XenoPort Inc. and ALZA Corp. are teaming up in a drug delivery pact.

They entered a collaboration to develop drugs that combine XenoPort's active transport technologies and ALZA's oral drug delivery technologies. Specifically, they intend to improve three existing products that can be better absorbed throughout the gastrointestinal tract.

"The drug delivery industry has developed a number of different formulation technologies for dealing with drugs that have short half-lives - controlled-release technologies," XenoPort President and CEO Ronald Barrett told BioWorld Today. "In order for them to work, the drug molecule that you put in this formulation has to be absorbable throughout the length of the intestine - most importantly in the lower intestine, the colon."

Under the multiyear agreement, they will collaborate to identify prodrug versions of three unspecified drugs. ALZA, a unit of New Brunswick, N.J.-based Johnson & Johnson, will further develop the prodrugs to create products with improved pharmacokinetic and therapeutic profiles.

"They are in multiple therapeutic areas, addressing important medical needs and existing large markets," Barrett said.

ALZA will make an up-front payment to Santa Clara, Calif.-based XenoPort, whose technology is designed to enhance drug absorption by creating prodrugs that are recognized by a body's natural absorption mechanisms. Mountain View, Calif.-based ALZA also will fund research and preclinical development at XenoPort, and pay for subsequent technical and clinical development of resulting products, for which it would pay XenoPort milestones and royalties.

More specific financial terms were not disclosed, though Barrett called the deal both balanced and favorable in generating revenue for the three-year-old private company.

Barrett said the agreement, XenoPort's first such deal, also achieves more than a financial goal for the firm. He pointed to the collaboration as a validation.

"XenoPort's overall technology mission is to enhance the bioavailabilty of drugs by modifying their structure so that they take advantage of active transport mechanisms that various tissues and cells express," Barrett said, adding that the company's chief focus centers on the oral absorption of drug molecules. "ALZA is a pioneer and remains one of the premier groups in oral, controlled-release technologies, and they were interested in working with us to come up with these modified versions of existing drugs so that they could be utilized with its OROS technology."

He said an ongoing program at XenoPort has served as proof of the technology's concept. The company plans to submit this year an investigational new drug application for its prodrug version of gabapentin (Neurontin, from Pfizer Inc.). Barrett said the drug, used to treat neuropathic pain, epilepsy and other central nervous system disorders, is dosed frequently with various inconsistent absorption rates.

"These are problems that we have been able to fix with our actively transported prodrug version of gabapentin," he said. "Our molecule is absorbed to a higher degree than gabapentin itself, it rapidly converts to gabapentin once it enters the body in the GI tract, and it is absorbable throughout the length of the intestine so that we can combine this prodrug with oral, controlled-release technology to reduce the frequency of dosing."

Barrett said XenoPort expects to begin Phase I testing late this year, with the intent to demonstrate the pharmacokinetic superiority of the reformulated version of gabapentin. It is not yet partnered, and Barrett said XenoPort would retain its rights at least through early clinical testing.

Other programs at the company include earlier-stage programs with both in vitro and in vivo proof of concept for other undisclosed molecules.