Penny stock biotech Synthetic Biologics sees its ‘breakthrough’ status pulled as FDA ponders safety issues

A little under a year ago the penny stock of Synthetic Biologics $SYN gyrated higher on the news that its drug SYN-004 (ribaxamase) — designed to protect the gut microbiome from the havoc caused by some antibiotics and guard against Clostridium difficile infection — had won the FDA’s not-so-rare breakthrough therapy designation.

Steven Shallcross, Synthetic interim CEO

Today, though, after the biotech reviewed plans for an upcoming Phase III program, they followed up with the rare news that the FDA is dropping the BTD after regulators concluded that they couldn’t figure out why the drug arm experienced a higher rate of deaths in their Phase IIb trial.

From their statement:

Following FDA’s review of the additional data, it was determined that the requirements for Breakthrough Therapy Designation were no longer met due to the numerical imbalance in fatal adverse events observed in the study which could not be fully evaluated due to the limited safety database, and the study’s method of statistical treatment of patients who did not complete the study for any reason. 

The biotech’s stock slid 12% in pre-market trading — falling to 30 cents a share.

You don’t often hear about BTD’s being withdrawn, but it happens more often than you might think. The Twitter buzz that met the news this morning included a link to the FDA’s page on BTDs that showed 4 breakthrough titles were rescinded so far in fiscal year 2018, which got started October 1.

The agency set up the BTD program in order to make a commitment to biotechs to help accelerate the review of drugs that warranted special attention. And it’s been gaining steam under Commissioner Scott Gottlieb, who would like to see more regulators embrace it the same way the oncology division has.

The FDA did express a willingness to keep helping, says Synthetic Biologics. And the biotech has worked out a plan with regulators on the Phase III design that will keep a careful focus on safety, so they can keep a rein on risk.

They also agreed that the primary endpoint should be “the reduction of the incidence of Clostridium difficile infection (CDI) in the ribaxamase treatment group relative to placebo.”

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Research Scientist - Immunology
Recursion Pharmaceuticals Salt Lake City, UT
Director of Operations
Atlas Venture Cambridge, MA

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