Baltimore biotech lands FDA approval of drug for rare digestive illness

The Food and Drug Administration on Tuesday approved Cholbam, developed by Baltimore biotechnology company Asklepion Pharmaceuticals, for treatment of a rare disease that prevents people from making key digestive acids.

The approval means Retrophin, a San Diego-based pharmaceutical company, will exercise its right to buy all rights to the drug from Asklepion for $27 million cash and 661,278 shares of Retrophin stock, valued Wednesday at $13.3 million.


Shares of Retrophin, which focuses on drugs for diseases for which there are no viable treatments, surged by more than a third Wednesday on news of the approval, closing at $20.17 per share.

The two companies struck a deal in January, with Retrophin paying Asklepion $5 million for the rights to buy the drug. Asklepion could receive $37 million more, based on the drug's hitting future sales milestones, plus royalties.


"We were fully prepared to take and commercialize Cholbam ourselves, but in the end, we were convinced that we could see more children benefit faster from this" by passing the drug off to Retrophin, said Asklepion's CEO, Dr. Gary Pasternack.

The companies and FDA officials said the approval means a treatment is now available for the estimated 1,500 to 3,000 people in the United States who can't produce bile acids that help the body absorb fat and fat-soluble vitamins.

"This approval underscores the agency's commitment to making treatments available to patients with rare diseases," said Dr. Julie Beitz, director of the Office of Drug Evaluation III in the FDA's Center for Drug Evaluation and Research, in a statement. "Prior to today's approval, patients with these rare bile acid synthesis disorders had no approved treatment options."

The FDA also approved Cholbam for treatment of peroxisomal disorders, which involve defects in other types of enzymes in the body. That broadens its pool of potential patients, Pasternack said.

FDA approval of a drug is a significant milestone for any pharmaceutical or biotechnology company. The agency approves only a few dozen each year, and only a small share of potential therapies tested in clinical trials even make it to final FDA review.

Pasternack said the FDA was accommodating in helping the company pursue a safe and effective treatment, something that was difficult to prove because the illness is so rare. The treatment was tested on about 100 people in a clinical review process under the FDA's "orphan drug" designation, which protects treatments for rare diseases from facing generic competition for seven years.

"They were just as interested in seeing us develop something to treat these patients, so they worked with us on what the plan would be to prove that this was safe and effective," Pasternack said.

For those unable to produce bile acids, symptoms including jaundice, apparent poor liver function, poor growth and malaise typically present in infancy or early childhood, Pasternack said. Some of the children end up in intensive care units, and for many of them, a diagnosis is difficult to reach.

Cholbam consists of cholic acid, one of two major bile acids produced by the liver.

The science behind Cholbam can be traced back two decades to Dr. Kenneth Setchell and Dr. James Heubi of Cincinnati Children's Hospital Medical Center, who treated patients with cholic acid after discovering they lacked the enzyme. Asklepion began pursuing FDA review of the treatment in 2007, and the company filed an application for approval of a new drug in 2013, Pasternack said.

The company moved to Baltimore from Nashville, Tenn., in 2010 in search of a stronger biotechnology workforce, Pasternack said.

As it hands over Cholbam to Retrophin, Asklepion turns to other drug candidates in its research pipeline, including one that looks to prevent an often deadly complication in children that can follow open heart surgery. That drug doesn't have an orphan drug designation from the FDA, but since relatively few children have open heart surgery, the company may pursue obtaining it, Pasternack said.


Asklepion employs about a dozen people. After the Cholbam sale, Pasternack said he expects that could grow.

For Cholbam, the next step is to make doctors aware of bile acid deficiencies, Pasternack said.

Retrophin has experience there: It already markets another treatment for patients with disorders related to bile acid, Chenodal.

Stephen Aselage, Retrophin's CEO, said Cholbam complements Chenodal and positions the company as the leading provider of treatments for patients with bile acid synthesis and peroxisomal disorders.

"We have to educate them about what these diseases are because they're not on the top 10 list of what people teach in medical school or residency," Pasternack said. "The approval allows us to really go out there and start the education program."


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