Many people are unaware that one of the main problems associated with chemotherapy is not the effectiveness of the treatment. This is even true with highly aggressive, difficult to treat cancers, such as pancreatic cancer, hepatocellular carcinoma and some types of lung cancers. Theoretically, if these cancers could be infused with enough chemotherapeutic agent, they would all be curable.
The limiting factor, then, is not whether or not the chemotherapeutic agent is effective, its how much chemotherapeutic agent can be pumped into the patient’s body without killing them. In general, the range between the amount of the drug below which no recognizable therapeutic effects are taking place and above which the patient is at risk of imminent death is referred to as the therapeutic window. Unfortunately, for chemotherapy, the therapeutic window tends to be quite narrow. And, as is the case with all drugs, exceeding the therapeutic window has potentially disastrous consequences for the patient, including death.
Therefore, it has always been one of the main goals of cancer researchers to discover a way to increase the therapeutic window, so that massive amounts of cytotoxic chemicals can be administered to the malignancy. One solution to this problem is a class of drugs known as antibody drug conjugates. One man, Clay Siegall, is more responsible than anyone else for the development of this class of highly innovative cancer-fighting drugs. As a senior researcher at Bristol-Myers Squibb, Dr. Siegall led a team of researchers throughout the ‘90s who are able to develop highly effective means of delivering cytotoxins directly to the surface of tumors, eliminating the main Achilles heel of chemotherapeutic treatment, the massive systemic release of poisons into the bloodstream.
After founding his own company, Seattle Genetics, in 1998, Dr. Siegall went on to develop the first FDA-approved antibody drug conjugate, called ADCetris. This drug has been approved for multiple indications, including treatment of refractory non-Hodgkin’s lymphoma. The drug has proven that the therapeutic window for the most potent chemotherapies can be increased by entire orders of magnitude through the use of antibody drug conjugates.