Halozyme Therapeutics Inc. significantly expanded its relationships with Baxter Healthcare Corp., continuing momentum at the company that gained full steam two months ago.

Baxter, which already had rights to the existing standalone indications of the hyaluronidase-based product Hylenex, gained additional rights to use the delivery technology with two of its small-molecule drugs, as well as with small-molecule generic agents. Halozyme gets an up-front payment of $10 million, a $20 million equity investment at a premium, $10 million in prepaid royalties, and up to $25 million in regulatory and commercial milestone payments.

In December, Halozyme entered a deal with F. Hoffmann-La Roche Ltd. covering the application of related Enhanze technology to large-molecule drug candidates. That deal provided Halozyme with $20 million up-front, an $11 million equity investment and up to $111 million in milestone payments on the first three targets, plus up to $47 million each for 10 additional targets to which Roche has options. (See BioWorld Today, Dec. 7, 2006.)

"We believe these partnerships are very complementary," Jonathan Lim, president and CEO of San Diego-based Halozyme, told BioWorld Today. "We believe we have optimal partnerships for both platforms."

Lim said the new deal with Baxter, of Deerfield, Ill., changed some other terms from their original, August 2004 agreement, under which they would be equal commercial partners for Hylenex (then called Enhanze SC), a recombinant human hyaluronidase. The FDA approved Hylenex in December 2005 for use as an adjuvant to improve absorption and dispersion of other injected drugs, and as an adjuvant for subcutaneous fluid administration. A full launch of the product is expected in the second quarter of this year.

Lin said Baxter now has worldwide rights, increased from rights previously held only in the U.S. and Europe. Halozyme also will no longer be entitled to a 50-50 profit split, as called for under the original deal, but instead will get royalties with "comparable economics to the prior agreement," Lim said.

Baxter's rights now also include use of Hylenex in kits and co-formulations, as well as with the nonproprietary small molecules and the two approved Baxter products - Suprane and Brevibloc, both anesthetics. Royalties on the use of the technology in kits, co-formulations, with generic agents and with Baxter products would be at a smaller percentage than will be paid for the already-approved standalone product.

The deal does not include use of Hylenex with cytostatic or cytotoxic chemotherapy agents, or with bisphosphatases. Halozyme will explore those applications internally, Lim said. He added that the new deal is more attractive to Halozyme than the original because it brings an immediate cash infusion, demonstrates Baxter's commitment to optimizing commercial potential of the technology and provides additional incentive to Baxter to get behind marketing efforts.

In addition, Baxter will assume all development, manufacturing, clinical, regulatory, sales and marketing costs.

Daniel Tasse, general manager of Baxter Pharmaceuticals and Technologies, said in a news release, "Hylenex recombinant offers an innovative drug delivery technology for small molecules and hydration fluids, and given Baxter's strong relationships with clinicians and channel strength, Baxter is well positioned to bring this technology to patients. Our priority this year is to continue to complete clinical trials, engage key opinion leaders and build clinical foundations with centers of excellence in a number of important clinical settings in preparation for our expanded Hylenex recombinant launch this year."

Baxter's $20 million equity investment in Halozyme was made at $9.66 per share, a 25 percent premium to the 30-day average. Baxter got nearly 2.1 million shares, or about 3 percent of the Halozyme.

Contrasting that investment with the one Roche made in December shows how far Halozyme has come in a few months. Roche had acquired about 5 percent of Halozyme with its $11 million equity investment. Halozyme's stock (AMEX:HTI), which had closed at $2.85 on Dec. 5, gained 101 percent to $5.73 in the two days following the Roche deal, and has continued climbing since. It closed at $8.76 Wednesday, up 91 cents, or 11.6 percent, on the day.

Lim said the Baxter and Roche deals still leave Halozyme significant room to grow. For example, Lim said, Roche's rights and options cover only 13 targets, while there are about 40 commercial or Phase III monoclonal antibodies and about 1,000 or so in discovery through Phase II stages, totals that do not include non-monoclonal antibody biologics.