Novel therapy delivers radioactive lipid nanospheres to tumors

UT Health Science Center, Azaya Therapeutics Inc. announce license agreement

SAN ANTONIO (Sept. 3, 2008)—The University of Texas Health Science Center at San Antonio and Azaya Therapeutics Inc. today announced a licensing agreement for a novel nano-scale, lipid-sphere technology conceived and pre-clinically tested by Health Science Center faculty.

Terms of the agreement were not disclosed, although it includes clinical development milestone payments, product sales royalties, and forecast of an aggressive U.S. Food and Drug Administration application and approval schedule.

The tiny therapeutic agents are approximately 100 nanometers in size (a nanometer is one-billionth of a meter). In concept, they may benefit head and neck cancer patients for whom surgery and radiation is no longer an option. The Health Science Center researchers recently discovered a way to incorporate a radioactive isotope, 186rhenium, into the lipid spheres, which are called liposomes. The scientists also demonstrated that the radioactive liposomes could kill cancer cells.

“Early studies indicate this method can deliver much higher radiation doses to tumors accurately while the surrounding normal tissue toxicity is minimal, which is different from external beam radiation,” said Ande Bao, Ph.D., assistant professor of radiology and otolaryngology-head and neck surgery at the Health Science Center.

If the first clinical application of 186rhenium liposomes in head and neck cancer patients is successful, follow-up clinical studies may target prostate, breast and brain cancers.

Azaya Therapeutics will develop and commercialize the novel cancer treatment, which is based on the work of Dr. Bao and William T. Phillips, M.D., and Beth Goins, Ph.D., professors of radiology at the Health Science Center. All are members of the Cancer Therapy & Research Center at the UT Health Science Center. For more than 15 years, these scientists have studied ways to use liposomes for the treatment of human disease.

Nano-scale liposomes are small enough to squeeze between cancer cells to distribute more evenly within the tumor, yet large enough to stay localized in the region of the tumor.

“Nano-scale liposomes deliver short-range powerful radiation where it is needed, sparing non-diseased tissue,” Dr. Phillips said. “This activity is so precise that it may be possible to treat the same area over and over as needed.”

External-beam radiation, by contrast, can be used only once because normal tissue in the head and neck region has a lifetime dose limit that cannot be exceeded.

Another potential usage is in the operating room. It is possible 186rhenium liposomes may be injected into residual tumor that surgeons cannot remove because of proximity to vital structures. “We could greatly increase the chance of eliminating all cancerous cells,” said Randal A. Otto, M.D., a clinical collaborator on the project, a CTRC member, and the Thomas Walthall Folbre, M.D., Endowed Chair in Otolaryngology at the Health Science Center.

This summer, the researchers presented encouraging preclinical data in the journal Clinical Cancer Research. In this study, human tumors grown in rats were partially removed, simulating a possible real-life situation of a patient with residual head and neck cancer.

The residual tumors were injected with either 186rhenium-liposomes or empty liposomes. After five weeks, tumors treated with empty liposomes grew back rapidly and increased 300 percent in size, while tumors treated with 186rhenium-liposomes decreased in size by three-fourths.

The exclusive license agreement is the first executed by South Texas Technology Management, the new regional technology transfer office that serves the UT Health Science Center, UT San Antonio, UT-Pan American and UT Brownsville. Kenneth W. Porter, Ph.D., directs the office, and license specialist Sean Thompson, M.S., M.B.A., played a leading role in this negotiation.

“Effective technology licensing takes time and patience,” Dr. Porter said. “Mr. Thompson recognized the complementary interests, introduced the parties a year ago, and nurtured the relationship through today’s license execution. Further patience and hard work will be required to bring a new drug to market.”

“This agreement represents the best of what the Health Science Center has to offer—thorough basic research leading to a promising new therapy for cancer patients who have few options, and the ability to license to a South Texas company that will turn it into a lifesaving product,” said Brian Herman, Ph.D., vice president for research at the Health Science Center.

Francisco G. Cigarroa, M.D., president of the Health Science Center, called the license development “a win for cancer patients and a demonstration that academic research can provide local economic development.”

Michael T. Dwyer, president and CEO of Azaya Therapeutics, said the technology nicely complements Azaya’s existing cancer therapy product pipeline.



The University of Texas Health Science Center at San Antonio is the leading research institution in South Texas and one of the major health sciences universities in the world. With an operating budget of $674 million, the Health Science Center is the chief catalyst for the $15.3 billion biosciences and health care sector in San Antonio’s economy. The Health Science Center has had an estimated $35 billion impact on the region since inception and has expanded to six campuses in San Antonio, Laredo, Harlingen and Edinburg. More than 23,000 graduates (physicians, dentists, nurses, scientists and allied health professionals) serve in their fields, including many in Texas. Health Science Center faculty are international leaders in cancer, cardiovascular disease, diabetes, aging, stroke prevention, kidney disease, orthopaedics, research imaging, transplant surgery, psychiatry and clinical neurosciences, pain management, genetics, nursing, allied health, dentistry and many other fields. For more information, visit

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