Therapy for idiopathic pulmonary fibrosis: lessons from pooled data analyses

Abstract

@ERSpublicationsThe pooled analysis of three large phase 3 trials sheds further light on the role of antifibrotic therapy in IPF http://ow.ly/UNTWQ In 2014, two landmark clinical trials (ASCEND and INPULSIS) were published demonstrating, for the first time, a treatment benefit for patients with idiopathic pulmonary fibrosis (IPF). Both pirfenidone and nintedanib were shown to have a clear therapeutic benefit in slowing the relentless disease progression evident in IPF patients. The results of these studies have had a major impact upon management of IPF patients worldwide, with subsequent changes made to international guidelines, which now recommend in favour of antifibrotic therapy. However, this is not the whole story: there are many unanswered questions with regard to the real-world treatment benefit and use of antifibrotic therapy. In this issue of the European Respiratory Journal, NOBLE et al.[1] present the pooled data of the three multinational, phase 3, placebo-controlled trials of pirfenidone in IPF patients, the ASCEND, and CAPACITY 004 and 006 studies. Examining the combined patient population reveals important insights about specific subgroups along with broader inferences that are only possible through pooled analysis.The history of clinical trials of pirfenidone in IPF patients is intriguing: 2011 saw the publication of two concurrent phase 3 trials (CAPACITY 004 and 006) [2]. These followed on from the promising findings of pre-clinical [3][4][5] and phase 2 studies [6,7], and a large phase 3 trial conducted in Japanese patients [8]. Unexpectedly, the results of the CAPACITY studies were disparate: CAPACITY 004 showed a significant reduction in forced vital capacity (FVC) decline and an improvement in progression-free survival at 72 weeks [2]; CAPACITY 006 was a negative study, with failure to meet either of these end-points [2].Why were the CAPACITY 004 and 006 results conflicting when the study populations were ostensibly the same? Subtle differences, in fact, did exist between the patient cohorts [2]. Interestingly, a difference in the change in FVC in the placebo arm was evident between the two studies. Further scrutiny revealed a greater degree of airflow limitation, as indicated by a lower spirometric ratio, in 006 than in 004. Perhaps this could explain the observed variation in physiological behaviour.Pirfenidone was subsequently approved for use across Europe based on its treatment effect demonstrated in the pooled analysis of the CAPACITY trials and previous data from Japanese studies [7][8][9]. However, in other countries, including the USA, regulatory bodies required further evidence of efficacy. Lessons were learnt and enabled enrichment of the ASCEND study cohort (a phase 3 study of 52 weeks duration) for patients at risk of disease progression, a strategy that has been used successfully in the study of agents for other diseases [10]. A major change was the centralisation of review of IPF diagnosis. The primary end-point remained "change in percentage predicted FVC or death", with the...

A Rnd3/p190RhoGAP pathway regulates RhoA activity in idiopathic pulmonary fibrosis fibroblasts

“…Interestingly, when we examined the IPF phenotype after pirfenidone or nintedanib treatment, we found a reduction in the levels of FN and collagen but SMA levels remained high ( Figure 9G ). This result is consistent with the observation that while both drugs are beneficial to a percentage of patients with IPF, either drug only slows the progression of disease ( Myllarniemi and Kaarteenaho, 2015 ; Troy and Corte, 2016 ). To examine the morphological consequences of nintedanib and pirfenidone treatment on IPF cells, we stained for stress fibers.…”

“…Currently, there are no effective therapies for IPF, which is typically fatal within 2–3 yr of diagnosis. However, in 2014 two drugs, pirfenidone and nintedanib, were approved for IPF patients after being found to be beneficial although not curative ( Myllarniemi and Kaarteenaho, 2015 ; Troy and Corte, 2016 ). Nintedanib is a tyrosine kinase inhibitor that acts on several receptor tyrosine kinases (PDGFR, FGFR, and VEGFR) ( Hilberg et al.…”

Mechanotransduction: from the cell surface to the nucleus via RhoA

“…In preliminary experiments we have found that Rnd3 levels are depressed when normal and breast cancer epithelial cells are cultured on more rigid substrates (E Monaghan-Benson 2018, unpublished results), suggesting that this pathway may be important in elevating RhoA activity in tumours. In previous work we found that drugs such as nintedanib and pirfenidone, which have been used to treat IPF [62,63], elevate Rnd3 expression and thereby decrease RhoA activity [57]. This raises the possibility that these drugs may also have therapeutic potential for solid tumours.…”

Cause of mortality and sarcopenia in patients with idiopathic pulmonary fibrosis receiving antifibrotic therapy

“…Clinical trials have demonstrated that nintedanib and pirfenidone inhibit the annual rate of decline of FVC in patients with IPF 5–8 . The efficacy of AFT on lung function was consistent in patients with IPF with preserved lung function as well as in those with impairments in lung function 18,20–22 . Furthermore, the effects were sustained for a long time, 23 suggesting that prompt treatment is beneficial for patients with IPF.…”

“…Besides its efficacy on the annual rate of decline in FVC, emerging evidence has confirmed that antifibrotic therapy (AFT) reduces the risks of acute exacerbation (AE), 16 respiratory-related hospitalization 17 and disease progression. 18 However, AFT was administered to only 60% of patients with IPF and certain time lags existed between diagnosis and AFT initiation. Furthermore, sufficient evaluation has not been done to determine disease course and prognostic determinants in patients with IPF based on the characteristics measured at AFT initiation.…”