Two deals under one umbrella are bringing Anadys Pharmaceuticals Inc. and Structural GenomiX Inc. into a joint partnership.

In the first arrangement, the San Diego-based companies will share equally in the costs to discover small-molecule antibacterial drugs, an area in which both have significant operations. Anadys’ Atlas screening technology bridges the gap regarding Structural GenomiX’s goals.

“We’re particularly excited about function-blind screens, which look for small molecules that bind to targets of interest and give you potentially new starting points for chemistry,” said Sean McCarthy, Structural GenomiX’s vice president of business development. “Atlas is a technology for doing such blind-function screening. We feel that this technology is giving us the opportunity to get new inputs for lead discovery programs.”

Anadys will apply Atlas, its ultra-high-throughput, affinity-based technology, to identify chemical hits as potential entry points for drug discovery from its medicinal chemistry-driven compound library. Structural GenomiX will then use its high-throughput structural determination capabilities to solve co-crystal structures of the compounds bound to their targets.

“The value is being able to use affinity-based screening to elucidate targets you might not be able to identify through functional screening,” said Michael Kamdar, Anadys’ vice president of corporate development and strategy. “And then to be able to use the structural information that can be generated through what Structural GenomiX focuses on, to really bring the two powerful technologies together. Half of our business model is in antibacterials, so this is really going to help round out our antibacterial pipeline.”

Anadys and Structural GenomiX said they have identified and prioritized a number of essential genes as optimal targets for drug discovery and already have determined the 3-dimensional structures of many of those targets.

“The two companies have compared their resources in [the antibacterial] area, and out of these resources selected a number of joint targets,” McCarthy said. “For the targets that have been selected for the collaboration, the work that has been done to date will be shared between the two companies, and the products will be advanced through pooled resourcing. The profits of the collaboration, in terms of the leads that are derived, will be shared by the companies in terms of their further advancement.”

With structural information already identified for a number of targets, the privately held companies will work quickly on the antibacterial project.

“It’s a very aggressive timeline to screen a significant number of targets over an 18-month period,” McCarthy said. “The screening has been initiated already the first targets are in screening, and we expect to see the first lead compounds emerging within a matter of months.”

Down the road, the companies are discussing a number of options regarding candidate development.

“Both companies retain a good deal of flexibility with regard to downstream partnering,” McCarthy said.

Kamdar agreed.

“If we saw something of real value, we’d move it forward, either with SGX or with another partner,” he said. “But we wanted to create flexibility so that if we had a number of successful lead candidates, we could then evolve those in collaboration with SGX or in collaboration with other partners.”

In the second arrangement, Structural GenomiX will use Atlas to screen for internal drug discovery efforts in additional, undisclosed therapeutic areas. The company pursues drug discovery in three other areas, including protein kinases, nuclear hormone receptors and membrane proteins.

“We’re very excited about the prospect of Atlas for all of Structural GenomiX’s therapeutic areas,” McCarthy said.

Detailed financial terms were not disclosed, but Anadys will receive an up-front technology access payment, research funding and potential milestones to apply Atlas to a specific class of Structural GenomiX targets from internal drug discovery programs.

“We’re looking to establish several key screening-based relationships,” Kamdar said. “It allows us to work on a different family or class of targets as well as in a different therapeutic area. We believe that affinity-based screening has broad applicability across a number of different therapeutic areas, and since we’re focused primarily on anti-infectives, this gives us a chance to start to leverage into some other therapeutic space.”

In addition to using its drug discovery capabilities internally, Anadys works in development collaborations with partners that include Aventis Pharma AG, of Frankfurt, Germany; Indianapolis-based Eli Lilly & Co.; and Pharmacia Corp., of Peapack, N.J.

Kamdar termed the Aventis partnership as similar to the Structural GenomiX deal, though involving more money. The collaboration is focused on Atlas and Gate, another Anadys technology, in antibacterial and antifungal work. The company aided Lilly in identifying novel approaches and leads.

Structural GenomiX recently entered into partnerships with Cambridge, Mass.-based Millennium Pharmaceuticals Inc., and Aventis. Both collaborations are focused on Structural GenomiX’s high-throughput structural biology platform for drug discovery.