In part 2 of a series on cancer treatments we take a look at drugs being used to treat the disease that were initially developed for other illnesses.

Doctors are working on effective new cancer therapies - using older drugs that were developed to treat different conditions.

“As we better understand the biology of cancer, what we’ve learned is in many cases the various drugs that we’re using for other indications will also affect that same biology,” said Dr. Robert DiPaola, director of the Rutgers Cancer Institute of New Jersey.”

He said cancer cells are “revved up” cells that require an extensive amount of nutrition, so their metabolism level is fairly high.

“What we found is there are some agents that are used in other venues that will affect metabolism overall," DiPaola said.

One example of this is the drug hydroxychloroquine, which is commonly used to treat malaria and certain types of arthritis.

“As it turns out it affects one pathway in a cell’s metabolism, and because cancer cells require more metabolism, hurts cancer cells in the laboratory more than it hurts normal cells, so clinical trials are underway to see if the drug inhibits cancer cells while not causing side effects,” he said.

Another older drug being used to treat cancer is metformin, which is used for diabetics.

“We have found it has an effect on metabolic pathways, and it appears, again in the laboratory, to do that in cancer cells more than in normal cells,” the doctor added.

Dr. DiPaola said the evidence is not conclusive, “but it allows us to at least have the opportunity to conduct further clinical trials with agents that have lower toxicity.”

He said the bottom line is as doctors better understand the biology of cancer, they can become “smarter” and look at what can target those abnormalities.

“In many cases they’re available to us, or were available to us, we just didn’t know how to use them before,” he said.

Dr. DiPaola also said if a drug is already approved for one indication and it can proven that  it has effectiveness in another use, it’s usually a much shorter timeline to approval.

He also points out because the Rutgers Cancer Institute of New Jersey is able to launch clinical trials, it gives patients state-of-the-art opportunities earlier than they would normally have them.

“In many cases it’s bringing opportunities, new agents, new possibilities really on that kind of cutting edge. Thirty years ago only about 50 percent of them survived beyond 5 years, or what we would consider cured, nowadays it’s close to 70 percent,” DiPaola said.