A new wave of more-accurately targeted and less-toxic cancer fighting drugs that involve armed antibodies is on the horizon now, based upon a presentation made last weekend at the American Society of Clinical Oncology.
Side effects should be lessened and lives prolonged by this latest class of cancer drugs, which should translate well for patients with mesothelioma, the aggressive cancer caused by an exposure to asbestos.
“To get to this point is an indescribable feeling,” Dr. John Lambert, executive vice-president for research at pharmaceutical company ImmunoGen told The New York Times.
According to the Times, there are at least 25 such drugs in various stages of development that should represent the biggest breakthrough in cancer treatment in many years.
The approach involves binding two drugs together to produce results that far exceed the sum of what they can do individually. It includes harnessing antibodies to help target higher toxicity directly to cancer cells without harming the good cells around them.
The Times report likened the effect to “guided missiles with toxic warheads.”
Biotechnology drugs, like Rituxan, Erbitux and Herceptin, are combined with conventional chemotherapy drugs to increase the cancer-killing effect. The toxic chemotherapy drug is effectively disguised and isn’t released until the antibody binds to a cancer cell and is taken inside it.
“I don’t think there is a major pharmaceutical, or midsized pharmaceutical with interest in cancer that doesn’t have a program (like this), or isn’t scrambling to put one together,” Stephen Evans-Freke of Celtic Therapeutics told the Times.
One of the combo drugs, T-DM1, has been especially effective for advanced breast cancer patients, effectively halting the disease without the toxic side effects like hair loss and severe nausea.
Results of a 1,000-patient trial showed the ability of T-DM1 to significantly delay the disease progression in women with advanced breast cancer after more standard treatments had failed.
“T-DM1 will become standard therapy for all patients . . . given the strong overall survival signal and excellent safety,” Joyce O’Shaughnessy, co-director of Breast Cancer Research at the Sammons Cancer Center in Dallas told CancerNetwork.com. “All late-line patients will receive T-DM1 once it is available.”
According to the trial results presented last weekend, patients who received T-DM1 had a median 9.6 months before disease progression. It compared to 6.4 months for those with standard therapy.
The armed antibody theory is similar to what medical oncologist Raffit Hassan of the National Cancer Institute discussed on a conference call last month involving mesothelin, the protein that is being used to bind toxic drugs to mesothelioma tumors.
Hassan considers the success with mesothelin and the drug SS1P as a significant breakthrough in mesothelioma treatment, allowing much more targeted therapy.