The U.S. FDA withheld approval of Cempra Inc.'s Solithromycin for the treatment of community-acquired bacterial pneumonia in adults.
The regulator said in a complete response letter that the available database of 920 patients was too small to fully characterize the potential risk of hepatotoxicity, or chemical-driven liver damage, in patients treated with the drug.
The FDA is instead recommending an additional study involving about 9,000 patients to rule out the risk of serious Solithromycin-induced liver injury.
Cempra is also required to address deficiencies at the manufacturing sites of the drug. "With more than $225 million of cash on hand, patent protection for solithromycin through 2032 and a pipeline that includes fusidic acid and other potential programs for solithromycin, including an ophthalmic formulation, we have flexibility to determine the best course forward for solithromycin and Cempra," the company's acting CEO, David Zaccardelli, said in a statement.