Although the experimental drug Albuferon made by US biopharmaceutical company Human Genome Sciences for the treatment of hepatitis C met its primary goal in trials, it was not sufficiently more effective than the existing standard of care drug Pegasys (from Hoffman La Roche) to convince analysts that doctors will switch to the new drug, and reports are coming in that the drug company’s shares have plunged to an all time low as investors come to the same conclusion.

The drug has just completed the second of two phase 3 trials, the company announced on March 9th. Although Human Genome Sciences described the results as “positive” in their press statements, a report by Reuters says analysts were expecting the drug not only to show it was not inferior to Pegasys, but to show a significantly better SVR (sustained virologic response), because this is what would encourage doctors to switch from the current medication.

According to the data released by Human Genome Sciences, who are headquarted in Rockville, Maryland, the key results of the trial known as ACHIEVE 1 were:

  • Albinterferon alfa-2b (Albuferon) given as 900 micrograms every two weeks showed a primary efficacy endpoint of sustained virologic response (SVR) that was comparable to peginterferon alfa-2a (Pegasys) given as a weekly 180 microgram dose in patients with genotype 1 chronic hepatitis C.

  • Patients receiving 900 micrograms of Albuferon had SVR rates of 48.2 percent, while patients receiving 180 micrograms of Pegasys had SVR rates of 51.0 percent.

  • Patients originally randomized to receive 1,200 micrograms of albuferon had SVR rates of 47.3 per cent, compared to 51.0 per cent in the 180 micrograms of Pegasys group.

  • Patients receiving 900 micrograms of albuferon had comparable rates of serious and/or severe adverse events compared to those receiving 180 micrograms of Pegasys.

One analyst from Piper Jaffray, Edward Tenthoff, told Reuters that while Albuferon was statistically comparable to Pegasys, a drug that doctors have been prescribing “for ever”, this was not going to be enough to persuade them to change.

Tenthoff said that doctors use SVR as a “key prescribing criteria”, and the numerically inferior SVR rate of Albuferon compared to Pegasys will make it difficult for the new drug to unseat the old one in the market place.

The hepatitis C virus causes liver inflammation, and estimates suggest about 170 million people worldwide are infected with the virus, including nearly 4 million in the US, about 75 per cent of whom are infected with the genotype 1 hepatitis C virus.

Chronic hepatitis C is when a person has carried the virus in their bloodstream for at least six months, and in the long term this causes serious liver disease, which can lead to cirrhosis, primary liver cancer and death.

Human Genome Sciences, who are developing Albuferon in partnership with Swiss drugmaker Novartis, said they intend to file for global marketing applications in the autumn.

Click here for more results from the Albuferon clinical trial (Human Genome Sciences).

Sources: Reuters, Human Genome Sciences.

Written by: Catharine Paddock, PhD