FDA panel vote not likely to end Cempra’s challenges

Cempra, a clinical-stage pharmaceutical company, has created an antibiotic (solithromycin) to treat pneumonia that outweighs the risk of liver injury, an advisory panel to the U.S. Food and Drug Administration concluded in a 7-6 vote on Friday.

However, the vote doesn’t mean Cempra has a clear path to winning FDA approval to sell it.

“Cempra will certainly lobby for a post-marketing liver toxicity data program, but even if the FDA agrees, restrictions on the use of solithromycin in patients are likely to be so severe as to make the product commercially unviable,” reported TheStreet.com on Monday..

“That’s exactly what happened to Ketek, a similar antibiotic, when regulators restricted use because of liver toxicity.”

Cempra’s drug is similar to Ketek, another antibiotic that was approved by the FDA in 2004 but later linked to dozens of serious or fatal liver problems and eventually discontinued in 2007.

The FDA is expected to make a final decision on solithromycin by Dec. 27.

Trading in Cempra shares was stopped Friday before the FDA panel meeting. Its shares had plunged to half their value earlier in the week.

A positive recommendation typically can lead to FDA approval, but there is no guarantee.

Panelists voted unanimously that the drug works as well to treat pneumonia, but most said the company had not fully characterized the potential risk of liver injury.

Agency reviewers stated that “there is a very clear signature of hepatic injury” in the solithromycin clinical trial data. Hepatic means “of the liver.”

The drug would treat the kind of pneumonia that recently affected U.S. presidential candidate Hillary Clinton.

Clinical trials showed a greater number of patients taking solithromycin developed elevated liver enzymes than those taking another drug, moxifloxacin. Elevated liver enzymes can be a sign of underlying liver damage.

Panelists recommended the company be required to conduct additional studies to further assess the potential liver risk after the drug has been approved.

Cempra’s drug is similar to Ketek, another antibiotic that was approved by the FDA in 2004 but later linked to dozens of serious or fatal liver problems and eventually discontinued in 2007.