Human Genome Sciences: Albuferon unlikely to threaten HCV standard of care

Human Genome Sciences' Albuferon has demonstrated non-inferiority to the current standard of care in a Phase III trial in treatment-naive genotype 1 hepatitis C patients. Although Albuferon's less frequent dosing schedule is an advantage, the fact that it did not show superior efficacy in this area of high unmet need suggests that the drug is unlikely to threaten existing interferon therapies.

Albuferon meets non-inferiority endpoint but fails to offer major benefits over existing treatments.

Human Genome Sciences (HGS) has announced results from Phase III trials for its investigational interferon therapy for the treatment of hepatitis C infection. Albinterferon alfa-2b (Albuferon) is a long-acting, injectable interferon therapy given once every two weeks which is being developed by HGS and Novartis.

The ACHIEVE 1 study investigated Albuferon and ribavirin in 1,278 treatment-naive patients with chronic hepatitis C genotype 1 for 48 weeks. The primary endpoint was the sustained virological response (SVR) rate, 24 weeks after the end of treatment. Top line results demonstrate that Albuferon met its primary efficacy endpoint of non-inferiority to peginterferon alfa-2a (Roche's market leading Pegasys), with 48.2% of patients achieving SVR in the 900-mcg Albuferon arm, versus 51% in the Pegasys treatment group in an intention-to-treat analysis. Importantly, the rate of Albuferon treatment discontinuations due to adverse events was more than double that of Pegasys, at 10.4% versus 4.1%. Adverse events observed were those typically associated with interferon therapy.

The standard of care in hepatitis C virus (HCV) therapy currently comprises pegylated interferon alpha in combination with ribavirin. There are two pegylated interferon therapies available, Schering Plough's PegIntron and Roche's Pegasys. Despite the ability of current HCV therapies to cure the infection in some patients, there remains significant room for improvement. Limited efficacy in patients infected with genotype 1 HCV is the greatest unmet need for this class; other drawbacks include high incidence of adverse events, long duration of treatment and consequently suboptimal patient compliance.

Although Albuferon has demonstrated efficacy in genotype 1 patients, the number achieving SVR in ACHIEVE 1 was similar to the current standard of care. Since the drug did numerically, albeit not statistically, slightly worse than Pegasys in genotype 1 patients, it does not address this unmet need any better than its marketed competitors. Moreover, the higher rate of discontinuations in the Albuferon arm indicates that it does not offer any benefits in terms of tolerability either.

Consequently, Datamonitor believes that while Albuferon reduces the dosing frequency, the lack of efficacy compliance benefits in genotype 1 patients makes it unlikely to threaten currently marketed interferon therapies. Therefore, Datamonitor forecasts annual peak sales of just over $200 million in the seven major markets by 2017.