Last week Cempra warned that manufacturing data from banned supplier Wockhardt in the solithromycin dossier may be viewed unfavourably by US Food and Drug Administration (FDA) reviewers scheduled to assess the drug on Friday.
The firm said it had asked a second supplier, Uquifa, to provide it with replacemnt information that it plans to submit to the FDA.
But active pharmaceutical ingredient (API) manufacturing data may not be the agency’s only concern about solithromycin according to a briefing document published last night.
The FDA said a “significant safety signal for hepatotoxicity was observed in the solithromycin development program.”
The agency said: "The rates of transaminase elevations were higher in solithromycin- treated patients than those treated with moxifloxacin and were related to solithromycin exposure.
"The high rate of infusion site-related reactions associated with solithromycin (31.3%) as compared to moxifloxacin (5.2%) is another safety concern."
The agency also referenced a 2001 briefing package it put together for Ketek (telithromycin), an antibiotic approved in the US 2004 that was later associated with serious liver damage.
Cempra declined to comment ahead of the FDA review on Friday.