Washington Editor

Enzon Pharmaceuticals Inc. and SkyePharma plc signed an agreement to develop up to three drugs, and another that transfers to Enzon North American rights to SkyePharma's DepoCyt, an injectable chemotherapeutic.

The companies kept mum about most financial terms, except to say that Enzon, of Bridgewater, N.J., will receive $3.5 million for giving SkyePharma access to its PEG modification technology, which helps a drug stay in the body longer. Terms of the deal give SkyePharma, of London, a milestone payment for each product based on its technology that enters Phase II development.

Kenneth Zuerblis, Enzon's chief financial officer, described the alliance to BioWorld Today as a joint 50-50 deal in which the companies will share research and development costs, and future revenues.

"Obviously, we have proven technology and DepoCyt is an example from the injectable side, but we also have oral and topical technology," Valerie Tate, SkyePharma's head of investor relations, told BioWorld Today. "There actually is value in combining the technology Enzon has with the technology we have, and we can see opportunities for that going forward."

Tate and Zuerblis would not discuss indications slated to become the focus of the collaboration. Zuerblis said the companies will set up a committee to make those decisions.

Meanwhile, Enzon will pay SkyePharma a $12 million licensing fee for rights to DepoCyt, a sustained-release formulation of cytarabine, or Ara-C, for patients with lymphomatous meningitis. DepoCyt gradually releases cytarabine into the cerebral spinal fluid and extends the dosing interval to once every two weeks, instead of the standard twice-weekly intrathecal chemotherapy dosing of cytarabine, the companies said.

Zuerblis said Enzon intends to use its oncology sales force, currently responsible for marketing Oncaspar, to sell DepoCyt.

While SkyePharma said it expects U.S. sales of DepoCyt to reach $5 million in 2002, Zuerblis said Enzon believes the product has the potential to generate $25 million in sales.

"Enzon shares our view that the market for DepoCyt, the only FDA-approved chemotherapeutic agent for the treatment of lymphomatous meningitis, is largely under-developed," Michael Ashton, SkyePharma's CEO, said in a prepared statement. "We believe that Enzon's focused oncology marketing effort is well placed to promote DepoCyt to physicians treating this life-threatening illness, and to achieve the product's full potential."

In order to license DepoCyt, SkyePharma had to reacquire U.S. marketing rights from Chiron Corp., of Emeryville, Calif., and Canadian rights from Paladin Labs Inc., of Montreal.

Tate said financial terms were not disclosed.

SkyePharma and Chiron relaunched DepoCyt in March 2001 after a 16-month hiatus caused by the discovery that batches of product failed to meet regulatory specifications. (See BioWorld Today, March 5, 2001.)

SkyePharma inherited DepoCyt through a $56 million acquisition of DepoTech Corp., of San Diego, in late 1998. As for Chiron's part, the California-based company had partnered with DepoTech in 1994 for rights to the product. (See BioWorld Today, Oct. 20, 1998.)

Tate said Elan Corp. plc, of Dublin, Ireland, owns European rights, but has yet to launch it.

SkyePharma will manufacture DepoCyt and Enzon will purchase it at 35 percent of net sales. SkyePharma also is entitled to milestone payments based on certain sales levels and the approval of additional indications.

DepoCyt currently is the subject of a Phase IV study for an expanded label that includes neoplastic meningitis.

Enzon's stock (NASDAQ:ENZN) closed Thursday at $16.86, up 14 cents. SkyePharma's stock (NASDAQ:SKYE) closed at $7.19, up 44 cents.