SPECT brain agent shipments cease as small firm faces financial hurdles

Regulatory restrictions in the U.S. and a slow-to-start market for single-photon emission computed tomography brain imaging have combined to cut off supplies of one of the two approved SPECT brain imaging agents. To their consternation, nuclear medicine physicians have found they cannot purchase Spectamine, an iodine-123 SPECT radiopharmaceutical, at a time when the clinical utility of this agent is becoming evident.

Hoffman-LaRoche developed Spectamine through its Medi-Physics subsidiary. Four years ago, it received the first Food and Drug Administration market approval for a brain SPECT agent (SCAN 3/16/88). Initial expectations were high, but clinical demand never quite materialized.

Medi-Physics was sold to Amersham of the U.K. in 1989 (SCAN 10/11/89). Hoffman-LaRoche was prohibited for antitrust reasons from including Spectamine in the Medi-Physics sale because Amersham owned the only other approved SPECT brain agent, technetium-labeled Ceretec.

To facilitate the sale, Spectamine was sold to IMP, a new firm formed by the original group of researchers who developed the agent. IMP has been struggling ever since to stay above water financially. The small Schaumburg, IL, firm continued to rely on Medi-Physics--its only competitor--to manufacture Spectamine on a contract basis. That Arlington, IL, firm ceased shipments in April after IMP proved unable to pay for the product.

"We supported IMP for the better part of the past two years with contract manufacturing," Allen F. Herbert, Medi-Physics' president told SCAN at the Society of Nuclear Medicine meeting in Los Angeles last week. "But we were forced to stop after discussing the critical financial situation for at least a year. We have talked to a number of people to help IMP get back in (the market)."

The Medi-Physics facility is the only FDA-approved manufacturing site for Spectamine, which limits the ability of other suppliers to step in immediately, said James F. Lamb, IMP president. IMP has been negotiating with Nordion of Canada, and that manufacturer appears interested in working out a supply arrangement. First, however, IMP must find financial support. Several parties are showing investment interest, he said.

Nordion already manufacturers iodine-123 but would still need to obtain FDA good manufacturing process approval. The Canadian firm is one of the few sites capable of producing high-grade radioiodine using the expensive xenon target necessary for this cyclotron production process. Some university cyclotron facilities have expressed willingness to help produce the agent but would have to spend in excess of $1 million for the xenon target, Lamb said.

Ironically, IMP was forced to halt shipments just when clinical demand for the SPECT agent was picking up.

"Brain imaging is here. It is just here a few years later than anyone anticipated," Lamb said. "March was our last month in production. It was also our best month."