Medivir AB’s experimental hepatitis C treatment TMC435 cured as many as 80 percent of patients 24 weeks after treatment ended, suggesting that the therapy prevents the virus from surging back.
The mid-stage Aspire trial looked at the medicine in combination with the current standard of care of interferon and ribavirin. The virus was cleared 24 weeks after treatment ended in 80 percent of patients who took a once daily TMC435 dose of 150 milligrams for 48 weeks. The sustained cure rate was 70 percent among patients who took 100 milligrams of the drug for 12 weeks. The results were announced today at a medical meeting in Barcelona.
Medivir is developing its TMC435 tablet with Johnson & Johnson. The drug is a protease inhibitor, which blocks the action of the protease enzyme the hepatitis virus needs to replicate, directly stopping it from spreading.
Doctors and analysts see TMC435 as a second-generation protease inhibitor following the introduction of Merck & Co.’s Victrelis and Vertex Pharmaceuticals Inc.’s Incivek last year. TMC435 reduces dosage to once a day from twice or three times daily and also has a better safety profile compared with Incivek and Victrelis, said Matti Sallberg, a professor of biomedical analysis at Karolinska University in Stockholm who wasn’t involved in the study.
About 51 percent of patients who didn’t respond to prior treatment were cured after taking TMC435 with interferon and ribavirin, compared with 19 percent who didn’t have TMC435 in the treatment regimen, the company said in November.
Competitors including Gilead Sciences Inc. and Bristol-Myers Squibb Co. are seeking to eliminate interferon from the treatment regimen because of side effects. Medivir is also studying TMC435 in combination with Gilead’s 7977 hepatitis C treatment and with Bristol-Myers’ daclatasvir, both without interferon.
The trial with Gilead’s 7977 will be the first to examine the efficacy of a protease inhibitor combined with a nucleotide polymerase inhibitor, which works differently to block the virus’s ability to replicate in the body, Credit Suisse analyst Ravi Mehrotra wrote in a note to investors this week. Positive results from the trial “will likely provide boost to perceptions of TMC435 as a real competitor in an interferon-free world,” he wrote.
A drug interaction study of TMC435 with Bristol-Myers’ BMS-986094 polymerase inhibitor will also be conducted, Medivir said yesterday.
“We see the expanded clinical collaboration as a strong validation of TMC435,” said Hans Jeppsson, an analyst at Danske Bank, in a note to investors.
Hepatitis C affects as many as 170 million people globally, putting them at risk of developing liver cancer, according to the World Health Organization. The growing population of patients infected with the virus spurred Gilead’s decision in November to buy experimental hepatitis C-treatment maker Pharmasset Inc. for $10.8 billion and Bristol-Myers’ acquisition in February of Inhibitex Inc. for $2.5 billion.
The disease is most commonly transmitted through contaminated blood transfusions, organ transplants, contaminated syringes and needle-injected drug use, according to the WHO.