Achillion’s development of its hepatitis C treatment sovaprevir will be delayed after reports of abnormal liver functions in some patients caused regulators to suspend its clinical trial programme.
The pharma company said the US Food and Drug Administration (FDA) made its decision to put the drug on clinical hold after elevations in liver enzymes were noted in healthy patients during a phase I drug-drug interaction study, which evaluated the use of sovaprevir alongside ritonavir-boosted atazanavir.
At the time these “unanticipated elevations” were detected, Achillion stopped further dosing of the drug and informed the FDA, although none of the incidences met the criteria for a serious adverse event.
Sovaprevir was granted fast-track status by the US Food and Drug Administration (FDA) in 2012 and is being developed to work as an inhibitor of the NS3 protease, which plays a role in the formation of the hepatitis C virus.
The drug is also being investigated in several other trials, including the phase II -007 clinical trial evaluating a 12-week course of treatment with sovaprevir in combination with Achillion’s other investigational drug ACH-3102 and ribavirin for patients with treatment-naive genotype 1 hepatitis C viral infection.
Similar elevations in liver enzymes have not been reported in this trial or in any other drug-drug interaction studies completed to date, and the FDA has allowed continued enrolment and treatment of patients in the -007 trial.
Achillion said it plans to plans to release interim clinical trial results in the third quarter of 2013, while further results, including sustained viral response data, will be released in the fourth quarter.
There are still questions over the drug’s future, however, and the FDA has asked for study reports from two drug-drug interaction studies and a safety analysis of ongoing sovaprevir trials.
According to Achillion, it expects to be able to provide the FDA with this information within the next six weeks.