Protestors rallied outside an HIV conference in Indonesia this week, demanding less expensive hepatitis C treatment for people coinfected with both viruses, reports Reuters.

According to the article, protesters accused pharmaceutical company Roche of setting the price of hepatitis C drug pegylated interferon too high; it costs $1,500 a month.

According to the World Health Organization (WHO), about 4 million to 5 million people living with HIV around world are also infected with hepatitis C, a disease that can cause hardening of the liver. However, the high cost of treatment has left many with limited access. A large number of people infected with both HIV and hepatitis C are injection drug users, the WHO said, so many countries exclude them from treatment because of concerns over drug interaction and the probability of reinfection.

About 25 to 30 percent of positive Europeans and Americans are coinfected with hepatitis C, but the prevalence rate among HIV-positive injection drug users in Asia is between 80 to 90 percent.