of this new combo regimen, so I made sure to ask George about that during a short call last week. She noted that more than 40 different studies that include about 4,000 patients make up Vertex’s application to the FDA. “It’s an extremely well-studied medicine,” George says.
The most common side effects among patients on telaprevir were rash and anemia, George says. As many as two-thirds of patients on the Vertex drug reported a rash in studies, although George says that 90 percent of those cases were mild-to-moderate in severity. Through experience in trials, Vertex and physicians learned to manage the rash by using immune-suppressing corticosteroid drugs or antihistamines, or by taking patients off telaprevir when it was no longer necessary, George says. About 1 percent of patients dropped out of the studies because of the rash, and the dropout rate declined as Vertex learned how to better manage the side effect, she says.
About one-third of patients on the current standard drugs get anemia, a depletion of oxygen-carrying red blood cells that makes people feel weakness and fatigue. The rates of anemia climbed slightly when researchers added the Vertex drug to the mix, George says. Most of the anemia cases in Vertex’s pivotal studies were managed the usual way, she says, as doctors lowered the dose of one of the standard drugs—ribavirin.
While Vertex and Merck have never studied their respective compounds head-to-head, it’s inevitable that the panel, doctors, and investors will make their judgments on which one they prefer as they appear on track to reach the market in what you could call a dead-heat. Regardless of which gets to the market first, most analysts see Vertex’s drug as best-in-class. We’ll have a clearer answer to that question after hearing what the FDA staff has to say this week about the drugs in its briefing documents, and in the questions that the FDA panel chooses to raise.