Exelixis (Nasdaq: EXEL) has faced many ups and downs over the past several years. Yesterday, the Rule Breakers pick released its first-quarter financial results, briefing investors on what to expect from an eventful second half of the year.

The most important upcoming event for Exelixis may be the American Society of Clinical Oncology (ASCO) conference at the end of May in Chicago. Exelixis plans to give seven presentations at ASCO, covering four of its compounds.

Since ASCO is the premiere medical conference for drugmakers working on treatments for solid tumors, the company has likely saved some of its most exciting data for this spotlight. For investors wanting an early look at part of these findings, abstracts for some of Exelixis's presentations should be out a week from Thursday on the conference's website.

ASCO won't be Exelixis's only chance to shine in the coming months. The company plans to submit phase 2 proof-of-concept data for its potential solid-tumor treatment XL184 to partner GlaxoSmithKline (NYSE: GSK) this summer. Glaxo should decide whether to add XL184 to its already selected XL880 in the fall.

Thus far, big pharma partners like Bristol-Myers Squibb (NYSE: BMY) and Genentech (NYSE: DNA) have selected six of Exelixis's drug candidates for advancement. There are few better ways to validate a drug company's pipeline than this, besides gaining FDA marketing approval.

I was on autopilot when Exelixis's stock dipped into the $4 and change range in March, and I completely missed the opportunity. Shares were a relative steal at that valuation, considering that multiple other development-stage pharmas with far less significant pipelines were trading at the same $500 million market capitalization. If Exelixis shares drift down toward this price again on no news, Fools should consider snapping them up.

Exelixis is an active pick of our Rule Breakers newsletter. You can check out all our other recommendations as well as get access to our message boards and exclusive content with a 30-day free trial.

Fool contributor Brian Lawler does not own shares of any company mentioned in this article. GlaxoSmithKline is an active Income Investor pick. The Motley Fool owns shares of Exelixis. The Fool has an A+ disclosure policy.