Pfizer, Genentech Cancer `Cocktails' Overpower Tumors (Update4)
By Angela Zimm
June 6 (Bloomberg) -- New cancer drugs from Pfizer Inc. and Genentech Inc., tested together for the first time, raised each medicine's tumor-fighting power, researchers reported this week.
The therapy is heralding a new era in treating cancer by combining drugs that interfere with the biochemical pathways that fuel the disease. By using Sutent, made by New York-based Pfizer, and Avastin from Genentech, in South San Francisco, researchers say they achieved a 71 percent reduction in difficult-to-treat kidney tumors in a small study.
La thérapie inaugure une nouvelle ère de traitement en combianant 2 médicament qui interfère avec le chemin biochimique qui nourrit la maladie. En utilisant Sutent, fait par Pfizer, et Avastin de genentech, dans le sud de San-Francisco, les chercheurs disent qu'ils arivent à 71 % de réduction avec les tumeurs du rein habituellement difficlle à traiter.
Scientists say medicines emerging from drugmakers have led companies that normally compete to conduct studies combining their separate therapies. More than a dozen trials presented at a science meeting this week suggest treatments mixing so-called targeted drugs, such as Pfizer's Sutent, with Iressa, made by London-based AstraZeneca Plc, may boost their potency.
``To make the biggest difference, we need to make targeted cocktails'' of different drugs, said Roy Herbst, chief of thoracic medical oncology at the University of Texas M.D. Anderson Cancer Center. ``And it's really beginning to happen.''
Finding the best ways to mix and match the new treatments is shaping the focus of cancer research as scientists seek to lessen or eliminate use of harsh chemotherapy, Herbst and other doctors said in a presentation this week at the American Society for Clinical Oncology meeting in Chicago.
Resistance, Side Effects
``If you can target more than one pathway, you can overcome resistance,'' said Lini Pandite, a researcher at London-based GlaxoSmithKline Plc. She runs the program developing pazopanib, an experimental drug the company plans to test with its new Tykerb medicine against breast cancer.
Traditional chemotherapy treatments use toxic chemicals that kill cancer cells or affect their ability to grow and divide. Because the treatment affects the whole body, normal cells can be harmed and side effects can include infections, hair loss, anemia and fatigue. Some types of chemotherapy can cause damage to the heart or kidneys.
The first of the targeted therapies was approved in the U.S. in 1997 when Genentech introduced Rituxan for non-Hodgkin's lymphoma, a blood cancer. In 1998, Genentech followed with Herceptin, the first drug designed to attack a protein that causes breast tumors to grow.
In 2004, the company introduced Avastin, which blocks blood flow to tumors. Avastin, for colon and lung cancer, generated $1.75 billion in sales in 2006, while Rituxan had $2.07 billion, making them Genentech's biggest sellers. Overall, the company was the world's biggest maker of cancer medicines last year with $5.45 billion in sales.
Genentech's shares fell $1.59, or 2 percent, to $75.90 at 4:02 p.m. in New York Stock Exchange composite trading. The stock has dropped 6.5 percent this year as big drugmakers have begun developing and selling targeted cancer medicines. Pfizer shares fell 49 cents, or 1.8 percent, to $26.79. They've gained 3.4 percent this year.
Fifteen targeted drugs have been released for sale worldwide since 1997 and six just last year. The Pharmaceutical Research and Manufacturers of America, based in Washington, D.C., says there are a record 646 cancer drugs in development by companies worldwide, and many target cancer-fueling pathways have been uncovered by scientists over the past two decades.
Some of the newest treatments, including Pfizer's Sutent and Nexavar from Onyx Pharmaceuticals Inc. of Emeryville, California, are changing the standard of care for certain cancers, doctors reported at the oncology conference.
Sutent, with sales of $219 million in its first year marketed in 2006, is replacing chemotherapy in treating lethal kidney cancer, doctors say. Researchers reported that Nexavar, approved for kidney cancer in 2005, is the first drug to prolong lives of people with liver cancer.
Shares of Onyx fell 84 cents, or 2.5 percent, to $33.09 in Nasdaq Stock Market composite trading. They've tripled this year. Shares of Bayer AG, the Leverkusen, Germany, drugmaker that markets the drug with Onyx, fell 1.53 euros, or 2.8 percent, to 52.91 euros at the close of trading in Frankfurt.
Glaxo, which won approval of Tykerb, plans tests of that drug in combination with its experimental pazopanib in a range of cancers including breast, brain and cervical, to see whether it can prevent breast tumors from spreading to the brain. Pazopanib is designed to block the activity of three proteins involved in tumor growth whereas Tykerb targets a separate one known as Her2.
``If you can replace chemo, that would be a dream come true,'' said Paolo Paoletti, Glaxo's director of oncology. ``In order to replace chemo, you need to be innovative in clinical development.''
Targeted drugs aren't free of side effects. Erbitux, New York-based ImClone Systems Inc.'s treatment for colon and head and neck cancer, can cause a severe skin rash. Herceptin raises the risk of heart failure. Sutent and Avastin may trigger bleeding in lung cancer patients.
Doctors say they are just beginning to find out which combinations of targeted therapies are safe.