Effectiveness of pirfenidone in idiopathic pulmonary fibrosis according to the autoantibody status: a retrospective cohort study

The Impact of Autoantibodies on Outcomes in Patients with Idiopathic Pulmonary Fibrosis: Post-Hoc Analyses of the Phase III ASCEND Trial

INTRODUCTION

Clinical practice guidelines recommend autoimmune serological testing in patients newly diagnosed with interstitial lung disease of apparently unknown cause who may have idiopathic pulmonary fibrosis (IPF), in order to exclude connective tissue disease (CTD). Autoantibody positivity has been associated with unique patient profiles and prognosis in patients with IPF who otherwise lack a CTD diagnosis.

METHODS

This post-hoc analysis of patients with IPF from the Phase III ASCEND trial (NCT01366209) evaluated the association of antinuclear antibodies (ANA), rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) status with baseline disease characteristics, disease progression [percent predicted forced vital capacity (%FVC), forced vital capacity (FVC) volume and progression-free survival (PFS)], and treatment outcomes with pirfenidone and placebo (%FVC, FVC and PFS).

RESULTS

Of 555 participants, 244/514 (47.5%) were ANA positive (ANA+), 83/514 (16.1%) had high ANA+ (ANA titre ≥ 1:160 or positive nucleolar- or centromere-staining patterns), 60/555 (10.8%) were RF positive (RF+) and/or anti-CCP positive (anti-CCP+) and 270/514 (52.5%) were autoantibody negative (AAb-). Baseline demographics and characteristics were generally comparable between autoantibody subgroups. Although not statistically significant, more placebo-treated participants with ANA+ or high ANA+ had a decline from baseline to Week 52 of ≥ 10% in %FVC or death (48.7% and 55.9%, respectively) or in FVC volume or death (48.7% and 47.1%, respectively) compared with the AAb- group (%FVC or death: 42.0%; FVC volume or death: 42.0%). The RF+ and/or anti-CCP+ group was similar to AAb-. No differences were observed in PFS. A treatment benefit for pirfenidone versus placebo was observed regardless of autoantibody status [PFS: ANA+ HR (95% CI): 0.56 (0.37 to 0.86), P = 0.007; AAb- HR (95% CI): 0.50 (0.32 to 0.78), P = 0.002].

CONCLUSION

IPF disease course did not differ by autoantibody status in ASCEND. Pirfenidone had a treatment benefit regardless of the presence of ANA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01366209.

Multicenter Population Pharmacokinetics and Exposure-Efficacy Analysis of Pirfenidone in Patients with Idiopathic Pulmonary Fibrosis

BACKGROUND AND OBJECTIVE

Pirfenidone is an antifibrotic agent that has been proven to slow down the progression of idiopathic pulmonary fibrosis (IPF). This study aimed to characterize the population pharmacokinetics (PK) and exposure-efficacy analysis of pirfenidone in patients with IPF.

METHODS

Data from 10 hospitals with 106 patients were used to develop a population PK model. The annual decline in forced vital capacity (FVC) over 52 weeks was integrated with pirfenidone plasma concentration to characterize the exposure-efficacy relationship.

RESULTS

A linear one-compartment model with first-order absorption and elimination processes and lag time best described the pirfenidone PK. The population estimates of clearance and central volume of distribution at steady-state were 13.37 L/h and 53.62 L, respectively. Bodyweight and food were statistically correlated with PK variability but had no significant influence on pirfenidone exposure. Annual decline in FVC with pirfenidone plasma concentration was described by a maximum drug effect (Emax) model. The typical EC50 was 1.73 mg/L (1.18-2.31 mg/L) and the corresponding EC80 was 2.18 mg/L (1.49-2.87 mg/L). Simulations showed that two dosing regimens of 500 and 600 mg three times daily were predicted to generate 80% of the Emax.

CONCLUSIONS

In patients with IPF, covariates such as bodyweight and food might not be sufficient for dose adjustment, and a low dose of 1500 mg/day could also provide 80% of the Emax, as the standard dose (1800 mg/day).

Clinical relevance of circulating autoantibodies in idiopathic pulmonary fibrosis; A NAt hard to break

Patients with idiopathic pulmonary fibrosis are screened for circulating autoantibodies as part of the initial interstitial lung disease workup. Management of seropositive idiopathic pulmonary fibrosis is currently considered no different than that of lone idiopathic pulmonary fibrosis. Emerging data however suggest that the former may possess distinct characteristics in terms of pathophysiology, histopathology, prognosis and amenability to immunomodulation. In that context, the aim of our study was to evaluate the influence of autoantibody status on: (i) the decline of forced vital capacity; (ii) the decline of diffusing capacity of lung for carbon monoxide; and (iii) 3-year survival; in a cohort of 102 idiopathic pulmonary fibrosis patients. In a pilot sub-study, we also sought to evaluate whether changes in antibody status during disease course affect the aforementioned parameters by potentially reflecting activity of the autoimmunity component of the pro-fibrotic mechanism.

The Efficacy and Safety of Pirfenidone Combined With Immunosuppressant Therapy in Connective Tissue Disease-Associated Interstitial Lung Disease: A 24-Week Prospective Controlled Cohort Study

Objective

Interstitial lung disease (ILD) is a common manifestation of connective tissue disease (CTD) that manifests as several subtypes with significant differences in prognosis. It is necessary to evaluate the efficacy and safety of pirfenidone (PFD) combined with immunosuppressant (IS) in the treatment of CTD-ILD.

Methods

A total of 111 patients with CTD-ILD were enrolled, including those with systemic sclerosis (SSc), inflammatory myopathy (IIM), rheumatoid arthritis (RA), and other CTDs (such as systemic lupus erythematosus, primary Sjogren's syndrome, and undifferentiated CTD). After evaluation of the high-resolution computed tomography (HRCT), pulmonary function (PF), and basic disease activity, patients either were or were not prescribed PFD and were followed up regularly for 24 weeks.

Results

After 24 weeks of treatment, predicted forced vital capacity (FVC%) in the SSc-PFD group had improved by 6.60%, whereas this value was 0.55% in patients with SSc-no-PFD. The elevation in FVC% was also significant in IIM-PFD over the IIM-no-PFD controls (7.50 vs. 1.00%). The predicted diffusing capacity for carbon monoxide (DLCo%) of RA-PFD was enhanced by 7.40%, whereas that of RA-no-PFD decreased by 5.50%. When performing a subtype analysis of HRCT images, the change in FVC% among patients with SSc with a tendency toward usual interstitial pneumonia (UIP) was higher in those given PFD (SSc-PFD-UIP) than the no-PFD group (8.05 vs. −3.20%). However, in IIM patients with a non-UIP tendency, PFD displayed better therapeutic effects than the control (10.50 vs. 1.00%). DLCo% improved significantly in patients with the PFD-treated RA-non-UIP subtype compared with the patients with no-PFD (10.40 vs. −4.45%). Dichotomizing the patients around a baseline FVC% or DLCo% value of 70%, the PFD arm had a more improved FVC% than the no-PFD arm within the high-baseline-FVC% subgroups of patients with SSc and IIM (6.60 vs. 0.10%, 6.30 vs. 1.10%). In patients with RA-PFD, DLCo% showed a significant increase in the subgroup with low baseline DLCo% compared to that in patients with RA-no-PFD (7.40 vs. −6.60%).

Conclusion

The response of PF to PFD varied between CTD-ILD subsets. Patients with SSc and IIM showed obvious improvements in FVC%, especially patients with SSc-UIP and IIM-non-UIP. In RA, the subsets of patients with non-UIP and a lower baseline DLCo% most benefited from PFD.

Novel approach for attenuation of pirfenidone-induced digestive symptoms: a respirable powder formulation of pirfenidone

Aim: Orally taken pirfenidone (PFD) often causes digestive symptoms. A respirable powder formulation of PFD (PFD-RP) was previously developed, and this study aimed to verify the risk of digestive symptoms after insufflation of PFD-RP. Materials & methods: Intestinal motility and gastrointestinal exposure levels was evaluated in PFD-RP (0.3-mg PFD/rat: a pharmacologically effective dose) and orally taken PFD (10-100 mg/kg) groups. Results & conclusion: Orally taken PFD at doses above 30 mg/kg significantly inhibited intestinal motility. In contrast, insufflated PFD-RP led to comparable intestinal motility in control group, and gastrointestinal exposure levels in PFD-RP group were markedly lower than those in orally taken PFD groups. Inhalation therapy using PFD-RP may be efficacious to reduce the risk of digestive symptoms frequently induced by orally taken PFD.