In one of its largest deals to date, Archemix Corp. partnered with Irish firm Elan Corp. plc to develop up to three aptamer-based drugs against autoimmune inflammatory disease and could earn more than $350 million in potential milestones.

The companies will work together over the course of three years, with Archemix providing its aptamer technology and Dublin-based Elan contributing its development and regulatory expertise in the autoimmune space. Elan will make an up-front payment of $7 million and handle development and commercialization, with milestone payments and royalties going to Archemix. The deal also includes a co-development option for Archemix on certain products.

"That, for me, was really key to the deal," said Errol De Souza, president and CEO of Cambridge, Mass.-based Archemix, and will allow "us to maintain some of the upsides that would come out of the collaboration."

The co-development option would relate to specific indications in the broad autoimmune space, such as the psoriasis market and non-parenteral routes of administrations, such as oral or topical, De Souza said.

Work will begin by developing an aptamer drug to IL-23, a cytokine that has "really become a hot target," he told BioWorld Today, with a number of publications demonstrating the target's selectivity and ability to mediate chronic autoimmune inflammatory disorders.

"Given the interest in the area, and the fact that we were able to develop selectivity in terms of our aptamer strategy, we really had multiple parties at the table" when it came time to consider collaborators, De Souza said. Elan emerged as the winner due to its experience in the disease area; it has a product pipeline aimed at multiple sclerosis and Crohn's disease, including the MS drug, Tysabri (natalizumab), marketed with Cambridge, Mass.-based Biogen Idec Inc.

De Souza said Archemix and Elan will begin identifying a drug candidate from the IL-23 program and anticipate entering the clinic with the first product in the next year-and-a-half to two years. The companies have not disclosed the remaining targets in the collaboration.

Aptamers, which are oligonucleotides that resemble antibodies in the way they bind to molecular targets, are gaining popularity because they can be produced quickly and result in less toxicity than monoclonal antibodies, De Souza said.

Archemix picked up its aptamer technology, SELEX, from Foster City, Calif.-based Gilead Sciences Inc. in 2001. That same technology created the aptamer pegaptanib, an anti-VEGF drug approved as Macugen in late 2004 for wet age-related macular degeneration. Macugen was created by Eyetech Pharmaceuticals Inc. (now part of Melville, N.Y.-based OSI Pharmaceuticals Inc.), which licensed rights to the compound in 2000.

In 2004, Archemix and Eyetech entered a collaboration to develop aptamer drugs for ophthalmic indications. In that deal, Eyetech agreed to handle development and commercialization in exchange for up-front, milestone and royalty payments. (See BioWorld Today, April 15, 2004.)

Archemix also has an ongoing partnership with Nuvelo Inc., of San Carlos, Calif., to develop anti-thrombin aptamers for use in acute cardiovascular indications. Last fall, the companies decided not to continue development with the first product to emerge from the deal, ARC183, an anticoagulant being tested in patients undergoing coronary artery bypass graft surgery, after early Phase I results indicated that a high dose of the drug was needed to produce efficacy. The partners now are focusing on creating a second-generation molecule.

Terms of the Nuvelo deal, signed in January 2004, call for Archemix to lead development and clinical activities, with the companies sharing development and marketing costs on a 50-50 basis.

On its own, Archemix is building an internal pipeline focused on cardiovascular, oncology and inflammatory indications, including a platelet inhibitor expected to start clinical trials at the end of this year or early next year, and an aptamer against IGE, the same antibody targeted by South San Francisco-based Genentech Inc.'s asthma drug, Xolair.

Archemix, which has raised about $100 million since its 2001 inception, completed its last financing in April 2004 when it brought in $50 million in a Series B round. (See BioWorld Today, April 7, 2004.)