WASHINGTON — A new drug is being developed that targets some aggressive cancers that are notoriously hard to cure. If the clinical trials that are underway continue to show promise, the drug may change the way some cancers are treated.
Scientists at Pfizer, the giant pharmaceutical company, and Stemcentrx, a small biotech firm in California recently acquired by AbbVie, have developed this novel drug that targets aggressive breast, ovarian and lung cancer stem cells.
Marc Damelin at Pfizer has been working on this drug, officially called PF-06647020, with Scott Dylla at AbbVie Stemcentrx.
In a Skype interview, Damelin told VOA, “We’re hoping to rip out the cancer by its roots, essentially. Like when you’re weeding a garden, you need to get the roots so the weed doesn’t grow back, and the way we’ve designed this drug, is to go after the roots of the tumor and we deliver the chemotherapy therapy that essential kills those cells.”
Relapses are common in aggressive forms of cancer, including triple-negative breast cancer, ovarian cancer and non-small cell lung cancer, which make them hard to cure.
The drug has already proven safe and effective in mice and in monkeys, and human trials are underway.
“The therapy is, essentially, a guided missile,” Damelin said.
Dylla at AbbVie Stemcentrx explained to VOA that the missile is an antibody molecule which attaches itself to a developing cancer cell and is able to enter the cell like a Trojan horse. Because the scientists also attached a cancer-fighting drug to the antibody, the drug delivers chemotherapy directly to cancer cells and kills them.
The missile’s target is a protein called PTK7 which is found in abundance in these particular cancer cells.
Early clinical trials are underway with patients whose cancers did not respond to other treatments or had relapsed. Damelin says nearly a third of participants with ovarian cancer are showing a positive response.
Dylla said patients in the current trial with triple negative breast cancer and non-small cell lung cancer are also responding well, although he didn’t provide the percentages.
He said even though this is an early clinical trial, “The responses are clearly drug related responses given that the only therapy patients are being given is our drug.” A larger human trial is scheduled to begin later this year.
Right now the researchers don’t know if this new drug would replace standard chemotherapy, radiation or surgery, or would complement those procedures, but Dylla said that is the hope. If it works, it could replace standard chemotherapy and the treatment would be a lot less toxic.
Damelin said this drug might also help patients with cancer of the stomach, esophagus and prostate, and an aggressive type of leukemia because the scientists have antibodies for these particular cancers.
The hope is that PF-06647020 could revolutionize the way these particular cancers are treated, in addition to dramatically extending the lives of those with these deadly cancers.