June 15, 1997|By Mark Guidera | Mark Guidera,SUN STAFF
For years, Michael G. Hanna had a radical vision for how cancer might be treated in the not-too-distant future.
His dream: A cancer patient is given an injection of a drug that is so "smart" it zooms directly to tumor cells, bypassing healthy ones. The body's own defenses are alerted to attack the tumor, and the triggers for new cancer growth are disarmed.
Like Hanna, cancer researchers in the United States and Europe have long toiled on just such a magic bullet. Hurdles, though, have been high.
The main one: Cancer cells smartly mask their alien identity from the body's immune system, making them difficult to target.
But thanks to dramatic advances in molecular and cell biology that have opened a window on cancer behavior, such therapies as the one Hanna dreamed of could be available within several years for some types of cancer.
Among the companies that appear close to commercializing new breakthrough cancer treatments is PerImmune Inc., a Rockville biotechnology company headed up by Hanna. The former National Cancer Institute researcher has spent more than a decade deciphering how the body's immune system might be used to fight the nation's No. 2 killer. More than 1.4 million new cases are diagnosed annually.
Privately held PerImmune has developed a drug for colon cancer using what are known as human monoclonal antibodies to block cancer growth. Monoclonal antibodies, considered one of the more important medical science advances in recent years, are genetically engineered agents that can recognize with a high degree of accuracy different types of cells. PerImmune's colon cancer treatment uses a patient's own tumor cells to stimulate an immune response which recognizes cancer cells and fights growth.
"We are allowing the body's own immune system to guide us in how to fight cancer," says Hanna.
His company's therapy, called OncoVax, is among a host of emerging treatments taking shape in biotechnology, pharmaceutical, university and government research labs in Maryland and elsewhere. Together, they hold the promise of radically changing the anti-cancer arsenal in just a few years, say experts.
Dr. Louise C. Strong, a genetics researcher at the University of Texas Anderson Cancer Center and president of the American Association for Cancer Research, is hopeful new therapies might soon replace, or at least reduce the need for the current standard treatments -- chemotherapy, radiation and surgery.
"There is a lot of excitement that at some point in the near future we'll have much more targeted cancer treatments than we do today, and we won't have to rely on some of these toxic approaches in which we go in and kill as many cells as possible," says Strong.
Many treatments
Radical new cancer treatments being developed in Maryland that may be available in a few years cover a broad range of approaches.
Some, like PerImmune's, are designed to either help the body's own disease fighting T-cells recognize cancer cells as foreign invaders and attack them, or otherwise deactivate cancer's biological mechanisms for growth.
One company is working on drugs that would shut off the blood supply to tumors, a key factor in some cancer growth.
Others are working on "vaccines" with antibodies and other materials that act as homing devices, carrying therapeutic agents to cancer cells.
Also in the pipeline at Maryland companies are gene therapies that seek to stimulate "suppressor genes," which block cancer.
For the near future, say experts, the therapies most likely to emerge on the market will be aimed at preventing cancer's spread or recurrence.
Experts such as Hanna at PerImmune and Dr. Strong believe these new therapies initially will be used in combination with surgery, chemotherapy, radiation or other treatments.
For example, PerImmune's monoclonal antibody therapy is designed to prevent a recurrence of cancer after tumors have been surgically removed.
But, says Hanna, "The ultimate goal is to create a therapy that could be given to people at a high risk for cancer," such as those with family cancer histories, to prevent cancer from ever occurring. In other words, a true vaccine.
Laying the groundwork for companies like PerImmune in the Baltimore-Washington area are institutions such as the Johns Hopkins School of Medicine, the University of Maryland and the National Cancer Institute.
Their researchers have provided crucial scientific keys to developing new treatments, and developed some of their own.
NCI, for example, has eight monoclonal antibody cancer treatments in clinical trials.
Some researchers, like Angela Brodie, a University of Maryland professor of pharmacology and experimental therapeutics, have developed treatments with such strong potential that companies and venture capitalists are interested.