Puma Biotechnology Inc (NYSE:PBYI) announced positive results in its ExteNET clinical trial of neratinib in HER2+ adjuvant breast cancer after the close on Tuesday. Shares of the firm have soared on the news and are up 283%! to $226 in early Wednesday trading.

Puma Biotechnology Inc (NYSE:PBYI)’s new drug improved disease-free survival by 33% relative to a placebo in a trial of 2,821 women with early-stage HER2-positive breast cancer, according to a statement released today by the company. Disease-free survival is the time a patient remains alive with no signs of the illness. Puma Biotechnology Inc (NYSE:PBYI) said it planned to apply for U.S. regulatory approval in 1H 2015 based on the positive results.

Puma Biotechnology sales forecast

Details on neratinib

Assuming neratinib is evetually is approved, it is likely to be used in many early-stage breast cancer patients whose tumors grow faster because of a gene called HER2. These patients are typically treated with Roche’s Herceptin today.

In Puma’s just-reported clinical trial, neratinib was given to women whose breast cancer tumors had been surgically removed and treated with Herceptin to prevent recurrence. Following the Herceptin treatment, was completed, some trial participants received neratinib and some received a placebo.

UBS raises Puma Biotechnology price target to $325

UBS Global Research published a new report on Puma Biotechnology Inc (NYSE:PBYI) on Tuesday, July 22nd, following the positive trial results for neratinib.

Analysts Matthew Roden and colleagues say these strong trial results are a game-changer for HER-2 cancer treatments. “In our view, the 33% reduction in risk of relapse or death in the adjuvant setting should establish neratinib as a standard of care in the $4bn+ segment.”

In modeling their $325 price target for Puma Biotechnology, the UBS analysts upped the probability that Puma Biotechnology Inc (NYSE:PBYI)’s neratinib would be approved for commercial use from 30% to 85%, and upped the potential market size to greater than three billion dollars. Roden et al. also calculate that Puma could have an upside of as high as $430, and a downside of $130 if other ongoing clinical trials for related indications fail.

Puma Biotechnology income statement

Puma Biotechnology valuation