By Ben Butkus
Vaccine company Advaxis said last week that it has inked a collaboration with City of Hope to develop a vaccine to treat certain forms of leukemia and lymphoma using Advaxis' proprietary live, attenuated Listeria monocytogenes vaccine platform.
This is the second vaccine-development partnership struck between Advaxis and City of Hope in as many years, further cementing an ongoing and mutually beneficial research partnership between the company and the cancer research center, an Advaxis executive said this week.
In April 2008, Advaxis inked a research collaboration with City of Hope to develop a cancer vaccine targeting also based on the Listeria monocytogenes, or Lm, platform, but targeting a different protein.
"Under the previous agreement, researchers from City of Hope did some good work and got some good results, and found activity using our construct," Rothman said. "Evidently there was some communication within the City of Hope community, and other investigators thought that if it was working in one lab, then maybe they should try it in their lab."
The newest research pact involves the laboratory of Don Diamond, a professor of virology and director of City of Hope's translational vaccine research division within City of Hope's Beckman Research Institute.
City of Hope created the translational vaccine research division within its department of virology last October to focus on developing vaccines for solid tumors and blood and immune system cancers, as well as infectious agents such as HIV and cytomegalovirus.
At the time, City of Hope said that the division was also designed to further strengthen the organization's vaccine program and provide more opportunities to translate Diamond’s work from the lab to the clinic.
This dovetails well with the vaccine-development program at Advaxis, which now has nine distinct cancer vaccine constructs under various stages of development.
Besides City of Hope, Advaxis also has an ongoing collaboration with the University of Pennsylvania, from whom the company originally licensed much of its core Lm vaccine technology. Meantime, the company is focusing its vaccine efforts on cervical, head and neck, breast, prostate, ovarian, and pancreatic cancers, among others.
Advaxis and Diamond's lab will study a vaccine provided by Advaxis and directed against the tumor associated antigen WT-1, which has been demonstrated in the literature to be over-expressed in certain cancers of the blood as well as some solid tumors such as breast, pancreas, and brain cancers.
As such, the protein makes it a potential target for a selective immune attack delivered via an Lm vector designed by Advaxis, the company said.
"In a world of novel antigens, we have arguably the best way to deliver antigens to the immune system," Rothman told BTW.
Advaxis and its collaborators are starting to produce data to back up Rothman's assertion. The collaboration announced last April — with Joshua Ellenhorn, director of the department of general and oncologic surgery at City of Hope — has yet to yield published results, but Rothman said that the group is planning to publish soon.
That collaboration centered on Advaxis' Adxs-LmddA159 vaccine, which targets the antigen p53 tumor target to deliver the fusion protein LLO-p53 into the cells of the immune system for antigen presentation (see BTW, 4/23/2008).
Ellenhorn had been trying to develop a wide variety of cancer vaccines targeting p53 for several years, but the antigen is weakly immunogenic, and the researcher has been using Advaxis' construct to boost p53's immunogenicity. Unrelated to the collaboration with Advaxis, Ellenhorn has also been testing a Vaccinia-based vaccine construct against p53.
Rothman said that the collaboration with Ellenhorn would not likely result in any new IP. "Most of the antigens we use are public domain antigens," he said. "I don't know if there is anything patentable … except for perhaps a possible use patent on the combined regimen. [Advaxis] certainly has an extensive IP portfolio on the Listeria side."
However, he added that Advaxis has "certainly benefited from the relationship, and based on the data they're generating, I think they're benefitting from the use of our construct. It was gratifying to see another lab in the same institution feel that this was something worth doing."
Rothman said that the company also has several undisclosed academic collaborations in the works but not yet fully developed. This is not surprising, as last year, following Advaxis' disclosure of the Ellenhorn collaboration, Rothman said the company had adopted an academic-collaboration strategy to broaden and further develop its Lm vaccine platform.
“To the extent that we do have an interesting and effective way of delivering antigens, we are interested in partners, and finding people to work with," Rothman said at the time.
In a statement last week, CEO Thomas Moore echoed Rothman's remarks: "As scientific excitement around Listeria technology grows, we believe more opportunities will develop. These collaborations add to our overall understanding of Listerial vaccines, generate further scientific standing, and accelerate the development of our pipeline. This new opportunity expands our potential pipeline beyond solid tumors."