Onyx Unveils Some Promising Results

Onyx Pharmaceuticals (ONXX - commentary - Cramer's Take) presented positive midstage data Saturday on its experimental cancer drug BAY 43-9006 and, along with partner, German drugmaker Bayer, said it has started a Phase III clinical trial in patients with advanced kidney cancer.

The Phase II data on BAY 43-9006 is still preliminary but paints the picture of a very active drug, and one with the ability to shrink tumors in a greater percentage of advanced kidney cancer patients than other, rival targeted cancer drugs also in development.

The Phase III study, now under way, will determine whether the drug's activity translates into helping kidney cancer patients actually live longer -- the gold standard for cancer drug efficacy.

Results from this new study will not be ready for some time, but Onyx shareholders will nonetheless welcome the new Phase II data as a validation of their faith in the company and Bay 43-9006. Onyx has been a hot stock since last fall, but much of the enthusiasm was based more on hope than on reality because, until Saturday, the real data on BAY 43-9006 had been early stage.

Onyx shares closed Friday at $24.76, a sevenfold increase in the price since last October, when it traded in the $3 range.

The interim results presented Saturday were from the first phase of a two-stage, Phase II study that is investigating BAY 43-9006 across a variety of different cancers. The initial analysis consisted of data from 41 patients with advanced renal cell carcinoma (kidney cancer) who were given BAY 43-9006 (an oral pill) twice a day for 12 weeks.

Of these 41 patients, 18 patients, or 44%, had tumor shrinkage of 25% or more, what Onyx and its investigators refer to as "partial responders." Twelve patients, or 29%, had their tumors stabilize within 25% of their pretreatment size; while another 11 patients, or 27%, saw their tumors continue to grow or dropped out because of adverse effects.

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Adam Feuerstein writes regularly for RealMoney.com. In keeping with TSC's editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet.com. He also doesn't invest in hedge funds or other private investment partnerships. He invites you to send your feedback.