The challenge of producing antibodies against specific cancer antigens has eluded scientists for many decades. Modern technologies for designing antibodies against a known disease require both the identification and availability of the antigens which characterize the disease. The putative tumor-specific antigens (TSA), presumed to exist on cancer cells, have eluded identification, thus making the generation of antibodies against them through current technologies virtually impossible. The task is further complicated if one assumes that there should be only a few "universal" TSA that are common to a given tumor type.

Classic Hybridoma technology is based on the generation of immortal "hybrid cells" (hybridoma), which follows the fusion of antibody-producing B-cells with myeloma tumor cells. Each hybridoma continuously "manufactures" a single type of ("monoclonal") antibody. MabCure has "re-engineered" the classic hybridoma technology into a highly efficient and optimized one, overcoming the inherent limitations of the former, yet exploits its benefits.

MabCure hybridoma technology exhibits several important advantages over competing technologies:

• Prior identity of cancer antigen(s) is not required for generating Mabs against these antigens. MabCure's approach to creating anti-cancer Mabs is unbiased and enhances the discovery of new cancer markers.
• Antigens are preserved in their natural conformations; the resulting Mabs are able to better recognize and bind more selectively to tumor cells.
• Unlimited quantities of antibodies produced against a selected cancer target. A large number of antibodies is the key factor for obtaining an antibody repertoire which would exhibit both tumor specificity and tumor "universality".

Cancer cells have an abundance of normal molecules (antigens) on their surface which are often "over-expressed" compared to normal cells and are also quite immunogenic, i.e. they can trigger robust immune response in the injected animal.

In contrast, tumor-specific antigens (TSA) on the surface of the cancer cells are thought to be much less numerous and are often poorly immunogenic (i.e. triggering weak immune response).

Consequently, the vast majority of Mabs produced by the injected animals is directed against normal antigens while only a few target the TSA. Therefore, one has to be able to produce copious amounts of Mabs in order to find and select those few which are not only tumor-specific, but also "universal" for that type of cancer.

Proof of Concept
MabCure has successfully generated hybridoma libraries for three different cancers that produce, respectively, antibodies to melanoma, to an aggressive form of prostate cancer and to ovarian carcinoma. These antibodies have been shown to be specific and "universal" to each cancer respectively, i.e. they recognize every cancer from different individuals having that particular disease and do not react with any normal antigen tested so far. These Mabs are the first candidates for the development of novel diagnostic tools, imaging agents and drugs to treat the corresponding cancers.