Optimer Wins FDA Panel Nod, Still Wrestling With Language to Describe Benefit

Xconomy San Diego — 

San Diego-based Optimer Pharmaceuticals (NASDAQ: OPTR) won the blessing of an FDA advisory panel today for its novel antibiotic, but now the big issue will likely be how the benefit of the drug will be communicated to doctors and patients.

Advisors to the FDA at a meeting in Silver Spring, MD voted 13-0 in favor of Optimer’s fidaxomicin, saying it has demonstrated it is safe and effective against a dangerous bacterial infection people get in hospitals known as C. difficile. But the panel was much less certain on a second question posed by the FDA, on whether Optimer’s antibiotic has proven a benefit against recurrences of the dangerous bug. The panel voted 7-6 against Optimer on that question, after having a discussion about how to properly define recurrences.

The FDA usually follows the advice of its expert panels, although it isn’t required to do. The agency’s deadline to complete its review of the Optimer drug is May 30.

Optimer CEO Pedro Lichtinger, reached by cell phone after the advisory panel’s vote, was quite upbeat. If the FDA clears the new antibiotic for sale, it will be Optimer’s first approved product in the U.S.

“This is an outstanding day for patients, healthcare providers and of course for Optimer,” Lichtinger says. “This drug is going to get approved.”

Optimer had argued that its antibiotic offered an advantage in terms of preventing recurrences of “C.diff,” which often lead to complex, costly, and risky cases of hospitalization. Optimer showed that its antibiotic can cure patients a little more than 90 percent of the time, which was slightly better than the standard vancomycin. The trials, which followed patients for 30 days, showed that about half as many patients on the Optimer drug had a single recurrence, when compared with those who got vancomycin.

Pedro Lichtinger

The Optimer trials weren’t designed to ask how patients fared in cases of more than one recurrence, which prompted much discussion on the panel about whether the company can actually say it has shown a benefit against recurrence, Lichtinger says. This means that the company and the FDA are going to spend some time working on the best terminology to accurately describe the benefit seen from the Optimer drug, he says.

“There’s no question this is a superior product at 30 days post-treatment,” Lichtinger says. “We’ll engage with FDA on the right language so the superiority can be properly communicated.” He added: “Using the word recurrence to describe its benefit was confusing” to some of the panel members.

Optimer’s drug has some other features that will help it differentiate itself in the market. The drug, an oral pill, is designed to be quite different than the standard vancomycin. The Optimer drug is a “narrow-spectrum” antibiotic, meaning it is specifically designed to kill “C.diff” without wiping out all kinds of other so-called “good” bacteria in the gut. The drug also stays in the gastrointestinal tract where it needs to be active, and doesn’t get absorbed, where it can cause side effects.

Stock trading in Optimer was halted today, which the NASDAQ sometimes does for development-stage biotech companies facing such critical moments at FDA public hearings. The stock closed yesterday at $13.80 a share, heading into the FDA committee meeting.