BioWorld International Correspondent
MUNICH, Germany - Intercell AG reported positive results from its Phase II trial of a hepatitis C vaccine.
The study, which focused on patients who had not responded to the standard combined treatment of interferon and ribavirin, showed that the vaccine brought about T-cell response without significant side effects.
"The results of the study represent a breakthrough in inducing T-cell activity, a key to the immune system, in an otherwise untreatable group of patients," Intercell's CEO, Alexander von Gabain, told BioWorld International. "This was pretty much an optimal outcome for our hopes."
Von Gabain said that regulatory agencies had insisted on starting with a challenging patient cohort, people who already had received treatment and didn't respond. "The best that you could hope for," he said, "is to induce a proper immune response, with the treatment being a tool to re-educate the immune system. We were clearly pleased to get T-cell reaction from such a difficult group."
Intercell's vaccine is based on virus-derived, T-cell-specific peptides and formulated with the company's first-generation adjuvant Polyarginine. The company characterized the patients' T-cell response as a milestone in developing therapeutic treatments for hepatitis C.
"The outcome [of the trial] means that we are safe," von Gabain said. "Hepatologists had expressed concerns that we were not safe, that the vaccination could produce an acute crisis because of T cells in the liver." Now that the trial has allayed those concerns, the company can go on to a trial with a less-difficult patient group.
The next step for Intercell, of Vienna, Austria, is an additional Phase II trial with patients who have a less-compromised immune system, such as those who have been diagnosed with the disease but do not yet show significant symptoms and are waiting for interferon/ribavirin treatment. Von Gabain said that the side effects of current treatments for hepatitis C mean that asymptomatic patients often wait a year or two before beginning treatment. By comparison, he said, a vaccination injection about once a month would be much less painful than interferon treatment.
Global sales of hepatitis C drugs are €2.8 billion annually, with demand expected to reach €3.7 billion by 2006, Intercell said. The company estimates that the global market for a vaccine could be up to €1.5 billion, of which €600 million would be in Europe.
"Hepatitis C is a large market, but the disease is a tough nut to crack," von Gabain said. "This is definitely not a blitz. We are looking at a move to the market in about 2011 or so, but there is no other product going out there. There are some discussions about small molecules, but they are not even in Phase I yet."
Intercell also has a prophylactic vaccine against Japanese encephalitis. That product is expected to enter Phase III trials this year.
Von Gabain said that Intercell's strategy for marketing the hepatitis C vaccine remains flexible and would depend on the results of additional trials.
"We have always known that treating hepatitis C with new technology is a systematic and long-term question," he said. "We are not in a hurry to choose [whether or not to partner]. Maybe at the end of the day, you would combine the vaccine with additional treatments. You need a sophisticated approach to the disease."