Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Puma Biotechnology (NASDAQ:PBYI), a clinical-stage biotech, crushed the market with a gain of more than 280% Wednesday after the company's breast cancer drug neratinib met its primary goals in a phase 3 clinical trial.

So What: Puma's neratinib trounced a placebo in the study, increasing disease-free survival for patients suffering from early stage HER2 positive breast cancer by 33% as compared to the control group. While many analysts had seen neratinib as capable of succeeding in the trial beforehand, Wall Street judged the data as one of the best case scenarios that Puma could have hoped for.

The biotech also announced an updated deal with Pfizer (NYSE:PFE), its licensing partner for the drug. Under the new terms, Puma will pay a fixed annual royalty rate on the drug's revenues in the teens, rather than an earlier agreement's arrangement to pay incremental royalties on sales.

Now What: The news is everything Puma investors could have hoped for, as the results prompted the company to announce its aims to apply for FDA approval sometime in the first half of next year. Numerous analysts raised their price targets on Puma, and given that neratinib -- Puma's lone drug in its pipeline -- is undergoing trials for other combinations and indications, there's more room to run in the future for this stock.

Puma will have to cover the costs of future research and development under its new deal with Pfizer, projecting that R&D costs could spike by $30 million. But with early stage HER2 breast cancer making up around 20% of overall cases of the disease, it wouldn't be surprising to see a takeover-hungry drugmaker come sniffing around Puma if neratinib continues its success in other trials.