Ahh, the American Society of Clinical Oncology (ASCO). It may not have the cool gadgets that the Consumer Electronics Show has, but it can affect the stock price of cancer drugmakers all the same. The meeting kicks off tomorrow; here's some things to keep an eye on.

Going for gold
Bayer and Onyx Pharmaceuticals' (NASDAQ:ONXX) Nexavar hasn't become a blockbuster yet -- sales were $678 million last year. It's approved to treat liver and kidney cancer, not the most prevalent of cancers, and it has to compete with Pfizer's (NYSE:PFE) Sutent for kidney cancer patients. Going after smaller markets isn't a bad idea for a company to get its foot in the door, but Bayer and Onyx will need to demonstrate that Nexavar can treat at least one major cancer to turn it into a mega-blockbuster.

There will be more than 65 studies about Nexavar at ASCO, but the one to keep your eye on is the phase 2 study in non-small cell lung cancer (NSCLC). Survival data wasn't available when the abstract was submitted, but markers for the progression of the disease and how well the drug is working both looked good. 76% of patients didn't see their cancer get worse after six weeks on the drug and it appears that Nexavar is working by cutting off the blood supply to the tumor.

Looking for rubies to add to the gold
The makers of Gemzar, Avastin, and Tarceva already have blockbusters, but that doesn’t mean that they're sitting on their gold stashes; each drug has presentations at ASCO that will try and increase their usage.

Eli Lilly (NYSE:LLY) is trying to expand Gemzar, which is already approved for four different cancers, into cervical and advanced cancer of the bile duct. The company will report the results of two different phase 3 trials at ASCO.

Results from Genentech's Ribbon trial testing Avastin in breast cancer will be presented. The Food and Drug Administration has already approved it to treat breast cancer, so this is essentially a chance for Roche -- Genentech's new owner -- to advertise the drug to doctors.

The most interesting of the three to watch may be Roche's and OSI Pharmaceuticals' (NASDAQ:OSIP) Tarceva. Data summarized in the abstract about testing Tarceva as a maintenance therapy for lung cancer looked lackluster at best, but OSI says that the full results will redeem Tarceva.

Would settle for silver or perhaps somebody else's gold
Investors are excited about Exelixis' (NASDAQ:EXEL) XL-184, which is licensed to Bristol-Myers Squibb (NYSE:BMY). The drug is in phase 3 trials for a type of thyroid cancer, but it’s the phase 2 trial in brain cancer that makes the drug so promising. Brain cancer is a notoriously hard cancer to treat and it appears that XL-184 has substantial activity, although the drug may have some unwanted side effects. More than half of the patients required a dose interruption or reduction. Without a control group, though, it's a little hard to know how bad the side effects really are.

OncoGenex Pharmaceuticals (NASDAQ:OGXI) has hit investors' radar screen lately, with the stock going from $4 to $20 over the last month or so. The company is still tiny, with a fair amount of risk, but data from its phase 2 cancer drug, OGX-011, looks promising. I expect that management will be using ASCO as an advertisement to find a partner, considering that the company only had $9.4 million in cash and equivalents at the end of last quarter.

Keep your eye on the wires
Investors not headed to ASCO will need to keep an eye on the news wires this weekend to get reports of the full results of these trials. And check back Monday for a Foolish recap.

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