Vertex Pharmaceuticals wants to make sure doctors walk away from this weekend’s big liver disease research meeting with two main ideas stuck in their heads. No. 1—The company’s experimental drug is showing that it can cure even the toughest-to-treat patients with hepatitis C. No. 2—it may work just as well in a twice-daily dose as it does when given three times a day.
The latest batch of clinical trial data from Cambridge, MA-based Vertex (NASDAQ: VRTX) shows that its telaprevir treatment was able to attain the clinical definition of a cure in more than 80 percent of patients who got the drug. That’s regardless of whether they got the drug three-times-a-day, or a more convenient twice-daily dose. Side effects were similar for each dosage. Results from the mid-stage 161-patient study, known as C208, are being presented this weekend at the American Association for the Study of Liver Diseases, being held in Boston.
This latest finding is part of the mounting evidence Vertex is gathering on its quest to develop the first-of-its-kind protease inhibitor for hepatitis C, a chronic liver disease. The drug is currently being tested as an oral pill that patients take in combination with the standard treatments—pegylated interferon alpha and ribavirin. Vertex is hoping to more than double the cure rate for patients who are new to treatment, and make it so most patients only need to take the standard treatments for 24 weeks instead of 48, which is important because those drugs cause flu-like symptoms that make most patients feel miserable. The new drug is expected to trigger an outpouring of patients seeking treatment if teleprevir reaches the market on schedule in 2011, and it could generate $2.3 billion in U.S. sales by 2013, according to an analysis by investment firm Cowen & Company.
While Vertex is considered to be at the front of the pack when it comes to treating hepatitis C, there is a growing crowd of competitors following fast behind with an estimated 40 different drugs in clinical trials. That includes drug candidates from deep-pocketed rivals like Schering-Plough and Roche. Vertex has sought to fend off the threats to future market share a couple of ways. One is by showing that its drug can eradicate the virus—and cause a clinical cure—for the majority of the toughest patient population—those who didn’t respond at all to a prior round of standard treatment. That result was shown earlier this week in a small study known as ‘107, and Vertex is attempting to prove that point on a larger scale in the ongoing trial of 650 patients called Realize.
While it’s important to be seen as the most potent drug on the block, it’s also vital to at least stay even with the other guys when it comes to convenience. Vertex’s original mid-stage trials looked at three doses per day of 750 milligram telaprevir pills. That means patients who work during the day need to take their pills with them, and take them after a snack or lunch, says Vertex chief medical officer Bob Kauffman. By going to twice-a-day, with 1,125 milligrams—the same total amount of telaprevir in a given 24-hour cycle—researchers hoped they could achieve the same antiviral activity without seeing extreme peaks or valleys in blood concentration that might lead to increased side effects, or weak potency that could allow the virus to bounce back over time, Kauffman says.
“We think this is a big deal,” Kauffman says. “For people who work, this means you can just take the drug in the morning before you go to work, and take another one when you come home in the evening. It is more patient-friendly.”
Side effects were the big concern, and the results from the C208 study suggest they are “similar” for the twice-daily and thrice-daily regimens, Kauffman says. Eight of the 161 patients dropped out of the study because of serious side effects, mostly because of rash (4 patients), and anemia (3 patients), Vertex said. It didn’t say how many of the serious side effects were in the twice-daily dosing group.
All of Vertex’s three pivotal studies—known as Advance, Realize, and Illuminate—are testing the three-times-a-day dosing regimen, so that’s where the bulk of the evidence is going to be in the FDA approved prescribing information, if telaprevir is cleared for sale. The company is talking with regulators about whether this result from C208 might be sufficient to include language in the label that says twice-a-day is OK, Kauffman says.