Rotaviruses, a major cause of gastroenteritis, generate 500,000 doctor visits and 50,000 hospital stays in the United States every year, Moskowitz says. Elsewhere they are far deadlier: diarrheal infection is one of the top five causes of death worldwide. Wyeth's rotavirus vaccine, RotaShield, was withdrawn five years ago after a severe side effect (intussusception, a potentially fatal telescoping of the intestine) appeared in 20 out of 1 million US infants within one month of vaccination. Moskowitz says Wyeth's vaccine was derived from the Rhesus monkey, whereas Merck's has a bovine source. Now in a Phase III safety study of 30,000 infants, RotaTeq has shown no serious side effects to date. The company expects to file a Biologics License Application (BLA) next year.

Biomedical Breakthrough

Abatacept, the first biologic discovered in-house by Bristol-Myers Squibb, is a genetically engineered fusion protein that would be the first in a new class of agents—selective T-cell costimulation modulators—for rheumatoid arthritis. Abatacept prevents the proliferation of T-cells and has been shown to work in patients who have not been helped by methotrexate or TNF antagonists. Jim Kelly, an analyst with Goldman Sachs, says it's going to be used "both when people fail with the current injectable agents and in their stead." Several Phase III trials are under way, including one testing abatacept for juvenile RA. The FDA granted abatacept fast-track status. A BLA is anticipated this year.

Muraglitazar is the first dual peroxisome proliferator-activated receptor (PPAR) alpha/gamma agonist. No other compound simultaneously stimulates both alpha and gamma PPARs. That means the drug is capable of both lipid and glucose alterations. Rauch thinks it could also be the first therapy to address metabolic syndrome, a major risk factor for cardiovascular complications reaching epidemic proportions. In one study involving 4,500 patients with Type 2 diabetes, muraglitazar significantly improved blood glucose, triglyceride, and HDL cholesterol levels. Says Kelly: "The key issue is not just to demonstrate that it raises good cholesterol but that doing so has a clinical benefit—leads to positive clinical outcomes—something that has not yet been proved." BMS and Merck plan to publish full Phase III data next year.

Nelarabine, a nucleoside analogue that kills cancer cells by accumulating in T-cells, has fast-track status for the treatment of acute lymphoblastic leukemia and lymphoblastic lymphoma in patients who have not responded to at least two other chemotherapy regimens. Viren Mehta, principal of New York-based Mehta Partners, is confident that nelarabine will eventually be approved to fight other forms of cancer. It may also be useful for treating other types of T-cell malignancies, such as Sézary syndrome.

Rituxan presents "a novel approach to treating autoimmune diseases," Gibbons says. Currently on the market for the treatment of non-Hodgkins lymphoma and other carcinomas, it works, he says, "by binding to a receptor on B-cells, effectively eliminating them." This is significant, Gibbons says, because "a lot of autoimmune diseases have been thought to be diseases of the T-cell and were treated by TNF drugs like Remicade [infliximab]. But it turns out that B-cells are also involved." So far, the data through Phase II on Rituxan look good, he says. Phase III trials have begun.