Zavante Therapeutics, a San Diego antibiotic developer, has raised $45 million from venture capital investors for clinical testing of its product to combat serious infections, including those caused bacterial “superbugs.”

The drug is an injectable form of fosfomycin, intended to be used against a broad spectrum of multi-drug resistant bacteria. A pivotal clinical trial for the treatment of complicated urinary tract infections is expected to begin this year. This trial will be the only one needed for approval, said Ted Schroeder, the company’s chief executive.

Called ZTI-01, the drug works by a different mechanism than other injectable antibiotics used in the United States, Schroeder said. That means it should work against bacteria that have evolved resistance to other antibiotics. It’s to be used for complicated urinary tract infections and other infections.

A privately held startup formed last year, Zavante raised $10 million of the total from the conversion of previously issued convertible notes. The rest came from a group of new investors. These include Frazier Healthcare Partners and Longitude Capital, along with Aisling Capital. The funding was announced on March 30.


The drug has been long been used in Europe and the United States in an oral form, but hasn’t been brought here in an intravenous form, Schroeder said. In recent years the drug was discovered to be highly active against multi-drug resistant bacteria.

“This is a rare opportunity in one’s career to bring a product to patients in the United States that potentially will have an immediate impact on human health,” Schroeder said. “The threat of so-called superbugs is real and growing, unabated, and this is a real advance that will benefit patients.”

The intravenous formulation would be especially useful for critically ill patients, who can’t receive the drug orally, Schroeder said. The infections it would be used against are typically acquired in a hospital or a nursing home.

Because of the pressing need for new antibiotics, the U.S. Food and Drug Administration has given Zavante a number of benefits, if the drug receives marketing approval.


In December, the FDA expanded the drug’s designation as a Qualified Infectious Disease Product from the original complicated urinary tract infections. These are complicated intra-abdominal infections; hospital-acquired bacterial pneumonia; ventilator-associated bacterial pneumonia; and acute bacterial skin and skin structure infections.

Moreover, the FDA gave these designations fast-track status. Benefits include priority FDA review and an additional five years of market exclusivity.

Zavante’s chief scientific officer, Evelyn Ellis-Grosse, took the initiative to bring fosfomycin to the United States in the intravenous formulation, Schroeder said. Ellis-Grosse saw that intravenous fosfomycin fit the criteria of the 2012 Generating Antibiotic Incentives Now or GAIN Act.

“She moved quickly to secure an exclusive license for the United States, and started working on development of the product through grants,” Schroeder said.


That was done under a previous company of the same name that needed cash to take the program forward, he said.

“We had the management team and the experience to do that, so we acquired the company and kept the name,” Schroeder said.

Zavante has multiple options to get the capital to market the drug, he said. A public offering is one of them, also an acquisition.

“It’s great to have options, and we’ll take the option that’s best for shareholders,” he said.