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`Targeted' Treatments Take on Toxic Chemotherapy


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Drugmakers' `Targeted' Treatments Take on Toxic Chemotherapy

June 5 (Bloomberg) -- When President Richard Nixon declared a ``War on Cancer'' in 1971, Len Lichtenfeld was just out of medical school, expecting scientific breakthroughs to change the way doctors treated the dreaded disease. He's had to wait more than 30 years.

Today, a wave of cancer drugs are emerging from insights into the genetic machinery that turns normal cells into cancer, the No. 2 cause of death in the U.S. These new ``targeted'' medicines may offer doctors and patients alternatives to toxic chemotherapies and in some instances are already extending life for people with previously untreatable cancer.

``I'm not one to get very excited because I've been so disappointed in the past, except these advances appear real,'' Lichtenfeld, 59, deputy chief medical officer for the American Cancer Society said in a June 3 interview.

The new medicines are notable for their precision in targeting biological mechanisms cancer needs to survive. For the first time, doctors have enough of the drugs to start thinking about using them in combination -- a staple of chemotherapy treatment. How to mix and match the new therapies is dominating talk at the American Society of Clinical Oncology meeting in Atlanta, the world's largest gathering of cancer doctors and researchers taking place in Atlanta this week.

In 1997, Genentech Inc., along with the predecessor company to Biogen Idec Inc., won approval for the first targeted cancer drug. That drug was Rituxan, for treating patients whose non- Hodgkin's lymphoma, a blood cancer, had relapsed. In 1998, Genentech, and its majority owner Roche Holding AG, introduced Herceptin, the first drug designed to attack a specific protein that scientists had found spurs tumor growth in breast cancer.

Reaching the Market

In the past two years, five new targeted therapies have reached the market, the most since South San Francisco-based Genentech introduced Rituxan. At least four drugs designed to attack precise biochemical pathways that fuel tumor growth are due to arrive by the end of next year.

Some of the world's biggest drugmakers, including No. 1 Pfizer Inc., GlaxoSmithKline Plc, Wyeth, Bayer AG, Bristol-Myers Squibb Co., Eli Lilly & Co. and Amgen Inc., are just now entering the cancer treatment market dominated by Genentech, whose portfolio of targeted drugs generated $3.98 billion in 2005.

At the cancer meeting this past weekend, Madison, New Jersey-based Wyeth reported that its experimental drug, temsirolimus, helps patients with the most advanced kidney cancer live longer. The drug works by inhibiting mTOR, a protein that regulates cell growth and survival.

Standard of Care

For patients with less advanced forms of kidney cancer, New York-based Pfizer's Sutent may become a new standard of care after research released June 3 showed that the drug slows the disease's progression, researchers reported.

The drug, which by itself blocks five different pathways that fuel tumor growth, was approved for treating kidney cancer by the U.S. Food and Drug Administration in January. Kidney tumors are among the hardest-to-treat tumors because they typically don't respond to chemotherapy.

Glaxo is heralding its first entry into the $24 billion cancer market with studies showing that its experimental drug Tykerb helped stall advanced breast cancer in women not helped by Genentech's Herceptin. The London-based drugmaker said it will seek U.S. approval of Tykerb before the end of this year and analysts predict it may generate as much as $1.5 billion by 2012.

Like Herceptin, Tykerb aims at the Her2 protein that spurs the growth and spread of cancer. The pill also is designed to block EGFR, or epidermal growth factor receptor, which controls tumor growth.


Bristol-Myers Squibb Co.'s dasatinib, first tested in humans just three years ago, was recommended for approval as a treatment for leukemia by a U.S. Food and Drug Administration advisory committee on Friday. The drug, from the New York-based drugmaker, works by blocking an abnormal protein that triggers uncontrolled cell growth.

The advances are keeping patients alive longer, doctors say. There are currently 10 million cancer survivors now living in the U.S., a three-fold increase since 1971 when Lichtenfeld graduated from medical school. For the first time since it began keeping records in 1930, the American Cancer Society reported a decline in cancer deaths in 2003 to 556,902 from 557,271 a year earlier.

Work is under way to see if giving these new drugs in combinations will make them more potent. Until now, targeted therapies have typically been added to chemotherapy drugs. With more cancer therapies to choose from, researchers are hoping they can eliminate chemotherapy and its harsh side effects from treatment regimens, while improving their results.

`Playing Field Changed'

``The whole playing field has changed,'' said Roy S. Herbst, chief of thoracic medical oncology at the University of Texas M.D. Anderson Cancer Center said. ``We're in a new era. I don't know a physician who doesn't use a targeted therapy everyday in practice.''

Combining the new drugs enables doctors to hit more of the molecular targets involved in the growth and spread of cancer, with the intent of curing patients.

``If we are smart enough and we are hitting two pathways, I think we can have results that are as dramatic or even better than chemotherapy,'' said Jose Baselga, director of medical oncology at Vall d'Hebron University Hospital in Barcelona. ``It's the wave of things to come.''


Genentech, with a stable of cancer therapies that include Rituxan, Avastin, Tarceva and Herceptin, finds itself a much sought-after partner.

Susan Hellmann, the company's president for product development, joked she's been tempted to put a bag over her head in the hallways of the conference center to avoid numerous approaches from researchers and companies looking to collaborate on a combination study. The company plans to spend $1 billion for drug research this year.

In one of the first looks at a mix of these targeted drugs without chemotherapy, researchers will present data later today on the benefits of Genentech's Avastin and Tarceva drugs in lung cancer.

``The key question is, can we really take advantage of combination therapies and get rid of chemo,'' Hellman said in a June 3 interview at the ASCO meeting. ``That's the next move for the field.''

Limits and Challenges

The new drugs aren't perfect. All women with the aggressive breast cancer affected by Herceptin eventually develop resistance to the drug. Resistant leukemia remains a problem for some patients taking Gleevec from Basel, Switzerland-based Novartis AG. Approved in 2001, Gleevec deactivates a genetic glitch in tumor cells and is the first medication to show effectiveness against the disease.

Pfizer's Sutent, like Genentech's Avastin, may trigger bleeding in lung cancer patients. Bristol-Myers' dasatanib can cause bleeding in the brain. Herceptin has been linked to heart problems.

The new drugs also come with big price tags. Erbitux, marketed by New York-based ImClone Systems Inc., homes in on a protein called epidermal growth factor receptor involved in tumor growth. It can cost as much as $40,000 for a course of treatment for advanced colon or head and neck cancer. Avastin costs about $44,000 for a 10-month course.

``It's great finally to offer stuff to patients that works,'' Yu-Ning Wong, a medical oncologist at Fox Chase Cancer Center in Philadelphia who presented a cost study at the medical meeting Sunday, said in an interview. ``Whether it's worth paying for is the million dollar question.''

The market for cancer therapies is expected to reach $55 billion in three years as the new drugs reach the market, according to IMS Health Inc., which tracks prescription trends.


Because the treatments aren't ``one-size-fits-all,'' doctors must become more selective about which drugs to give to which patients. Tests are in now in development designed to help match genetic profiles of patients and molecular markers on tumors to the correct medications.

``Now we're in a situation where you have a plethora of targets and a plethora of drugs to attack those targets in the cancer cell,'' Lichtenfeld said. ``I'm getting confused, but it's the kind of confusion you want to have.''

To contact the reporter on this story:

Michelle Fay Cortez in Minneapolis at


Angela Zimm in Atlanta at azimm@bloomberg.net;

Last Updated: June 5, 2006 07:47 EDT

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