In recent years, several monoclonal antibody products have gained strong market acceptance, principally because these compounds can provide anticancer activity while avoiding many of the side effects of traditional anticancer drugs. Monoclonal antibodies can selectively affect cancer cells because scientists can engineer them to bind to antigen targets present on cancer cells and not on normal cells.
Although with some targets, binding of an antibody leads to the death of the cancer cell, with many targets binding of an antibody has little, if any, anticancer effect. Our Tumor-Activated Prodrug (TAP) technology is designed to provide tumor-targeting antibodies with significant anticancer activity and yet maintain their excellent tolerability. We attach a potent cell-killing agent to the antibody as a payload. The antibody serves to deliver the payload selectively to a cancer cell, while the payload is designed to kill the cell to which it is delivered.
Our portfolio of payload molecules includes DM1 the payload in all TAP compounds now in clinical testing plus other highly potent, proprietary molecules. Each is able to be attached to an antibody using one of our linkers. Our linkers are designed to keep the payload attached to the antibody until it binds to its target on a cancer cell and is internalized by the cell. This design serves to focus the killing power of the TAP compound on cancer cells rather than on normal tissue to avoid the debilitating side effects of traditional anticancer drugs.
Generally speaking, antibodies that target cancer cells fall into one of two categories those that have anticancer activity and those that dont. Out TAP technology can be used to impart anticancer activity to those that dont, and improve the performance of those that do. For example, Genentech has licensed the right to use our technology with antibodies to the target HER2, including trastuzumab (Herceptin®), an approved treatment for breast cancer.
We used our TAP technology together with our own antibodies to create our product candidates huN901-DM1 and cantuzumab mertansine and the two preclinical TAP compounds that we licensed to Aventis. In each case, we used our internal expertise to identify and evaluate promising cancer targets.
In some cases, a promising target is owned by another company and not available to us for our own product development. In this situation, we may do the next best thing and outlicense our technology to the other company. This enables the other company to develop a TAP compound with its antibody and enables ImmunoGen to derive a financial return that would not otherwise be possible.
Our TAP technology outlicenses typically include upfront and milestone payments that potentially can total over $40 million per target, plus royalties on product sales. We also manufacture preclinical and clinical material for our partners and are reimbursed on a cost- or cost-plus basis. Our partners are responsible for product development, later-stage manufacturing, clinical testing, registration, and commercialization.
Each new TAP compound in development, either by us or by our partners, increases our opportunity for commercial and financial success.
Notice on Forward-Looking Statements
Herceptin® is a registered trademark of Genentech.