Optimer, Developer of Drug For “C. Diff” Bacteria, Awaits Pivotal Results
Optimer Pharmaceuticals will find out soon whether it has come up with the first new drug for a dangerous bacteria known as “C. difficile” in more than two decades. The San Diego-based company (NASDAQ: OPTR) is eagerly awaiting results from a 660-patient clinical trial of its experimental drug, OPT-80. By the end of this year, the company will see whether its candidate is as good or better than a standard antibiotic at getting rid of the so-called “C. difficile” bug, and maybe whether it’s better at preventing relapses.
I got the lowdown on what’s at stake from Stuart Johnson, of Loyola University in Chicago, a consultant to Optimer and one of the country’s leading researchers in the world of “C. Diff” He’s going to be joined by thousands of colleagues this weekend in Washington D.C. at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), where Optimer will be shaking the bushes to get doctors excited about the possibilities with this new drug.
First, a little background. This bug causes really awful diarrhea, the kind that can lead to severe dehydration, inflammation of the colon, hospitalization, and death. It is a thorn in the side of hospitals and nursing homes, who try to use bleach to kill it where it hides on toilets and handrails, but not always successfully, he says. This pathogen has been rising in prevalence, with about 30-40 cases per 100,000 people discharged from hospitals in 2001, and about 100 cases per 100,000 discharges in 2005, according to data from the Centers for Disease Control and Prevention. These cases are so ugly that some doctors are experimenting with stool transplants given via enema—I’m not making this up—in order to restore normal bacteria in the colon that can help ward off a C. Diff infection, Johnson says.
“My wife goes running with a woman who had to go to the hospital with appendicitis, and ended up getting C. Diff. She said she was way more sick with C. Diff. That gives you an idea how bad this is,” Johnson says.
The main treatments for this are old generic stand-bys, metronidazole (Flagyl) and vancomycin. The latter drug is usually the standard, because it has fewer side effects, Johnson says. It can cure patients of the bug about 90 percent of the time, so that gives Optimer “a high bar” to clear, he says. The problem with vancomycin is that about one-fourth of patients relapse a week or two later, and become even tougher cases to treat, Johnson says.
Optimer’s drug is the only candidate in the final stage of clinical trials, so physicians are eagerly anticipating the results, Johnson says. The trial looked at patients who took OPT-80 twice-daily for 10 days on an outpatient basis, compared with patients who took vancomycin four times a day, Johnson says. The Optimer drug has shown potent activity against C. Diff in the test tube, and hopes are high that it will translate in a final-stage study of effectiveness, he says. The drug is designed, unlike some broad-sweeping antibiotics like metronidazole and vancomycin, to kill the pathogen while mostly sparing the normal, healthy bacteria we all have in the gut. If OPT-80 can show roughly equal effectiveness at curing patients, while lowering the risk of relapses, “this could have a significant public health benefit,” Johnson says.
Optimer may be in the lead, but other companies aren’t very far behind with new treatments for this bug. Princeton, NJ-based Medarex (NASDAQ: MEDX) is working on a genetically-engineered antibody drug against the pathogen, while Cambridge, UK-based Acambis is working on a vaccine against it, Johnson says.
Optimer has another 660-patient study of its drug candidate, which is currently enrolling patients, and is expected to wrap up by June 2009. The results from the first trial aren’t expected to be out in time for this year’s ICAAC meeting, but if Optimer can hit its goals in both of these trials, it will surely have an easier time generating buzz about this new treatment for a nasty bug.