Terminally Ill Kids Get `Chance' of Cancer Cure From Wyeth Drug

June 26 (Bloomberg) -- Two children under age 10 with terminal cancer have been recruited into an experiment testing a novel way of treating the disease by targeting stem cells.

Researchers at the Hospital for Sick Children in Toronto are administering Rapamune, an organ transplant medicine from the drugmaker Wyeth, to two youngsters with a nervous system cancer called neuroblastoma. In test tube and mice studies, the drug killed stem cells that scientists say may be responsible for driving the cancer's growth.

Since 1997, researchers have found that certain stem cells fuel tumors in leukemia and in breast, lung and brain cancers. Scientists at universities and biotechnology companies led by Infinity Pharmaceuticals Inc. of Cambridge, Massachusetts, and Australia's ChemGenex Pharmaceuticals Ltd. are developing treatments to block the cells. The Toronto test is the first to use an existing medicine on the cells in neuroblastoma patients.

``If you can therapeutically target cancer stem cells -- the cells that are resistant to chemo and radiation -- you have a chance of curing cancer,'' said Judy Lieberman, a researcher with the Immune Disease Institute, a Boston-based affiliate of Harvard Medical School. ``It can revolutionize cancer therapy.''

In the U.S., 650 children are diagnosed each year with neuroblastomas and four out of five victims older than age 1 die within five years. The experiment in the two young patients is the latest in a handful of human tests by scientists to determine whether attacking stem cells can thwart cancer, researchers say. The study took an innovative approach by testing thousands of existing drugs against cells drawn from the patients' own tumors.

`Bullet-Proof Vests'

Stem cells are capable of copying themselves and turning into other cell types. The new treatment theory is based on the idea that in some cancers, stem cells get stuck in a pattern of endless self-renewal. Research has found that these stem cells may be immune to chemotherapy and radiation, making conventional cancer treatments fail.

``Standard chemo is like using a bomb to kill the cells,'' Lieberman said in a June 18 telephone interview. ``But the cancer stem cells are wearing bullet-proof vests.''

The strategy of finding and attacking these cells results from pioneering work by John Dick, a University of Toronto scientist who in 1997 showed that certain cells in leukemia propelled the growth of new cancer cells. Last year, he identified similar cells in colon cancer. His research indicates that some cells, for reasons not yet known, are more prone than others to propel the unchecked growth that typifies cancer.

From Lab to Clinic

``Our data show that there are some cells that are more potent at sustaining the growth of a cancer than others,'' Dick said in a June 18 telephone interview. ``These are the cells we called cancer stem cells.''

Researchers are trying different strategies to disable the cancer-initiating cells. The Hospital for Sick Children researchers tried the theory by testing thousands of approved drugs in lab dishes and animals to see whether any could inactivate the cells.

``We chose approved drugs so we could very quickly go from the lab to the clinic,'' said Kristen Smith, one of the Toronto researchers, in a June 13 interview in Philadelphia, where she presented her findings to a meeting of the International Society for Stem Cell Research.

After the researchers found that Rapamune, also known as rapamycin, showed activity against the cells, Canadian regulators said the drug could be tested in the children because no other treatment was likely to work for them. The researchers wouldn't identify the patients because clinical trials are confidential.

Killing Tumor Cells

The drug, which also is used to coat Johnson & Johnson's Cypher heart stent to keep cleared arteries from reclosing, may work by inhibiting a gene that affects cell growth, Smith said. The children were given the drug over the past few months, with treatment on the second child ending about a month ago, she said. She wouldn't provide details on their condition and cautioned that it's too early to consider the drug a proven treatment for neuroblastomas.

Smith and her colleagues found that rapamycin decreased the number of tumor-forming cells in laboratory dishes while leaving other cells within the tumors intact. When they injected cancer- starting cells from the children's tumors into mice, the rodents grew their own tumors. When they treated the mice with rapamycin, the tumors shrank.

``This suggests that we killed most of the tumor-initiating cells,'' she said.

The Toronto research was supported by the James Fund, an organization started by Sydney and Pam Birrell in honor of their son James, who died of a neuroblastoma in 2001 at age 8.

The foundation has provided seed grants for ``crazy ideas'' that might give kids a better shot at surviving, said Sydney Birrell in a June 16 telephone interview. He said he hopes doctors will be able to do for children with neuroblastomas what they've accomplished for kids with leukemia.

``Eighty-five percent of those kids used to die,'' he said. ``Now 85 percent of them survive.''

To contact the reporter on this story: Rob Waters in San Francisco at rwaters5@bloomberg.net.

Alzheimer's Drug Trial Helps Investors Forget Wyeth Troubles

With patent expiration wiping out its blockbusters, Wyeth has been desperate to find new drugs.

It may have one. The beaten-down pharmaceutical company released data Tuesday that brings hope that an Alzheimer's treatment has significant potential.


Wyeth and its Irish partner Elan said Tuesday that a Phase 2 clinical trial of Alzheimer's treatment Bapineuzumab had yielded "encouraging preliminary findings."

Analysts were encouraged as well. Leerink Swann analyst Seamus Fernandez upgraded Wyeth to "outperform" because he believes bapineuzumab has long-term potential. Fernandez expects sales of bapineuzumab to be $150.0 million in 2011 and $750.0 million in 2012.

Shares in Elan (nyse: ELN - news - people ) closed up 5.7%, to 18.18 euros ($28.19), in Dublin. Wyeth (nyse: WYE - news - people ) rose 4.8%, or $2.08, to $45.16.

The 18-month trial generated statistically significant and clinically meaningful benefits for patients not carrying a gene known as "ApoE4," which apparently accounts for 40% to 70% of Alzheimer's sufferers.

Doug Petkus, a spokesman for Wyeth told Forbes.com that the company was planning to release the complete data in July.

"The data in itself was better than our own expectations, especially in a subset of the patient population that doesn't carry this ApoE4 gene," said Jack Gorman, analyst with Davy Stockbrokers. He told Forbes.com that the drug was still at an early stage of testing, but that it showed signs of being able to change the progression of Alzheimer's rather than only tackling the symptoms.

According to Elan, for non-carriers of ApoE4, the study's preliminary results showed a smaller loss of brain volume among treated patients than for placebo patients. Loss of brain volume is associated with the onslaught of Alzheimer's, and any ability to fight this would be significant.

The results did show an increase in adverse side-effects for carriers of ApoE4, especially at higher doses; some patients who were given the drug experienced "vasogenic edema," or brain swelling, but this did not affect placebo patients. According to an Elan spokesman, this was as expected and did not reach clinically significant levels.

The Bapineuzumab treatment is an antibody designed to clear amyloid from the brain, which is seen as the most likely path to success for fighting Alzheimer's. Amyloids are protein deposits found in the brains of Alzheimer's victims, and the pharmaceutical industry seems confident that a major part of tackling the disease will involve defeating amyloids. (See "Attacking Alzheimer's")

"The preliminary analysis of the Phase 2 study are a continued validation of the amyloid approach to Alzheimer's disease, and an important milestone in our companies' ongoing commitment to bring new treatment options to patients," Elan Chief Executive Kelly Martin said in a press release Tuesday.

Last week, Elan resumed testing of another Alzheimer's treatment, this time a vaccine designed to stimulate the immune system. Testing had been suspended in April after a potentially serious side-effect suffered by one patient, involving skin lesions.

The company has been under pressure to find a new blockbuster now that Effexor, its antidepressant drug, faces patent expiration in 2010. The company also faced generic competition for its blockbuster heartburn drug Protonix at the end of last year.

Cancer Revolution, Or Me-Too Mess?

Over the next decade, drug companies could either start selling more cancer drugs than at any time in history or face the biggest string of clinical failures ever.

Four hundred medicines are being tested on human volunteers, aimed at common diseases like colon, breast and lung cancer and also rare ones like hereditary thyroid tumors or myelofibrosis. Driving this influx is a new understanding of the molecular mishaps that turn healthy cells into malignant killers, and a desperation among large drug companies that will soon lose more sales at once to blockbuster drugs going off-patent than at any time in the past. Six big drug firms are testing more than a dozen cancer medicines each.

How will this giant cancer battle play out? Some clues can be found in the current race to develop anti-cancer medicines that hit a cellular receptor known as insulin-like growth factor one (IGF-1).

"It is the second big pathway that seems to be important for growth in many cancer cells," says John Mendelsohn, president of M.D. Anderson Cancer Center and co-inventor of Erbitux, now sold by ImClone Systems (nasdaq: IMCL - news - people ). Erbitux hits the first big pathway important in cancer cells growth, the epidermal growth factor receptor (EGFR).

Almost a decade ago, ImClone, AstraZeneca (nyse: AZN - news - people ), Genentech (nyse: DNA - news - people ) and Pfizer (nyse: PFE - news - people ) were all involved in a race to develop EGFR drugs. Only Erbitux has passed the $1 billion sales mark, and AstraZeneca's Iressa wound up being withdrawn from the U.S. market because a big trial failed to prove it extended the lives of lung cancer patients.

Pfizer, Merck (nyse: MRK - news - people ), Amgen (nasdaq: AMGN - news - people ), ImClone , and Roche (other-otc: RHHBY.PK - news - people ) are all testing drugs against IGF-1 in human trials.

"It's a me-too world," says Stephen Friend, head of oncology at Merck. He notes that many companies went after IGF-1 just because of its similarity to EGFR. They were looking for the next molecular pathway that might stop tumors from growing. (Merck entered later.)

Right now Pfizer is ahead. Its IGF-1 antibody is in a big trial in lung cancer. Seventy-eight percent of patients with a particular type, squamous cell cancer, responded to the drug. Alison Ayres, head of the company's oncology marketing operations, says Pfizer's plan for dealing with the new me-too environment of cancer drugs is to work on important cancer targets wherever the company can manage a lead.

"If we're not among the front-runners, we don't see any point," says Ayres.

The reason is that once a particular type of drug is established in a particular type of cancer, it is tough for a competitor to dislodge. Amgen developed a copycat to Erbitux, called Vectibix, and priced it significantly lower. But Vectibix has had trouble getting traction, while Erbitux is a blockbuster, in part because Vectibix is not approved to be used in combination with chemotherapy like Erbitux. Another reason is that once a drug is approved, any new medicines must beat it in a big clinical trial. That can only happen if there is a big advantage for the new medicine.

To catch up with rivals in creating drugs that hit a target called hsp90 (heat shock protein 90), Pfizer bought an outfit called Serenex. The logic, Ayres says, was that it was too far behind rivals like Bristol-Myers Squibb (nyse: BMY - news - people ) and AstraZeneca in developing drugs to hit this molecule, which repairs dysfunctional proteins. Block it, and more cancer cells should die.

Merck is taking a different approach, betting that an especially deep understanding of a biological pathway will allow it to design better clinical trials. Friend says that he is cognizant of the fact that he's trailing Pfizer, and that he is investing in IGF-1 only because he thinks Merck can develop a market for the drug by having a better scientific understanding of how the drug works--and testing it in populations, and as part of drug combinations, where it will be most effective.

Unlike Pfizer, which is testing a wide array of cancer drugs, Friend is focusing on medicines that are related in a few, distinct biochemical pathways. The idea is that his researchers will be able to better understand the biology of patients who will be helped by the drug. The key question, Friend says, is, "Can I be the smartest at understanding how that would work?"

Merck has started randomized Phase 2 trials in 240 patients in colon cancer. The trial can be made bigger, so that it could be used for Food and Drug Administration approval, if the initial results due later this year are positive. To better understand which patients will benefit from the drug, Merck is testing it on tumor samples from the Moffitt Cancer Center in Florida. The idea is that it might be possible to predict which patients will respond.

"It is a pretty big race," says Merck Vice President Eric Rubin.

Right now, despite the influx of cancer drugs into human tests, the field of oncology is in a lull. For a while, it was as if a new breakthrough cancer drug hit every year: Gleevec, Erbitux, Avastin. The past two annual cancer meetings held by the American Society for Clinical Oncology have delivered few such surprises.

"We're hitting a lot of base hits that move the science but don't mean a lot to patients," says Otis Brawley, chief medical officer of the American Cancer Society. He's calling for more government funding of basic research to help new ideas take root.

If IGF-1 fails, it wouldn't be the first time a rush to develop copycat cancer drugs has led drug firms into a dead end. One notorious example came when just about every major drug company in the mid-1990s rushed to develop drugs to block a cancer-causing gene called ras. The companies pressed ahead into trials even as evidence emerged that cancer cells had bypass mechanisms that would allow the tumors to sidestep the drugs' effects.

One company, however, was smart enough to ignore the industry wide peer pressure and abandon its ras project in the mid-1990s. Instead, it focused on treating cancer with monoclonal antibodies, an approach that was highly unpopular at the time. Smart move. That company, Genentech, is now the biggest seller of targeted cancer treatments in the world.

`Good' Cholesterol May Not Benefit Heart, Study Says

By Shannon Pettypiece

June 3 (Bloomberg) -- `Good' cholesterol that scientists have thought helped unclog arteries had no effect on heart disease in a study, casting doubt on a theory drugmakers have spent more than $1 billion pursuing.

Researchers studied people who have a genetic condition that causes them to produce very low levels of HDL cholesterol, expecting they'd be about twice as likely to have heart disease. Instead, they had no greater risk, according to a study published today by the Journal of the American Medical Association.

Pfizer Inc., Merck & Co. and Roche Holdings AG have spent years developing drugs that increase production of HDL cholesterol based on the theory that raising the so-called good cholesterol helps ferry artery-clogging plaque from the body. The new research throws that strategy into question and shows HDL plays no role in preventing heart attacks, said Anne Tybjaerg- Hansen, a study author and clinical biochemistry researcher at Copenhagen University Hospital.

``There is really no evidence that this method is going to work,'' said Tybjaerg-Hansen in a telephone interview. ``This theory has been around for a long time, but this study just doesn't support it.''

The reason may be that other HDL cholesterol research examined patients with high levels of triglycerides, the chemical form of fat. Triglycerides, not patients' low HDL levels, may have caused their increased heart risk, Tybjaerg-Hansen said.

Why Pfizer Flopped

This may explain why the experimental drug torcetrapib, which New York-based Pfizer spent more than $1 billion developing, raised HDL levels without providing heart benefits, the study said. Analysts had expected torcetrapib would have more than $14 billion in annual sales. Pfizer quit developing it in 2006 because it increased deaths. Whitehouse Station, New Jersey- based Merck and Basel, Switzerland-based Roche also are developing HDL-raising drugs.

Yale Mitchel, Merck vice president of cardiovascular disease research, said the study, which was small and in a rare patient population, won't persuade the company to change its plans for an HDL-raising drug given the large body of data suggesting HDL provides a benefit.

Merck has spent five years developing a drug called anacetrapib, which raises HDL by blocking the cholesterol ester transfer protein. The drug is in the third and final stage of testing necessary to gain regulatory approval.

`Too Attractive'

``The hypothesis on whether CETP inhibition is a benefit or not hasn't been tested and it is too attractive a mechanism to disregard right now,'' said Mitchel. ``We have to be careful about not over interpreting it at this point. There is a large contextual database that suggests low HDL levels are associated with an increased risk.''

Pfizer has said the company's HDL-raising research is temporarily on hold. Roche said its drug is in the final stages of testing and it will file for U.S. regulatory approval after 2011.

``We haven't had an opportunity to evaluate this study yet, but epidemiological data does show there is a strong inverse relationship between HDL and cardiovascular risk,'' said Roche spokesman Terence Hurley.

The idea that HDL helps purge artery plaque is based mostly on animal studies, which Tybjaerg-Hansen said are sometimes difficult to understand and apply to humans.

The new study looked at data collected from almost 57,000 Danish patients between 1976 and 2007, of which 148 had a rare genetic condition called Tangier disease that caused them to produce very low levels of HDL cholesterol.

The study adjusted for age and other factors that could raise the risk of a heart attack.

To contact the reporter on this story: Shannon Pettypiece in New York at spettypiece@bloomberg.net

Novartis Steals The Show

Chicago -

Retired PepsiCo executive David Scherb was in bad shape 15 months ago. Kidney cancer had spread to his lungs and one tumor became so big it ate through his sternum and bulged right through the surface of his skin. It was so painful he couldn't wear a shirt.

But last April, he started on a clinical trial of a new experimental kidney cancer drug from Novartis (nyse: NVS - news - people ) called RAD001. The pain declined, and by summer of 2007 the tumor was no longer visible. A full year later, the tumor remains in check. "If it wasn't for this drug, I don't feel like I would be here," Scherb says.

Novartis is emerging as the surprise winner at this year's annual meeting of the American Society of Clinical Oncology, the year's biggest cancer conference. The company looks to have a sure-fire new drug for kidney cancer patients who have failed other options. Its bone drug Zometa was unexpectedly shown to reduce risk of breast cancer recurring by 35%. And perhaps most intriguing of all, the same kidney drug seems to have big potential for treating advanced breast cancer.

The most immediate sales impact could come from the surprise finding that the company's bone-boosting drug Zometa slashed the recurrence of breast cancer in pre-menopausal women by about 35% in an 1,800 person trial, when combined with standard treatment. That could yield new sales for a drug that now has been used merely as supportive care to prevent fractures in patients with cancer bone metastases. The new study shows it may actually prevent new metastases. The mechanisms aren't entirely clear, but may be because the drug inhibits blood vessel formation in the bone.

The current data is in only one small set of breast cancer patients. Novartis is conducting a big study to see whether the dug can also prevent relapse in the much bigger group of postmenopausal women with breast cancer. But with little downside to giving the drug, many doctors probably won't wait, predicts Julie Gralow of the University of Washington.

"There will be great uptake," says Gralow. "People will say, 'Why not?" I'm losing bone, my insurance will pay, there is hardly any toxicity and it may decrease recurrence.' " The drug is given as a twice-yearly infusion.

In another study at the meeting, researchers reported RAD001 delays progression of kidney cancer by about two months in tough cases that had failed with other treatments. While not a huge effect, the results are all but certain to lead to approval of the drug, doctors said. It could establish RAD firmly as the agent of choice for those who have failed Pfizer's (nyse: PFE - news - people ) Sutent, the drug mostly commonly used for initial kidney cancer therapy.

This could cut into sales for Onyx Pharmaceuticals (nasdaq: ONXX - news - people ) and Bayer's (nyse: BAY - news - people ) Nexavar drug for kidney cancer. Wyeth (nyse: WYE - news - people ) also sells a kidney cancer drug that is similar to RAD001.

"There are a lot of treatment options for patients now," says Memorial Sloan-Kettering Cancer Center's Robert Motzer, who led the study. Together, the various new kidney cancer drugs "have changed the prognosis."

But kidney cancer may be "the tip of the iceberg" for RAD001, says David Epstein, president of Novartis' cancer unit. The drug, which hits a key growth-promoting molecule inside cells, called mTOR, is also showing surprising preliminary promise in treating advanced breast cancer patients. It appears to restore the effectiveness of Genentech's (nyse: DNA - news - people ) Herceptin drug after that drug has failed.

In one small trial from doctors in France of 13 patients who had failed on Herceptin, tumors shrank dramatically in six when RAD001 was added to the mix; in three the tumors vanished entirely. In another study of RAD in breast cancer, three out of of 22 patients had big tumor shrinkage, while the disease stabilized in another 13 for prolonged periods.

"The percentage of responses is dramatic. We usually don't see that," says UCLA oncologist Dennis Slamon, who played a pivotal role in developing Herceptin. He says mTOR may be a key resistance mechanism that cells use to evade the effects of Herceptin.

The results are highly preliminary. But Novartis' Epstein is so excited by the data he is considering jumping right from these trials into a large final-stage tests. "I tell people I want to be involved in one more drug like Gleevec" before retiring, Epstein says, referring to Novartis' breakthrough leukemia pill. He hopes RAD001 is it.

Cancer Drug Winners And Losers

Chicago -

Every year, drug companies big and small make their way to the annual meeting of the American College of Clinical Oncology, a showplace for new cancer medicines.

The data presented at ASCO can have a huge impact both on the share prices of drug firms and on the long-term sales of their medicines. Here's a roundup of the most important drug studies from the meeting and a look at how they will affect the companies involved.

Winner: Novartis (nyse: NVS - news - people )

The pharmaceutical giant stole the show. Zometa, a drug already approved to treat weakening bones in cancer patients, slashed the recurrence of breast cancer in pre-menopausal women by about 35% in an 1,800-person trial, when combined with standard treatment. It's not clear why, but it may prevent tumors from spreading (see "Novartis Steals The Show").

Novartis' kidney cancer treatment RAD001 delayed tumor growth by two months in patients who had failed Pfizer's (nyse: PFE - news - people ) Sutent. The drug would compete with Nexavar, from Onyx Pharmaceuticals (nasdaq: ONXX - news - people ) and Bayer (nyse: BAY - news - people ), and Torisel, from Wyeth (nyse: WYE - news - people ), but could benefit from a clinical trial designed that tested it specifically as an option in Sutent failures. The other drugs are approved as first choices, and compete with Sutent, which has the lion's share. Novartis shares are up 2.3% to $53.50.

Novartis has 13 cancer drugs in development, more than any company but Pfizer, AstraZeneca (nyse: AZN - news - people ) and Genentech (nyse: DNA - news - people ). It expects to soon rank second in oncology sales after Genentech.

Loser: ImClone Systems (nasdaq: IMCL - news - people )

ImClone and its partners, Bristol-Myers Squibb (nyse: BMY - news - people ) and Merck (nyse: MRK - news - people ) KgAA disclosed last September that its Erbitux had extended survival in patients with non-small cell lung cancer in a clinical trial. But the final results--a five-week extension of life for the average patient--were barely statistically significant. That will allow ImClone and its partners to grab sales in the lung cancer market, especially in those patients who can't take Avastin.

But it may not make up another result: clear proof that a gene test can help predict whether Erbitux is going to help colon cancer patients. Patients with a mutant version of a gene called KRAS comprise 40% of the people getting Erbitux, and they've been getting no benefit at all. As Forbes reported two weeks ago, this could lead to a sales slump. ImClone shares dropped 6% in early morning trading to $40. (See: ImClone's Gene Test Battle.)

Winner: Genentech

Genentech's Avastin won't face as much competition as many feared from ImClone's Erbitux in non-small cell lung cancer, but new data also supported Avastin's use in breast cancer. Shares are up 3.4% to $73.

Winners: Infinity Pharmaceuticals (nasdaq: INFI - news - people ) and Exelixis (nasdaq: EXEL - news - people )

On Saturday, Infinity announced it was skipping mid-stage trials and going directly from early-stage safety and efficacy tests into a study designed to get its IPI-504 approved as a treatment for patients with stomach tumors who are no longer being helped by Novartis' Gleevec or Pfizer's Sutent. It's a small market, but it could result in a speedy approval.

Sunday Exelixis also said it is jumping directly into an approval trial, known as a Phase III study, from very early stage tests of its cancer drug XL184 in medullary thyroid cancer. It will be the first of Exelixis' drugs to enter phase III. Fifty-three percent of patients taking the drug saw their tumors shrink. Infinity shares jumped 11% to $8.13, and Exelixis shares slipped 2% to $6.20.

Winner: Avant Immunotherapeutics (nasdaq: AVAN - news - people )

Avant is developing an immunotherapy, or cancer vaccine, for brain tumors with Pfizer. The vaccine is targeted against a mutated protein that only occurs in brain cancer cells. In a phase II trial, the average patient with glioblastoma who received the therapy, known as CDX-110, lived 33 months, twice as long as expected. Avant shares are up 36% to $19.20.

"When we look at our patients they live at least twice as long" as would be expected, says Duke University neurosurgeon John Sampson, who invented the vaccine. "We have a number of patients three or four years out with no evidence of tumors."

Wall Street: Genentech to lead lung cancer market

NEW YORK -

Genentech Inc.'s drug Avastin will likely remain dominant in the lung cancer market over rival ImClone Systems Inc.'s Erbitux, several analysts said Monday following the release of clinical data at the American Society of Clinical Oncology's annual meeting in Chicago.

ImClone (nasdaq: IMCL - news - people ) said adding Erbitux to standard chemotherapy added about 5 weeks to a patient's life when compared with a chemotherapy regimen alone. The FLEX study results were positive, but Wall Street still expects Avastin prescriptions to lead Erbitux because the drug's survival benefit is nearly a month longer.

However, many patients can't take Avastin because of blood disorders or blood thinner regimens, and if approved for lung cancer, analysts think Erbitux will be the prescription of choice for that patient population - leaving ImClone and partner Bristol-Myers Squibb Co. (nyse: BMY - news - people ) with at least some portion of a lucrative market. Lung cancer is the leading cause of cancer death in the United States.

"Initial feedback from physicians confirms our theory that Avastin will still be considered the gold-standard front-line agent and Erbitux's use will be predominantly in Avastin-ineligible patients," said Piper Jaffray (nyse: PJC - news - people ) analyst Thomas Wei, in a note to investors.

Avastin, which is FDA-approved to treat colon, lung and breast cancer, is Genentech (nyse: DNA - news - people )'s key revenue driver and brought in just under $2.3 billion in 2007. Erbitux - ImClone's only product - is approved to treat colon and head and neck cancers and the company hopes it will be approved for lung cancer.

"FLEX (study data) is Erbitux's ticket into the lucrative lung cancer market," said Cowen and Co. analyst Eric Schmidt. He said that with 40 percent to 50 percent of lung cancer patients ineligible for Avastin treatment, ImClone and Bristol-Myers could see peak Erbitux sales in lung cancer of $700 million.

Dr. Edward Kim, an assistant professor of medicine at the University of Texas' M.D. Anderson Cancer Center, said the addtiional five weeks of survival time can be significant for many of the advanced lung cancer patients he sees each week. Those patients are often told they have less than a year to live, even with treatment.

"When I put my physician hat on and I'm seeing patients, I'm extremely happy that I have more options to offer patients," he said in an interview with The Associated Press.

Other lung cancer developments at ASCO included an M.D. Anderson Center study showing Pfizer Inc. (nyse: PFE - news - people )'s arthritis drug Celebrex could help prevent lung cancer in heavy smokers. The findings are still early, though, and Kim said additional work on identifying risk factors and assessing the drug's benefit need to be done.

"We'll be looking at tissue to try and define who is at highest risk for cancer and who may benefit the most from a drug like Celebrex," he said.

Meanwhile, Exelixis Inc. (nasdaq: EXEL - news - people ) said midstage study data showed its drug candidate XL-647 appeared to attack lung cancer tumors. The company hopes to start a late-stage study by the second half of 2009.

Shares of South San Francisco, Calif.-based Genentech rose $2.47, or 3.5 percent, to reach $73.33 in afternoon trading, while shares of New York-based ImClone fell $2.63, or 6 percent, to $40.95.

New York-based Pfizer saw shares fall 26 cents to $19.10, while shares of South San Francisco, Calif.-based Exelixis fell 20 cents, or 3.1 percent, to $6.12.