Paratek Pharmaceuticals Inc. has found a partner to jointly develop the lead compound from a group of internally discovered antibiotics.

The Boston-based company entered a collaborative development and license agreement with Bayer AG to further advance BAY 73-6944/PTK 0796, a preclinical compound that has shown broad antibacterial activity and potency against Gram-positive bacteria resistant to conventional antibiotics. Paratek named it the lead compound from a new antibiotic class called aminomethylcyclines.

"Our drug hits all the Gram-positive infectious agents, whether they're resistant or susceptible to any drug you name," Stuart Levy, the chief scientific officer and a co-founder of Paratek, told BioWorld Today. "Secondly, it also hits some of the important Gram-negative infections. It's broad in the right sense to be helpful to a clinician, but it's not so broad as to say you're taking a mallet to a fly. It's just right, a nice fit, and it's unique."

Paratek discovered the aminomethylcyclines through research efforts focused on tetracycline. Levy, who studied the molecule at Tufts University and was a leader in developing the technology on which the company was founded, said the compound has proved very safe to date, an attribute of the entire class.

But he added that such discoveries appear less common as a number of companies have left the field. As a result, Levy said pipelines have dried up and partnering efforts have become more rare.

"Where do you find a partner who's committed, and whom do you start talking to that you don't know won't leave the field in the next six months?" he asked. "We were primed and ready for this event - we were what Bayer wanted, and Bayer is what we need. We're a discovery outfit, and I think this is a paradigm for the future. When you see companies closing up, this says to the infectious disease community that there is still a chance to get more infectious disease agents if they follow this route."

Paratek, which will play an active role in the development process going forward, will contribute directly to global development costs. The privately held company will receive undisclosed up-front and milestone payments, as well as access to development funds through a convertible funding vehicle. Should the product reach the market, Paratek would retain co-promotion and profit-sharing rights in the U.S. and receive royalties on net overseas sales.

Leverkusen, Germany-based Bayer is paying for an exclusive, global license to develop, manufacture and market injectable preparations of BAY 73-6944/PTK 0796. Levy said the product would enter clinical studies in the next six to eight months.

"They need our expertise, and we need their expertise," he added. "We're going to have joint development and scientific committees. But the preclinical work is done. Now we're to prepare the drug for clinical trials."

Paratek reported preclinical data during this week's Interscience Conference on Antimicrobial Agents and Chemotherapy in Chicago. An outside research firm presented two posters, while Paratek detailed eight others.

"They showed superb activity of our compound, with inhibition of all the Gram-positive infections of less than 1 microgram per milliliter," Levy said. "The others dealt with the chemistry, its mechanism of action to inhibit protein synthesis, and we showed it has no toxicity. We gave a slew of 10 or 12 animal models with different bacteria in which it did as well or better than any comparators, including vancomycin and linezolid."

Given the promising activity of BAY 73-6944/PTK 0796, Paratek is developing later-generation derivatives from the aminomethylcycline class as well. Levy said the company is working on an oral formulation of an aminomethylcycline drug and another designed to treat opportunistic infections.

A separate antibacterial research program at Paratek is based on its multiple antibiotic resistance technology to prevent Gram-negative infections from the beginning. Levy said animal models to date have shown that small molecules developed from the program prevent such infections by stopping signals from a bacterial response protein.

"This is the second focus of Paratek, to develop this area to complement our area in looking to treat infections when you have them," Levy said. "Now, let's see if we can prevent an infection when you're at high risk."

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