Positive Phase III Results Reported for Faldaprevir in HCV/HIV Co-Infected Patients
Oral protease inhibitor targets viral replication in the liver
Positive results have been reported for the oral protease inhibitor faldaprevir (Boehringer Ingelheim) in patients co-infected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV).
HCV cure 12 weeks after the conclusion of treatment (SVR12) was achieved by 72% of the patients in the phase III STARTVerso 4 trial. Further, 80% of the patients were eligible for randomization to a shortened duration of treatment (24 weeks versus 48 weeks) because they had achieved protocol-defined early treatment success. Of these patients, 86% achieved SVR12.
The STARTVerso4 study evaluated the efficacy and safety of faldaprevir (120 or 240 mg) in combination with pegylated interferon (peg-IFN) and ribavirin in 308 HCV treatment-naïve or treatment-experienced patients with HCV/HIV co-infection.
In the faldaprevir groups, 71% (120 mg) and 72% (240 mg) of patients achieved SVR12. These results were consistent across patients regardless of HCV genotype-1 subtype (GT1a or GT1b); the presence of compensated cirrhosis; the dose and duration of faldaprevir treatment; and the duration of pegIFN and ribavirin. In a post hoc analysis, 75% of patients with the Q80K variant achieved SVR12 compared with 71% of patients who did not have the variant.
Serious adverse events (AEs) were reported in 32 patients (10%). To date, 24 patients have prematurely discontinued faldaprevir because of AEs. The most frequent AEs were nausea (37%), fatigue (34%), diarrhea (27%), headache (25%), and weakness (23%). Patients will be followed to 24 weeks after the conclusion of treatment (SVR24).
A new drug application (NDA) for faldaprevir has been accepted for filing by the FDA. Faldaprevir is currently under review as a component of a combination antiviral treatment regimen for the treatment of chronic HCV infection in adult patients who are treatment-naïve or who have been previously treated with interferon-based therapy, as well as in those with compensated liver disease, cirrhosis, or HCV/HIV co-infection. The FDA target action date for faldaprevir is in the fourth quarter of 2014.
In separate reports presented at the 2014 Conference on Retroviruses and Opportunistic Infections (CROI), held March 3–6 in Boston, investigators described the results from analyses that evaluated drug–drug interactions of faldaprevir with common HIV medications, including efavirenz, atazanavir/ritonavir, darunavir/ritonavir, raltegravir, and tenofovir. In each of these analyses, there was no clinically relevant effect of faldaprevir on the pharmacokinetics of any of the HIV medications studied. Patients in the STARTVerso 4 trial already taking ritonavir-boosted HIV protease inhibitors (darunavir or atazanavir) or efavirenz were enrolled into the 120-mg and 240-mg faldaprevir groups, respectively.
Faldaprevir is an investigational oral protease inhibitor that is designed to target viral replication in the liver. It has not been approved by the FDA for this indication, and its safety and efficacy have not been established.
Source: Boehringer Ingelheim; March 6, 2014.