Miércoles 1 de Junio de 2005, Ip nº 111

A Paradigm Shift in Battling Cancer
Por Catherine Arnst

The slow pace of cancer research over the last few years has generated considerable comment. Three decades after the nation committed itself to a "war on cancer," the disease has become the largest killer in the U.S. for people under 85, causing one in four deaths each year.

The percentage of people who are still alive five years after diagnosis with lung cancer, which kills more people than breast, colon, and prostate cancer combined, currently stands at just 15%. Ten years ago, it was 14%. And most cancer victims are still treated with devastating surgery, chemotherapy, or radiation, which leave many patients more fearful of the treatment than the disease.

But -- and this is a very significant but -- a major paradigm shift is occurring in cancer treatment. It was highlighted at the major showcase for new cancer treatments, the annual American Society of Clinical Oncology (ASCO) annual meeting, held in Orlando May 13-17. A confluence of insights in genetics, smarter drug development, and two decades of hard, slogging research have produced a new generation of targeted cancer therapies that are keeping patients alive longer, with minimal side effects. As a result, glimmers of hope have arisen that cancer can be, if not cured, at least controlled -- and there are living patients proving that such hope is not misplaced.

"VITAL PIPELINE." In Orlando, some 30,000 specialists and researchers heard about experimental drugs and many treatments already on the market that can improve the outlook for a whole range of cancers. They listened to reports on drugs that can be employed once a patient grows resistant to the first tailored therapy used. By using successive drug therapies, cancer could be turned into a manageable disease.

"The message of this meeting is that there's now a vital pipeline of targeted therapeutics and a clearer vision of what tailored, personalized treatment regimens will look like," says Dr. Roy Herbst of M.D. Anderson Cancer Center in Houston.

Granted, the advances can seem incremental to the outside observer. Avastin, a much-heralded drug from Genentech (DNA ) that won approval last year for colon cancer, proved, in a clinical trial, able to also extend the lives of lung-cancer patients when added to standard chemotherapy treatment. Oncologists consider this a major breakthrough because lung cancer is notoriously hard to treat -- see the survival data above.

THALIDOMIDE'S RETURN? But Avastin added only 2.3 months to the median survival point in the study -- 12.5 months for patients who received the drug, vs. 10.2 months for those on chemo alone. Still, lung cancer specialist Dr. Alan Sandler of Nashville's Vanderbilt-Ingram Cancer Center considers those results "very exciting" because it proves that combination therapies can extend life.

Plus, he notes, that 12.5-month figure is a median point, meaning half the patients in the trial lived longer, and some are still living. Now doctors can work on figuring out just who might be the best in responding to Avastin or a number of other targeted therapies.

Most of the meeting's headlines focused on Avastin and two other targeted therapies from Genentech -- Herceptin, a breast-cancer treatment, and Tarceva, a lung-cancer drug that the company shares with OSI Pharmaceuticals (OSIP ). Pfizer (PFE ) also drew a lot of attention for Sutent, a drug it inherited when it acquired Phamacia in 2002, which is showing promising results against kidney cancer and a rare form of stomach cancer. However, literally thousands of new drugs were discussed at the meeting. Here are some other notable results from ASCO:

• Celgene (CELG ) has been working for years to find new uses for thalidomide, the notorious sleeping aid taken off the market in the 1960s when it was discovered that the drug caused horrific birth defects. But the medication is believed safe if kept from pregnant women, and it's being tested in a number of cancers.

Celgene received a lot of notice when a variation of thalidomide called Revlimid proved effective against myelodysplastic syndromes (MDS), a group of diseases that affect the bone marrow. Between 10,000 and 15,000 people are diagnosed with MDS each year in the U.S., and no effective treatments exist. In a trial of 115 patients, Revlimid reduced the number of cancer cells that contained the abnormality in 81 patients, and 66% no longer needed blood transfusions after six months.

• Brain tumors called gliablastomas are among the hardest cancers to treat because most drugs don't reach the brain, and surgery is often not an option. In a small clinical trial, Eli Lilly (LLY ) was able to shrink these tumors in 25% of patients by using enzastaurin, an experimental drug that blocks blood-vessel growth and tumor-growth agents.

• Several biotech companies are testing vaccines that would prevent the recurrence of prostate cancer after initial treatment. These trials take a long time to conduct, and results so far have been far from definitive.

However, Dendreon (DNDN ) reported promising data on Provenge, its prostate vaccine, which is one of the furthest along in this group. The late-stage trial found that patients on Provenge had a median survival of 25.9 months, compared with 21.4 months for the placebo group. Also, 34% of patients on Provenge were still alive at 36 months, compared with 11% on placebo.

• Chemotherapy is still the main treatment for most cancers, and doctors are still figuring out better ways to use these highly toxic drugs. Some of the best data reported at the meeting came from a study that added Taxotere, from Sanofi-Aventis (SNY ), to a traditional regimen of chemotherapy-plus-radiation therapy for lung cancer. The combination produced the longest reported survival rate yet for patients with advanced lung cancer -- 29% of patients who received Taxotere were still alive after five years, compared with 17% without it.

Such a finding provided another instance of progress, albeit slow, in the long fight against cancer.


  19/05/2005. Business Week Magazine.