A month after its peripheral arterial disease drug, rifalazil, failed to show sufficient efficacy in a Phase III study, Lexington, Mass.-based ActivBiotics Inc. has put itself up for sale.

The privately held firm, after reviewing its strategic options, decided to sell all, or substantially all, of its assets on an "as is" basis.

Bidding on those assets, which include compounds for inflammatory diseases and bacterial infections, began yesterday and will go through Feb. 1. Interested parties will be able to purchase those programs and other assets separately or as a group.

Among those products is rifalazil, an antibacterial agent aimed at Gram-positive infections. Despite promising efficacy in earlier trials, the compound missed its mark in a Phase III study in intermittent claudication associated with peripheral arterial disease (PAD), failing to show statistical significance in any clinically relevant PAD parameters. Results of that study, reported last month at the American Heart Association meeting in Orlando, Fla., showed that the efficacy signal in the rifalazil-treated group was only 4 percent greater than the placebo group. (See BioWorld Today, Nov. 8, 2007.)

Rifalazil previously was found efficacious in a Phase II chlamydia STD trial, and ActivBiotics submitted a separate protocol for the FDA for a Phase II program in carotid artery atherosclerosis. The drug also has received fast-track designation for Clostridium difficile-associated diarrhea.

The rest of ActivBiotics' pipeline includes a superoxide dismutase mimetic program consisting of two clinical-stage candidates, M40403 and M40419, as well as a library of 250 small molecules, which might have potential in inflammatory diseases.

M40403 has an open investigational new drug application to allow for a Phase II study in postoperative ileus and protocol for a separate study in oral mucositis.

The firm also has an antibacterial library of compounds consisting of about 800 small molecules, which could be developed to treat bacterial infections such as complicated skin and skin structure infections, endocarditis, osteomyelitis, foreign-body infections, C. difficile-associated diarrhea and peptic ulcer disease due to Helicobacter pylori.

ActivBiotics filed for an initial public offering in August 2006, seeking to raise as much as $46 million, but yanked the filing a few months later, citing market conditions. (See BioWorld Today, Aug. 16, 2006.)