Pacific Beach Biosciences Inc., an anti-infectives player founded last year with seed money from Paramount Biosciences LLC, licensed a novel antibiotic called zabofloxacin from Dong Wha Pharmaceutical Ind. Co. Ltd.

The deal calls for San Diego-based PB Biosciences to pay Seoul, Korea-based Dong Wha an undisclosed up-front payment and up to $56.5 million in development and commercialization milestones, as well as royalties. In exchange, PB Biosciences gets exclusive rights to zabofloxacin outside Japan, Korea, China, Taiwan, Singapore, Indonesia, India, Thailand, Malaysia, Vietnam, Hong Kong, Australia and New Zealand.

Zabofloxacin is a member of the fluoroquinolone class, which includes antibiotics ranging from older products like Cipro (ciprofloxacin, Bayer Pharmaceuticals Corp.) to relatively newer products like Factive (gemifloxacin mesylate, Oscient Pharmaceuticals Corp.). Yet microbiological studies have indicated that zabofloxacin is the "most potent antimicrobial" available, explained Matthew Wikler, president and CEO of PB Biosciences. Additionally, the drug's potency appears to span a broad spectrum of microbes responsible for community-acquired respiratory infections, including multidrug-resistant strains of Streptococcus pneumoniae.

That high potency should allow the drug to be administered once daily at a low dose, which "should translate to a very effective drug with very little toxicity," Wikler added. He noted that zabofloxacin is being developed in both intravenous and oral formulations to ease the transition from hospital-based acute care to home-based treatment.

Dong Wha already conducted a Phase I multiple-dose study of zabofloxacin, which it calls DW-224a. PB Biosciences plans to begin a Phase II study of the drug, which it calls PB-101, before the end of the year. The first Phase II trial will focus on the treatment of community-acquired pneumonia, but later trials may evaluate the drug in acute bacterial exacerbations of chronic bronchitis or acute bacterial sinusitis. Dong Wha will follow a similar development timeline in Asia.

Behind zabofloxacin, fledgling PB Biosciences already has two other anti-infectives in its pipeline, PB-200 and PB-201.

PB-200 is an antifungal platform licensed from Oxford GlycoSciences plc (now part of UCB SA). The PB-200 drug candidates have demonstrated activity against both Candida and Aspergillus without evidence of the toxicity issues that plague other Aspergillus drugs, Wikler said. Additionally the PB-200 mechanism of action may allow the drugs to target drug-resistant antifungal strains. As with zabofloxacin, both IV and oral formulations are in the works, although Wikler said the program is 18 to 24 months from the clinic.

PB-201 is a novel formulation of itraconazole, marketed as Sporanox by Janssen Pharmaceutica NV for treating toenail fungus. Yet while standard itraconazole is absorbed erratically, causing toxicities in patients who receive high levels and prompting physicians to stick with low doses, PB-201 is formulated for more predictable absorption. The product, which is based on technology licensed from Rongdajia Pharmaceuticals Co. Ltd., will follow a 505(b)(2) pathway, starting with a Phase I trial later next year.

Although PB Biosciences has rapidly built an anti-infective pipeline, Wikler said none of the product candidates had been identified when the company was formed in late 2006. Instead, Wikler and the Paramount team felt the time was right to found a company focused on infectious diseases, given that "there are a lot of needs and very few companies actually working on them," Wikler said.

In building PB Biosciences, Wikler drew on his experience as chief medical officer for antibacterial companies such as start-up Mpex Pharmaceuticals Inc. and Peninsula Pharmaceuticals Inc., which was acquired by Johnson & Johnson for $245 million. He also spent two years as the deputy director of the FDA's Division of Anti-Infective Drug Products and previously helped pharmaceutical employers license antiviral drugs from Asia. (See BioWorld Today, April 20, 2005.)

Joining Wikler on the PB Biosciences team are Mark Lotz, vice president of regulatory affairs; Jim Rock, director of new product development; and an as-yet-unnamed chief scientific officer who is expected to start in October. Wikler said the company anticipates "raising some additional funds from both private and institutional investors" before the end of the year.