BioWorld International

Intercell AG is looking to launch its lead product, a vaccine against Japanese encephalitis virus (JEV), around 12 months from now, following a preliminary analysis of data that indicated it attained its primary endpoint of noninferiority in a Phase III trial involving 868 randomized subjects against an existing product, JE-Vax.

"We achieved extremely high seroconversion levels, which were comparable to those in the Phase II trial, of 95 to 100 percent," Intercell CEO Gerd Zettlmeissl told BioWorld International.

The Vienna, Austria-based company will unveil in November the full dataset at the annual meeting of the American Society of Tropical Medicine in Atlanta. The Phase III program also involves a pivotal safety trial, a single-shot trial and a co-vaccination trial for travelers. So far the company has dosed more than 4,800 of the 5,370 subjects it plans to recruit.

The company is reporting preliminary data ahead of schedule because of faster-than-expected recruitment for the trial and faster analysis of the data from its CRO, Zettlmeissl said.

It aims to initiate a rolling biologics license application submission in October or November and to complete the process during the upcoming first quarter. It hopes to attain FDA regulatory approval by mid-2007.

In Europe, the company has adopted a more conservative timeline. It will file for approval in early 2007 and hopes to reach the market before mid-2008.

Intercell's product comprises an inactivated, attenuated virus grown in Vero monkey kidney cell culture. It is being positioned as a replacement for JE-Vax, manufactured by Biken - the Research Foundation for Microbial Diseases of Osaka University in Japan - and distributed by Sanofi Pasteur SA, the vaccines arm of Paris-based Sanofi-Aventis Group.

The latter also is an inactivated vaccine but is grown by inoculating the brains of mice.

While its efficacy is acceptable, Zettlmeissl said, it has an unfavorable safety profile due to a relatively high incidence of serious allergic reactions. Moreover, JE-Vax requires three immunizations, whereas Intercell's product requires just two. Intercell also is investigating a single-dose regimen.

The vaccine originally was developed by Seoul, South Korea-based CJ Corp. (formerly Cheil Jedang) in collaboration with the Walter Reed Army Institute, of Silver Spring, Md. Intercell acquired the rights at the beginning of 2003.

It stands to pay third-party royalties "in the low- to mid-single-digit range," Zettlmeissl said. The product has orphan drug status in the European Union. "We assume that we will have market exclusivity for 10 years," Zettlmeissl said.

Acambis plc, of Cambridge, UK, said it completed enrollment into a Phase III trial of a rival product, ChimeriVax-JE, last month.

The latter is a live attenuated recombinant vaccine based on a chimeric yellow fever viral vaccine. "There's never been a vaccine like that approved in the past," Zettlmeissl said.

Although JEV infection occurs, primarily in Asia, following mosquito bite, initial sales are likely to come from Western travelers and military personnel. The existing product has annual sales of about €150 million (US$192.2 million), Zettlmeissl said. Intercell aims to push that up to €200 million to €300 million by improving market penetration.

"The old vaccine, we assume, will completely disappear because it has no registration in Europe," Zettlmeissl said.

Intercell's share price hit a 52-week high at €13.79 during trading on the Vienna stock exchange last Thursday, following the release of the news. It closed at €13.10, up almost 4 percent from the previous day's close of €12.60.