Vertex Drug for Hepatitis C Shows Durable Virus-Killing Ability in Tough-to-Treat Patients
More data is rolling in from Vertex Pharmaceuticals on its lead drug for hepatitis C, and it looks like the medicine is continuing to live up to its own high expectations. The Cambridge, MA-based company said today that telaprevir’s effect on killing the virus is remaining durable on follow-up analysis, and the drug appears to just about as good in a more convenient twice-daily pill form instead of its standard three-times-a-day dosing schedule.
The data dump came in front of a prime audience of physicians attending the American Association for the Study of Liver Disease annual meeting today in San Francisco. The results appear to match up pretty consistently with what Vertex has reported previously, which I wrote about in this advance story.
To recap what’s at stake, telaprevir is aiming to be a first-in-class protease inhibitor against hepatitis C, a chronic liver disease. If it can deliver in the final stage of clinical trials, it will change the standard of treatment for the disease. An estimated 3.2 million people in the U.S. have hepatitis C infections, and about 170 million have it worldwide. Telaprevir must be taken with a pair of standard drugs, pegylated interferon alpha and ribavirin, which cause flu-like symptoms and must be taken for almost a year. The Vertex drug is highly anticipated, though, because it has shown in earlier trials that it can almost double the cure rate for patients when added to standard therapy, and in half the time. If approved, the product could generate $2.6 billion in U.S. sales in 2013, according to Rachel McMinn, an analyst with Cowen & Co. in San Francisco.
“These are strong and striking early results,” says Freda Lewis-Hall, Vertex’s executive vice president for medicines development.
In the spirit of helping you keep all this data straight, because there’s a lot of it, we’re breaking this down into bite-size chunks. .
—The ’107 study. This trial of patients who didn’t respond to previous treatment, produced data from more patients who were followed over a longer period than was previously reported. Researchers found that 68 of 104 patients, or about two-thirds, who got telaprevir along with standard drugs had no evidence of the virus in their blood after four weeks. That effectiveness appeared to be long-lasting. Researchers found that 41 of 71 patients (58 percent) followed for 24 weeks still had no evidence of the virus in the blood. Importantly, telaprevir is showing that it can wipe out the virus about 43 percent of the time in the toughest patients of all to treat—those who didn’t respond at all to a prior round of therapy.
The last time Vertex reported results from this trial, at a European meeting in April, it didn’t have any follow-up data that extended this long, or such strong data for what are called “null responder” patients. Of course, there were side effects, though. About 8 percent of patients dropped out of the study because of adverse events, with about half of them quitting because they developed a rash, the company said.
—The C208 study. This trial is about convenience for patients. Telaprevir is designed to be taken three times a day in combination with standard drugs, and its ongoing final-stage clinical trials are enrolling patients on that dosing schedule. But the company also wants to know if it might be equally good in a more convenient twice-daily form. The results of this study suggest it could be. Researchers found 76 of 82 patients (93 percent) had their virus completely wiped out in the blood after three months on the usual telaprevir-containing regimen, while more than 80 percent in a comparison group did that well on a twice-daily telaprevir dose. “The question is do we continue to study twice-daily regimens based on what we see? The answer is yes,” says Lewis-Hall.
—Prove 3. Not a lot of news on this one. The Prove 3 study of telaprevir for patients who failed on previous therapy, first released in June, found that 60 of 115 patients (52 percent) who got the Vertex drug along with the standard drugs had no signs of the virus after about three months of follow-up after finishing treatment, the company said. That number is consistent with what Vertex is reporting to doctors at the liver meeting. It notes that 34 of 114 patients (30 percent) in a control group taking the standard meds had undetectable amounts of virus in the blood after they were three-quarters of the way through their nearly yearlong course of treatment. The true test of what’s considered a “clinical cure” is when patients have no sign of virus a full 24 weeks after they finish treatment, and that data isn’t yet available for release at this meeting, Vertex says.
About 16 percent dropped out of the Prove 3 study early because of adverse events, while just four percent of patients in the control group quit, the company says. In the final analysis of the Prove 2 study, which enrolled patients who were new to treatment, about 14 percent dropped out because of adverse events, compared with half that many in the control group.
When looked at altogether, Vertex now has more than 1,000 patients who have been analyzed for the safety of its drug.
Based on my conversation with Vertex’s chief commercial officer, Kurt Graves, heading into the meeting, it doesn’t seem like this data will surprise physicians who have been following the telaprevir story. He sounds like he’ll be keeping an eye on competitors like Schering-Plough’s boceprevir and other types of antivirals in development, like polymerase inhibitors and NS5A inhibitors, which might be combined with telaprevir. We’ll keep a close eye on this to see if anybody makes any big steps forward or back.