- An experimental Pfizer drug has scored positive data in a mid-stage clinical trial of patients with fatty liver disease, a precursor condition to the now intensely studied non-alcoholic steatohepatitis, or NASH.
- The trial tested two doses of the drug. After six weeks of treatment, patients on the higher dose experienced statistically greater reductions in their whole liver fat than patients on placebo. Notably, these specific results were based on a 90% confidence interval, a wider range than typically used. Participants on the lower dose actually had increased whole liver fat compared to the placebo arm.
- Pfizer's drug inhibits an enzyme that helps metabolize fruit sugar. Excess consumption of that sugar can promote insulin resistance and the development of a fatty liver, according to Pfizer scientists. In an abstract, those scientists concluded the Phase 2 study's findings warrant further investigation of the drug in NASH and the broader area of non-alcoholic fatty liver disease.
With an estimated 30 million patients in the U.S. alone, NASH has become one of the most attractive therapeutic markets across pharma.
Drugmakers both large and small are racing to secure the first Food and Drug Administration approval for a NASH treatment. So far, Intercept Pharmaceuticals' obeticholic acid leads, having secured the field's first positive Phase 3 readout back in February.
The late-stage data, however, showed just one in four patients treated with Intercept's drug had an improvement of one stage or greater in fibrosis without worsening of NASH after 18 months. While the results were significantly better than placebo, the general thinking is that additional NASH therapies could carve out a place in the market even if obeticholic acid enters earliest.
Pfizer is looking to own at least one of those therapies. About six months ago, the company teamed up with fellow big pharma Novartis to research combinations of their respective NASH candidates. The collaboration includes three Pfizer drugs, including the enzyme inhibitor for which there is now Phase 2 data.
The drug takes a different approach than many of the most advanced therapies in the global NASH pipeline. Rather than targeting protein receptors or pro-inflammatory enzymes, Pfizer's therapy goes after sugar — and, in particular, how the body breaks it down.
More in-depth results from the Phase 2 trial will come on April 11 through a data release at The International Liver Congress, which is being held in Vienna, Austria.
An abstract issued ahead of the meeting details how Pfizer's drug was well-tolerated across the six-week testing period, with a low incidence of treatment-emergent adverse events and no serious adverse events reported.
Yet questions still remain.
Why patients on the lower dose regimen ended up with increases in whole liver fat will be a likely focal point. So too will be the drug's mechanism of action. Since it targets sugar metabolism, some may wonder how much lifestyle modifications like adopting a diet lower in fructose could weigh on this drug's viability.