Source: Celldex Therapeutics

What: After announcing long term, mid-stage, survival data for brain cancer patients, shares in Celldex Therapeutics (CLDX -1.43%) climbed by over 11% this afternoon.

So what: Celldex Therapeutics is developing Rintega, a treatment for glioblastoma, and results presented today show a significant increase in long-term overall survival for patients who participated in Rintega's phase 2 trials.

According to Celldex Therapeutics, 25% of people who received Rintega alongside Roche's (RHHBY 1.20%) top-selling Avastin remained alive two years later, versus 0% of patients who received placebo and Roche's drug.

Celldex also reported that a clinical benefit for Rintega continues to be observed across progression-free survival and overall response rate.

Previously, Celldex had reported that 10 out of 36 patients receiving Rintega plus Avastin were alive at six months, versus 6 out of 37 in the control group.

The findings suggest that Rintega could be a life-saving medication for glioblastoma patients who see their disease return and who are also positive for a mutation to the EGFRvIII protein.

Source: Celldex Therapeutics

Now what:  Celldex has an ongoing phase 3 study evaluating Rintega's use in newly diagnosed, rather than recurring, glioblastoma, and independent monitors recommended that trial continue when they reviewed data this past June.

The company believes that a second review by independent monitors could occur early next year, and today's data is certainly encouraging that the data will be compelling.

If it is, then monitors could either continue the study until its completion, or halt the study early so that all patients can get access to Rintega.

Since we won't know whether or not Celldex Therapeutics truly has a revolutionary new drug for brain cancer on its hands until that upcoming data is digested, investors should remember that Celldex Therapeutics is a clinical stage company without any revenue and therefore, it's still a stock that's best suited to risk-tolerant investors. Having said that, I'm rooting for this company's success.