Immunotherapy is the hot topic in oncology these days. Anyone reading HWC regularly knows that! Here’s a lengthy excerpt from an even longer, more comprehensive article my good friend and lifestyle columnist for our daily MultipleMyelomaBlog.com (MMB), Danny Parker, passed-along last week:
No more chemo: Docs say it’s not so far-fetched
By Alice Park – June 26, 2013
…So researchers were especially excited by a pair of studies published in the New England Journal of Medicine last week that showed a new type of anti-cancer drug, which works in an entirely different way from chemotherapy, helped leukemia patients tally up to an 83% survival rate after being treated for two years.
The report was only the latest to emerge since 2001, when imatinib, or Gleevec, the first drug to veer away from the take-all-comers approach on which cancer therapies have been built, accomplished similar improvements in survival for patients with chronic myeloid leukemia (CML) and gastrointestinal stromal tumor (GIST).
Could the end of chemotherapy be near?
“It’s a question we are all asking,” says Dr. Martin Tallman, chief of the leukemia service at Memorial Sloan Kettering Cancer Center. “I think we are definitely moving farther and farther away from chemotherapy, and more toward molecularly targeted therapy.”
It’s the difference between carpet bombing and “smart bomb” strategies for leveling an enemy — in this case, a fast-growing mass of cells that can strangle and starve surrounding normal tissues.
Targeted therapies, as they are called, are aimed at specific pathways that tumor cells use to thrive, blocking them in the same way that monkeying with a car’s ignition, or it’s fuel intake, can keep it from running properly. The advantage of such precise strategies is that they leave healthy cells alone, which for patients means fewer side effects and complications.
“The field is moving toward using the right drugs at the right time in the right patients,” says Dr. George Demetri, senior vice president of experimental therapeutics at the Dana Farber Cancer Institute. “We’re moving toward a more precise understanding of cancer, and being able to tailor therapies toward an individual’s cancer.”
In the case of the NEJM studies, researchers were able to target an active receptor on immune cells responsible for enticing them to grow out of control, blocking the protein and essentially shutting down two different type of leukemia tumors.
Already, patients diagnosed with GIST can avoid chemotherapy altogether, thanks to Gleevec. “No patient diagnosed with GIST should be getting chemotherapy today,” says Demetri.
Patients who develop certain types of lung cancer or melanoma caused by a cancer-promoting mutation known as BRAF are also starting to replace toxic chemotherapy agents with new, more precise medications designed to thwart the BRAF pathway.
And a study presented at the most recent meeting of the American Society of Clinical Oncology showed for the first time that a chemotherapy-free regimen led to a higher survival rate after two years than traditional chemotherapy for acute promyelocytic leukemia, a cancer of the bone marrow.
The refined approach does have a weakness, however. Cancer cells, like bacteria and viruses, are wily enough to bypass roadblocks to their survival, and often mutate to overcome the effects of targeted drugs. That’s the case for a small percentage of patients on Gleevec.
But even that shortcoming isn’t insurmountable. With growing knowledge about the molecular processes that drive tumor biology, researchers are able to design medications that thwart cancer cells’ attempts to bypass medications. It’s all about staying one or two steps ahead of the cancer, and already, researchers are testing drugs that address Gleevec resistance and hoping to widen the resistance gap.
“The field is moving so fast that there are new drugs already being developed to tackle new resistant clones,” says Tallman. “(Resistance) is a concern, yes, but it doesn’t negate our excitement about the future…”
If these therapies work half as well as researcher’s hope, it will be a miraculous acceleration in what oncologists and hematologists can do for their patients. But please don’t hold your breath. Not to be a “Debbie Downer” here, but most of these new therapies end-up helping less than one half of the patients treated. And that’s under the best of circumstances. Until researchers can improve those numbers, I’m afraid immunotherapy is only an expensive tease.
Five, or more likely ten years from now, maybe. But I’m on “myeloma time.” The meter is ticking for me and millions of other incurable cancer patients. Work hard into the night, dear friends. Your work is appreciated, but there is still so much to do…
Here’s the link to the rest of the article:
Feel good and keep smiling! Pat