Medivir’s hepatitis C clinical compound TMC435, which is being developed in collaboration with Tibotec, attracted considerable attention at this year’s conference of the American Association for the Study of Liver Diseases (AASLD), which concluded in San Francisco on 4 November 2008. AASLD is by far the largest annual meeting in the US as regards liver diseases.

Hepatitis C is a therapeutic area where there is currently a large medical need for new and more efficacious pharmaceuticals. Only about 40% of patients respond to current treatments. The disease is prevalent throughout the world and the incidence rate is still large and growing.

Medivir is at the cutting edge of the development of new HCV pharmaceuticals. We have today two projects with different modes of action against HCV in collaboration with our partner Tibotec, a subsidiary within the Johnson & Johnson family of companies. One of these is TMC435, a protease inhibitor for which we presented data for the on-going phase IIa clinical trial. The other HCV project relates to development of a polymerase inhibitor and is in advanced preclinical development.

Several companies presented interesting data at the 2008 AASLD conference in San Francisco, indicating that progress is being made in the HCV area, but also that HCV is an intensely interesting area for developing new pharmaceuticals.

The project TMC435 compares very favorably with the competition.
“The data on our hepatitis C drug TMC435 which we presented at the conference attracted considerable attention, says Börje Darpö, Medivir’s Vice President for Clinical Development.

Right from the very first doses in the phase IIa clinical trial, “Opera-1”, powerful antiviral efficacy was apparent. After four weeks treatment with 75 mg TMC435 on top of Standard of Care treatment interferon/ribavirin, 8 out of 9 patients with chronic HCV genotype 1 were virus-free.

“The side-effect profile also looks good and all patients in the study were able to complete the TMC435 treatment. If these results stand up in larger and longer trials, it means that TMC435 may be a new effective treatment alternative for patients with the most common and least responsive forms of chronic hepatitis C”.

HCV is attracting a lot of research activity and several other companies have compounds in clinical development.
“When we now compare our data with other protease inhibitors, especially those that have proceeded further in clinical development, TMC435 looks like being a more efficacious and safer alternative”

The development of polymerase inhibitors for the treatment of this same patient group has also been boosted by promising clinical data. Many believe that polymerase inhibitors will be combined with protease inhibitors for the treatment of certain more severe forms of hepatitis C, for example patients who are non-responders to current pharmaceuticals.

“In this context, our preclinical collaboration with Tibotec on polymerase inhibitors gives us the opportunity to be able to contribute to new, more efficacious drugs for the treatment of chronic hepatitis C”, says Börje Darpö.