Lack of biopsies could spell trouble for liver disease drugs

Lack of biopsies could spell trouble for liver disease drugs

Needles and NASH

It is estimated that 10 million to 30 million U.S. patients have nonalcoholic steatohepatitis (NASH), a condition in which fat built up in the liver leads to swelling, scarred tissue and possibly cirrhosis. It is also predicted that drugs to treat NASH drugs could be on the market as soon as 2020.

The problem is that liver biopsy, the gold standard for detecting NASH using a long needle, is not happening, according to an article by Jacob Bell in Biopharma Dive. Without better diagnostic tools, patients may not have access to these NASH drugs.

While biopsies are a valuable source of information, they are invasive, painful, expensive and potentially linked to infection and damage to other organs. Patients tend to put off the procedure, because NASH may be asymptomatic until it is in advanced stages. Thus, according to Scott Friedman, chief of the liver diseases division in the Icahn School of Medicine at Mount Sinai, "There's a really intense effort now to use every means necessary or possible to establish a diagnosis of NASH without biopsy."

Even if all possible NASH wanted a biopsy, there are not enough liver doctors to perform the procedure. Of the 16,400 gastroenterologists holding certification from the American Board of Internal Medicine, only a fraction of these doctors do liver biopsies. This could present problems to the uptake of NASH drugs approved, especially if payers require the tests for coverage and reimbursement. It may change predictions for NASH drugs to boost revenues for pharmaceutical companies. According to Douglas Dieterich, a professor of medicine in the liver diseases division of the Mount Sinai School of Medicine, "That's what we're all afraid of, including the pharma people."

The first wave of NASH drugs will probably be used to treat patients with serious liver scarring. Patients with less severe fibrosis may not even want drug therapy. While biopsies are the best way to distinguish between the two, many doctors are still not using them. According to Friedman, “Without a treatment, it's hard to justify a mad rush to screen everybody." Zachary Henry, a hepatologist at University of Virginia Health System, also avoid biopsies he thinks a patient has advanced fibrosis and might benefit from enrolling in a clinical trial. As he explained, "Treatment options currently are limited basically to lifestyle modification. A liver biopsy isn't really going to change that."

Brent Tetri of St. Louis University, who sees 15 to 20 NASH patients weekly, does biopsies frequently; his clinic attracts patients interested in joining clinical trials. However, he either tells patients that a biospy will be necessary without lifestyle changes or conducts a biopsy to demonstrate that they are on the path to cirrhosis.

If there are fewer biopsies, there will be less data on how much of the NASH population has simple fatty tissue as opposed to more serious liver damage. That could mean trouble for drug companies wanting to tap into NASH. The National Institute of Diabetes and Digestive and Kidney Diseases, which funds the NASH Clinical Research Network, lacks statistics on the number of U.S. patients with NASH or a precursor disease named NAFLD as well as the breakdown of NASH patients by fibrosis stage.