CymaBay Therapeutics Stumbles in NASH Race, Shares Fall

Xconomy San Francisco — 

One of the entrants in the ultra-competitive race to develop treatments for the fatty liver disease known nonalcoholic steatohepatitis (NASH) suffered a setback in clinical testing today, but the company, Cymabay Therapeutics, still believes its drug could show promise as the study continues.

Cymabay (NASDAQ: CBAY), of Newark, CA, reported interim results from a Phase 2 study of its experimental drug seladelpar in 181 NASH patients. After 12 weeks of treatment, seladelpar led to “minimal and not significant” reductions in patients’ liver fat compared to placebo—the study’s main goal.

Indeed, by that measure, seladelpar actually performed worse than a placebo. Patients on CymaBay’s drug saw average absolute decreases in liver fat, from the start of the study, of 2.6 percent on a low dose of seladelpar, 3.3 percent on a medium dose, and 2.7 percent on a high dose. The results weren’t statistically significant. Liver fat levels of placebo patients, by comparison, fell an average of 4.7 percent after 12 weeks.

CymaBay pointed to reductions in biological markers—high levels of various liver enzymes—that indicate its drug may reduce damage to patients’ livers. The hope is these markers will translate to a benefit for patients once CymaBay conducts liver biopsies after 52 weeks of treatment. “While the reductions in liver fat were minimal, we remain encouraged by the significant improvements in biochemical markers of liver injury that we observed at week 12,” Chief Medical Officer Pol Boudes said in a prepared statement.

“Seladelpar could still possibly have an effect on fibrosis longer-term,” wrote RBC Capital Markets analyst Brian Abrahams, in a research note. “Nonetheless, we believe these data do clearly reflect the underappreciated complexity and challenges in NASH.”

CymaBay shares fell about 40 percent, to $6.60 apiece, in pre-market trading on Tuesday.

NASH is a liver disease driven recently by the obesity epidemic and sugary diets. It occurs when the livers of a portion of patients with fatty liver disease becomes inflamed, stiff, and scarred, and it leads to thousands of liver transplants a year in the US alone. There are no marketed drugs for NASH. Intercept Pharmaceuticals (NASDAQ: ICPT) should file for approval of what could be the first NASH drug, obeticholic acid (OCA), later this year. OCA is the first in a long, growing line of experimental treatments to near the finish line, followed by a drug from the French firm Genfit (NASDAQ: GNFT) and many more. Pharmaceutical companies and biotechs including Gilead Sciences (NASDAQ: GILD), Bristol-Myers Squibb (NYSE: BMY), Allergan (NYSE: AGN), Madrigal Pharmaceuticals (NASDAQ: MDGL), Viking Therapeutics (NASDAQ: VKTX), CymaBay, and more are all in the race with different types of drugs.

Seladelpar, for instance, targets a receptor expressed on multiple cell types in the liver and is meant to reduce inflammation and scarring in patients with the disease (GenFit’s NASH drug elafibronor works similarly; Phase 3 results are expected this year.).  CymaBay is developing the drug for NASH and other liver diseases like primary biliary cholangitis and primary sclerosing cholangitis.

CymaBay is holding a conference call this morning to discuss the results.

Here’s more on the many therapies in development for NASH.