Effects of pirfenidone on vascular smooth muscle cell proliferation and intimal hyperplasia following arterial balloon injury

Antagonism of adenosine A2A receptor expressed by lung adenocarcinoma tumor cells and cancer associated fibroblasts inhibits their growth

Recently it has become clear that the cost associated with the Warburg effect, which is inefficient production of ATP, is offset by selective advantages that are produced by resultant intracellular metabolic alterations. In fact tumors may be addicted to the Warburg effect. In addition these alterations result in changes in the extracellular tumor microenvironment that can also produce selective advantages for tumor cell growth and survival. One such extracellular alteration is increased adenosine concentrations that have been shown to impair T cell mediated rejection and support angiogenesis. The expression of the A2A receptor in non-small cell cancer (NSCLC) tissues, cell lines and cancer associated fibroblasts (CAF) was determined by performing immunohistrochemistry and immunoblot analysis. The efficacy of the A2A receptor antagonists in vivo was evaluated in a PC9 xenograft model. To determine the mode of cell death induced by A2A receptor antagonists flow cytometry, immunoblot, and cytotoxic analysis were performed. We found that a significant number of lung adenocarcinomas express adenosine A2A receptors. Antagonism of these receptors impaired CAF and tumor cell growth in vitro and inhibited human tumor xenograft growth in mice. These observations add to the rationale for testing adenosine A2A receptor antagonists as anticancer therapeutics. Not only could there be prevention of negative signaling in T cells within the tumor microenvironment and inhibition of angiogenesis, but also an inhibitory effect on tumor-promoting, immunosuppressive CAFs and a direct inhibitory effect on the tumor cells themselves.

Emerging drugs for idiopathic pulmonary fibrosis

Pulmonary fibrosis is often the end stage of chronic, persistent, low-level lung injury, either of known or unknown cause. The most severe form of pulmonary fibrosis is idiopathic pulmonary fibrosis (IPF), a disease process of unknown aetiology and one that often leads to respiratory failure and death. At present there are no proven or effective drug therapies for IPF. Recent advances in understanding of disease pathogenesis have focused attention on drug targeting of fibrogenic pathways, as opposed to traditional anti-inflammatory approaches. In this report, the present status of drug development of a number of emerging antifibrotic strategies and agents that may prove more effective in the therapy of this progressive, debilitating and fatal disease are reviewed.

Idiopathic pulmonary fibrosis: emerging concepts on pharmacotherapy

Idiopathic pulmonary fibrosis (IPF) is a progressive, fibrosing disease of the distal air spaces of the lung of unknown aetiology. IPF is usually fatal with a median survival of < 3 years. There are currently no effective pharmacotherapeutic agents for the treatment of IPF. In this review, unifying concepts on the pathogenesis of IPF based on understanding of host responses to tissue injury are presented. These host responses involve tightly regulated and contextually orchestrated inflammatory and repair processes. Dysregulation of either of these processes can lead to pathological outcomes. Fibrosis results from an exaggerated or dysregulated repair process that proceeds 'uncontrolled' even after inflammatory responses have subsided. Disease heterogeneity may arise when inflammation and repair are in different (dys)regulatory phases, thus accounting for regional disparity. Usual interstitial pneumonia (UIP), the histopathological correlate of clinical IPF, represents a more fibrotic tissue reaction pattern and for which anti-inflammatory agents are ineffective. Emerging 'antifibrotic' drugs and strategies for UIP/IPF are discussed. The importance of accurately phenotyping a highly heterogeneous disease process that may require individualised and 'combined' therapies is emphasised.

Open-label study of pirfenidone in patients with progressive forms of multiple sclerosis

BACKGROUND

Pirfenidone is an oral medication with a number of actions affecting the immune system. It has been proposed as a possible treatment for multiple sclerosis (MS).

METHODS

An early-phase study of progressive forms of MS was conducted. Pirfenidone was slowly titrated to 2400 mg/day. Safety, clinical, quality-of-life, and magnetic resonance image (MRI) outcomes were measured.

RESULTS

Twenty people were enrolled (13 with secondary progressive and seven with primary progressive MS). The mean age was 47.7 years; the mean Expanded Disability Status Scale (EDSS) was 5.15; 75% were female. Eighteen patients achieved the full dose, although five additional patients eventually had to decrease the dose, primarily because of nausea. The Neurologic Rating Scale showed a slight worsening, from 69.8+/-8.4 at baseline to 71.8+/-8.9 at one year (P = 0.03). Other clinical outcomes remained stable, including the EDSS, ambulation index, and nine-hole peg test. The Short-Form Health Survey (SF-36) quality-of-life measure remained unchanged. Comparisons of MRI scans at baseline and one year found that 715 plaques were unchanged, six were better, and 10 were worse. Three patients had plaques that improved and two patients had plaques that were worse. There were eight gadolinium-enhancing lesions on the baseline scans and 14 on the one-year scans.

CONCLUSIONS

Pirfenidone was well tolerated in patients with MS. Patients with primary progressive or secondary progressive MS tolerated the medication and remained clinically stable during the one year of follow up. Placebo-controlled blinded studies are needed to determine clinical effectiveness.