By Randall Osborne

On schedule, Ligand Pharmaceuticals Inc. submitted its new drug application (NDA) to the FDA for Panretin gel (alitretinoin) as a treatment for AIDS-related Kaposi's sarcoma.

"We're building a cancer business," said Susan Atkins, spokeswoman for San Diego-based Ligand, which earlier this month disclosed its $67 million plan to take over Seragen Inc., of Hopkinton, Mass. (See BioWorld Today, May 12, 1998, p. 1.)

The NDA, Ligand's first, is based on positive results from international and U.S.-based Phase III clinical trials of the drug, a topical formulation of 9-cis retinoic acid.

Atkins said Ligand plans to submit three more NDAs this year and next for Panretin capsules, which showed positive results in Phase II trials, and for Targretin as a treatment for cutaneous T cell lymphoma (CTCL) in gel and capsule form. (See BioWorld Today, Feb. 12, 1998, p. 1.)

"Kaposi's sarcoma and CTCL are not the biggest markets in the world, but with aggressive pricing and marketing, we can get the company to profitability in 1999," Atkins told BioWorld Today.

"Our strategy has always been to target [smaller patient indications] first, so we don't deplete our resources," Atkins said. "With other biotech companies, their Phase III pivotal trials [enroll] thousands and thousands of patients. If they win, fine. If they don't, their shareholders lose all their money."

Targretin is a synthetic retinoid analogue that selectively activates a subclass of retinoid receptors called retinoid X receptors, which play an important role in several cellular activities, including apoptosis.

Seragen, which Ligand is acquiring, filed a biologics license application (BLA) last December with the FDA for its CTCL treatment, Interleukin-2 Fusion Protein. The BLA is slated for consideration Tuesday by the FDA's Oncologic Drugs Advisory Committee. (See BioWorld Today, Dec. 10, 1997, p. 1.)

"With Targretin [and Seragen's drug], we'll have a topical, oral and systemic treatment for CTCL, if everything gets approved," Atkins said.

Ligand also is studying Targretin for breast cancer, and will disclose data later this year from studies of Targretin and Panretin for psoriasis.

"We want to get the products approved, get the money coming in and continue to do Phase II trials," Atkins said.

The NDA filing was disclosed after the market closed Wednesday. Ligand's stock (NASDAQ:LGND) closed at $13.687, down $0.437. *