You'd think that a disease that is involved in half of all deaths in the developed world would not have trouble attracting interest from the biopharma industry.

That's been the case for fibrosis, though – a buildup of scar tissue that can be the result of many causes, some known, some unknown. The disease is only beginning to get the sort of attention from industry that its market size might suggest.

Scott Friedman, who is at the Mount Sinai School of Medicine, told BioWorld Insight that he believes fibrosis' Cinderella status has several reasons.

Fibrosis tends to be "a largely silent, below-the-radar cause of death." For example, when patients die of liver failure, even though the failed liver is most likely fibrotic, the direct cause of death is often sepsis. Fibrosis contributes to failed hearts and kidneys, but in those cases, the official cause of death is simply organ failure.

Friedman is a fibrosis researcher himself, and even he was surprised when a paper estimating that fibrosis contributes to 45 percent of all deaths was published in 2008. So surprised, in fact, that he followed up with the corresponding author to find out more about the paper's methodology (which was indeed rigorous).

One reason, he said, is that fibrosis is "not viewed as a discrete disease, it's viewed as a tissue response."

And even when it is viewed as a disease, that view is usually organ-centric. There is an overarching understanding that cancer is a single disease in meaningful ways, even if it manifests itself in different ways in different organs. But the appreciation that the study of idiopathic pulmonary fibrosis and liver cirrhosis might have useful insights for each other has been slower in coming.

Finally, while the market size for fibrotic disease is not necessarily obvious at first glance, the risks of fibrosis trials are. The disease is, in many cases, slowly progressing – "the amount of scarring is the end result of a lot of processes that go on for a long time," he said.

The liver, for example, is "so resilient that many patients have no symptoms" even after they are diagnosed – which they may not be for years.

Idiopathic pulmonary fibrosis usually progresses more rapidly. But it may be analogous to Alzheimer's disease, with outright disease becoming apparent only after damage has accumulated quietly for years.

But Friedman said he hopes that the time is ripe for a change. In the Jan. 10, 2013, issue of Science Translational Medicine, he and co-authors have laid out the case that fibrosis treatment may be "Nearing the Starting Line."

The basic reason that the field is ready to take off, Friedman said, is that "the fundamental biology has been uncovered, and a variety of targets have emerged." In addition to those targets have come biomarkers, which offer the hope of faster, less risky trials.

And if new targets have emerged, unpromising ones have been debunked by recent findings. Friedman said that several basic ideas about fibrosis – that it is essentially a passive tissue and that it originates from epithelial cells – have been shown to be wrong in recent years.

"What is coalescing now is a broad and durable interest" from industry, he said. Companies including Sanofi SA subsidiary Genzyme Inc. and big biotech Biogen Idec Inc. are targeting TGF-beta, FibroGen Inc. is developing drugs targeting hypoxia-inducible factor and connective tissue growth factor, and other companies are targeting cytokines that activate fibroblasts.

But even as those various approaches are making their way through clinical trials, Friedman said there is plenty of room for additional players; "it is not too late at all" for new approaches.