Single- and Multiple-Dose Pharmacokinetics of Pirfenidone, an Antifibrotic Agent, in Healthy Chinese Volunteers

No drug-drug interactions between selective prolyl-tRNA synthetase inhibitor, bersiporocin, and pirfenidone or nintedanib in healthy participants

Bersiporocin, a potent and selective prolyl-tRNA synthetase inhibitor, is expected to show a synergistic effect with pirfenidone or nintedanib in patients with idiopathic pulmonary fibrosis. To validate the combination therapy of bersiporocin with pirfenidone or nintedanib, a randomized, open-label, two-part, one-sequence, three-period, three-treatment study was designed to evaluate the effect of drug-drug interactions (DDI) regarding their pharmacokinetics, safety, and tolerability in healthy participants. In addition, the pharmacokinetic profiles of the newly formulated, enteric-coated bersiporocin tablet were evaluated after single and multiple administrations. The potential effects of cytochrome P450 2D6 (CYP2D6) genotyping on bersiporocin pharmacokinetics and DDI were also explored. In Part 1, participants were sequentially administered a single dose of pirfenidone 600 mg, a single dose of bersiporocin 150 mg followed by multiple doses, and bersiporocin in combination with pirfenidone. In Part 2, participants were sequentially administered a single dose of nintedanib 150 mg, multiple doses of bersiporocin 150 mg, and bersiporocin in combination with nintedanib. Forty-six participants completed the study. There was no significant pharmacokinetic DDI between bersiporocin, and pirfenidone or nintedanib. All adverse events (AEs) were mild to moderate and did not include serious AEs, suggesting bersiporocin alone or in combination therapy were well-tolerated. The newly formulated bersiporocin 150 mg tablet showed a moderate accumulation index. There was no significant difference in the pharmacokinetic profiles after administration of bersiporocin alone or in combination therapy between CYP2D6 phenotypes. In conclusion, there are no significant DDI regarding the pharmacokinetics, safety, and tolerability of bersiporocin administration with pirfenidone or nintedanib.

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).

Simultaneous estimation of voriconazole, moxifloxacin, and pirfenidone in rabbit lacrimal matrix using LC-MS/MS: an application to preclinical ocular pharmacokinetics

Dynamic emergence of microbial keratitis (MK) requires a promising therapeutic arsenal of antifungal and antibacterial agents like voriconazole (VCZ) and moxifloxacin (MOXI), respectively. Parallelly, another paradigm of MK associated with ulcerative wounds cannot be left unnoticed and requires antifibrotic remedy (pirfenidone, PIR) as an authalic antimicrobial to retain the primordial vision. For designing an effective clinical cure, a combination of these three agents is required at a therapeutic dosage regimen. Following the quest, we have developed a simple and sensitive LC-MS/MS bioanalytical method for simultaneous quantification of VCZ, MOXI, and PIR in rabbit lacrimal fluid. The method was validated as per US-FDA norms using ketoconazole as an internal standard for linearity, accuracy-precision, matrix effect, dilution integrity, selectivity, and stability. The five minutes chromatographic set-up includes isocratic elution with a C18 column using MeOH (80%, v/v) and ultrapure water containing 0.2% formic acid (20%, v/v), respectively. The MS-based analyte detection was achieved in ESI⁺ multiple reaction monitoring mode. The sample extraction was performed using the protein precipitation method with minimal sample size. The validated methodology was employed to determine the ocular pharmacokinetics profile of marketed formulations containing VCZ, MOXI, and PIR in rabbit lacrimal matrix.

The role of autophagy in idiopathic pulmonary fibrosis: from mechanisms to therapies

Idiopathic pulmonary fibrosis (IPF) is an interstitial pulmonary disease with an extremely poor prognosis. Autophagy is a fundamental intracellular process involved in maintaining cellular homeostasis and regulating cell survival. Autophagy deficiency has been shown to play an important role in the progression of pulmonary fibrosis. This review focused on the six steps of autophagy, as well as the interplay between autophagy and other seven pulmonary fibrosis related mechanisms, which include extracellular matrix deposition, myofibroblast differentiation, epithelial-mesenchymal transition, pulmonary epithelial cell dysfunction, apoptosis, TGF-β1 pathway, and the renin-angiotensin system. In addition, this review also summarized autophagy-related signaling pathways such as mTOR, MAPK, JAK2/STAT3 signaling, p65, and Keap1/Nrf2 signaling during the development of IPF. Furthermore, this review also illustrated the commonly used autophagy detection methods, the currently approved antifibrotic drugs pirfenidone and nintedanib, and several prospective compounds targeting autophagy for the treatment of IPF.

Pharmacological basis of the antifibrotic effects of pirfenidone: Mechanistic insights from cardiac in-vitro and in-vivo models

Pirfenidone is a small drug with marked antifibrotic activity approved for the treatment of Idiopathic pulmonary fibrosis. Recently, its peculiar pharmacological profile has attracted attention for its potential therapeutic benefit for extra-pulmonary disorders characterized by pathological fibrosis, such as kidney, liver, and cardiac failure. A major pitfall of pirfenidone is the lack of consistent understanding of its mechanism of action, regardless of the target. In addition to the increasing attention to the role of inflammation and its mediators in several processes, a better knowledge of the variety of fibroblasts' population, of signals controlling their activation and trans-differentiation, and of crosstalk with other cell resident and non-resident cell types is needed for prevention, treatment and possibly reverse of fibrosis. This review will focus on pirfenidone's pharmacological profile and its effects on cardiac fibroblasts.

New Antifibroblastic Medication in Dermatology: Could Nintedanib Treat Scarring?

There are a wide variety of disfiguring dermatological conditions whose pathologic substrate is represented by the unwanted deposition of collagen from dermal fibroblasts. Pirfenidone has demonstrated efficiency in the treatment of disordered collagen production when applied topically. Due to a similar mechanism of action, we also hypothesize that a similar medication, nintedanib, might have similar applications. We also propose that a liposomal technology may assist in the penetration of nintedanib and enhance its clinical effects.

Pirfenidone is a renal protective drug: Mechanisms, signalling pathways, and preclinical evidence

Renal fibrosis, a characteristic of all chronic kidney diseases, lacks effective therapeutic drugs currently. Pirfenidone (PFD), a small molecule drug with good oral bioavailability, is widely used in idiopathic pulmonary fibrosis and exerts anti-fibrotic, anti-inflammatory, antioxidant, and anti-apoptotic effects. These effects have been attributed to the suppression of cell growth factors (in particular, but not exclusively, transforming growth factor-β) and the epithelial-mesenchymal transition, as well as the possible down-regulation of pro-inflammatory mediators (such as tumour necrosis factor-α), the protection of mitochondrial function, and the regulation of inflammatory cells. Considering the activation of similar anti-fibrotic pathways in lung and kidney disease and the broad activity of PFD, this drug has improved the treatment of the renal fibrotic disease. In this review, we briefly summarize the pharmacokinetics and safety of PFD as well as the mechanisms of PFD focusing on kidney disease. We summarize the effects of PFD on renal function and pathological alterations based on animal experiments, as well as changes in growth factors based on both animal and renal cell experiments. Moreover, given the activation of similar profibrotic pathways in pulmonary diseases and other disorders, we reviewed in-depth the possible signalling pathways targeted by PFD to attenuate renal fibrosis and protect renal function. Finally, we provide an overview of the current clinical trials of PFD for the treatment of renal fibrosis.

Pharmacological Interactions of Nintedanib and Pirfenidone in Patients with Idiopathic Pulmonary Fibrosis in Times of COVID-19 Pandemic

The discovery of antifibrotic agents have resulted in advances in the therapeutic management of idiopathic pulmonary fibrosis (IPF). Currently, nintedanib and pirfenidone have become the basis of IPF therapy based on the results of large randomized clinical trials showing their safety and efficacy in reducing disease advancement. However, the goal of completely halting disease progress has not been reached yet. Administering nintedanib with add-on pirfenidone is supposed to enhance the therapeutic benefit by simultaneously acting on two different pathogenic pathways. All this becomes more important in the context of the ongoing global pandemic of coronavirus disease 2019 (COVID-19) because of the fibrotic consequences following SARS-CoV-2 infection in some patients. However, little information is available about their drug–drug interaction, which is important mainly in polymedicated patients. The aim of this review is to describe the current management of progressive fibrosing interstitial lung diseases (PF-ILDs) in general and of IPF in particular, focusing on the pharmacokinetic drug-drug interactions between these two drugs and their relationship with other medications in patients with IPF.

Antifibrotic drugs in connective tissue disease-related interstitial lung disease (CTD-ILD): from mechanistic insights to therapeutic applications

Fibrosing interstitial lung disease (ILD) is one of the most important causes of morbidity and mortality in patients with connective tissue diseases (CTDs), which include systemic sclerosis, rheumatoid arthritis, Sjögren's syndrome, idiopathic inflammatory myositis and systemic lupus erythematosus. The treatment of CTD-ILDs is challenging due to the paucity of proven effective treatments. Recently, two antifibrotic drugs conditionally approved for use in patients with idiopathic pulmonary fibrosis, nintedanib and pirfenidone, have been trialled in CTD-ILDs based on overlapping pathological and clinical features between the two diseases. In this narrative review, we discuss the experimental evidence and clinical trials investigating the efficacy and safety of antifibrotic drugs in patients with CTD-ILDs and the potential mechanisms of action involved. Results from clinical trials suggest that nintedanib use retards lung function decline in progressive fibrotic CTD-ILDs. By contrast, the evidence for the efficacy of pirfenidone in these groups is not equally compelling. Further, well-designed randomized clinical trials are needed to evaluate the efficacy and safety of individual antifibrotic drugs in specific CTD-ILD subgroups.

Low-Dose of Intrapulmonary Pirfenidone Improves Human Transforming Growth Factorβ1-Driven Lung Fibrosis

Idiopathic pulmonary fibrosis is a chronic, progressive, and lethal lung disease of unknown etiology. Antifibrotic drugs, including pirfenidone, are currently used for the treatment of the disease. The oral administration of pirfenidone is an effective therapy, as demonstrated by several clinical trials, although it causes severe adverse events in some patients. We hypothesized that low-dose intrapulmonary delivery of pirfenidone is effective in human transforming growth factorβ1-driven pulmonary fibrosis. To demonstrate our hypothesis, we compared the therapeutic efficacy of varying doses of pirfenidone administered by oral and intranasal routes in a human transforming growth factor-β1 transgenic mouse with established pulmonary fibrosis. We found similar amelioration of lung cell infiltration, inflammatory and fibrotic cytokines, lung fibrosis score, and hydroxyproline content in mice with human transforming growth factor-β1-mediated pulmonary fibrosis treated with low-dose intranasal pirfenidone and high-dose oral pirfenidone. This study showed that pirfenidone is a potent inhibitor of human transforming growth factor-β1-driven lung fibrosis and that intrapulmonary delivery of low-dose pirfenidone produces therapeutic responses equivalent to high-dose of oral pirfenidone.

Pharmacokinetic evaluation of two pirfenidone formulations in patients with idiopathic pulmonary fibrosis and chronic hypersensitivity pneumonitis

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease characterized by an abnormal activation of lung epithelium and fibroblasts, as well as an excessive accumulation of extracellular matrix. Pirfenidone was introduced as a therapeutic option for IPF and chronic hypersensitive pneumonitis (cHP), a related disease. However, high plasma concentrations, which can be achieved even at recommended doses, are frequently associated with adverse events. Hence, an extended release formulation (XP), yielding lower peak plasma concentrations, has been developed. The aim of this study was to compare the pharmacokinetic properties of XP with those of the immediate (IR) formulation in patients with IPF or cHP. Data were analyzed using two pharmacokinetic approaches, conventional non compartmental analysis and a population analysis using the nonlinear mixed effects model technique. Results observed with both approaches were consistent. Drug exposure was similar with both formulations. However, XP exhibited less concentration fluctuations and a longer mean resident time. These results suggest that XP could be a feasible option to reduce adverse events associated to pirfenidone elevated concentrations. Nevertheless, efficacy studies are required to fully document the therapeutic potential of XP.

Pharmacological management of Idiopathic Pulmonary Fibrosis: current and emerging options

INTRODUCTION

Idiopathic Pulmonary Fibrosis is a chronic, progressive lung disease characterized by worsening lung scarring and the radiological/histological pattern of usual interstitial pneumonia. Substantial progress has been made in the clinical management of IPF in the last decade. The two novel antifibrotics, Nintedanib and Pirfenidone have changed the landscape of IPF, by hindering disease progression; however, the drugs have significant discontinuation rates, due to adverse events and do not offer a definitive cure, as such IPF remains a deleterious disease with poor survival.

AREAS COVERED

In this review, the authors focus on the current and emerging pharmacological options in the treatment of IPF. They include a summary of the current approach including treatment of comorbidities and then discuss promising drugs in the drug pipeline.

EXPERT OPINION

IPF remains a disease with detrimental outcomes. The plethora of emerging pharmacological treatments brings hope for the future. The current pharmacological 'one fits all' approach has been proven effective in slowing disease progression. The future lies in an oncological approach with combination of therapies. We expect to see a change in clinical trial endpoints and a more inclusive approach for the diagnosis of IPF.

ABBREVIATION LIST

AE: Acute ExacerbationA-SMA: a smooth muscle actinATX: AutotaxinCOPD: Combined Obstructive Pulmonary DiseaseCPFE: Combined Pulmonary Fibrosis and EmphysemaGER: Gastro-esophageal refluxFVC: forced vital capacityECMO: extracorporeal membrane oxygenationILD: Interstitial Lung DiseaseIPF: Idiopathic Pulmonary FibrosisNAC: N-acetylcysteineLPA: Lysophosphatidic acidPH: Pulmonary RehabilitationPR: Pulmonary rehabilitationRCTs: randomized placebo-controlled trialsUIP: usual interstitial pneumonia.

The effect of pirfenidone on rat chronic prostatitis/chronic pelvic pain syndrome and its mechanisms

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is an intractable problem of the urogenital system. The aetiopathogenesis and effective treatments for CP/CPPS are needed to be untangled. Pirfenidone is a molecule that exhibits anti-inflammatory, antifibrotic, and antioxidative stress capacities in a variety of animal experiments and clinical trials. This study was aimed to investigate the therapeutic effect of pirfenidone on CP/CPPS and to identify the mechanism responsible for it.

METHODS

A CP/CPPS model was induced in rats by intraprostatic injection of complete Freund's adjuvant (CFA). Blood and prostatic tissues were harvested for assessment after the administration of pirfenidone or vehicle for 4 weeks.

RESULTS

The findings revealed that pirfenidone significantly ameliorated chronic pelvic pain and inhibited prostatic inflammation and fibrosis. Further study found that pirfenidone suppressed the expression of proinflammatory mediators, including tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, IL-8. Pirfenidone exhibited a potent antioxidant capacity through improving the activities of glutathione, catalase, total superoxide dismutase, and reducing the production of malondialdehyde. Furthermore, pirfenidone also facilitated the polarization of M2 macrophages and suppressed the activation of the nuclear factor-κB (NF-κB) signaling pathway.

CONCLUSIONS

Pirfenidone can exert a beneficial effect against CFA-induced CP/CPPS by anti-inflammatory, antioxidative, antifibrotic properties, and the function is mediated at least partly through the M2 polarization of macrophages and the inhibition of NF-κB signaling pathway. These findings suggest that pirfenidone holds promise as a potential therapeutic for the treatment of CP/CPPS.

Pirfenidone: Molecular Mechanisms and Potential Clinical Applications in Lung Disease

Pirfenidone (PFD) is a pharmacological compound with therapeutic efficacy in idiopathic pulmonary fibrosis. It has been chiefly characterized as an antifibrotic agent, although it was initially developed as an antiinflammatory compound because of its ability to diminish the accumulation of inflammatory cells and cytokines. Despite recent studies that have elucidated key mechanisms, the precise molecular activities of PFD remain incompletely understood. PFD modulates fibrogenic growth factors, thereby attenuating fibroblast proliferation, myofibroblast differentiation, collagen and fibronectin synthesis, and deposition of extracellular matrix. This effect is mediated by suppression of TGF-β1 (transforming growth factor-β1) and other growth factors. Here, we appraise the impact of PFD on TGF-β1 production and its downstream pathways. Accumulating evidence indicates that PFD also downregulates inflammatory pathways and therefore has considerable potential as a viable and innovative antiinflammatory compound. We examine the effects of PFD on inflammatory cells and the production of pro- and antiinflammatory cytokines in the lung. In this context, recent evidence that PFD can target inflammasome pathways and ensuing lung inflammation is highlighted. Finally, the antioxidant properties of PFD, such as its ability to inhibit redox reactions and regulate oxidative stress-related genes and enzymes, are detailed. In summary, this narrative review examines molecular mechanisms underpinning PFD and its recognized benefits in lung fibrosis. We highlight preclinical data that demonstrate the potential of PFD as a nonsteroidal antiinflammatory agent and outline areas for future research.

Pirfenidone is a cardioprotective drug: Mechanisms of action and preclinical evidence

Myocardial fibrosis is an endogenous response to different cardiac insults that may become maladaptive over time and contribute to the onset and progression of heart failure (HF). Fibrosis is a direct and indirect target of established HF therapies, namely inhibitors of the renin-angiotensin-aldosterone system, but its resilience to therapy warrants a search for novel, more targeted approaches to myocardial fibrosis. Pirfenidone is a drug approved for idiopathic pulmonary fibrosis, a severe form of idiopathic interstitial pneumonias. Pirfenidone is a small synthetic molecule with high oral bioavailability, exerting an antifibrotic activity, but also anti-oxidant and anti-inflammatory effects. These effects have been attributed to the inhibition of several growth factors (in particular transforming growth factor-β, but also platelet-derived growth factor and beta fibroblast growth factor), matrix metalloproteinases, and pro-inflammatory mediators (such as interleukin-1β and tumour necrosis factor-α), and possibly also an improvement of mitochondrial function and modulation of lymphocyte activation. Given the activation of similar profibrotic pathways in lung and heart disease, the crucial role of fibrosis in several cardiac disorders, and the wide spectrum of activity of pirfenidone, this drug has been evaluated with interest as a potential treatment for cardiac disorders. In animal studies, pirfenidone has shown cardioprotective effects across different species and in a variety of models of cardiomyopathy. In the present review we summarize the pharmacological characteristics of pirfenidone and the data from animal studies supporting its cardioprotective effects.

Therapeutically Effective Controlled Release Formulation of Pirfenidone from Nontoxic Biocompatible Carboxymethyl Pullulan-Poly(vinyl alcohol) Interpenetrating Polymer Networks

The present study was conducted to develop therapeutically effective controlled release formulation of pirfenidone (PFD) and explore the possibility to reduce the total administered dose and dosing regimen. For this purpose, pH-sensitive biomaterial was prepared by inducing carboxymethyl group on pullulan by Williamson ether synthesis reaction, and further, interpenetrating polymeric network microspheres were prepared by glutaraldehyde-assisted water-in-oil (w/o) emulsion cross-linking method, which showed higher swelling ratio in acidic and basic pH. The formation of microspheres was confirmed by different spectral characterization techniques, and thermal kinetic study indicated the formation of thermally stable microspheres. Cell viability and biocompatibility studies on hepatocellular carcinoma (HepG2) cell showed the polymeric matrix to be biocompatible. In vitro dissolution of optimized formulation (F5) showed releases of 54.09 and 76.37% in 0.1 N HCl after 2 h and phosphate buffer (pH 6.8) up to 8 h, respectively. In vivo performances of prepared microsphere and marketed product of PFD were compared in rabbit. T max (time taken to reach peak plasma concentration) was found to be achieved at 0.83 h, compared to 0.5 h for Pirfenex with no significant difference complementing the immediate action, while area under curve was significantly greater for optimized formulation (9768 ± 1300 ng h/mL) compared to Pirfenex (4311 ± 110 ng h/mL), complementing the sustained action. In vivo pharmacokinetic study suggested that the prepared microsphere could be a potential candidate for therapeutically effective controlled delivery of PFD used in dyspnea and cough management due to idiopathic pulmonary fibrosis.

Dose modification and dose intensity during treatment with pirfenidone: analysis of pooled data from three multinational phase III trials

INTRODUCTION

Temporary dose modifications, such as reductions or interruptions, may allow patients to better manage adverse events (AEs) associated with pirfenidone use and continue treatment for idiopathic pulmonary fibrosis (IPF). However, the impact of such dosing adjustments on efficacy and safety is uncertain.

METHODS

Patients randomised to receive treatment with pirfenidone 2403 mg/day or placebo in the Clinical Studies Assessing Pirfenidone in Idiopathic Pulmonary Fibrosis: Research of Efficacy and Safety Outcomes (CAPACITY (Study 004 (NCT00287716)) and Study 006 (NCT00287729))) and Assessment of Pirfenidone to Confirm Efficacy and Safety in Idiopathic Pulmonary Fibrosis (ASCEND (Study 016 (NCT01366209)) trials were included in the analysis (n=1247). Descriptive statistics and a linear mixed-effects model (slope analysis) for annual rate of decline in forced vital capacity (FVC) by dose intensity were performed. Treatment-emergent AEs (TEAEs) were summarised and grouped by dose intensity or body size.

RESULTS

Dose reductions and interruptions occurred in 76.9% (95% CI 73.4% to 80.1%) and 46.5% (95% CI 42.6% to 50.6%) of patients receiving pirfenidone vs 72.0% (95% CI 68.3% to 75.4%) and 31.1% (95% CI 27.5% to 34.9%) of patients receiving placebo, respectively. Dose interruptions tended to occur during the first 6 months of treatment, whereas dose reductions exhibited more variability. Less FVC decline from baseline was observed in patients receiving pirfenidone versus placebo at >90% dose intensity (p<0.001) or ≤90% dose intensity (p=0.0191), showing treatment benefit in both subgroups of dose intensity. No meaningful relationship between weight and TEAEs was observed.

CONCLUSION

Dose interruptions, which may be required to manage TEAEs, mostly occurred during the first 6 months of treatment. Despite dose reductions and interruptions, most patients with IPF maintained relatively high dose intensity on pirfenidone, without compromising its treatment effect compared with placebo.

TRIAL REGISTRATION NUMBERS

NCT00287729, NCT00287716, NCT01366209.

Targeting an oncogenic kinase/phosphatase signaling network for cancer therapy

Protein kinases and phosphatases signal by phosphorylation and dephosphorylation to precisely control the activities of their individual and common substrates for a coordinated cellular outcome. In many situations, a kinase/phosphatase complex signals dynamically in time and space through their reciprocal regulations and their cooperative actions on a substrate. This complex may be essential for malignant transformation and progression and can therefore be considered as a target for therapeutic intervention. p38γ is a unique MAPK family member that contains a PDZ motif at its C-terminus and interacts with a PDZ domain-containing protein tyrosine phosphatase PTPH1. This PDZ-coupled binding is required for both PTPH1 dephosphorylation and inactivation of p38γ and for p38γ phosphorylation and activation of PTPH1. Moreover, the p38γ/PTPH1 complex can further regulate their substrates phosphorylation and dephosphorylation, which impacts Ras transformation, malignant growth and progression, and therapeutic response. This review will use the p38γ/PTPH1 signaling network as an example to discuss the potential of targeting the kinase/phosphatase signaling complex for development of novel targeted cancer therapy.

Pirfenidone reduces subchondral bone loss and fibrosis after murine knee cartilage injury

Pirfenidone is an anti-inflammatory and anti-fibrotic drug that has shown efficacy in lung and kidney fibrosis. Because inflammation and fibrosis have been linked to the progression of osteoarthritis, we investigated the effects of oral Pirfenidone in a mouse model of cartilage injury, which results in chronic inflammation and joint-wide fibrosis in mice that lack hyaluronan synthase 1 (Has1^-/- ) in comparison to wild-type. Femoral cartilage was surgically injured in wild-type and Has1^-/- mice, and Pirfenidone was administered in food starting after 3 days. At 4 weeks, Pirfenidone reduced the appearance, on micro-computed tomography, of pitting in subchondral bone at, and cortical bone surrounding, the site of cartilage injury. This corresponded with a reduction in fibrotic tissue deposits as observed with gross joint surface photography. Pirfenidone resulted in significant recovery of trabecular bone parameters affected by joint injury in Has1^-/- mice, although the effect in wild-type was less pronounced. Pirfenidone also increased Safranin-O staining of growth plate cartilage after cartilage injury and sham operation in both genotypes. Taken together with the expression of selected extracellular matrix, inflammation, and fibrosis genes, these results indicate that Pirfenidone may confer chondrogenic and bone-protective effects, although the well-known anti-fibrotic effects of Pirfenidone may occur earlier in the wound-healing response than the time point examined in this study. Further investigations to identify the specific cell populations in the joint and signaling pathways that are responsive to Pirfenidone are warranted, as Pirfenidone and other anti-fibrotic drugs may encourage tissue repair and prevent progression of post-traumatic osteoarthritis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:365-376, 2018.

Pirfenidone safety and adverse event management in idiopathic pulmonary fibrosis

Pirfenidone is one of two approved therapies for the treatment of idiopathic pulmonary fibrosis (IPF). Randomised controlled clinical trials and subsequent post hoc analyses have demonstrated that pirfenidone reduces lung function decline, decreases mortality and improves progression-free survival. Long-term extension trials, registries and real-world studies have also shown similar treatment effects with pirfenidone. However, for patients with IPF to obtain the maximum benefits of pirfenidone treatment, the potential adverse events (AEs) associated with pirfenidone need to be managed. This review highlights the well-known and established safety profile of pirfenidone based on randomised controlled clinical trials and real-world data. Key strategies for preventing and managing the most common pirfenidone-related AEs are described, with the goal of maximising adherence to pirfenidone with minimal AEs.

Using key strategies to prevent and manage pirfenidone-related AEs can help maximise adherence to pirfenidonehttp://ow.ly/Veyk30gsFTs

A Pharmacokinetic Bioequivalence Study Comparing Pirfenidone Tablet and Capsule Dosage Forms in Healthy Adult Volunteers

Introduction

Pirfenidone film-coated tablets were developed to offer an alternative to the marketed capsule formulation. This study assessed the bioequivalence of the tablet and capsule formulations under fed and fasted states.

Methods

A Phase I, open-label, randomized, four-treatment-period, four-sequence, crossover pharmacokinetics study (NCT02525484) was conducted. Each subject received an 801-mg single dose of pirfenidone as three 267-mg capsules or one 801-mg tablet under fasted and fed conditions. Pirfenidone plasma C_max, AUC_0–t and AUC_0–∞ were used to assess bioequivalence.

Results

Forty-four subjects were randomized to treatment. The 801-mg tablet in the fasted state met bioequivalence criteria [90% confidence intervals (CI) 80.00–125.00%] for the GLSM ratios of natural log-transformed C_max, AUC_0–t and AUC_0–∞. Under fed conditions, the 801-mg tablet met the bioequivalence criteria for AUC_0–t and AUC_0–∞, but slightly exceeded the bioequivalence criteria for the C_max (90% CI of 108.26–125.60%). The tablet C_max was approximately 17% higher than that of the capsules. In the fed state, the tablet C_max, and both AUC_0–t and AUC_0–∞ were reduced by 39% and 17%, respectively, relative to the fasted state. The tablet and capsules had acceptable tolerability profiles.

Conclusions

The pirfenidone 801-mg tablet met bioequivalence criteria when compared with three 267-mg capsules in the fasted state. The tablet C_max was slightly higher relative to capsules in the fed state, but this is not expected to have a clinically meaningful impact on the benefit–risk profile of pirfenidone.

Funding

This work was supported by F. Hoffmann-La Roche Ltd.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0594-8) contains supplementary material, which is available to authorized users.

Pirfenidone for the treatment of idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a diffuse parenchymal lung disease with no cure. Up until recently, no treatment had been proven to alter its natural history as judged by rate of lung function decline. In 2014 however, the emergence of two novel anti-fibrotic agents, Pirfenidone and Nintedanib revolutionized the management of this condition. Both have demonstrated the ability to deliver a major reduction in the rate of chronic IPF progression. Areas Covered: This review article focuses on Pirfenidone - a pyridone derivative initially designed as an analgesic and anti-pyretic agent. Here we describe the history of the drug from its inception through to exploratory pre-clinical in-vitro and in-vivo studies where its anti-fibrotic potential was identified, and eventually to large multicenter randomized controlled trials. Expert Commentary: This article also summarizes some of the difficulties surrounding clinical end-point selection in IPF trials and addresses some of the challenges facing the IPF community over the coming years.

Pirfenidone: A Novel Agent for the Treatment of Idiopathic Pulmonary Fibrosis

OBJECTIVE

To evaluate the published clinical literature on the role of pirfenidone for the treatment of idiopathic pulmonary fibrosis (IPF).

DATA SOURCES

A systematic literature search was performed using the key words pirfenidone or Esbriet, alone and in combination, with IPF or idiopathic pulmonary fibrosis (expanded using MESH terminology). MEDLINE (1948-September 2012) was the primary database used for search purposes. In addition, all available articles and abstracts referenced by the articles identified via literature search were included.

STUDY SELECTION AND DATA EXTRACTION

The search was limited to English-language publications. All available clinical trials of pirfenidone pertinent to its pharmacology, pharmacokinetics, efficacy, and safety were included.

DATA SYNTHESIS

Pirfenidone is the first agent specifically developed for the treatment of IPF. It has been approved for use in Europe and Japan, but not in the US. Although Phase 3 trials have shown pirfenidone to improve certain clinical (6-minute walk test) and functional (change in forced vital capacity) outcomes in patients with IPF, an independent benefit on either mortality or acute exacerbation rates has yet to be demonstrated. Until more definitive supportive data are available, international guidelines have recommended against using pirfenidone to treat most patients with IPF.

CONCLUSIONS

Although pirfenidone appears to be an effective treatment for IPF, additional clinical trials are needed to better delineate its risk-benefit profile.

Pharmacokinetic and pharmacometabolomic study of pirfenidone in normal mouse tissues using high mass resolution MALDI-FTICR-mass spectrometry imaging

Given the importance of pirfenidone as the first worldwide-approved drug for idiopathic pulmonary fibrosis treatment, its pharmacodynamic properties and the metabolic response to pirfenidone treatment have not been fully elucidated. The aim of the present study was to get molecular insights of pirfenidone-related pharmacometabolomic response using MALDI-FTICR-MSI. Quantitative MALDI-FTICR-MSI was carried out for determining the pharmacokinetic properties of pirfenidone and its related metabolites 5-hydroxymethyl pirfenidone and 5-carboxy pirfenidone in lung, liver and kidney. To monitor the effect of pirfenidone administration on endogenous cell metabolism, additional in situ endogenous metabolite imaging was performed in lung tissue sections. While pirfenidone is highly abundant and delocalized across the whole micro-regions of lung, kidney and liver, 5-hydroxymethyl pirfenidone and 5-carboxy pirfenidone demonstrate heterogeneous distribution patterns in lung and kidney. In situ endogenous metabolite imaging study of lung tissue indicates no significant effects of pirfenidone on metabolic pathways. Remarkably, we found 129 discriminative m/z values which represent clear differences between control and treated lungs, the majority of which are currently unknown. PCA analysis and heatmap view can accurately distinguish control and treated groups. This is the first pharmacokinetic study to investigate the tissue distribution of orally administered pirfenidone and its related metabolites simultaneously in organs without labeling. The combination of pharmametabolome with histological features provides detailed mapping of drug effects on metabolism as response of healthy lung tissue to pirfenidone treatment.

Effect of grapefruit juice and food on the pharmacokinetics of pirfenidone in healthy Chinese volunteers: a diet-drug interaction study

1. Ingestion of grapefruit juice and food could be factors affecting the pharmacokinetics of pirfenidone, a promising drug for treatment of idiopathic pulmonary fibrosis. 2. A randomized, open-label, three-period crossover study was carried out in 12 healthy Chinese male volunteers who were randomized to one of the three treatments: pirfenidone tablets (0.4 g) were orally administered to fasted or fed subjects, or with grapefruit juice. The washout period was 7 d. 3. Significantly reduced maximum plasma concentration (Cmax, 5.0 5 ± 1.39 versus 10.9 0 ± 2.94 mg·L(- 1)), modestly affected area-under-the-plasma concentration-time curve (AUC) from time zero to 12 h post dosing (AUC0-12 h, 21.8 9 ± 6.47 versus 26.1 6 ± 7.32 mg·h·L(- 1)) and delayed time to reach Cmax (Tmax) were observed in fed group compared with fasted group. Similar effects on Cmax (5.8 2 ± 1.23 versus 10.9 0 ± 2.94 mg·L(- 1)) and AUC0-12 h (modest but not statistically significant, 24.4 4 ± 7.40 versus 26.1 6 ± 7.32 mg·h·L(- 1)) were observed for grapefruit juice compared to fasted subjects. 4. Co-administration of pirfenidone with grapefruit juice resulted in modestly reduced overall oral absorption and significantly reduced peak concentrations compared to fasting, which was similar to effect of food ingestion. No adverse events were observed in the study, but relatively dramatic reduction of peak concentrations should raise concerns for clinical efficacy and safety.

Pirfenidone vs. sodium hyaluronate/carboxymethylcellulose as prevention of the formation of intra-abdominal adhesions after colonic surgery. A randomized study in an experimental model

INTRODUCTION

Up to 93% of patients undergoing abdominal surgery will develop intra-abdominal adhesions with the subsequent morbidity that they represent. Various substances have been tested for the prevention of adhesions with controversial results; the aim of our study is to compare the capability of pirfenidone in adhesion prevention against sodium hyaluronate/carboxymethylcellulose.

METHODS

A randomized, prospective, longitudinal experimental study with Winstar rats. They were divided into 3 groups. The subjects underwent an exploratory laparotomy and they had a 4cm(2) cecal abrasion. The first group received saline on the cecal abrasion, and groups 2 and 3 received pirfenidone and sodium hyaluronate/carboxymethylcellulose respectively. All rats were sacrificed on the 21st day after surgery and the presence of adhesions was evaluated with the modified Granat scale. Simple frequency, central tendency and dispersion measures were recorded. For the statistical analysis we used Fisher's test.

RESULTS

To evaluate adhesions we used the Granat's modified scale. The control group had a median adhesion formation of 3 (range 0-4). The pirfenidone group had 1.5 (range 0-3), and the sodium hyaluronate/carboxymethylcellulose group had 0 (range 0-1). There was a statistically significant difference to favor sodium hyaluronate/carboxymethylcellulose against saline and pirfenidone (P<0.009 and P<.022 respectively).

CONCLUSIONS

The use of sodium hyaluronate/carboxymethylcellulose is effective for the prevention of intra-abdominal adhesions. More experimental studies are needed in search for the optimal adhesion prevention drug.

Simultaneous determination of pirfenidone and its metabolite in human plasma by liquid chromatography-tandem mass spectrometry: application to a pharmacokinetic study

A simple and rapid analytical method for the simultaneous determination of pirfenidone and its metabolite, 5-carboxy-pirfenidone, in human plasma using liquid chromatography-tandem mass spectrometry has been developed and validated. Aliquots of plasma (0.1 mL) containing pirfenidone and 5-carboxy-pirfenidone, as well as deuterium-labeled internal standards (ISs), were deproteinized using acetonitrile. An Agilent Zorbax Plus C18 column was used for the chromatography, with isocratic elution. The mobile phase was a mixture of acetonitrile and aqueous ammonium formate solution (5 mM) containing 0.1% formic acid (60 : 40, v/v). Using multiple reaction monitoring in positive ionization mode, transitions m/z 186.1 → 65.1, m/z 216.0 → 77.0, m/z 191.1 → 65.1 and m/z 221.0 → 81.0 were chosen to quantify pirfenidone, 5-carboxy-pirfenidone and the two ISs, respectively. The time of analysis was <3 min. The calibration curve was linear over the concentration ranges 0.005-25 μg/mL for pirfenidone, and 0.005-15 μg/mL for 5-carboxy-pirfenidone. The lower limit of quantification for both analytes was 0.005 μg/mL. The intra- and interday precision and relative errors in quality control samples were between -11.7 and 1.3% for pirfenidone and between -5.6 and 2.5% for 5-carboxy-pirfenidone, with mean recoveries ≥90%. The method that has been developed is easy to carry out, sensitive and rapid, and has been successfully used to investigate the pharmacokinetics of pirfenidone in healthy human volunteers.

Assessment of the effect of potential antifibrotic compounds on total and αVβ6 integrin-mediated TGF-β activation

Transforming growth factor‐β (TGF‐β) plays an important role in the development of tissue fibrosis, and molecules inhibiting this pathway are attractive therapeutic targets for fibrotic diseases such as idiopathic pulmonary fibrosis (IPF). Activation of TGF‐β is the rate‐limiting step in TGF‐β bioavailability, and activation by the αVβ6 integrin is important in fibrosis of the lung, liver, and kidney. Activation of TGF‐β by αVβ6 requires direct cell–cell contact and measurable release of active TGF‐β in extracellular fluid compartments does not reflect tissue specific activation. The aim of this study was to determine the effect of antifibrotic compounds on both total, and specific αVβ6 integrin‐mediated TGF‐β activity. Using a transformed mink lung cell (TMLC) TGF‐β reporter, the effects of potential antifibrotic therapies including an activin‐like kinase (Alk5) inhibitor, Dexamethasone, Pirfenidone, N‐acetylcysteine (NAC), and BIBF1120 were assessed. Effects due to αVβ6 integrin‐mediated TGF‐β activity were measured using reporter cells cocultured with cells expressing αVβ6 integrins. These high‐throughput studies were validated using a phosphorylated Smad2 Enzyme‐Linked Immunosorbent Assay. Alk5 inhibitors are potent inhibitors of TGF‐β activity, whereas the novel antifibrotics, Pirfenidone, BIBF1120, and NAC are only moderate inhibitors, and Dexamethasone does not specifically affect TGF‐βactivity, but inhibits TGF‐β‐induced gene expression. None of the current small molecular inhibitors inhibit αVβ6‐mediated TGF‐β activity. These results demonstrate the potential of this high‐throughput assay of αVβ6‐specific TGF‐β activity and illustrate that currently available antifibrotics have limited effects on αVβ6 integrin‐mediated TGF‐β activity.

e00030

Pirfenidone: significant treatment effects in idiopathic pulmonary fibrosis

Pirfenidone has been shown in three recently published trials to slow down the progression of the devastating interstitial lung disease, idiopathic pulmonary fibrosis (IPF). The precise mechanisms that initiate and perpetuate the histopathological process leading to lung fibrosis in IPF are still uncertain, but increased concentrations of reactive oxidative species and fibrogenetic factors have been observed in the pulmonary tissue of patients. Although the exact mechanisms of its action are unknown, pirfenidone is a small molecule with antifibrotic and some hydroxyl scavenger properties that has recently been approved in Europe and elsewhere for the treatment of IPF. Along with the new ATS/ERS/JRS/ALAT 2011 statement for 'Evidence Based Guidelines for Diagnosis and Management', there is now a more profound basis for offering IPF patients an evidence-based evaluation and treatment. This review summarizes the background to the recommended use of pirfenidone for the treatment of IPF.

Adverse events of pirfenidone for the treatment of pulmonary fibrosis: a meta-analysis of randomized controlled trials

Background

Pirfenidone (PFD) is a novel antifibrotic agent approved for patients with pulmonary fibrosis. However, there are concerns regarding toxicity of the drug. In this meta-analysis, we analyzed the adverse events (AEs) of PFD for the treatment of pulmonary fibrosis.

Methods

We performed a systematic search of PubMed, Embase, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials for trials published between January 1999 and October 2011. Data extracted from literature were analyzed with Review manager 5.0.24.

Results

The results of six randomized controlled trials (1073 participants) revealed that the number of individuals who discontinued PFD therapy was significantly higher than patients receiving placebo. The PFD group had a significantly higher rate of gastrointestinal (nausea, dyspepsia, diarrhea, and anorexia), neurological (dizziness and fatigue), and dermatological (photosensitivity and rash) AEs compared to the placebo group.

Conclusions

PFD used for the treatment of pulmonary fibrosis is not so safe or well-tolerated. Notably, gastrointestinal, neurological and dermatological adverse effects were more common in patients receiving PFD therapy, and therefore appropriate precaution is needed.

Genotoxic evaluation of pirfenidone using erythrocyte rodent micronucleus assay

Pirfenidone is a non-steroidal antifibrotic compound that has been proposed in clinical protocols and experimental studies as a pharmacological treatment for fibroproliferative diseases. The objective of this study was to determine the genotoxicity or cytotoxicity of three doses of pirfenidone using the micronuclei test in peripheral blood erythrocytes of rodent models. Pirfenidone was administered orally to Balb-C mice for 3 days, and also was administered topically to hairless Sprague Dawley rats during the final stage of gestation. Mice were sampled every 24 h over the course of 6 days; pregnant rats were sampled every 24 h during the last 6 days of gestation, and pups were sampled at birth. Blood smears were analyzed and the frequencies of micronucleated erythrocytes (MNEs), micronucleated polychromatic erythrocytes (MNPCEs), and the proportion of polychromatic erythrocytes (PCEs), were recorded in samples from mice, pregnant rats and rat neonates. Increases in MN frequencies (p<0.03) were noted only in the positive control groups. No genotoxic effects or decreased PCE values were observed neither in newborn rats transplacentally exposed to pirfenidone, or in two adult rodent models when pirfenidone was administered orally or topically.

Pirfenidone: in idiopathic pulmonary fibrosis

Pirfenidone is an orally administered pyridine that has orphan designation for the treatment of mild to moderate idiopathic pulmonary fibrosis (IPF) in the EU. Pirfenidone 2403 mg/day for 72 weeks administered to patients with IPF was associated with a significantly lower mean decline in the percent predicted forced vital capacity than placebo (primary endpoint) according to data from one of two randomized, double-blind, multinational trials (studies 004 and 006 [also known as the CAPACITY trials]), and data from a pooled analysis of both trials. In another randomized, double-blind, multicentre Japanese trial, the adjusted mean in the change in vital capacity from baseline to week 52 was significantly lower in patients with IPF who received pirfenidone 1800 mg/day (considered to be comparable to the 2403 mg/day dose in studies 004 and 006 on a weight-normalized basis) than in those who received placebo (primary endpoint). Pirfenidone had an acceptable tolerability profile in clinical trials, with most adverse events being mild to moderate in severity.

Pirfenidone treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a discrete clinicopathologic entity defined by the presence of usual interstitial pneumonia on high-resolution CT scan and/or open lung biopsy and the absence of an alternate diagnosis or exposure explaining these findings. There are currently no FDA-approved therapies available to treat this disease, and the 5-year mortality is ∼80%. The pyridone derivative pirfenidone has been studied extensively as a possible therapeutic agent for use in this deadly disease. This review will present the unique clinical features and management issues encountered by physicians caring for IPF patients, including the poor response to conventional therapy. The biochemistry and preclinical efficacy of pirfenidone will be discussed along with a comprehensive review of the clinical efficacy, safety, and side effects and patient-centered foci such as quality of life and tolerability. It is hoped that this information will lend insight into the complex issues surrounding the use of pirfenidone in IPF and lead to further investigation of this agent as a possible therapy in this devastating disease.

The multifaceted role of pirfenidone and its novel targets

BACKGROUND

Pirfenidone (PFD) is a molecule that exhibits antifibrotic properties in a variety of in vitro and animal models of lung, liver and renal fibrosis. These pathologies share many fibrogenic pathways with an abnormal fibrous wound-healing process; consequently, tissue repair and tissue regeneration-regulating mechanisms are altered.

OBJECTIVE

To investigate the usefulness of PFD as an antifibrotic agent in clinical and experimental models of fibrotic disease.

CONCLUSIONS

There is a growing understanding of the molecular effects of PFD on the wound healing mechanism, leading to novel approaches for the management of fibrosis in lung, liver and renal tissues. Although the optimum treatment for fibrosis remains undefined, it is possible that combined therapeutic regimens that include this wide-application molecule, pirfenidone, could offer a useful treatment for fibrotic disease.

Pirfenidone: an anti-fibrotic therapy for progressive kidney disease

IMPORTANCE OF THE FIELD

Many chronic diseases of various etiologies lead to fibrosis and organ dysfunction. Despite many advances in medicine in recent years, options to slow the progression of fibrotic diseases have remained limited. The recent availability of pirfenidone, an antifibrotic and anti-inflammatory investigational agent, thus offers a new hope for treating progressive fibrotic diseases.

AREAS COVERED IN THIS REVIEW

This review provides concise review of the available data regarding the mechanism and pharmacokinetics of pirfenidone and preclinical and clinical data regarding efficacy and safety in fibrotic diseases of the kidney. It also reviews results of clinical trials involving pirfenidone in other fibrotic diseases.

WHAT THE READER WILL GAIN

The review will provide in-depth review of pirfenidone with a renal focus.

TAKE HOME MESSAGE

Because many of the available clinical trials have been small and/or uncontrolled, conclusive evidence regarding efficacy and safety of pirfenidone is lacking, particularly in patients with renal or hepatic dysfunction. Larger studies are needed to better understand long-term efficacy and safety of this medication in various patient populations.