Abbott's hepatitis C combinations promising in phase II

Abbott Laboratories has reported encouraging data with two of its combination therapies for hepatitis C virus, which suggest it can achieve high cure rates in treatment-naïve patients.

The company said that the phase II trials indicate it is a step closer to achieving sustained virologic responses (SVR) after just 12 weeks of therapy using combinations of orally-active antiviral drugs and without any need for injectable interferon-based treatment.

The first study, known as Co-Pilot, looked at the combination of the HCV protease inhibitor ABT-450 (boosted with low-dose ritonavir) with ABT-333, a non-nucleoside HCV NS5B polymerase inhibitor, plus ribavirin in 50 HCV patients.

After 12 weeks' treatment, 93 to 95 per cent of patients who had not been treated earlier for HCV achieved an SVR, depending on the dose used.

The SVRs appeared to be independent of the HCV subtype or the patient's IL28B genotype, a factor which has been shown to affect a patient's response to HCV protease inhibitor drugs. For those who had not responded to earlier interferon-based therapy with SVR rate was 47 per cent.

The second study, called Pilot, studied the ritonavir-boosted ABT-450 given alongside another non-nucleoside HCV NS5B polymerase inhibitor called ABT-072 and ribavirin in 11 treatment-naïve HCV patients.

The trial found that 100 per cent of patients achieved an SVR at 12 weeks, with 91 per cent maintaining the response out to 24 weeks.

"We are extremely encouraged to see this level of sustained response with only 12 weeks of therapy in patients who were new to treatment, and to see a response in patients who had failed past treatment because options to cure this population are limited," commented Fred Poordad of Cedars-Sinai Medical Center in Los Angeles, US, who was the lead investigator for Co-Pilot and an investigator for Pilot.

Current treatments for HCV remain interferon-based and a significant number of HCV patients are unable or unwilling to take interferon due to contraindications and/or side effects, according to Abbott.

The company is racing to develop non-interferon-based HCV regimens against the likes of Vertex Pharma, Bristol-Myers Squibb, Gilead Sciences and Merck & Co.

The results are scheduled to be presented later this month at the European Association for the Study of the Liver (EASL) meeting in Barcelona, Spain.

Abbott's hepatitis C portfolio is expected to be one of the main assets of the company's pharmaceutical operations, which are due to be spun out into a new company called AbbVie later this year. Analysts have predicted peak sales for the portfolio upwards of $2bn a year.