Why Tesaro Shares Vaulted Higher

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 Tesaro , a biopharmaceutical company focused on cancer-based therapies, rose as much as 17% after the company announced its final phase 1 data for Niraparib, an inhibitor of poly ADP-ribose polymerase for the treatment of breast and ovarian cancer.

So what: Tesaro announced today that it plans to present its findings at the upcoming American Society of Clinical Oncology meeting at the end of the month. Results from the final examination of its phase 1 trial (originally presented in 2011 at ASCO) confirmed the initial results in 2011, as the company noted plans to move directly to phase 3 trials for ovarian cancer by mid-year and breast cancer by the second half of this year.

Now what: While these confirmatory findings are encouraging, Tesaro shares have practically tripled since they debuted less than a year ago. As a purely clinical-stage company, it's very difficult to justify this $1.1 billion valuation, especially with investors pumping up the valuations of many oncology-based biotechs in anticipation of ASCO in two weeks. I'd suggest carefully watching the data here, but I certainly don't feel Tesaro is anywhere near an intriguing buy.

Craving more input? Start by adding Tesaro to your free and personalized watchlist so you can keep track of the latest news with the company.

While you can certainly make huge gains in biotechs like Tesaro, the best investing approach is to choose great companies and stick with them for the long term. The Motley Fool's free report "3 Stocks That Will Help You Retire Rich" names stocks that could help you build long-term wealth and retire well, along with some winning wealth-building strategies that every investor should be aware of. Click here now to keep reading.

The article Why Tesaro Shares Vaulted Higher originally appeared on Fool.com.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.

Copyright © 1995 - 2013 The Motley Fool, LLC. All rights reserved. The Motley Fool has a disclosure policy.