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Targeted therapies from Pfizer, Bayer provide new hope


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Cancer drugs offer chance for normal life

Targeted therapies from Pfizer, Bayer provide new hope



Hope for Julia Barchitta comes in the form of a daily pill that attacked the kidney cancer which had spread to her lungs and lymph nodes. She has been cancer-free for the past year.

Barchitta, 62, a dean and head of the nursing department at Staten Island's Wagner College, was part of a study of the Pfizer cancer drug Sutent, which is now on the market after being approved by the Federal Drug Administration in late January.

Sutent is one of an emerging group of drugs called targeted therapies that focus on the processes and materials that make cancer cells grow, and which offer researchers hope that cancers can be detected earlier, treatments can be less toxic, longer lasting, and that cancer mortality rates drop dramatically.

"This is a big effort,"said Pfizer's Dr. Charles Baum, the global clinical leader for Sutent research headquartered in La Jolla, Calif. Targeted therapies "attack the mechanisms of cancer. There is a long way to go, but the prognosis is better and better."

Dr. Michael Kane, director or oncology at Mountainside Hospital, part of Atlantic Health System that includes Morristown Memorial Hospital, ran a trial using the drug Nexavar, a drug similar to Sutent but developed by Bayer Pharmaceuticals and Onxy Pharmaceuticals and approved by the FDA last December for treatment of kidney cancer.

Tumors in approximately half the participants stopped growing and spreading, Kane said.

"That was the most important outcome," Kane said. While the drug did not reduce the size of tumors, the fact that they stabilized means that those patients have the chance to live longer and have better quality lives, he said.

In time, he said, such treatments could change cancer into one of a number of illness like heart disease and diabetes that are considered chronic illnesses -- there is no cure, but the treatments keep the illness stable and patients live more normal lives.

Kane said he is planning a trial using Sutent.

Barchitta, who had already battled colon cancer and watched her husband die of the disease in 2003, said she was diagnosed with a spreading kidney cancer in July 2002. A year later, the cancer had spread to her lung and lymph nodes.

"Kidney cancer does not have a high success rate," she said, knowledge supported by the fact that her treatment --interferon, which is supposed to boost the body's immune system to help fight the spread of cancer -- was not effective.

"A year ago I thought I would not be here," she said.

She said she felt the flu-like symptoms, fatigue and shortness of breath that are the side effects of interferon use. It became a challenge to perform her job and affected her ability to enjoy her three children and two grandchildren.

Barchitta said she entered the Sutent trial in July 2004, pretty much as a last resort.

"I didn't have a choice," she said. "I had to hope a recovery was possible. I had to go on with hope. I prayed a lot."

Tests done six weeks after she started taking Sutent, showed a "noticeable reduction" in the tumor, she said. Six weeks later it was smaller yet, and now there is no evidence of cancer.

"It has been a miracle for me," Barchitta said. "I will take it as long as I need to. It's working. I'm afraid to stop."

Sutent, like all powerful medications, has side effects, including diarrhea, skin discoloration, mouth irritation, weakness and altered taste, the FDA said in its Jan. 26 approval of the drug.

For Barchitta, the noticeable side effect is intense hand and foot pain -- "like walking on glass."

In response, she said she stopped wearing high heels and skirts to work and started wearing sneakers.

"I gave up the high fashion,"she said. "Now it's sneakers. It's okay. If I have to wear sneakers for the rest of my life, I'll wear sneakers."

"My life" is a phrase that a year ago meant something different to Barchitta.

"I can not say that the cancer won't recur, and I can't say this is a cure," she said. "But I'm very happy to be here. It is important for people with the disease to have hope, some hope."

The first research steps toward today's targeted therapies began 30 to 35 years ago when Dr. Judah Folkman of Children's Hospital and the Harvard Medical School in Boston studied how tumors grow and spread, said Dr. Arnold Baskies, a medical advisor for the American Cancer Society who serves on the society's board of directors for New York and New Jersey.

Folkman studied how tumors use a process called angiogenesis -- the creation of new blood vessels -- to see how cancer sustains itself and spreads throughout the body.

That work led to the creation of drugs that inhibit angiogenesis, said Baskies

The major research breakthrough was the discovery 10 years ago of the human genome -- human beings'genetic code, said Baskies, who is also a member of the New Jersey's Governor's Task Force for Cancer Prevention, Early Detection and Treatment.

"We learn what controls cancer and the triggering mechanism that begin cancer and spreads it, " Baskies said.

That knowledge lead to the discoveries of the targeted therapies, he said.

"Targeted treatments can pinpoint the mechanism or enzyme that stops cancer," he said. "It is like using a BB instead of a shotgun pellet."

Baum said that the general approach to cancer treatment such as chemotherapy kills cells that divide, but since all cells are always reproducing, the drugs would attack them as well as the cancer.

"Chemotherapy says, 'if it is dividing, it must be bad,'"Baum said.

With Sutent, he said, "we know that cancer cells are genetically different. We target that difference. The drug attacks the blood supply to the tumor and the nutrients it needs to grow and spread."

In its approval of Sutent, the FDA said in the cases of renal cell carcinoma, the drug showed an ability to shrink tumors -- 26 to 37 percent in patients with advance kidney cancer -- and the ability to slow the growth of gastrointestinal stromal tumors in patients who are unable to tolerate treatments by Gleevac, the current treatment.

It was the first time the FDA had simultaneously approved a single drug for two separate treatment uses.

Baum said Pfizer was able to get Sutent ready for FDA approval in five years, although work that resulted in the drug was started 10 years ago. The work was aided by the development of improved radiography imaging, which allowed scientists to know with more certainty if a treatment was working, he said.

The reduction of side effect is also a key development, Baum said, as is the pill form of the medicine.

Barchitta said that she once had to inject herself with interferon. She said taking a pill daily was much better.

Baum said, "there is a big improvement in the quality of life. Patients don't have to take radiation, or plan a day to visit a clinic."

Baskies called the pill form, "the nice part of it."

Baum said that targeted therapies are treatments, not cures. "But these efforts are a new paradigm," he said.

It is the future that these therapies represent that "make this an exciting time to be in cancer treatment," Kane said.

There are successes, but also challenges, he said.

"There is evidence that cancers are smart and we can not underestimate how smart," he said. One goal is to match cancer's mechanisms of growth with the body's mechanisms of resistance.

A breast cancer treatment, he said, targets the enzymes associated with the growth of those tumors, Kane said. "It targets proteins, the fuel of cancer cells," he said. "This could be the magic bullet. It kills the cancer cells without harming normal tissue."

It is possible that combinations of chemotherapy and targeted therapies could be developed, he said.

There is also work that is examining the potential connection of stem cells to cancer cells, he said. When a cancer dies, it leaves behind a small percentage of cells that could be the reason that the same cancer returns, he said. Researchers are trying to determine if there is a link between how stem cells can become any type of cell and how cancer cells grow.

Baskies said there is the possibility that by examining cancers at the molecular level, breast cancer deaths could be reduced in a decade by 50 percent. That would mean that 35,000 fewer women would die of the disease , he said.

The real promise of this approach, he said, is that it could become possible to examine a person's genome to determine the possibility that they would develop cancer and, if so, provide a preventative therapy that could alter that person's body chemistry so that the cancer would not form.

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