YM BioSciences announces results of collaborative antibody development program

Dec 10 2009

Collaboration to Create Optimized Antibodies Produces First Candidates Which Selectively Target HER2 in Breast Cancer

YM BioSciences Inc. (NYSE Amex:YMI, TSX:YM), today announced the first results of a collaborative program between YM and the National Research Council of Canada's Biotechnology Research Institute (NRC-BRI). Utilizing YM's IntelliMab(TM) technology, the program is designed to generate novel antibodies that target cell surface receptors associated with cancer, uniquely optimized to produce efficacy with reduced toxicities. The first successfully designed and delivered products from the collaboration are a number of antibodies that bind to HER2/neu-over-expressing breast cancer cells while minimally binding to HER2 on normal cardiac cells. The lead candidate antibody for conjugation is in the final stages of selection from that number.

"This is a new generation of rationally designed antibodies that bind to HER2/neu on cancer cells to an extent similar to that seen with trastuzumab (Herceptin(R), Genentech/Roche) but are distinguished from trastuzumab by their minimal targeting of HER2 on cardiac cells, which is expected to result in reduced collateral cardiac toxicity," said David Allan, Chairman and CEO of YM BioSciences. "The improved specificity of these anti-HER2 antibodies makes them amenable to conjugation with highly potent toxins which would permit the selected IntelliMab anti-HER2/neu conjugate antibody to be an important competitor to Trastuzumab-DM1 (Genentech/Immunogen)."

"Subsequent to the soon-to-be-completed functional studies for this panel of antibodies, the optimal candidate will be entered into full development," added Mr. Allan. "This work was informed by published observations for our lead antibody, nimotuzumab, which is differentiated from its competitors by its remarkably diminished toxicity."

HER2 (also known as ErbB-2, ERBB2), is associated with more aggressive breast cancers. Unwanted targeting of HER2 on cardiac myocytes (heart tissue) has been associated with damage to the heart in up to 28% of patients currently treated with trastuzumab when combined with certain chemotherapies (www.herceptin.com Full Prescribing Information).

Dr. Gregory P. Adams, Co-Leader, Molecular Medicine Program, Department of Medical Oncology, Fox Chase Cancer Center commented, "Antibodies with better selectivity for tumor tissue over normal tissues are an important goal for improved cancer therapy. They may offer improved efficacy over less selective antibodies on their own and their major advantage should lie in the precise delivery of toxic payloads to tumor cells, sparing toxicity to normal tissues."

The collaborative program is a multi-target, parallel-discovery research project funded by YM and NRC-BRI to develop YM's IntelliMab(TM) technology, a proprietary platform for generating new therapeutic antibodies that are designed to be as effective as, but safer than the current generation of antibodies. Collateral toxicity is an important challenge for numerous antibodies that indiscriminately target receptor in normal tissues as well as in the intended cancer cells. Furthermore, these antibodies are expected to be ideal candidates for delivering potent toxins to cancer cells. Depending on the cancer target selected, IntelliMab(TM) antibodies will be developed as naked antibodies and/or antibody conjugates. The YM team is led by Mr. Sean Thompson, Vice President of Strategic Projects and Corporate Development, who is collaborating with Dr. Maureen O'Connor, Leader of the NRC Genomics and Health Initiative Cancer Program.

"YM BioSciences has combined forces with the NRC-BRI, harnessing its world-class facility and considerable scientific expertise to create what we expect will be a suite of novel, high-value antibodies for a broad range a cancer types," added Mr. Thompson. "Dr. O'Connor has assembled a team of outstanding scientists with a depth of expertise that is complementary to our own insights and experience with antibody development. We look forward to working with the NRC to advance this new portfolio of therapeutic candidates and to being able to disclose further details on our antibody candidates from this program in the near future as additional optimized antibodies are delivered under this program. I would like to acknowledge the important contribution to YM from its Associate Director for Science, Ilia Tikhomirov, for making the initial observations of the principle that led to the creation of the IntelliMab(TM) platform."

The IntelliMab(TM) platform provides YM with an opportunity for an expanded and valuable intellectual property position in the lucrative monoclonal antibody market. All intellectual property resulting from this collaboration will be owned jointly and commercial rights for drug candidates will be retained by YM. The costs associated with the drug discovery collaboration with NRC-BRI are not anticipated to be material to YM.