According to a new study Roche's brand of interferon can help control the potentially deadly liver infection, hepatitis B, better than a competitor's drug.
Researcher George Lau and his team at Queen Mary Hospital in Hong Kong, found that after treating patients with Roche's drug for 48 weeks, pegasys suppressed the virus better than GlaxoSmithKline's drug lamivudine.
In a separate hepatitis B study it was found that a third drug, Gilead Sciences, Hepsera, was effective only with continued use. Its effects apparently disappearing within weeks after patients stopped taking the drug.
It is believed that some 400 million people worldwide are believed to be infected with hepatitis B.
The disease is caused by a virus, often spread through having unprotected sex or sharing needles with an infected person, and it attacks the liver.
It can lead to liver cancer and death.
It is debatable whether the handful of drugs which have been approved to treat the condition, are useful, especially when treatment costs can range from $5,000 to $15,000 per year.
The patients treated with pegasys suffered more side effects such as depression, fatigue, headache, fever and muscle pain, but the researchers maintain their finding supporting the use of Pegasys as a drug for a common type of long-term hepatitis B.
The study of Hepsera, monitored people with another form of hepatitis B, HbeAg-negative, which accounts for about 14 percent of U.S. cases and even more elsewhere.
The team led by Stephanos Hadziyannis of Henry Dunant Hospital in Athens, tracked 185 volunteers, some of whom who have gone on and off the drug for as long as 144 weeks, and discovered that Hepsera continues to work in more than two out of three patients, but only as long as they were taking it.
When patients stopped taking the drug, the hepatitis B virus became reactivated, with amounts of the virus returning to pre-treatment levels within a month.
So they concluded that long-term therapy will be needed for the majority of patients.
The Athens team reported that after nearly three years of treatment, only 6 percent of patients had developed a mutation that made the virus resistant to the drug.
By comparison, when lamivudine is given, the drug typically loses its effectiveness in 20 percent of patients each year.
However the studies were financed by the drug companies, who held and analyzed the data and more than half of the named authors had financial ties to those companies.
The studies are published in the latest edition of the New England Journal of Medicine.