DZL researchers wanted to study the efficacy and safety of pirfenidone in patients with four different types of IDL other than IPF.
Since 2016, 17 centers with experience in treating ILD have collaborated in a multi-center, double-blind, randomized, placebo-controlled, and parallel phase 2b trial. All 127 patients in this trial suffered from progressive ILD, each with one of the following four different diagnoses: (1) connective tissue disease-associated ILD, (2) fibrotic, non-specific interstitial pneumonia (NSIP), (3) hypersensitivity pneumonia (HP), and (4) asbestos-induced lung fibrosis (asbestosis). The patients ranging from age 18 to 80 were randomized to receive either pirfenidone or placebo in addition to their current medication. All patients, investigators, statisticians, study administrators and coordinators were blinded until data collection had been completed and thus had no insight as to which patient was assigned to which of the two groups. The main criterion for evaluating the effect was what is referred to as forced vital capacity (FVC) – the lung volume that can be exhaled at maximum speed (forced) following maximum inhalation (inspiration).
Statistical analysis showed a significantly smaller reduction in FVC under pirfenidone compared to placebo (p = 0· 043). Due to the fact that the study had to be terminated early because of insufficient patient recruitment, these findings ought to be interpreted cautiously. Nevertheless, the data presented suggest that, in patients with fibrotic ILD other than IPF whose condition deteriorates despite conventional therapy, disease progression could be attenuated by adding pirfenidone to the existing treatment.
Behr J et al. Pirfenidone in patients with progressive fibrotic interstitial lung diseases other than idiopathic pulmonary fibrosis (RELIEF): a double-blind, randomised, placebo-controlled, phase 2b trial. The Lancet Respiratory Medicine, 2021.
Entry in the trial database EudraCT under number 2014-000861-32 https://www.clinicaltrialsregister.eu/ctr-search/trial/2014-000861-32/DE