Days after Ligand Pharmaceuticals Inc. disclosed its plan to buy Seragen Inc. — acquiring, among other things, the rights to Simulect (basiliximab), a monoclonal antibody for acute organ transplant rejection — the FDA has cleared Simulect for marketing. Novartis AG, which sublicensed rights to certain Simulect patents from Seragen, filed a new drug application for it last November. The FDA approved Simulect for acute rejection episodes in renal transplant recipients.

Laurie Ostroff, spokeswoman for Novartis, said Simulect will be launched "sometime in the next few weeks. We don't have an exact date yet." She declined to provide sales estimates.

San Diego-based Ligand acquired the drug as part of a $67 million buyout of Hopkinton, Mass.-based Seragen. (See BioWorld Today, May 12, 1998, p. 1.)

Susan Atkins, spokeswoman for Ligand, said the royalty stream likely will begin in the year 2001, on a sliding scale.

"Our deal [to acquire Seragen] hasn't closed yet, so it would be premature for us to speculate on that yet," Atkins said. "What's more important is that the intellectual property is valuable, and will spawn these royalties and others."

Simulect works by blocking the receptor for interleukin-2, a protein that simulates proliferation of T-lymphocytes, which play a key role in organ transplant rejection. — Randall Osborne