US FDA cmmte says solithromycin effective but liver risk has not been characterized

Solithromycin’s benefits outweigh its risks but developer Cempra has not adequately characterized how likely the antibiotic is to cause liver damage according to a US FDA panel.

The Food and Drug Administration's (FDA) antimicrobial drugs advisory committee met to discuss Cempra’s candidate community-acquired bacterial pneumonia (CABP) drug last week.

Members unanimously agreed there is substantial evidence of efficacy and also concluded solithromycin has a favourable risk benefit profile by a narrow margin of 7 votes to 6.

According to Cempra, the Committee also concluded, by 12 votes to 1, that the risk of hepatotoxicity has not been adequately characterized.

The reviewers discussed approaches to characterize the existing liver safety information on solithromycin. According to a Reuters report they recommended that Cempra conduct additional studies to assess the potential liver risk after the drug has been approved.

Liver damage

Last week a Food and Drug Administration (FDA) briefing document released before the meeting revealed that a “significant safety signal for hepatotoxicity was observed in the solithromycin development programme.”

The document – and the FDA’s reference to a briefing package it put together for Ketek (telithromycin) – saw Cempra’s share price fall by as much as 41%.

Cempra response

CEO Prabhavathi Fernandes welcomed the recommendation, commenting that: “We appreciate the meaningful discussion from today’s panel.

Their supportive view and thoughtful comments on approaches to ensuring appropriate use are consistent with Cempra’s commitment to make solithromycin available to the right patients for a five to seven day course of an oral and/or IV macrolide as monotherapy for CABP.”

Solithromycin has been issued with target Prescription Drug User Fee Act (PDUFA) dates in late December.

Wockhardt data

The FDA panel’s recommendation also comes a week after Cempra said it had asked Barcelona, Spain headquartered active pharmaceutical ingredient firm Uquifa to provide it with manufacturing data.

The current solithromycin dossier includes data generated at a facility in Ankleshwar by Indian ingredient firm Wockhardt that was subsequently issued with a US import ban.